CN210637860U

CN210637860U - Elongated substrate and lighting strip

Info

Publication number: CN210637860U
Application number: CN201921062052.6U
Authority: CN
Inventors: M·J·范尤登; C·M·苏
Original assignee: Philips Lighting Holding BV
Current assignee: Signify Holding BV
Priority date: 2018-08-31
Filing date: 2019-07-09
Publication date: 2020-05-29
Anticipated expiration: 2029-07-09
Also published as: CN110873296B; WO2020043727A1; CN110873296A

Abstract

The utility model discloses an extension base plate and illumination strip. Wherein an elongated substrate is provided having opposite ends in its elongated direction, and comprising: a conductive line arrangement comprising conductive lines arranged to have a first polarity; a further conductive line arranged with a polarity opposite to the first polarity and spatially separated from the conductive line, each of the conductive line and the further conductive line extending between opposite ends and terminating in a respective metal pad at each of the opposite ends; and at least one solid state lighting arrangement comprising a plurality of strings of N series-connected solid state elements, where N is a positive integer, the strings being connected in parallel to a conductive line and a further conductive line and being separated from each other by spacer segments. Also disclosed is a lighting strip assembled from such elongate substrates.

Description

Elongated substrate and lighting strip

Technical Field

The present disclosure relates to an elongated substrate having opposite ends in an elongated direction thereof, and comprising: a conductive line arrangement comprising conductive lines arranged to have a first polarity; a further conductive line arranged to have a polarity opposite the first polarity and spatially separated from the conductive line, each of the conductive line and the further conductive line extending between and terminating at a respective metal pad at each of the opposite ends; and at least one solid state lighting arrangement comprising a plurality of strings of N series-connected solid state elements, where N is a positive integer, the strings being connected in parallel to a conductive line and a further conductive line and being separated from each other by spacer segments.

The present disclosure also relates to an illumination strip comprising a plurality of such elongate substrates interconnected to form a strip.

The disclosure also relates to the manufacture of such lighting strips.

Background

Lighting applications based on Solid State Lighting (SSL) elements require more and more flexibility. Therefore, the variation of linear elongated substrates with surface mounted SSL elements, such as PCBs (printed circuit boards), is rapidly increasing. Such lighting strips may be provided on a reel, so as to allow the lighting strip to be cut to a desired length, particularly in the case of flexible elongate substrates such as flexible PCBs. For example, US2015/0138772a1 discloses an LED strip lighting fixture having an array of LEDs mounted on a frangible rigid aluminum base having a predetermined thickness, the thickness including a predetermined weak point, whereby the rigid (preferably aluminum) base may be broken at the predetermined weak point. A rigid base is provided with a laminated integrated circuit on which are mounted a plurality of electrical components including a plurality of light emitting diodes electrically connected in series on the laminated integrated circuit, whereby the frangible section of the rigid base provides a predetermined length dimension that is easily customized to provide a rigid aluminum base and an LED mounted lighting fixture.

However, the manufacture of such illumination strips is not without challenges. Such a tape may be produced using a roll-to-roll production method, but this usually requires professional equipment to manufacture the (flexible) elongated substrate and to perform a Surface Mount Device (SMD) process, wherein a chip comprising SSL elements is mounted on the elongated substrate. This is quite expensive, which is why many manufacturers use a strip-to-strip soldering method to produce such lighting strips, wherein elongated substrates are soldered together to form the lighting strip, which is then overmolded to protect and electrically insulate the electronic components exposed on the surface of the lighting strip to form the final product. In this way, for example, lighting strips of 5-50m or more in length can be provided, while such lighting strips can still be manufactured using standard tools, since the SMD process of mounting SSL element chips onto an elongated substrate, such as a (flexible) PCB, is performed using a relatively short substrate, for example a substrate of about 50cm in length, which can still be processed by such standard tools.

To facilitate cutting these strips into lengths, the strips typically comprise a plurality of strings of SSL elements (e.g. LEDS), which strings are connected in parallel, so that the lighting strip can be cut with the space between adjacent pairs of such parallel strings. To this end, the illumination strip may include a marking at such a space that indicates where the illumination strip may be safely cut (e.g., using scissors). However, in such designs, the spaces between adjacent parallel strings on adjoining elongated substrates (i.e., the joints between such adjoining elongated substrates) cannot be easily cut due to the soldering of conductive wires extending across the elongated substrates.

In addition, in order to reconnect the cut strap sections, a connector box is generally used into which the cut strap sections are inserted. Where such a strip segment is cut on such a solder bump, the thickness of the solder bump segment will generally prevent such a cut strip segment from being inserted into the connector box. For this reason, users of such soldered lighting strips tend to avoid cutting the strip on the soldered interconnect interconnecting adjacent elongated substrates. However, this means that the lighting strip has spaces between the strings of regularly spaced SSL elements that are not easily cut, which therefore hinders the flexibility of use of such lighting strips.

For example, for a woven lighting strip welded together from 50cm long substrates, a user wishing to cut a length of 50cm or multiples thereof cannot simply cut the length of the lighting strip, as this means cutting across the welded interconnects between adjacent substrates. Instead, the user must first cut out a smaller portion, e.g. a 5cm or 10cm portion, after which a 50cm portion or a multiple thereof can be cut out of the remaining length of the lighting strip, since now a cut across the lighting strip at the length of the desired portion will be made at the space between the strings of SSL elements positioned on the same substrate. This is rather cumbersome and results in unnecessary waste of parts of the illumination strip.

SUMMERY OF THE UTILITY MODEL

The present disclosure aims to provide an elongate substrate (elongated substrate) for use in such lighting strips, wherein a user can cut the lighting strip between each pair of adjacent strings of SSL elements with the same ease, thereby increasing the flexibility of use and reducing waste of such lighting strips.

The present disclosure is also directed to a lighting strip formed from a plurality of such elongate substrates.

The present disclosure is also directed to a method of manufacturing such an illumination strip.

According to a first aspect, there is provided an elongate substrate having opposite ends in its elongate direction, and comprising: a conductive line arrangement comprising conductive lines arranged to have a first polarity; a further conductive line arranged with a polarity opposite to the first polarity and spatially separated from the conductive line, each of the conductive line and the further conductive line extending between opposite ends and terminating in a respective metal pad at each of the opposite ends; and at least one solid state lighting arrangement comprising a plurality of strings of N series-connected solid state elements, where N is a positive integer, the strings being connected in parallel to a conductive line and a further conductive line and being separated from each other by spacer segments; and at least one of: a string of M series-connected solid state elements, where M is a positive integer and M < N, the string being proximate one of the opposing ends and connected between the conductive line and a first additional metal pad at the one of the opposing ends; and a string of N-M series-connected solid state elements, the string being proximate to another one of the opposing ends and connected between an additional conductive line and a second additional metal pad at the another one of the opposing ends. When the elongate substrate is interconnected with another elongate substrate having a complementary string of N-M series-connected solid state elements and/or a complementary string of M series-connected solid state elements, one string of the string of M series-connected solid state elements and the string of N-M series-connected solid state elements on the elongate substrate is connected with a corresponding complementary string of the complementary string of N-M series-connected solid state elements and the complementary string of M series-connected solid state elements on another elongate substrate to form a string of N series-connected solid state elements across adjacent elongate substrates; wherein the string of N series-connected solid state elements is identical in electrical and optical properties to each of the plurality of strings of N series-connected solid state elements across adjacent elongated substrates.

According to the present disclosure, there is provided an elongate substrate, when used to form a lighting strip by interconnecting a plurality of such substrates, ensuring that the lighting strip can be cut between each pair of adjacent strings of Solid State Lighting (SSL) elements, thereby reducing waste of such lighting strips and increasing user flexibility thereof. This is achieved by dividing such a string of series-connected SSL elements at their intersections across adjacent elongate substrates, such that a first portion of such a string (i.e. a string of M series-connected solid state elements) is positioned on a first of the adjacent elongate substrates, which first portion may be interconnected to a second portion of such a string (i.e. a string of N-M series-connected solid state elements) on another of the adjacent elongate substrates, thereby forming a string of M + (N-M) ═ N series-connected SSL elements across the adjacent elongate substrates. Thus, the interconnections (e.g. solder bumps) between adjacent elongate substrates are no longer positioned between a pair of strings of serially connected SSL elements, but rather are positioned within such strings, i.e. outside the potential target cut area of the lighting strip formed by a plurality of such interconnected substrates. The string of N series-connected solid state elements has the same electrical and optical properties across adjacent elongated substrates as a normal string of the plurality of strings of N series-connected solid state elements, such that the lighting strip formed by interconnecting such substrates does not have variations in its elongated direction.

In case the elongated substrate comprises only one of a string of M series-connected solid state elements and a string of N-M series-connected solid state elements, the elongated substrate may be used as a terminal substrate for such a lighting strip, since in this case the further elongated substrate does not need to be connected to a terminal end of the elongated substrate, such that no string portion at this terminal end is needed. On the other hand, in case an elongated substrate is used as an intermediate substrate for such a lighting strip, the at least one solid state lighting arrangement comprises a string of M series-connected solid state elements and a string of N-M series-connected solid state elements, such that the elongated substrate may be interconnected at its opposite two ends to another elongated substrate, so as to form across the interconnected elongated substrates a string of N series-connected SSL elements as described above.

In the context of the present application, when referring to electrically conductive wires arranged to have a specific polarity, it is to be understood that this means that the electrically conductive wires are intended to be connected to a specific terminal of the power supply, e.g. a positive or a negative terminal. For example, a conductive wire arranged to have a first polarity may be intended to be connected to a positive terminal of a power supply, in which case a conductive wire having an opposite polarity is intended to be connected to a negative terminal of such a power supply, and vice versa.

Preferably, each of the strings of N series-connected solid state elements extends in the elongate direction of the elongate substrate.

It is further preferred that the elongated substrate is flexible in order to maximize the flexibility of the lighting strip formed by a plurality of such interconnected elongated substrates.

Each solid state element may be provided as a separate chip mounted on an elongate substrate. This facilitates cost-effective manufacturing of such elongated substrates, for example using SMD processes.

Embodiments of the present disclosure are not limited to a single SSL arrangement on an elongate substrate. For example, in another embodiment, the electrically conductive wire arrangement comprises a pair of said electrically conductive wires arranged to have said first polarity, and a pair of said solid state lighting arrangements comprising a first solid state lighting arrangement and a second solid state lighting arrangement, wherein a respective string of the first solid state lighting arrangement is connected to one of said pair of electrically conductive wires arranged to have said first polarity if connected to the electrically conductive wire arranged to have said first polarity, and a respective string of the second solid state lighting arrangement is connected to the other of said pair of electrically conductive wires arranged to have said first polarity if connected to the electrically conductive wire arranged to have said first polarity. In such embodiments, the elongate substrate comprises a plurality of individually addressable SSL arrangements, which may for example be used to provide the elongate substrate with different types of SSL elements, such as white SSL elements in a first SSL arrangement and SSL elements in a second SSL arrangement that produce a particular color (e.g. red, green or blue). This enhances the functionality of such an elongated substrate and of a lighting strip formed by a plurality of such elongated substrates.

The elongate substrate generally includes a first major surface and a second major surface opposite the first major surface. In one embodiment, a pair of electrically conductive wires arranged to have the above-mentioned first polarity and a pair of solid state lighting arrangements are positioned on the first main surface, and a further electrically conductive wire is positioned on the second main surface. This has the following advantages: more space is available on the first main surface, e.g. the main surface which serves as a light generating surface visible in the lighting strip, which may facilitate including a further SSL arrangement on the first main surface.

For example, the electrically conductive line arrangement may comprise a third electrically conductive line arranged to have the above-mentioned first polarity, the elongated substrate further comprising a further solid state lighting arrangement, wherein the respective string of further solid state lighting arrangements is connected to the third electrically conductive line if connected to the electrically conductive line arranged to have the above-mentioned first polarity. Further SSL arrangements may further enhance the functionality of the elongated substrate and the lighting strip formed by a plurality of such substrates, e.g. by providing a plurality of SSL elements within such SSL arrangements that generate light having a further spectral component. In this way, an elongate substrate and lighting strip having up to four or five different SSL arrangements may be provided, such as an elongate substrate and lighting strip comprising one or two SSL arrangements having SSL elements producing (different) white light, and three further SSL arrangements having SSL elements producing respectively different colors of light, such as red, green and blue light.

In one embodiment, each of the conductive line arranged to have the first polarity and the further conductive line comprises a plurality of further metal pads, wherein each of the further metal pads is conductively connected to a junction between the conductive line and one end of the plurality of strings of N series-connected solid state elements connected to the conductive line. Such additional metal pads facilitate the re-connection of the section of the lighting strip cut near such a joint, for example when the lighting strip section is to be used in or as a lighting device. Such further metal pads may be positioned in the above-mentioned spacer sections, so that the design of the elongated substrate is kept particularly compact.

According to another aspect, there is provided an illumination strip comprising a plurality of elongated substrates according to any one of the embodiments described herein, wherein the respective substrates are interconnected by a pair of interconnects and a further interconnect, the pair of interconnects interconnecting metal pads of corresponding conductive lines and further conductive lines at facing ends of adjacent elongate substrates, further interconnects interconnect the first further metal pads of each solid state lighting arrangement on one of the adjacent elongate substrates to the second further metal pads of the corresponding solid state lighting arrangement on the other of the adjacent elongate substrates at the facing ends, wherein the string of N series-connected solid state elements is the same as each of the plurality of strings of N series-connected solid state elements in the elongated direction of the elongated substrate across adjacent elongated substrates.

The interconnects (e.g., solder bumps) of such a lighting strip are positioned within the SSL arrangements of N serially connected SSL elements, as explained in more detail above, so that the lighting strip can be easily cut between each pair of adjacent or neighboring SSL arrangements. This is an improvement over the prior art, where such cutting cannot easily be made between adjacent SSL arrangements at different substrates, since the solder bumps between such substrates are typically positioned between adjacent SSL arrangements, i.e. in the area to be cut, which practically excludes making such cutting between SSL arrangements at different substrates. By appropriately selecting the length of the string of M series-connected solid state elements on one substrate and the length of the string of N-M series-connected solid state elements on another (adjacent and complementary) substrate, the length of the string of N series-connected solid state elements across an adjacent elongated substrate can be the same as a normal string of multiple strings of N series-connected solid state elements, such that the lighting strip formed by interconnecting such substrates has even better uniformity along its elongated direction.

It should be noted that such a lighting strip may be formed of elongated substrates, each substrate comprising string portions of M series-connected solid state elements (where M is a positive integer) and string portions of N-M series-connected solid state elements, in which case the terminals of the lighting strip may be cut off the portions of the elongated substrates to form the terminals of the lighting string which may be connected to a power supply or the like. In order to save costs, the portion of the terminal elongated substrate of the lighting strip to be discarded may not carry SSL elements, e.g. not mounted in an SMD process. It will be appreciated that this approach is feasible when it is known beforehand what length of lighting strip is required by the end user. An advantage of this approach is that only a single type of elongated substrate needs to be produced for assembling such a lighting strip, i.e. an elongated substrate comprising string portions of M series-connected solid state elements (where M is a positive integer) and string portions of N-M series-connected solid state elements at opposite ends of the substrate.

However, without knowing how much of the lighting strip will be used by the end customer, it is preferred that the lighting strip further comprises a pair of terminal elongate substrates at opposite ends of the lighting strip, said pair of terminal elongate substrates comprising: a first terminal elongated substrate that does not include strings of M series-connected solid state elements such that a terminal end portion of the first terminal elongated substrate includes only metal pads of the above conductive line and the additional conductive line; and a second terminal elongated substrate that does not include the string of N-M series-connected solid state elements, such that a terminal end portion of the second terminal elongated substrate includes only the metal pads of the above conductive line and the additional conductive line.

According to a further aspect, there is provided a method of manufacturing a lighting strip according to any of the embodiments described herein, the method comprising interconnecting a plurality of elongate substrates according to any of the embodiments described herein, wherein the respective substrates are interconnected by a pair of interconnects interconnecting the metal pads of the corresponding conductive lines and further conductive lines at facing ends of adjacent elongate substrates, and further interconnects interconnecting, at the facing ends, the first further metal pads of each solid state lighting arrangement on one of the adjacent elongate substrates to the second further metal pads of the corresponding solid state lighting arrangement on the other of the adjacent elongate substrates. This approach provides a lighting strip that can be easily cut between any pair of adjacent SSL arrangements, at the expense of additional interconnects between string portions of SSL arrangements distributed across a pair of adjacent elongate substrates.

The method may further include terminating opposite ends of the lighting strip with a pair of terminal elongated substrates comprising: a first terminal elongated substrate that does not include a string of M series-connected solid state elements such that a terminal end portion of the first terminal elongated substrate includes only the conductive line and the metal pad of the further conductive line; and a second terminal elongate substrate that does not include a string of N-M series-connected solid state elements, such that a terminal end portion of the second terminal elongate substrate includes only the conductive line and the metal pad of the further conductive line; interconnecting respective metal pads of said conductive lines of the first terminal elongate substrate to respective metal pads of corresponding conductive lines of an adjacent elongate substrate of the first terminal elongate substrate at opposite ends of said substrate and interconnecting one or more second further metal pads of the first terminal elongate substrate to corresponding first further metal pads of an adjacent elongate substrate of the first terminal elongate substrate at said facing ends; and interconnecting respective metal pads of said conductive lines of the second terminal elongated substrate to corresponding metal pads of conductive lines of an adjacent elongated substrate of the second terminal elongated substrate at facing ends of said substrates, and interconnecting one or more first further metal pads of the second terminal elongated substrate to corresponding second further metal pads of an adjacent elongated substrate of the second terminal elongated substrate at said facing ends. In this way, a lighting strip is manufactured which can be connected directly to a power supply or the like at its terminals.

In a preferred embodiment, the above-mentioned interconnection comprises soldering in order to provide a particularly robust and reliable interconnection.

According to various embodiments, an elongated substrate (100) is provided, characterized in that it has opposite ends (103, 105) in the direction of elongation of said elongated substrate (100), and that said elongated substrate (100) comprises: a conductive line arrangement comprising conductive lines (110, 110') arranged to have a first polarity; a further conductive line (120) arranged with a polarity opposite to the first polarity and spatially separated from the conductive line, each of the conductive line and the further conductive line extending between the opposing ends and terminating in a respective metal pad (111, 111 '; 112, 112'; 121, 122) at each of the opposing ends; and at least one solid state lighting arrangement (50, 50', 50 ") comprising: a plurality of strings (130, 130 ', 130 ") of N series-connected solid state elements (101, 101', 101"), where N is a positive integer, the strings being connected in parallel to the conductive line and the further conductive line and being separated from each other by spacer segments (115); and at least one of: a string (140, 140 ', 140 ") of M series-connected solid state elements, where M is a positive integer and M < N, the string being proximate to one of the opposing ends (105) and connected between the conductive line and a first further metal pad (141, 141') at the one of the opposing ends; and a string (150, 150 ', 150 ") of N-M series-connected solid state elements, the string being proximate to another one of the opposing ends (103) and connected between the further conductive line and a second further metal pad (151, 151') at the another one of the opposing ends; wherein when said elongate substrate (100) is interconnected with another elongate substrate (100) having a complementary string of N-M series-connected solid state elements and/or a complementary string of M series-connected solid state elements, one string of said string of M series-connected solid state elements and said string of N-M series-connected solid state elements on said elongate substrate is connected with a corresponding complementary string of said complementary string of N-M series-connected solid state elements and said complementary string of M series-connected solid state elements on said another elongate substrate to form a string of N series-connected solid state elements across adjacent elongate substrates; wherein the string of N series-connected solid state elements is identical in electrical and optical properties to each of the plurality of strings of N series-connected solid state elements across the adjacent elongated substrates.

According to various embodiments, an elongated substrate (100) is provided, characterized in that the above-mentioned at least one solid state lighting arrangement (50, 50 ', 50 ") comprises the above-mentioned string of M series-connected solid state elements (140, 140 ', 140") and the above-mentioned string of N-M series-connected solid state elements (150, 150 ', 150 ").

According to various embodiments, an elongated substrate (100) is provided, characterized in that each string of the above-mentioned strings (130, 130', 130 ") of N series-connected solid state elements extends in the above-mentioned elongated direction of the elongated substrate.

According to various embodiments, an elongated substrate (100) is provided, characterized in that the elongated substrate is flexible.

According to various embodiments, an elongated substrate (100) is provided, characterized in that each solid state element (101, 101', 101 ") is provided as a separate chip mounted on the above-mentioned elongated substrate.

According to various embodiments, there is provided an elongated substrate (100), characterized in that the above-mentioned electrically conductive line arrangement comprises: a pair of said electrically conductive lines (110, 110') arranged to have said first polarity; and a pair of the above-mentioned solid state lighting arrangements (50, 50 ') comprising a first solid state lighting arrangement and a second solid state lighting arrangement, wherein a respective string (130, 140) of the above-mentioned first solid state lighting arrangement (50) is connected to one (110) of the above-mentioned pair of electrically conductive wires arranged to have the above-mentioned first polarity if connected to the electrically conductive wire arranged to have the above-mentioned first polarity, and a respective string (130 ', 140 ') of the above-mentioned second solid state lighting arrangement (50 ') is connected to the other (110 ') of the above-mentioned pair of electrically conductive wires arranged to have the above-mentioned first polarity if connected to the electrically conductive wire arranged to have the above-mentioned first polarity.

According to various embodiments, an elongated substrate (100) is provided, characterized in further comprising a first main surface (103) and a second main surface opposite to the first main surface, wherein the pair of electrically conductive wires (110, 110 ') and the pair of solid state lighting arrangements (50, 50') arranged to have the first polarity is positioned on the first main surface and the further electrically conductive wire (120) is positioned on the second main surface.

According to various embodiments, an elongated substrate (100) is provided, characterized in that the above-mentioned electrically conductive line arrangement comprises a third electrically conductive line (110 ") arranged to have the above-mentioned first polarity, the above-mentioned elongated substrate further comprising a further solid state lighting arrangement (50"), wherein a respective string (130 ", 140") of the above-mentioned further solid state lighting arrangement is connected to the above-mentioned third electrically conductive line if connected to the electrically conductive line arranged to have the above-mentioned first polarity.

According to various embodiments, an elongated substrate (100) is provided, characterized in that each of the above mentioned conductive line (110, 110 ', 110 ") and the above mentioned further conductive line (120) arranged with the above mentioned first polarity comprises a plurality of further metal pads (114, 114', 124), wherein each of the above mentioned further metal pads is conductively connected to a junction between the above mentioned conductive line and one end of a plurality of strings (130, 130 ', 130") of N series connected solid state elements (101, 101', 101 ") connected to the above mentioned conductive line.

According to various embodiments, an elongated substrate (100) is provided, characterized in that the further metal pads (114, 114', 124) are positioned in the spacer section (115).

According to various embodiments, a lighting strip (10) is provided, comprising a plurality of the above-mentioned elongated substrates (100), wherein the respective substrates are interconnected by a pair of interconnects (12, 14) and a further interconnect (16), the pair of interconnects (12, 14) interconnecting the corresponding conductive lines and the above-mentioned metal pads (111, 112; 111 ', 112'; 121, 122) of the further conductive lines (110, 110 ', 110 "; 120) at facing ends (103, 105) of adjacent elongated substrates, the further interconnect (16) interconnecting the above-mentioned first further metal pad (141, 141') of each solid state lighting arrangement (50, 50 ', 50") on one of the adjacent elongated substrates to the above-mentioned second further metal pad (151, 141') of the corresponding solid state lighting arrangement on the other of the adjacent elongated substrates at the facing ends, 151'); wherein the string of N series-connected solid state elements is the same as each of the plurality of strings of N series-connected solid state elements in the elongated direction of the elongated substrate across the adjacent elongated substrates.

According to various embodiments, there is provided a lighting strip (10), characterized in that it further comprises a pair of terminal elongated substrates (100) at opposite ends of said lighting strip, said pair of terminal elongated substrates comprising: a first elongated substrate of terminals, not comprising strings (140, 140 ', 140 ") of M series-connected solid state elements, such that a terminal end portion of said first elongated substrate of terminals comprises only said metal pads (111, 111 '; 121) of said conductive line and said further conductive line (110, 110 ', 110"; 120); and a second terminal elongated substrate not comprising a string (150, 150 ', 150 ") of N-M series-connected solid state elements, such that a terminal end portion of the second terminal elongated substrate comprises only the metal pads (112, 112'; 122) of the conductive line and the further conductive line.

According to various embodiments, there is provided a method of manufacturing the above-described illumination strip (10), the method comprising: interconnecting a plurality of said elongate substrates (100), wherein respective substrates are interconnected by a pair of interconnects (12, 14) and a further interconnect (16), said pair of interconnects (12, 14) interconnecting at facing ends of adjacent elongate substrates said metal pads (111, 112; 111 ', 112 '; 121, 122) of corresponding and further conductive lines (110, 110 ', 110 "; 120), said further interconnect (16) interconnecting at said facing ends said first further metal pad (141, 141 ') of each solid state lighting arrangement (50, 50 ', 50") on one of said adjacent elongate substrates to said second further metal pad (151) of a corresponding solid state lighting arrangement on the other of said adjacent elongate substrates.

According to various embodiments, the method as provided above further comprises terminating opposite ends of the lighting strip (10) with a pair of terminal elongated substrates (100), the pair of terminal elongated substrates (100) comprising: a first elongated substrate of terminals, not comprising strings (140, 140 ', 140 ") of M series-connected solid state elements, such that a terminal end (103) of said first elongated substrate of terminals comprises only said metal pads (111, 111 '; 121) of said conductive line and said further conductive line (110, 110 ', 110"; 120); and a second terminal elongated substrate not comprising a string (150, 150 ', 150 ") of N-M series-connected solid state elements such that a terminal end (105) of said second terminal elongated substrate comprises only said metal pads (112, 112 '; 122) of said conductive line and said further conductive line (110, 110 ', 110"; 120); interconnecting respective metal pads of said conductive lines of said first terminal elongated substrate to respective metal pads of corresponding conductive lines of an adjacent one of said first terminal elongated substrates at facing ends of said substrates, and interconnecting one or more second further metal pads of said first terminal elongated substrate to corresponding first further metal pads of an adjacent one of said first terminal elongated substrates at said facing ends; and interconnecting respective metal pads of said conductive lines of said second terminal elongated substrate to corresponding metal pads of conductive lines of an adjacent one of said second terminal elongated substrates at facing ends of said substrates, and interconnecting one or more first further metal pads of said second terminal elongated substrate to corresponding second further metal pads of an adjacent one of said second terminal elongated substrates at said facing ends.

According to various embodiments, there is provided the above method, wherein the interconnecting comprises welding.

Drawings

Embodiments of the present disclosure are described in more detail by way of non-limiting examples with reference to the accompanying drawings, in which:

FIG. 1 is a circuit diagram of a first type of elongate substrate according to one embodiment;

FIG. 2 is a circuit diagram of a second type of elongate substrate according to one embodiment;

FIG. 3 is a circuit diagram of a third type of elongate substrate according to one embodiment;

FIG. 4 schematically depicts a layout of a portion of an elongated substrate according to an example embodiment;

FIG. 5 is a circuit diagram of a portion of an assembled lighting strip according to one embodiment of a method of the present disclosure;

FIG. 6 is a circuit diagram of another portion of an assembled illumination strip according to one embodiment of a method of the present disclosure;

FIG. 7 schematically depicts a layout of a portion of an illumination strip according to an example embodiment;

FIG. 8 is a circuit diagram of a first type of elongate substrate according to another embodiment;

FIG. 9 is a circuit diagram of a second type of elongate substrate according to another embodiment;

FIG. 10 is a circuit diagram of a third type of elongate substrate according to another embodiment;

FIG. 11 schematically depicts a layout of a portion of an illumination strip according to another example embodiment;

FIG. 12 is a circuit diagram of a first type of elongate substrate according to yet another embodiment;

FIG. 13 is a circuit diagram of a second type of elongate substrate according to yet another embodiment;

FIG. 14 is a circuit diagram of a third type of elongate substrate according to yet another embodiment;

FIG. 15 schematically depicts a layout of a portion of an illumination strip according to yet another example embodiment; and

fig. 16 schematically depicts the layout of a portion of another illumination strip (not part of the present disclosure).

Detailed Description

It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

Fig. 1 schematically depicts a circuit diagram of an elongated substrate 100 of a first type for assembly into a lighting strip according to one embodiment of the present disclosure. The elongate substrate 100 may be made of any suitable material. For example, the elongated substrate 100 may be a Printed Circuit Board (PCB), and preferably, the elongated substrate 100 is a flexible PCB. It should be noted that flexible PCBs are well known per se, and therefore, for the sake of brevity, how such flexible PCBs are provided will not be explained. The elongated substrate 100 extends between opposite ends 103 and 105 along its elongated direction. Further electrically conductive lines 120 arranged with a first polarity and further electrically conductive lines 120 arranged with a polarity opposite to the first polarity each extend between the opposite ends 103 and 105. For example, the conductive line 110 may be arranged with a positive polarity and the further conductive line 120 may be arranged with a negative polarity, or vice versa.

The conductive lines 110 terminate at

respective metal pads

111 and 112 at opposite ends 103 and 105 of the elongate substrate 100, the

metal pads

111 and 112 may be used to interconnect the conductive lines 110 of the elongate substrate 100 to corresponding conductive lines on another elongate substrate or to a terminal (e.g., a positive terminal) of a particular polarity of a power supply, for example. The further conductive lines 120 terminate at

respective metal pads

121 and 122 at opposite ends 103 and 105 of the elongate substrate 100, the

metal pads

121 and 122 may be used to interconnect the further conductive lines 120 of the elongate substrate 100 to corresponding further conductive lines on a further elongate substrate or to a further terminal (e.g. a negative terminal) of a particular polarity of e.g. a power supply. The conductive line 110 and the further conductive line 120 may be made of any suitable conductive material, such as copper, for example. Similarly, the

respective metal pads

111, 112, 121, and 122 may be made of any suitable conductive material (such as copper), for example. The metal pads may also be coated with additional conductive material (e.g., gold, etc.) to facilitate electrical interconnection of the metal pads with additional metal pads, power supplies, etc. (e.g., using soldering).

The elongate substrate 100 also carries an SSL arrangement comprising a plurality of strings 130 of N series-connected SSL elements 101, the strings 130 being connected in parallel between the conductive lines 110 and the further conductive lines 120. In the context of the present application, N is a positive integer having a value of at least 2, and preferably having a value of at least 5. For example, N may be 5, 6, 7, 8, 9, 10, or more. In fig. 1, the SSL arrangement further comprises a first further string 140 of M serially connected SSL elements 101, where M is a positive integer, where M < N. The first further string 140 is connected between the conductive line 110 and a first further metal pad 141 at the first end 105 of the elongated substrate 100. The SSL arrangement further comprises a second further string 150 of N-M series-connected SSL elements 101 connected between a second further metal pad 151 and a further conductive line 120 at the other end 103 of the elongate substrate 100. In the present application, such an elongated substrate 100 will also be referred to as a B-type substrate. The SSL elements 101 within a single SSL arrangement are typically of the same type, i.e. typically produce substantially the same luminous output in terms of luminous output intensity and spectral composition.

When interconnecting a pair of B-type elongated substrates 100 into a lighting string, the end portion 105 of a first B-type elongated substrate 100 will face the end portion 103 of an adjacent B-type elongated substrate 100. Such elongated substrates 100 are then interconnected by: interconnecting (e.g. soldering) the metal pads 112 of the conductive lines 110 on the first B-type elongated substrate 100 to the metal pads 111 of the corresponding conductive lines 110 of the adjacent B-type elongated substrate 100, and interconnecting (e.g. soldering) the metal pads 122 of the further conductive lines 120 on the first B-type elongated substrate 100 to the metal pads 121 of the corresponding further conductive lines 120 of the adjacent B-type elongated substrate 100. Furthermore, the first further metal pads 141 of the first further string 140 on the first B-type elongated substrate 100 are interconnected (e.g. soldered) to the second further metal pads 151 of the second further string 150 on the adjacent B-type elongated substrate 100, thereby forming a further string 130 of N series-connected SSL elements 101, which further string 130 is distributed over the first B-type elongated substrate 100 and its adjacent B-type elongated substrate 100.

Thus, the elongated substrate 100 (e.g. when forming part of a lighting strip) may be cut as symbolically depicted by the dashed line terminating in a pair of scissors at a spacer or cutting area 115 between any adjacent strings 130, the spacer or cutting area 115 being kept free of interconnections between adjacent elongated substrates 100, as no strings 130 terminate in a position coinciding with an edge of the elongated substrate 100 due to the formation of strings 130 by interconnecting the first and second

further strings

140, 150 across respective boundaries of adjacent elongated substrates 100. Each string 130 of N series-connected SSL elements 101 may further be connected to a further metal pad 114 of the conductive line 110 and a further metal pad 124 of the further conductive line 120, such that such further metal pad is conductively connected to a junction between its conductive line and one end of such string 130. The presence of such additional metal pads 114, 124 (which may be located in the spacer region 115 in some embodiments) facilitates the reconnection of the cut portions of the elongated substrate 100, for example, when forming a portion of a daisy chain or string of interconnected elongated substrates 100 (e.g., lighting strips, etc.).

The B-type elongated substrate 100 may be used as an intermediate substrate for such a daisy-chained arrangement, e.g. a lighting strip according to embodiments of the present disclosure, which is why both

string portions

140, 150 are present at respective ends 105, 103 of the elongated substrate 100 in order to interconnect the B-type elongated substrate 100 at both ends to another elongated substrate 100 according to embodiments of the present disclosure. However, in case such an elongated substrate 100 is to be used as a terminal substrate for a daisy chain of such interconnected elongated substrates 100 (e.g. lighting strips, etc.), only one of its

ends

103, 105 is to be connected to the other elongated substrate 100, such that the other end does not need to contain the first further string 140 or the second further string 150 of SSL arrangements.

Fig. 2 schematically depicts a circuit diagram of an elongated substrate 100 suitable for use as such a terminal substrate, wherein at its end 105 only a first further string 140 of SSL arrangements is present. Such an elongated substrate 100 will also be referred to as an a-type substrate in the present application. Thus, the opposite end 103 of the a-type elongated substrate 100 does not comprise the second further string 150, but only

metal pads

111, 121 for interconnecting the conductive line 110 and the further conductive line 120, respectively, to e.g. a power supply or the like.

Fig. 3 schematically depicts a circuit diagram of an elongated substrate 100 suitable for use as such a terminal substrate, wherein at its end 103 there is only a second further string 150 of SSL arrangements. Such an elongated substrate 100 will also be referred to as C-substrate in the present application. Thus, the opposite end 105 of the C-shaped elongated substrate 100 does not comprise the first further string 140, but only

metal pads

112, 122 for interconnecting the conductive line 110 and the further conductive line 120, respectively, to e.g. a power supply or the like.

At this point it should be noted that each of the a-, B-and C-type elongated substrates 100 may comprise any suitable number of strings 130 of N series-connected SSL elements 101. Different types of elongated substrates 100 may include different numbers of strings 130. Similarly, different instances of the same type of substrate 100 (e.g., different instances of the B-type elongated substrate 100) may include different numbers of strings 130, but for manufacturing simplicity, it is preferred that different instances of the same type of elongated substrate 100 include the same number of strings 130.

Fig. 4 schematically depicts a layout of a portion of an elongated substrate 100 according to an example embodiment. In this layout, which depicts the terminal section of such a substrate 100 including its end 105, it can be shown that the strings 130 of N series-connected SSL elements 101 extend in the elongated direction of the elongated substrate 100, with

further metal pads

114, 124 positioned in the spacer section 115, which can be used to cut the elongated substrate 100 between adjacent strings 130, as symbolically indicated by the dashed lines ending in opposite pairs of scissors. The SSL elements 101 may be mounted as separate chips onto the exposed portions of the conductive lines 110 and the further conductive lines 120, respectively, e.g. as surface mounted devices using conventional SMD mounting techniques. At the end 105 of the elongated substrate 100, the SSL arranged first further string 140 on the elongated substrate 100 is positioned between the spacer section 115 and the metal pad 112 connected to the conductive line 110, the metal pad 122 connected to the further conductive line 120, and the first further metal pad 141 connected to the first further string 140, which are typically arranged at the edge of the elongated substrate 100 to facilitate interconnection of the elongated substrate 100 with another elongated substrate as described before. It should be noted that although in a preferred embodiment there is each string of

strings

130, 140, 150 of SSL arrangements extending in the elongate direction of the elongate substrate 100, it should be understood that alternative arrangements are also envisaged, such as an arrangement in which the strings of SSL elements 101 meander between opposing conductive lines, or the like.

Fig. 5 schematically depicts a circuit diagram of a first end portion of an illumination strip 10, wherein an a-type elongate substrate 100 is interconnected at facing ends thereof to a B-type elongate substrate 100, according to one embodiment of the present disclosure. Specifically, the metal pads 112 of the a-type elongated substrate 100 are interconnected to the metal pads 111 of the B-type elongated substrate 100 by interconnects 12 (e.g., solder bumps, etc.), thereby interconnecting the corresponding conductive lines 110 of the respective elongated substrate 100. The metal pads 122 of the a-type elongated substrate 100 are interconnected to the metal pads 121 of the B-type elongated substrate 100 by interconnects 14 (e.g., solder bumps, etc.), thereby interconnecting the corresponding further conductive lines 120 of the respective elongated substrate 100. The first further metal pad 141 of the a-type elongated substrate 100 is interconnected to the second further metal pad 151 of the B-type elongated substrate by an interconnect 16 (e.g. a solder bump or the like), thereby interconnecting the first further string 140 on the a-type elongated substrate 100 to the second further string 150 on the B-type elongated substrate 100. As previously described, interconnecting a first further string 140 of M series-connected SSL elements 101 on an a-type elongate substrate 100 to a second further string 150 of N-M series-connected SSL elements 101 on a B-type elongate substrate 100 forms a string 130 of N series-connected SSL elements 101 distributed across two adjacent elongate substrates 100, which allows cutting any of the elongate substrates 100 at the end of the distributed string in the spacer or cutting area 150 on any of these substrates near the boundary between these substrates.

Fig. 6 schematically depicts a circuit diagram of a further end portion of an illumination strip 10 according to one embodiment of the present disclosure, wherein a B-type elongated substrate 100 is interconnected at its facing ends to a C-type elongated substrate 100. Specifically, the metal pads 112 of the B-type elongated substrate 100 are interconnected to the metal pads 111 of the C-type elongated substrate 100 by interconnects 12 (e.g., solder bumps, etc.), thereby interconnecting the corresponding conductive lines 110 of the respective elongated substrate 100. The metal pads 122 of the B-type elongated substrate 100 are interconnected to the metal pads 121 of the C-type elongated substrate 100 by interconnects 14 (e.g., solder bumps, etc.), thereby interconnecting the corresponding further conductive lines 120 of the respective elongated substrate 100. The first further metal pads 141 of the B-type elongated substrate 100 are interconnected to the second further metal pads 151 of the C-type elongated substrate 100 by interconnects 16 (e.g. solder bumps, etc.), thereby interconnecting the first further strings 140 on the B-type elongated substrate 100 to the second further strings 150 on the C-type elongated substrate 100. As previously described, interconnecting the first further string 140 of M series-connected SSL elements 101 on the B-type elongated substrate 100 to the second further string 150 of N-M series-connected SSL elements 101 on the C-type elongated substrate 100 forms a string 130 of N series-connected SSL elements 101 distributed across two adjacent elongated substrates 100, which allows cutting any of the elongated substrates 100 at the end of the distributed string in the spacer or cutting area 150 on any of these substrates close to the boundary between these substrates.

In the same manner, two adjacent B-type elongated substrates 100 may be interconnected at their facing ends, i.e., the metal pads 112 of the B-type elongated substrates 100 are interconnected to the metal pads 111 of the adjacent B-type elongated substrates 100 by interconnects 12 (e.g., solder bumps, etc.), thereby interconnecting the corresponding conductive lines 110 of the respective elongated substrates 100. The metal pads 122 of the B-type elongated substrates 100 are interconnected to the metal pads 121 of the adjacent B-type elongated substrates 100 by interconnects 14 (e.g., solder bumps, etc.), thereby interconnecting the corresponding further conductive lines 120 of the respective elongated substrates 100. The first further metal pads 141 of the B-type elongated substrate 100 are interconnected to the second further metal pads 151 of the adjacent B-type elongated substrate 100 by interconnects 16 (e.g. solder bumps, etc.), thereby interconnecting the first further strings 140 on the B-type elongated substrate 100 to the second further strings 150 on the adjacent B-type elongated substrate 100, so as to form the distributed strings 130.

The illumination strip 10 assembled in this manner may take the form of an a-B]_n-form C, which depicts a daisy chain of interconnected elongated substrates of types a, B and C, where n is a positive integer, typically a positive integer having a value of at least 5, preferably at least 8, more preferably at least 10. Therefore, it is necessary to provide three different types of elongated substrates 100, for example, three different types of (flexible) PCBs. By providing a detachable elongated substrate comprising an a-type elongated substrate portion and a C-type elongated substrate portion, it may be simplified to provide an elongated substrate 100 for use in such an assembly process, such that only two types of different elongated substrates (a + C and B) need to be provided, since the a-and C-type elongated substrates 100 may be produced by splitting the detachable a + C-type elongated substrate. Such a separable a + C type elongated substrate is generally similar to the B type elongated substrate 100 in that the opposite ends of the substrate comprise a first further string 140 and a second further string 150, respectively, wherein a cutting area is provided between the a and C type substrate portions, wherein each of these portions comprises a

metal pad

111, 121 and 112, 122, respectively, close to (adjacent to) the cutting area.

Alternatively, the illumination strip 10 assembled in accordance with the teachings of the present disclosure may take the shape [ B ] n, i.e., there are a-type and C-type elongated substrates 100, and the opposite ends of the illumination strip 10 may be omitted. As will be understood by those skilled in the art, in this case, the first further string 140 at a first end of the lighting strip 10 and the second further string 150 at the opposite end of the lighting strip 10 will not be used (i.e. not be present). Preferably, the first further string 140 at the first end of the lighting strip 10 and the second further string 150 at the opposite end of the lighting strip 10 are unoccupied, i.e. no SSL elements 101 are mounted on these strings of the respective B-type elongated substrate 100 to be positioned at the opposite end of the lighting strip 10, since such SSL elements 101 will remain unconnected, such that their presence will unnecessarily increase the manufacturing costs of such B-type elongated substrate 100 and the lighting strip 10 comprising such substrate.

Fig. 7 schematically depicts a layout of a portion of a lighting strip 10 according to an example embodiment, wherein adjacent elongated substrates 100 are interconnected by the previously described

interconnects

12, 14 and 16, forming a string 130 of N series-connected SSL elements 101 distributed across the adjacent elongated substrates 100. Because the

interconnects

12, 14, and 16 are positioned within the distributed string 130, the lighting strip 10 may be cut at either side of the distributed string 130 in respective spacer or cut regions 115. In this way, a lighting strip 10 is provided which may be cut between any adjacent pair of strings 130 of N serially connected SSL elements 101, such that the lighting strip 10 may be cut to any desired length. This increases the user flexibility of such a lighting strip 10 compared to prior art lighting strips in which the

interconnects

12 and 14 are typically positioned between adjacent pairs 130 of N series connected SSL elements 101 on adjacent elongate substrates 100, such that the spacer or cut region 115 of such an arrangement will coincide with the

interconnects

12 and 14 as previously described. The spacer sections 115 are typically spaced apart at regular intervals in such an illumination strip 10, such as for example 5cm or 10cm intervals. The overall length of the illumination strip 10 according to embodiments of the present disclosure is not particularly limited, as the illumination strip 10 may take any suitable length, e.g., 5m, 50m, or longer.

Embodiments of the present disclosure are not limited to an elongate substrate 100 comprising only a single SSL arrangement and a lighting strip 10 comprising such an elongate substrate. For example, fig. 8 is a circuit diagram of a B-type elongated substrate 100, fig. 9 is a circuit diagram of an a-type elongated substrate 100, and fig. 10 is a circuit diagram of a C-type elongated substrate 100, wherein the elongated substrate 100 comprises a first SSL arrangement 50 having a first type of SSL elements 101 (e.g. SSL elements producing light having a first spectral component), and a second SSL arrangement 50 'having a second type of SSL elements 101' (e.g. SSL elements producing light having a second spectral component different from the first spectral component, such as light of a different color or white light having a different color temperature). In such an arrangement, each SSL arrangement 50, 50 'is connected between a dedicated conductive line 110, 110' arranged to have a first polarity and a common further conductive line 120 arranged to have a polarity opposite to the first polarity.

Each conductive line is connected at opposite ends to dedicated metal pads, i.e. conductive line 110 is connected between

metal pads

111 and 112, conductive line 110 ' is connected between metal pads 111 ' and 112 ', and conductive line 120 is connected between

metal pads

121 and 122, so that when assembling a lighting strip 10 comprising such a substrate as previously described, the respective conductive line can be interconnected to the corresponding conductive line on the adjacent elongated substrate. In other words, during such assembly, the metal pad 112 of the conductive line 110 of the first elongated substrate 100 is interconnected to the metal pad 111 of the conductive line 110 on the adjacent elongated substrate, the metal pad 112 'of the conductive line 110' of the first elongated substrate 100 is interconnected to the metal pad 111 'of the conductive line 110' on the adjacent elongated substrate, and the metal pad 122 of the further conductive line 120 of the first elongated substrate 100 is interconnected to the metal pad 121 of the conductive line 110 on the adjacent elongated substrate. Similarly, the first further metal pads 141, 141 'of the first further strings 140, 140' of SSL arrangements 50, 50 'on the first elongated substrate 100 are interconnected to the corresponding second further metal pads 151, 151' of the second further strings 150, 150 'of SSL arrangements 50, 50' on the first elongated substrate 100, i.e. the first further metal pads 141 on the first elongated substrate 100 are interconnected to the second further metal pads 151 on the adjacent elongated substrate, and the first further metal pads 141 'on the first elongated substrate 100 are interconnected to the second further metal pads 151' on the adjacent elongated substrate.

Each conductive line at its junction with the string 130, 130 'of N series-connected SSL elements 101, 101' may comprise a further metal pad to facilitate reconnection of the cut section of the elongate substrate 100, e.g. when forming part of the lighting strip 10 as described previously. For example, the string 130 may be connected between a first conductive line 110 arranged to have the first polarity and a further conductive line 120 to which the

further metal pads

114, 124 are respectively connected, and the string 130 ' may be connected between a second conductive line 110 ' arranged to have the first polarity and a further conductive line 120 to which the further metal pads 114 ', 124 are respectively connected. By providing each of the SSL arrangements 50, 50 'with a dedicated conductive wire 110, 110' arranged to have a first polarity, each SSL arrangement can be individually addressed such that the respective SSL elements 101 and 101 'of these SSL arrangements 50 and 50' can operate independently of each other, thereby providing a lighting strip 10 that can be configured in accordance with its luminous output.

Fig. 11 schematically depicts an example layout of a portion of an elongated substrate 100 comprising a plurality (here two) SSL arrangements 50, 50'. In this example embodiment, the first SSL arrangement 50, comprising the string 130 of N series-connected SSL elements 101 and the further string 140 of M series-connected SSL elements 101, and the further SSL arrangement 50 ', comprising the string 130' of N series-connected SSL elements 101 'and the further string 140' of M series-connected SSL elements 101 ', are positioned on the first major surface 103 of the elongate substrate 100 together with the conductive lines 110, 110' and the

metal pads

112, 112 ', 122, 141' on the edge or end 105 of the elongate substrate 100. Further electrically conductive lines 120 are positioned on the main surface of the elongated substrate 100 opposite the first main surface 103. To connect the respective SSL elements 101, 101' to further conductive lines 120, conductive structures (such as vias) may extend through the elongate substrate 101 in order to provide such interconnections. The positioning of all the metal pads on one of the main surfaces of the elongated substrate 100 has the following advantages: interconnection of the elongated substrate 100 with an adjacent elongated substrate, e.g. as described before, is easily achieved, while the positioning of the further conductive lines 120 on the opposite main surface frees space on the first main surface 103 for positioning thereon a plurality of individually controllable SSL arrangements 50, 50'.

As can be seen in fig. 11, the strings 130, 130 'of respective SSL arrangements 50, 50' on the first major surface 103 of the elongate substrate 100 are generally aligned in the elongate direction of the elongate substrate 100 such that the spacer or cut region 115 extends across the entire width of the elongate substrate 100.

Respective metal pads

114, 114', and 124 may be positioned within such a spacer or cut region 150 to facilitate reconnection of the cut section of the elongate substrate 100 (e.g., when forming part of the lighting strip 10) to another elongate substrate, a power supply, etc., e.g., using a wire-to-substrate (PCB) interconnect, etc.

For example, fig. 12 is a circuit diagram of a B-type elongated substrate 100, fig. 13 is a circuit diagram of an a-type elongated substrate 100, and fig. 14 is a circuit diagram of a C-type elongated substrate 100, wherein the elongated substrate 100 includes: a first SSL arrangement 50 having

strings

130, 140, 150 comprising SSL elements 101 of a first type (e.g. SSL elements producing light having a first spectral composition); a second SSL arrangement 50 ' having strings 130 ', 140 ', 150 ' comprising SSL elements 101 ' of a second type (e.g. SSL elements producing light having a second spectral composition different from the first spectral composition); and a third SSL arrangement 50 "having strings 130", 140 ", 150" comprising SSL elements 101 "of a third type (e.g. SSL elements producing light having a third spectral composition different from the first and second spectral compositions). The light with different spectral components may be light of different colors and/or white light with different color temperatures. As previously mentioned, each

SSL arrangement

50, 50 ', 50 "is connected between its dedicated

conductive line

110, 110', 110" arranged to have a first polarity and a common further conductive line 120 arranged to have a polarity opposite to the first polarity, such that the respective SSL arrangements can be individually controlled. In this way, the elongate substrate 100 as explained in more detail above and the lighting strip 10 assembled from a plurality of such elongate substrates 100 may comprise thereon any suitable number of SSL arrangements, such as for example a first SSL arrangement comprising white SSL elements and three further SSL arrangements comprising red, green and blue light generating SSL elements, respectively. In addition, there may be further SSL arrangements comprising white SSL elements, thereby providing a pair of SSL arrangements comprising white SSL elements that respectively produce white light of different color temperatures (e.g. cold white light and warm white light). This may result in a lighting strip comprising such a pair of SSL arrangements generating white light and three such further SSL arrangements generating different colors of light, wherein each SSL arrangement may be individually addressed by a respective dedicated conductive wire as described above. Many other variations will be apparent to the skilled person.

The layout of a portion of an elongated substrate 100 comprising three individually controllable SSL arrangements on a first main surface is schematically depicted in fig. 15. The first SSL arrangement comprises SSL elements 101 and is connected between a first conductive line 110 on a first major surface and a common further conductive line 120 on the opposite major surface. As previously described, the first conductive line 110 extends between the

metal pads

111 and 112 on the first major surface at opposite ends of the elongated substrate. The metal pads 114 may be present in spacer regions between the series-connected strings of N SSL elements to allow such strings to be reconnected after cutting the elongate substrate in such regions, as explained in more detail above. The second SSL arrangement comprises SSL elements 101 'and is connected between a second conductive line 110' on the first major surface and a common further conductive line 120 on the opposite major surface. As previously described, the second conductive line 110 extends between the metal pads 111 'and 112' on the first major surface at opposite ends of the elongated substrate. Metal pads 114' may be present in spacer regions between the series-connected strings of N SSL elements to allow such strings to be reconnected after cutting the elongate substrate in such regions, as explained in more detail above. The third SSL arrangement comprises SSL elements 101 "and is connected between a third conductive line 110" on the first major surface and a common further conductive line 120 on the opposite major surface. As previously described, the third conductive line 110 "extends between the metal pads 111" and 112 "on the first major surface at opposite ends of the elongated substrate. Metal pads 114 "may be present in the spacer regions between the series-connected strings of N SSL elements to allow such strings to be reconnected after cutting the elongate substrate in such regions, as explained in more detail above.

As previously mentioned, the respective SSL arrangements may be individually controlled by the respective dedicated conductive lines (i.e. the first, second and third conductive lines 110, 110', respectively) to which they are connected. Further dedicated conductive lines may be added to the first main surface, to which further SSL arrangements may be connected. In this way, the first major surface may carry any suitable number of individually controllable SSL arrangements, as previously described. This can be facilitated by increasing the width of the elongate substrate 100, if desired.

As previously mentioned, the connection of the SSL elements on the first major surface with the further conductive lines on the opposite major surface may be provided by connections such as vias extending through the elongated substrate 100. Preferably, also on the first main surface are the respective metal pads of the

conductive lines

110, 110 ' and 110 "and the common further conductive line 120, i.e.

metal pads

111, 111 ', 111", 112 ' and 112 "and

metal pads

121 and 122. The metal pads (here

metal pads

141, 141' and 141 ") of the truncated string portion (i.e. the first further string of M series-connected SSL elements and/or the second further string of N-M series-connected SSL elements) are preferably also on the first major surface. By having all metal pads located on the same main surface, interconnection of adjacent elongate substrates 100, such as in the lighting strip 10, is particularly simple.

Embodiments of the present disclosure may be used with any suitable arrangement of SSL elements on an elongate substrate, such as any suitable pitch of SSL elements, for example, a pitch equal to or less than 10 mm. Of course, pitches in excess of 10mm are also envisaged. However, for pitches exceeding 10mm, alternative solutions (not part of the present disclosure) may be envisaged. An example layout of this alternative solution is schematically depicted in fig. 16, fig. 16 depicting a portion of an illumination strip 10, wherein two adjacent elongated substrates 100 are soldered together by a first solder joint 12 interconnecting

respective metal pads

111, 112 of a first conductive wire 110, and by a further solder joint 14 interconnecting

respective metal pads

121, 122 of a further conductive wire 120. As previously mentioned, the SSL elements 101 on each elongate substrate 100 are arranged in a plurality of strings 130, each string 130 comprising N SSL elements 101 connected in series. The pitch P between the SSL elements 101 (preferably equally spaced) is greater than 10 mm. As previously mentioned, spacers or cut regions 115 are positioned between adjacent strings 130, wherein there may be

metal pads

114, 124 for reconnecting the first conductive line 110 and the further conductive line 120, respectively.

However, due to the relatively large pitch P, additional spacer regions 115 may be positioned between the strings 130 immediately adjacent or near the end or edge of each elongate substrate 100 and the

metal pads

111, 121 or 112, 122 at that edge. In fig. 16, by way of non-limiting example only, the spacer region 115 is positioned between the

metal pads

111, 121 and the first string 130 of the right-hand elongate substrate 100; it is also feasible to position the spacer region between the

metal pads

112, 122 and the last string 130 of adjacent elongated substrates 100.

To ensure that the pitch P of the SSL elements 101 is maintained across the interconnected adjacent elongate substrates 100, the metal pads (here

metal pads

111, 121, as a non-limiting example only) on the elongate substrate 100 adjacent to the elongate substrate including the spacer region 115 near its edge may be located closer to the terminal SSL elements 101 of the final string 130 on the adjacent elongate substrate 100 (i.e. the SSL elements 101 near its edge). Thus, in this embodiment, each string 130 is positioned entirely on a single elongate substrate 100, i.e. no string 130 extends across adjacent elongate substrates 100, while maintaining a constant pitch P of SSL elements 101 across the lighting strip 10 and providing spacers or cut regions 115 at regular intervals across the entire lighting strip 10. This eliminates the need for additional interconnects to interconnect the M SSL elements and the N-M SSL element portions of such a distributed string 130, making this embodiment characterized by no interconnects between adjacent elongated substrates 100 of the interconnect as compared to the above-described embodiment of the present disclosure (e.g., where no interconnects 16 are present).

When interconnecting such adjacent elongated substrates 100 (e.g. by soldering metal pad 111 to metal pad 112 to form solder bump 12, and by soldering metal pad 121 to metal pad 122 to form solder bump 14), care must be taken that solder does not flow into the adjacent spacer region 115 intended for cutting, as such soldering would make this region more difficult to cut, which is undesirable. To prevent this, as a non-limiting example, the metal pads (here, metal pads 111, 121) adjacent to the spacer region 115 are separated from the spacer region by a barrier structure 20 (e.g., a dam structure or a bump-like structure), which barrier structure 20 prevents solder applied to the metal pads from flowing from the metal pads to the adjacent spacer region 115. Such a barrier structure may be a discrete structure positioned between the

metal pads

111, 121 and the adjacent spacer region 115, or alternatively may be an unexposed region of the

metal pads

111, 121 proximate to the spacer region. In other words, when the

metal pads

111, 121 are formed by removing the capping material therefrom, only a portion of the capping material may be removed such that the remaining capping material forms the barrier structure 20. This has the further advantage of: the area of the

metal pads

111, 121 is kept small, which makes it possible to selectively plate such pads with gold in order to improve the reliability of the interconnection between the elongated substrates 100.

Finally, it is noted that for the avoidance of doubt, the spacer regions 115 (forming part of and not forming part of the present disclosure) in the foregoing embodiments symbolically depict two cut lines on either side of such spacer regions merely to indicate that such spacer regions 115 may be cut on either side. This should not be interpreted as meaning or implying that two cuts have to be made. However, because such spacer regions 115 may be cut on either side, such spacer regions may be re-cut, for example, after first cutting and then re-connecting the elongate substrate 100 including the spacer regions.

It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosure, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. An elongated substrate (100) having opposite ends (103, 105) in an elongation direction of the elongated substrate (100), and the elongated substrate (100) comprising:

a conductive line arrangement comprising conductive lines (110, 110') arranged to have a first polarity;

a further conductive line (120) arranged with a polarity opposite to the first polarity and spatially separated therefrom, each of the conductive line and the further conductive line extending between the opposite ends and terminating in a respective metal pad (111, 111 '; 112, 112'; 121, 122) at each of the opposite ends; and

at least one solid state lighting arrangement (50, 50', 50 "), comprising:

a plurality of strings (130, 130 ', 130 ") of N series-connected solid state elements (101, 101', 101"), where N is a positive integer, the strings being connected in parallel to the conductive line and the further conductive line and being separated from each other by spacer segments (115); and at least one of:

a string (140, 140 ', 140 ") of M series-connected solid state elements, where M is a positive integer and M < N, the string being proximate to one of the opposing ends (105) and connected between the conductive line and a first further metal pad (141, 141') at the one of the opposing ends; and

a string (150, 150 ', 150 ") of N-M series-connected solid state elements, the string being proximate to another one of the opposite ends (103) and connected between the further conductive line and a second further metal pad (151, 151') at the another one of the opposite ends;

wherein when the elongate substrate (100) is interconnected with another elongate substrate (100) having a complementary string of N-M series-connected solid state elements and/or a complementary string of M series-connected solid state elements, one string of the M series-connected solid state elements and the string of N-M series-connected solid state elements on the elongate substrate is connected with a corresponding complementary string of the N-M series-connected solid state elements and the complementary string of M series-connected solid state elements on the other elongate substrate to form a string of N series-connected solid state elements across adjacent elongate substrates;

wherein the string of N series-connected solid state elements is identical in electrical and optical performance to each of the plurality of strings of N series-connected solid state elements across the adjacent elongated substrates.

2. The elongated substrate (100) of claim 1, wherein the at least one solid state lighting arrangement (50, 50 ', 50 ") comprises the string of M series-connected solid state elements (140, 140 ', 140") and the string of N-M series-connected solid state elements (150, 150 ', 150 ").

3. The elongated substrate (100) of claim 1 or 2, wherein each string of the N strings (130, 130', 130 ") of series-connected solid state elements extends in the elongated direction of the elongated substrate.

4. The elongated substrate (100) of claim 1 or 2, characterized in that the elongated substrate is flexible.

5. The elongated substrate (100) of claim 1 or 2, characterized in that each solid state element (101, 101', 101 ") is provided as a separate chip mounted on the elongated substrate.

6. The elongated substrate (100) of claim 1 or 2, wherein the electrically conductive line arrangement comprises: a pair of said electrically conductive lines (110, 110') arranged to have said first polarity; and a pair of said solid state lighting arrangements (50, 50 ') comprising a first solid state lighting arrangement and a second solid state lighting arrangement, wherein a respective string (130, 140) of said first solid state lighting arrangement (50) is connected to one (110) of said pair of electrically conductive wires arranged to have said first polarity if connected to an electrically conductive wire arranged to have said first polarity, and a respective string (130 ', 140 ') of said second solid state lighting arrangement (50 ') is connected to the other (110 ') of said pair of electrically conductive wires arranged to have said first polarity if connected to an electrically conductive wire arranged to have said first polarity.

7. The elongated substrate (100) of claim 6, further comprising a first main surface and a second main surface opposite to the first main surface, wherein the pair of electrically conductive wires (110, 110 ') and the pair of solid state lighting arrangements (50, 50') arranged to have the first polarity are positioned on the first main surface and the further electrically conductive wire (120) is positioned on the second main surface.

8. The elongated substrate (100) of claim 7, wherein the arrangement of conductive wires comprises a third conductive wire (110 ") arranged to have the first polarity, the elongated substrate further comprising a further solid state lighting arrangement (50"), wherein a respective string (130 ", 140") of the further solid state lighting arrangement is connected to the third conductive wire if connected to the conductive wire arranged to have the first polarity.

9. The elongated substrate (100) of any one of claims 1-2 and 7-8, wherein each of the conductive lines (110, 110 ', 110 ") and the further conductive lines (120) arranged to have the first polarity comprises a plurality of further metal pads (114, 114', 124), wherein each of the further metal pads is conductively connected to a junction between the conductive line and one end of a plurality of strings (130, 130 ', 130") of N series-connected solid state elements (101, 101', 101 ") connected to the conductive line.

10. The elongated substrate (100) of claim 9, characterized in that the further metal pads (114, 114', 124) are positioned in the spacer sections (115).

11. A lighting strip (10) comprising a plurality of elongate substrates (100) according to any one of claims 1-10, wherein the respective substrates are interconnected by a pair of interconnects (12, 14) and a further interconnect (16), the pair of interconnects (12, 14) interconnecting the metal pads (111, 112; 111 ', 112 '; 121, 122) of the corresponding and further conductive lines (110, 110 ', 110 "; 120) at facing ends (103, 105) of adjacent elongate substrates, the further interconnect (16) interconnecting the first further metal pad (141, 141 ') of each solid state lighting arrangement (50, 50 ', 50") on one of the adjacent elongate substrates to the second further metal pad (151) of the corresponding solid state lighting arrangement on the other of the adjacent elongate substrates at the facing ends, 151');

wherein the string of N series-connected solid state elements is the same size across the adjacent elongated substrates as each string of the plurality of strings of N series-connected solid state elements in the elongated direction of the elongated substrates.

12. The lighting strip (10) of claim 11, further comprising a pair of terminal elongate substrates (100) at opposite ends of the lighting strip, the pair of terminal elongate substrates comprising:

a first terminal elongated substrate not comprising strings (140, 140 ', 140 ") of M serially connected solid state elements such that a terminal end portion of the first terminal elongated substrate comprises only the metal pads (111, 111 '; 121) of the conductive line and the further conductive line (110, 110 ', 110"; 120); and

a second terminal elongated substrate not comprising a string (150, 150 ', 150 ") of N-M series-connected solid state elements, such that a terminal end portion of the second terminal elongated substrate comprises only the metal pads (112, 112'; 122) of the conductive line and the further conductive line.