EP2156469A1 - Illuminant - Google Patents

Abstract

The invention relates to an illuminant (40) comprising a standardised connection socket (42) and a cover (50) consisting of a light-permeable material defining an inner chamber (52). A light chip arrangement (10; 110) comprising at least one semiconductor structure (14; 114) is contacted between contact regions (48a, 48b) of at least two supply lines (44a, 44b).

Description

 Lamp

The invention relates to a luminous means according to the preamble of claim 1.

Such bulbs find widespread use in many applications and are characterized by a matched to the particular application terminal socket, which can cooperate with a corresponding version.

Between the contact areas of the supply lines there is usually a luminous element, e.g. a filament, contacted.

Such lamps often have the disadvantage that they have only a relatively short life at partially high initial cost, since the light-emitting element is prone and already narh. 1 000 operating hours is no longer functional.

The object of the invention is to provide a lamp of the type mentioned, in which the life is increased.

This is achieved in a luminous means of the type mentioned above in that the contact regions of the supply lines contact a luminous chip arrangement which comprises at least one light-emitting semiconductor structure.

As light-emitting semiconductor structure, semiconductor Terkristalle with a pn junction in question, which emit light when exposed to voltage. Such semiconductor crystals are characterized by a high energy yield coupled with a long life.

Advantageous developments of the invention are specified in subclaims.

By means of the measure according to claim 2, the power supply lines can be connected via the supply lines in addition to the power supply

Luminescent chip arrangement and a heat dissipation of the heating up under voltage Leuchtchip- arrangement can be ensured.

Known contacting methods can be favorable

Be used when the contacting of the supply lines with the lighting arrangement as specified in claim 3, is formed.

Alternatively, it may be favorable to form, as described in claim 4, this contacting to encrypt higher temperature loads of the light chip arrangement shun ^".

A higher light output of the luminous means can advantageously be achieved by the measures according to claim 5 or claim 6.

If several semiconductor structures are combined in a Leuchtchip- arrangement, it is advantageous if they are conductively connected together according to claim 7. Such a connection is more stable than a connection by bonding, as is common in semiconductor structures. Claim 8 has the advantage that the vapor-deposited compounds have uniform thickness, although they have to overcome a difference in height on the chip.

If the light chip arrangement is designed as specified in claim 9, a light emission in substantially all spatial directions can be achieved.

The development of the invention according to claim 9 has the advantage that one receives a higher amount of light and at the same time comes with the operating voltage of the lamp in higher areas for which standard voltage sources such as batteries, power supplies and standard power line are available.

According to claim 10, it is possible to adapt the operating voltage of the luminous means to the output voltage of common voltage sources.

An illuminant according to claim 11 radiates forward and backward light.

Advantageous materials for the carrier substrate are specified in claim 12.

By the measure according to claim 13, a good heat dissipation is achieved by the light chip arrangement through the interior of the bulb to the outside.

If the wavelength of the light emitted from the light-emitting-chip arrangement does not coincide with a desired wavelength, this can be adjusted by the measure according to claim 14. Phosphor particles absorb radiation impinging on them and emit radiation of at least one other wavelength. at a suitable choice of phosphor particles or phosphor particle mixtures can thus umgewände11 the radiation emitted by the Leuchtchip arrangement in a radiation with a different spectrum.

According to claim 15, one can ensure the homogeneous distribution of the phosphor particles in a simple manner.

According to claim 16 and 17, the phosphor particles are fixed in their homogeneous distribution.

According to claim 18, the efficiency of the color specification of the light is improved by the phosphor particles.

In this case, one can set the desired spacing between phosphor particles and light-emitting semiconductor structures according to claim 19 safely and permanently.

In this case, a light-transmissive substrate provided in any case, which carries the semiconductor structures, can simultaneously ensure the desired spacing on one side of the light-chip arrangement.

In a luminous means according to claim 21, the semiconductor light-emitting structures are connected by interconnects running parallel to the substrate planes. These can be particularly well and particularly even by vapor deposition show (no shading of the metal vapor).

Embodiments of the invention will be explained in more detail with reference to the drawings. In these show:

Figure IA is a side view of a light chip arrangement with a semiconductor structure;

FIG. 1B is a top view of the luminous chip arrangement according to FIG. 1A;

FIG. 2A shows a modified light chip arrangement with three semiconductor structures;

FIG. 2B shows a plan view of the modified light-emitting chip arrangement according to FIG. 2A;

FIG. 3 shows a detailed view of the region enclosed between an ellipse in FIG. 2A between two semiconductor structures;

FIG. 4 shows a luminous means with a standardized bayonet base, wherein supply lines contact a luminescent chip arrangement and a transparent bulb is shown separated from the bayonet base;

5 shows a detail view of the Leuchcmictels of Figure 4 on an enlarged scale, the supply lines contact the light chip arrangement according to Figures IA and IB;

FIG. 6 is a view corresponding to FIG. 5, wherein the light chip arrangement is enveloped by a material with phosphor particles;

FIG. 7 shows a view corresponding to FIG. 5 of a modified luminous means according to FIG. 4, in which the luminous chip arrangement according to FIGS. 2A and 2B is contacted on the supply lines; FIG. 8 shows a light-emitting chip arrangement with light-emitting semiconductor structures connected in parallel; and

9 shows a section through a modified light chip arrangement with series-connected semiconductor structures.

In FIGS. 1A and 1B, denoted overall by 10 is a luminescent chip arrangement, which comprises a carrier substrate 12 made of sapphire glass. Sapphire crystal is also known as corundum (Al ₃ O glass). The carrier substrate 12 has a thickness of about 400 μm in the light chip arrangement 10, but it can also have other thicknesses, which may be, for example, between 5 μm and 600 μm. Instead of the sapphire glass, a cheaper material in the form of a high-temperature-resistant glass such as pyrex glass may also be used for the carrier substrate 12.

The carrier substrate 12 carries a semiconductor structure 14, which in turn comprises three layers:.

A lower layer 16 attached to the sapphire glass support substrate 12 is an n-type layer, which may be e.g. consists of n-GaN or n-InGaN.

A middle layer 18 is an MQW layer. MQW is the abbreviation for "Multiple Quantum Well". An MQW material is a superlattice which has an electronic band structure modified according to the superlattice structure and accordingly emits light at other wavelengths. The choice of the MQW layer can influence the spectrum of the radiation emitted by the pn-semiconductor structure 14. An upper layer 20 is made of a p-type III-V semiconductor material, for example, P-type GaN.

The semiconductor structure 14 has a circumferential U-shaped circumferential step 22, whose step surface 24 is located in the height between the Trägerstubstrat 12 and the MQW layer 18. In this way, the n-type layer 16 projects laterally beyond the MQW layer 18 and the p-type layer 20 in the region of the step surface 24. The step surface 24 is covered with a correspondingly U-shaped vapor-deposited conductor track 26 with two parallel conductor tracks 26a and 26b and a conductor track 26c running perpendicular thereto. The conductor 26c forms a contact terminal to the n-type layer 16.

In order to also contact the p-type layer 20, a conductor surface 30 is vapor-deposited on its upper side next to the region 28 flanked laterally by the U-shaped conductor track 26, which forms a contact connection to the p-type layer 20. From the conductor surface 30 extend on the surface of the p-type layer 20, three initially parallel conductor tracks 32a, 32b, 32c in the region 28 of the p-type layer 20 into it. The free ends of the two outer conductor tracks 32a and 32c are angled in each case by 90 ° in the direction of the middle conductor track 32b, as can be clearly seen in FIG. 1A.

The region 28 of the semiconductor structure 14 has an extension of 280 μm × 280 μm to 1 800 μm × 1 800 μm.

The conductor tracks 26a, 26b, 26c and 32a, 32b, 32c and the conductor surface 30 are formed by vapor deposition of a copper Obtained gold alloy. Alternatively, silver or aluminum alloys may also be used. In the region of the contact terminals 26c and 30, gold may be provided, which is doped in a manner known per se for connection to a p-type layer or an n-type layer.

In FIGS. 2A and 2B, a modified light chip arrangement 10 'is shown in each case. Components which correspond to those of the light chip arrangement 10 according to FIGS. 1A and 1B have the same reference sign plus a dash.

In the light-chip arrangement 10 ', three semiconductor structures 14' a, 14 'b and 14' c are provided on a carrier substrate 12 'which essentially correspond to the semiconductor structure 14 according to FIGS. 1A and 1B. The semiconductor structures 14 'a, 14' b and 14 'c are connected in series, with the conductor surface 30' of the middle semiconductor structure 14 'b with the conductor track 26' c of the semiconductor structure 14 ⁽ a and the conductor track 26 'c of the semiconductor structure 14 'b is connected to the conductor surface 30' of the semiconductor structure 14 'c.

A preferred implementation of the connection between a conductor track 26'c and a conductor surface 30 'is shown in greater detail in FIG. 3 on the example of the connection between the semiconductor structures 14 "b and 14'c (see FIG.

Between the semiconductor structures 14 'b and 14 ¹ C, a ramp-shaped insulator 34 is provided. For this purpose, for example, an electrically insulating material can be sputtered between the corresponding semiconductor structures 14 '. The distance between two halves Conductor structures 14 ', in Figure 3, the semiconductor structures 14' b and 14 'c, is of the order of 100 microns.

On the ramp-shaped insulator 34, a conductor 36 is vapor-deposited, which may for example consist of the same material, which has been explained above in connection with the conductor tracks 26 and 32 and the conductor surface 30.

Due to the ramp shape, a uniform thickness of the applied printed circuit is guaranteed. There are no shadowed areas, as would be expected with perpendicular to the carrier substrate 12 extending conductor track sections.

The conductor track 36 ensures a secure and stable conductive connection between the semiconductor structures 14 '. Conventionally used bonding structures with extremely thin bonding wires are less resistant to thermal and / or mechanical stress.

As can be seen in FIG. 3, the semiconductor structure 14 'c is somewhat modified there, and a recess 38 filled with the insulator material of the ramp 34 is provided below the conductor track 36.

FIG. 4 shows a luminous means 40 which has a standardized bayonet socket as the terminal base 42. Instead of the bayonet base (such as a GU10O socket and the like) may also be a standard Edison socket (eg E12, E26 and the like), a standardized socket or a standardized glass squeeze base may be provided. Of the here not specifically designated by a reference numeral and known per se outer terminal areas of the terminal base 42 extend in the interior of two supply lines 44a, 44b. These pass above the connection base 42 a spacer 46 made of an electrically insulating material. This prevents that the supply lines 44a, 44b touch, which would lead to a short circuit.

The free ends 48a and 48b of the supply lines 44a and 44b form contact areas, which contact a light chip arrangement 10 or 10 ', which is merely indicated in FIG.

The lighting means 40 comprises a piston 50 made of a light-transmitting material which, in the mounted state, together with the connection base 42, delimits an interior 52 of the light-emitting means 40.

The piston 50 is made of glass or an epoxy resin, for example, and may also, if desired, fulfill the function of collecting optics.

The inner space 52 is filled with a silicone oil 54, through which heat generated by the light chip arrangement 10 or 10 'is dissipated to the radially outer area of the pistons 50.

Also for the purpose of heat dissipation, the supply lines 44a, 44b, in addition to their electrical conductivity on a good thermal conductivity, which should preferably at least equal to that of copper. 33

11

So that a satisfactory heat dissipation via the supply lines 44a, 44b can take place, these have a diameter of 0.3 mm to 2 mm, preferably between 0.5 mm and 1.0 mm, more preferably about 0.7 mm.

FIG. 5 shows an enlarged view of how the light chip arrangement 10 is contacted with a single semiconductor structure 14 between the contact regions 48a, 48b of the supply lines 44a, 44b. As can be seen there, the contact region 48a of the supply line 44a is contacted to the conductor track 26c of the semiconductor structure 14 by brazing by means of a silver solder 56a. Their conductor surface 30 is also connected to the contact region 48b of the second supply line 44b of the luminous means 40 via a silver solder designated 56b.

Instead of the respective silver solder 56a, 56b for contacting the luminous chip arrangement 10, the contact areas 48a, 48b of the supply lines 44a, 44b can also be conductively connected to the corresponding conductor track 26c or the conductor surface 30 of the semiconductor structure 14 by means of an electrically conductive adhesive be.

In a modification shown in FIG. 6, the light chip arrangement 10 is additionally enveloped by a transparent material 58, in which phosphor particles 60 indicated by dots are distributed homogeneously. The material 58 may be, for example, a transparent two-component adhesive. The material 58 is shown in a broken view. However, the light chip assembly 10 is actually completely enveloped by the material 58.

The semiconductor structure 14 radiates upon application of a Voltage ultraviolet light and blue light in a wavelength range of 420 nm to 480 nm from. The material layer 58 enveloping the light-emitting chip arrangement 10 with the phosphor particles 60 makes it possible to obtain a white-light LED. Suitable phosphor particles 60 are made from color centered transparent solid state materials. In order to convert the ultraviolet and blue light emitted from the semiconductor structure 14 into white light, three types of phosphor particles 60 are used, which partially absorb the ultraviolet and blue light and emit themselves in yellow and red. If desired, it is also possible to add phosphor particles which emit in the blue.

A change in the spectrum of the light generated by the illuminant 40 is also possible by constructing the semiconductor structure 14 from layers 16, 18 and 20 formed of materials known in the art other than those specified herein.

As an alternative to the material 58 with the phosphor particles 60, the latter can also be distributed homogeneously in the silicone oil 54 in the interior 52 of the luminous means 40.

In a modification of the luminous means 40, the silicone oil 54 can also be dispensed with. In this case, for example, the inner surface of the interior 52 of the piston 50 could be coated with a layer of material 58 with phosphor particles 60 of the type discussed above.

The phosphor particles 60 or the material 58 receiving them can also be applied on the outside to a transparent plastic or glass envelope, which is designed such that it forms the semiconductor structure 14 in the envelope used illuminated chip assembly 10 or 10 'in all directions in space at substantially the same distance surrounds.

A favorable distance between the material 58, in which the phosphor particles 60 are homogeneously distributed, to the semiconductor structure 14 is between about 0.3 mm and 3.0 mm, preferably 0.5 mm and 1.5 mm, preferably about 1 mm ,

FIG. 7 shows, on an enlarged scale, the contacting of the luminescent chip arrangement 10 'with the three semiconductor structures 14' a, 14 'b, 14' c via the supply lines 44a, 44b. Apart from the fact that there the Leuchtchip arrangement 10 'is provided, the above applies for contacting the Leuchtchip arrangement 10 said mutatis mutandis accordingly. The luminescent chip arrangement 10 'can also be enveloped by a material 58, in which phosphor particles 60 are homogeneously distributed, in order to achieve white-light radiation. The material 58 is indicated by dashed lines in FIG.

The respectively formed illuminant 40 with the Leuchtchip- arrangement 10 or 10 'is screwed or plugged into a correspondingly designed version suitable for operation with its terminal base 42. Via the terminal block 42, the supply lines 44a, 44b and above the corresponding light chip arrangement 10 or 10 'are applied to an operating voltage, whereby the corresponding semiconductor structures 14 and 14' are excited to shine.

The illustrated semiconductor structures 14 and 14 'and the corresponding light chip arrangement 10 and 10' are characterized by a long life with high luminosity. In this way, long-lasting luminaires realized means that can replace known standard bulbs with a shorter life, without structural changes must be made, for example, in associated lamp holders.

Each semiconductor structure 14 or 14 'is operated with an operating voltage of approximately 3.5 to 4 V, so that the light chip arrangement 10 formed of three semiconductor structures 14' a, 14 'b and 14' c can be operated with 12 V. , This is particularly advantageous for the motor vehicle sector.

Inside the terminal base 42 electronic components such as one or more ^■ corresponding series resistors, or the like may additionally be provided, which are connected between the external terminal portions of the connecting base 42 and the supply lines 44a, 44b connected and a substantially constant operating current to the semiconductor structures 14 or 14 'guarantee. In addition, inside the

Terminal base 42 may be provided electronic components by which ^' one of the required operating voltage of the semiconductor structures 14 and 14' deviating external supply voltage, such as a mains voltage, is transformed to the required operating voltage.

At 1 W power consumption, each semiconductor structure 14 or 14 'achieves a light output of about 40 lumens.

In the light chip arrangement of Figure 8 are on a

Carrier substrate 12 six semiconductor light-emitting structures 14 are provided, which are electrically connected in parallel, as is apparent from the contact by terminals 36. 08833

15

In the luminescent chip arrangement 10 according to FIG. 9, six semiconductor structures 14 are arranged on a carrier substrate 12, which are adjacent to the carrier substrate 12 with their n-layer or their p-layer, which carry both transparent electrodes 26, 30. It can therefore be connected in series by parallel to the substrate plane conductors 70 and 72, which can be easily produced in the required thickness and uniformity by vapor deposition.

The spaces lying between the semiconductor structures 14 are filled by transparent insulating material volumes 74. These can be obtained by screen printing glass frit and then fusing together or sintering the frit together.

Claims

claims 1. Lamp, in particular for a motor vehicle, with a) a terminal socket (42); b) a bulb (50) of translucent material which at least partially defines an interior space (52) and is carried by the terminal base (42); c) a first supply line (44a) and a second supply line (44b), which are acted upon via the terminal base (42) with an operating voltage and with contact areas (48a, 48b) protrude into the interior space (52), characterized in that d) the contact regions (48a, 48b) of the supply lines (44a, 44b) are connected to a luminescent chip arrangement (10, 110) which comprises at least one light-emitting semiconductor structure (14, 114). 2. Lamp according to claim 1, characterized in that the supply lines (44 a, 44 b) have a diameter between 03, and 2.0 mm, preferably 0.5 mm and 1.0 mm, again preferably about 0.7 mm and are made of an electrically conductive material, which has a good thermal conductivity. 3. Lamp according to claim 1 or 2, characterized characterized in that the contact areas of the supply lines (44a, 44b) with the Leuchtchip arrangement (10; 110) are each connected by a braze-contact (56a, 56b), in particular by a silver solder contact. 4. Lamp according to claim 1 or 2, characterized in that the contact regions of the supply lines (44a, 44b) with the light chip arrangement (10; 110) are connected by an electrically conductive adhesive. 5. Lamp according to one of claims 1 to 4, characterized in that the light chip arrangement (110) comprises at least two light-emitting semiconductor structures (114a, 114b, 114c). 6. Lamp according to claim 5, characterized in that the light chip arrangement comprises three light emitting semiconductor structures (114a, 114b, 114c). 7. Lamp according to claim 5 or 6, characterized in that the semiconductor structures (114a, 114b, 114c) are conductively connected to one another by means of vapor-deposited conductor tracks (136). 8. Lamp according to one of claims 1 to 7, characterized in that a plurality of light-emitting Semiconductor structures (144a, 114b, 114c) is electrically connected in series. 9. Lamp according to one of claim 8, characterized in that the semiconductor structures (114a, 1114b) with the same layers to a support substrate (12) carrying them and by printed conductors (36) are connected, which are supported by a ramp (34). 10. Lamp according to claim 8 or 9, characterized in that the number of series-connected light-emitting Halbleitsterstrukuren (114a, 114b, 114c) is selected so that the total voltage drop is 12 V, 24 V, 110 V or 220 V. 11. Lamp according to one of claims 1 to 10, character- ized in that the light chip arrangement (10; 110) comprises a support substrate (12; 112) of transparent material carrying the light-emitting semiconductor structure (14; 114). 12. Lamp according to claim 11, characterized in that the transparent material of the carrier substrate (12 12) is sapphire crystal or a highly heat-resistant glass. 13. Lamp according to one of claims 1 to 12, characterized in that the interior space (42) is filled with a thermally conductive electrically insulating liquid such as silicone oil (54). 14. Lamp according to one of claims 1 to 13, characterized in that the Leuchtchip arrangement (10; 110) is at least partially surrounded by substantially homogeneously distributed phosphor particles which absorb light emitted by the light-emitting semiconductor structures (14; in complementary light, such that the light source emits substantially white light in total. 15. Lamp according to claim 14, characterized in that at least a part of the phosphor particles in a Trägerermediura, preferably a liquid carrier medium such as silicone oil (54) are distributed substantially homogeneously. 16. A luminous means according to claim 14 or 15, characterized in that at least a part of the Phosphorpar- is supported by the Leuchtchip arrangement (10). 17. Lamp according to one of claims 14 to 16, characterized in that at least a part of Phosphor particles from the piston (50) is supported, preferably mounted on the inner surface. 18. Lamp according to one of claims 14 to 17, characterized in that between the substantially homogeneously distributed phosphor particles and the light-emitting semiconductor structures (14; 114) a distance of about 0.3 mm to 3.0 mm, preferably from about 0 , 5 to 1.5 mm, again preferably about 1 mm remains. 19. Lamp according to claim 18, characterized in that the light-emitting semiconductor structures (14, - 114) is arranged between two transparent substrates whose thickness corresponds to the desired spacing between light-emitting semiconductor structures (14, 114) and phosphor particles. 20. Illuminant according to claim 19, characterized in that one of the light-transmissive substrates is replaced by a semiconductor structure (14; 114) carrying the transparent plate is formed. 21. Lamp according to one of claims 8 to 20, characterized in that at least a portion of the light-emitting semiconductor structures (14) in pairs T / EP2007 / 008833 20 are arranged facing away from a carrier substrate (12) and are connected in series via parallel to the carrier substrate plane extending tracks (36, 37). 22. Lamp according to one of claims 1 to 21, characterized in that at least a portion of the light-emitting semiconductor structures (14) are arranged in pairs with the same layers pointing to a carrier substrate and are connected via parallel to the carrier substrate plane extending conductor tracks (36, 37).