CN104681550A - Integrated light source driving circuit and light source module using it - Google Patents

Abstract

An integrated light source driving circuit and a light source module using the same. The integrated light source driving circuit comprises a power transistor, a driving chip and a diode. The power transistor comprises a substrate, a first active region, a second active region, a gate region and an isolation region. The first active region and the second active region are disposed on opposite sides of the substrate. The second active region and the gate region are arranged on the same side of the substrate. The isolation region is electrically connected with the first active region and is electrically independent from the second active region and the gate region. The driving chip is stacked on the second active region of the power transistor and electrically connected to the gate region. The diode is arranged in the isolation area of the power transistor, wherein the anode end of the diode faces the isolation area to be electrically connected to the first active area.

Description

Integrated light source driving circuit and light source module using it

technical field

The present invention relates to a light source drive design, and in particular to an integrated light source drive circuit and a light source module using the same.

Background technique

Generally, a light source driving circuit for driving a light emitting unit is composed of a driving chip, a power transistor, a diode, a resonant circuit and the like. Wherein, the driving chip can provide a control signal to switch the power transistor, so that the light emitting unit can emit light according to the current generated by switching the power transistor.

In the current design of the light source driving circuit, the above-mentioned circuit components are usually only the driving chip itself because of the high circuit complexity, so it will be made in an integrated manner, while the rest of the circuit components are generally in the structure of discrete components. To achieve, in order to combine the light source driving circuit. However, in this way, the light source driving circuit will occupy a larger area in the light source module, which will adversely affect the design freedom of the designer and the production cost of the product.

On the other hand, even if the above-mentioned circuit components are packaged together in an integrated/integrated manner, under the existing technology, due to the structural limitations of circuit components such as power transistors, driver chips, and diodes, designers can only The circuit layout is carried out on the same plane, so integrating the above circuit elements in a general integrated manner cannot significantly reduce the area of the overall light source driving circuit. In addition, since a general integrated layout method is used to integrate the light source driving circuit, a large chip area is required, so the overall packaging cost will also be greatly increased.

Contents of the invention

The invention provides an integrated light source driving circuit and a light source module using the same, which can integrate the circuit elements in the light source driving circuit in a stacked configuration.

The integrated light source driving circuit of the present invention is suitable for driving the light emitting unit. The integrated light source driving circuit includes a power transistor, a driving chip and a diode. The power transistor includes a substrate, a first active area, a second active area, a gate area and an isolation area. The first active area and the second active area are disposed on opposite sides of the substrate. The second active region and the gate region are disposed on the same side of the substrate. The isolation region is electrically connected to the first active region, and the isolation region is electrically independent from the second active region and the gate region. The driver chip is stacked on the second active area of the power transistor and electrically connected to the gate area. The diode is arranged in the isolation area of the power transistor, wherein the anode end of the diode faces the isolation area to be electrically connected to the first active area.

In an embodiment of the present invention, the power transistor is controlled by the driving chip to selectively electrically connect or electrically separate the first active region and the second active region.

In an embodiment of the present invention, the substrate and the second active region have openings corresponding to each other, and the opening extends to the first active region through the second active region and the substrate, wherein the isolation region is disposed in the opening .

In an embodiment of the present invention, the opening is located in the central area of the power transistor, and the periphery of the opening is adjacent to the second active area and the substrate.

In an embodiment of the present invention, the opening is located on the edge region of the power transistor, and at least one side around the opening is not adjacent to the second active region and the substrate.

In an embodiment of the invention, the power transistor further includes a termination area. The terminal area is arranged around the substrate, the first active area and the second active area.

In an embodiment of the present invention, the integrated light source driving circuit further includes a lead frame. The lead frame has a chip seat and a plurality of welding pads, and the plurality of welding pads are arranged around the chip seat, wherein the power transistor is arranged on the chip seat, and the first active area faces the chip seat.

In an embodiment of the present invention, the cathode end of the diode is electrically connected to at least one of the pads, the first active region is electrically connected to at least another one of the pads, and the second pad is electrically connected to at least one of the pads. The two active regions are electrically connected to at least another one of the plurality of welding pads.

In one embodiment of the present invention, the power transistor is a vertical double-diffused metal oxide semiconductor transistor (vertical double-diffused MOS, VDMOS), the first active region is the drain of the VDMOS, and the second active region is the VDMOS The source (source), and the gate area is the gate (gate) of VDMOS.

In one embodiment of the present invention, the power transistor is an insulated gate bipolar transistor (insulated gate bipolar transistor, IGBT), the first active region is the collector of the IGBT, and the second active region is the emitter of the IGBT ( emitter), and the gate region is the gate of the IGBT.

The light source module of the present invention includes an integrated light source driving circuit, a resonant circuit and a light emitting unit. The integrated light source driving circuit includes a power transistor, a driving chip and a diode. The power transistor includes a substrate, a first active area, a second active area, a gate area and an isolation area. The first active area and the second active area are disposed on opposite sides of the substrate. The second active region and the gate region are disposed on the same side of the substrate. The isolation region is electrically connected to the first active region, and the isolation region is electrically independent from the second active region and the gate region. The driver chip is stacked on the second active area of the power transistor and electrically connected to the gate area. The diode is arranged in the isolation area of the power transistor, wherein the anode end of the diode faces the isolation area to be electrically connected to the first active area. The resonant circuit is electrically connected to the anode end of the diode and the first active area. The light emitting unit is electrically connected to the cathode end of the diode.

Based on the above, the embodiments of the present invention provide an integrated light source driving circuit and a light emitting module using the same. The integrated light source driving circuit can integrate power transistors, driving chips and diodes in a stacked configuration to save the packaging area of the whole circuit, thereby effectively reducing the design cost of the light emitting module.

Description of drawings

In order to make the above features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings as follows, wherein:

FIG. 1 is a schematic circuit diagram of a light emitting module according to an embodiment of the present invention.

2A to 2C are structural schematic diagrams of an integrated light source driving circuit according to an embodiment of the present invention.

FIG. 3 is a top view of an integrated light source driving circuit according to an embodiment of the present invention.

FIG. 4 is a top view of an integrated light source driving circuit according to another embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide an integrated light source driving circuit and a light emitting module using the same. The integrated light source driving circuit can integrate power transistors, driving chips and diodes in a stacked configuration to save the packaging area of the whole circuit, thereby effectively reducing the design cost of the light emitting module. In order to make the content of the present disclosure easier to understand, the following specific embodiments are taken as examples in which the present disclosure can indeed be implemented. Here, wherever possible, elements/members/steps with the same reference numerals are used in the drawings and embodiments to represent the same or similar components. In addition, descriptions such as "up", "down", "left", and "right" mentioned in the embodiments are all referring to the directions shown in the drawings, and are not intended to limit the present invention.

FIG. 1 is a schematic circuit diagram of a light emitting module according to an embodiment of the present invention. Please refer to FIG. 1 , the light emitting module 10 of this embodiment includes an integrated light source driving circuit 100 , a resonant circuit RC and a light emitting unit LU.

In this embodiment, the integrated light source driving circuit 100 is formed by integrating/integrating the power transistor 110 , the driving chip 120 and the diode 130 . In the integrated light source driving circuit 100 , the control terminal of the power transistor 110 is coupled to the driving chip 120 , and the first terminal of the power transistor 110 is coupled to the anode terminal of the diode 130 . In addition, the integrated light source driving circuit 100 has at least three pins (such as P1, P2, P3) for connecting external circuit components, wherein the cathode end of the diode 130 is coupled to the pin P1, and the first end of the power transistor 110 The anode terminal of the diode 130 is coupled to the pin P3, and the second terminal of the power transistor 110 is coupled to the pin P2.

In view of the overall circuit configuration of the light source module 10 , the resonant circuit RC is coupled to the pin P3 of the integrated light source driving circuit 100 to be coupled to the first terminal of the power transistor 110 and the anode terminal of the diode 130 via the pin P3 . The light emitting unit LU is coupled to the pin P1 of the integrated light source driving circuit 100 so as to be coupled to the cathode terminal of the diode 130 via the pin P1. The pin P2 of the integrated light source driving circuit 100 is coupled to a ground terminal GND.

From the perspective of the operation of the light source module 10, during the start-up of the light source module 10, the driver chip 120 in the integrated light source driver circuit 100 will provide periodic control signals to control the conduction state of the power transistor 110, so that the resonant circuit The RC is charged/discharged in response to the switching of the power transistor 110 , thereby generating a stable driving current, which is provided to the light emitting unit LU through the diode 130 . Based on this, the light emitting unit LU can respond to the driving current provided by the integrated light source driving circuit 100 to emit light.

Here, the resonant circuit RC of this embodiment can be, for example, a resonant tank (Cresonant tank) composed of passive components such as capacitors, inductors, and resistors. The light emitting unit LU can be, for example, a light emitting diode module composed of a plurality of light emitting diode strings LEDS connected in parallel, but the present invention is not limited thereto. In addition, in the integrated light source driving circuit 100, the diode 130 can be, for example, a Schottky diode (schottky diode), a fast recovery diode (fast recovery diode), a super junction diode (super junction diode, SJ-diode) or Diodes based on TTI-V group elements (such as gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC)), the invention is also not limited thereto.

In detail, the power transistor 110 of the embodiment of the present invention is implemented by using a transistor structure with vertical diffusion characteristics (further description will be given in subsequent embodiments). Based on the structural characteristics of the power transistor 110 , the driver chip 120 and the diode 130 of this embodiment are arranged on the power transistor 110 in a stacked manner. In other words, the integrated light source driving circuit 100 of the embodiment of the present invention is packaged by stacking the power transistor 110 , the driving chip 120 and the diode 130 layer by layer.

Compared with the packaging structure of the traditional light source driving circuit, the light source driving circuit 10 formed in a stacked manner can save more packaging area, so that the degree of freedom of circuit layout/design can be further improved, Moreover, the overall design and production costs of the light source module 10 can also be reduced accordingly.

The structural configuration of the integrated light source driving circuit of the embodiment of the present invention is described below with the embodiments of FIG. 2A to FIG. 2C . 2A shows a schematic top view of the integrated light source driving circuit 100 , FIG. 2B shows a schematic bottom view of the integrated light source driving circuit 100 , and FIG. 2C shows a schematic cross-sectional view of the integrated light source driving circuit 100 .

Please refer to FIGS. 2A to 2C at the same time. In this embodiment, the power transistor 110 includes a substrate S, a first active region 112 , a second active region 114 , a gate region 116 and an isolation region. The first active region 112 and the second active region 114 are disposed on opposite sides of the substrate S (as shown in FIG. 2C , respectively located on the lower side and the upper side of the substrate S). The second active region 114 is disposed on the same side of the substrate S as the gate region 116 . The isolation region 118 is disposed on or around the second active region 112 (subsequent embodiments will be described separately, and the position shown here is only for illustration, so it is indicated by a dashed box). Wherein, the isolation region 118 is electrically connected to the first active region 112 , and the isolation region 118 is electrically independent from the second active region 114 and the gate region 116 . In addition to the above-mentioned structural configuration, the power transistor 110 may also include a termination region (termination region) TR for dispersing the effect of the electric field, which is arranged around the substrate S, formed by the first active region 112 and the second active region 114. around the stack structure.

The driver chip 120 is stacked on the second active region 114 of the power transistor 110 and electrically connected to the gate region 116 of the power transistor 110 . The diode 130 is disposed on the isolation region 118 of the power transistor 110 , wherein the anode of the diode 116 faces and bears against the surface of the isolation region 118 electrically connected to the first active region 112 to be electrically connected to the first active region 112 .

More specifically, comparing the schematic diagram of the circuit shown in the embodiment of FIG. 1 , the first active region 112 corresponds to the first end of the power transistor 110 , and the second active region 114 corresponds to the end of the power transistor 110 The second end, and the gate region 116 is corresponding to the control end of the power transistor 110 . In other words, in this embodiment, the above-mentioned driving chip 120 controls the power transistor 110 to turn on/off periodically by establishing a channel between the two active regions 112 and 114, so that the first active region 112 and the second active region 112 The two active regions 114 are selectively/periodically electrically connected or electrically separated to realize the action of turning on/off the power transistor 110 .

In an exemplary embodiment, the power transistor 110 may be, for example, a vertical double-diffused metal oxide semiconductor transistor (vertical double-diffused MOS, VDMOS). In this exemplary embodiment, the first active region 112 is the drain of the VDMOS, the second active region 114 is the source of the VDMOS, and the gate region 116 is the gate of the VDMOS. ).

In another exemplary embodiment, the power transistor 110 may also be, for example, an insulated gate bipolar transistor (IGBT). In this exemplary embodiment, the first active region 112 is the collector of the IGBT, the second active region 114 is the emitter of the IGBT, and the gate region 116 is the gate of the IGBT.

However, it should be noted that the power transistor 110 of the present invention is not limited to the above-mentioned examples. Any transistor structure with vertical diffusion characteristics (that is, a structure in which two electrodes for establishing a conduction channel are disposed on both sides of the substrate) can be applied here, and the present invention is not limited thereto. In addition, the cross-sectional structure of the integrated light source driving circuit 100 shown in FIG. 2C is only for simply showing the substrate S, the first active region 112 , the second active region 114 and the gate region 116 in the power transistor 110. The relative configuration relationship between the two is not intended to limit the specific cross-sectional structure of the integrated light source driving circuit 100 of the embodiment of the present invention.

To facilitate the description of the configuration relationship in the subsequent embodiments, the area within the edge of the power transistor 110 is defined as the central area CR (the area surrounded by the inner dotted line box), and the area outside the edge of the power transistor 110 is defined as the edge area. PR (the area surrounded by two dotted boxes), as shown in FIG. 2B , in the following embodiments, if the central area CR and the peripheral area PR are mentioned, the description is based on this definition. In addition, in FIG. 2A to FIG. 2C , the relative arrangement among the regions 112 118 in the power transistor 110 is only for illustration, and the present invention is not limited thereto.

The specific implementation examples of the above-mentioned integrated light source driving circuit are respectively described below with the embodiments of FIG. 3 and FIG. 4 . Wherein, FIG. 3 and FIG. 4 are diagrams of integrated light source driving circuits in different embodiments of the present invention respectively.

Please refer to FIG. 3 . In this embodiment, the integrated light source driving circuit 300 includes a leadframe 340 and an isolation region 350 in addition to a power transistor 310 , a driving chip 320 and a diode 330 . Wherein, the lead frame 340 includes a plurality of bonding pads 342 (such as bonding pads P1 , P2 , P3 ) and a chip holder 344 .

In the power transistor 310 of this embodiment, the relative configuration among the substrate S (not shown in the top view), the first active region 312, the second active region 314, and the gate region 316 is similar to that of the aforementioned embodiment in FIG. 2 . The bonding pads 342 of the lead frame 340 are disposed around the die pad 344 , and the power transistor 310 is disposed on the die pad 344 with the first active region 312 facing the die pad 344 . The isolation region 350 is disposed around the outside of the termination region TR to isolate the electrical connection between the integrated light source driving circuit 300 and external components. In this embodiment, the welding pads 342 are shown as an example of disposing four welding pads on each side, but the invention is not limited thereto.

Furthermore, in the power transistor 310 of this embodiment, the substrate S and the second active region 314 have openings OP corresponding to each other, and the opening OP is located in the central region CR, so the periphery of the opening OP will be in contact with the second active region 314. The region 314 is adjacent to the substrate S, and extends to the first active region 112 via the second active region 314 and the substrate S in sequence (in terms of the direction from the top to the bottom). In this embodiment, the isolation region 318 of the power transistor 310 is disposed in the opening OP.

In an exemplary embodiment, the isolation region 318 can be covered with an insulating material on the inner wall of the opening OP and coated with conductive glue on the surface of the bottom of the opening OP (that is, the exposed surface of the first active region 312 in the opening OP) ( conductive epoxy) configuration method to form. Wherein, the anode terminal of the diode 330 is arranged at the bottom of the opening OP, so as to be electrically connected to the first active region 312 through the conductive glue at the bottom of the opening OP, and to make itself electrically independent through the insulating material on the inner wall of the opening OP. In the second active region 314 and the gate region 316 .

On the other hand, in this embodiment, the integrated light source driving circuit 300 can be electrically connected to the pads 342 through wire bonding or ribbon bonding, and then connected to the external pads 342 through the corresponding pads. The electronic components are electrically connected to each other. Taking the structure shown in FIG. 3 as an example, the cathode terminal of the diode 330, the second active area 314, and the first active area 312 can be electrically connected to the corresponding pads P1, P2, P3. Comparing the circuit structure of the embodiment of FIG. 1 , the pads P1 , P2 , P3 described here correspond to the pins P1 , P2 , P3 of the integrated light source driving circuit 100 . In other words, in this embodiment, the cathode end of the diode 330 can be electrically connected to the light emitting unit LU through the pad P1, the first active area 312 can be electrically connected to the resonant circuit RC through the pad P2, and the second active The area 314 can be electrically connected to the ground terminal GND via the pad P3. It should also be mentioned that although the diode 330, the second active region 314 and the first active region 312 are only wired/strapped to one corresponding pad P1-P3, the present invention is not limited thereto. , the designer can also wire the same component/area to multiple pads at the same time based on their design needs and considerations.

Please refer to FIG. 4 again, the integrated light source driving circuit 400 includes a substrate S (not shown), a power transistor 410, a driving chip 420, a diode 430, a lead frame 440 and an isolation region 450, and its overall configuration is substantially the same as that of the foregoing embodiments. The integrated light source driving circuit 300 is similar. Wherein, the main difference between the two lies in the configuration of the isolation region 418 .

Specifically, in this embodiment, the opening OP of the power transistor 410 is formed on the edge region PR of the power transistor 410, so at least one side around the opening OP is not adjacent to the second active region 414 and the substrate S. (In this embodiment, the opening OP is formed at the upper right corner of the power transistor 410, but the present invention is not limited thereto). Here, the isolation region 418 (which may be formed, for example, by conductive glue) will be directly electrically connected to the first active region 412, and can be regarded as a block separated from the second active region 420 and the substrate S, so the isolation region 418 will be separated from the substrate S. The second active region 420 and the substrate S are electrically independent from each other. Based on this, the anode terminal of the diode 430 can be directly vertically placed on the isolation region 418 facing the surface of the isolation region 418 to be electrically connected to the first active region 312 through the isolation region 418 .

In addition, similar to the aforementioned embodiment in FIG. 3 , the integrated light source driving circuit 400 of this embodiment can also be electrically connected to the pad 442 by wire bonding/tape bonding, and then through the corresponding pad 442 (such as a pad P1, P2, P3) are electrically connected with external electronic components.

To sum up, the embodiments of the present invention provide an integrated light source driving circuit and a light emitting module using the same. The integrated light source driving circuit can integrate power transistors, driving chips and diodes in a stacked configuration to save the packaging area of the whole circuit, thereby effectively reducing the design cost of the light emitting module.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (13)

1. An integrated light source driving circuit, comprising: A power transistor includes a substrate, a first active region, a second active region, a gate region and an isolation region, the first active region and the second active region are arranged on opposite sides of the substrate, the The second active region and the gate region are disposed on the same side of the substrate, the isolation region is electrically connected to the first active region, and the isolation region is electrically independent from the second active region and the gate region. : a driver chip stacked on the second active region of the power transistor and electrically connected to the gate region; and A diode is arranged in the isolation area of the power transistor, wherein the anode end of the diode faces the isolation area and is electrically connected to the first active area. 2. The integrated light source driving circuit as claimed in claim 1, wherein the power transistor is controlled by the driving chip to selectively electrically connect or electrically separate the first active region and the second active region. 3. The integrated light source driving circuit according to claim 1, wherein the substrate and the second active area have an opening corresponding to each other, and the opening extends to the first active area through the second active area and the substrate, Wherein the isolation area is disposed in the opening. 4. The integrated light source driving circuit as claimed in claim 3, wherein the opening is located in a central area of the power transistor, and a periphery of the opening is adjacent to the second active area and the substrate. 5. The integrated light source driving circuit as claimed in claim 3, wherein the opening is located on an edge region of the power transistor, and at least one side around the opening is not adjacent to the second active area and the substrate. 6. The integrated light source driving circuit as claimed in claim 1, wherein the power transistor further comprises: A terminal area is arranged around the substrate, the first active area and the second active area. 7. The integrated light source driving circuit according to claim 1, further comprising: A lead frame has a chip seat and a plurality of welding pads, and the welding pads are arranged around the chip seat, wherein the power transistor is arranged on the chip seat, and the first active area faces the chip seat. 8. The integrated light source driving circuit as claimed in claim 7, wherein the cathode terminal of the diode is electrically connected to at least one of the pads, and the first active region is electrically connected to at least one of the pads The other one of them, and the second active region is electrically connected to at least another one of the welding pads. 9. The integrated light source driving circuit as claimed in claim 1, wherein the power transistor is a vertical double diffused metal oxide semiconductor transistor, the first active region is the drain of the vertical double diffused metal oxide semiconductor transistor, the The second active region is the source of the vertical double diffused metal oxide semiconductor transistor, and the gate region is the gate of the vertical double diffused metal oxide semiconductor transistor. 10. The integrated light source driving circuit as claimed in claim 1, wherein the power transistor is an IGBT, the first active region is the collector of the IGBT, and the second active region is the emitter of the IGBT, and the gate region is the gate of the IGBT. 11. A light source module, comprising: An integrated light source driving circuit, including: A power transistor includes a substrate, a first active region, a second active region, a gate region and an isolation region, the first active region and the second active region are arranged on opposite sides of the substrate, the The second active region and the gate region are disposed on the same side of the substrate, the isolation region is electrically connected to the first active region, and the isolation region is electrically independent from the second active region and the gate region. : a driver chip stacked on the second active region of the power transistor and electrically connected to the gate region; and a diode disposed on the isolation region of the power transistor, wherein the anode end of the diode faces the isolation region to be electrically connected to the first active region; a resonant circuit electrically connecting the anode terminal of the diode and the first active region; and A light emitting unit is electrically connected to the cathode end of the diode. 12. The light source module according to claim 11, wherein the integrated light source driving circuit further comprises: A lead frame has a chip seat and a plurality of welding pads, and the welding pads are arranged around the chip seat, wherein the power transistor is arranged on the chip seat, and the first active area faces the chip seat. 13. The light source module according to claim 12, wherein the solder pads include at least one first solder pad, at least one second solder pad and at least one third solder pad, and the cathode end of the diode is connected via the first solder pad. The pad is electrically connected to the light emitting unit, the first active area is electrically connected to the resonant circuit through the second pad, and the second active area is electrically connected to a ground terminal through the third pad.