LED lamp bead with high air tightness

Abstract

The utility model relates to the field of semiconductor photoelectric devices, and particularly discloses a high-air-tightness LED lamp bead, which comprises a first resin substrate, a second resin substrate and a third resin substrate, the second resin substrate is fixed on the first resin substrate, the front surface of the second resin substrate is provided with a front surface circuit layer, the front surface circuit layer comprises a die bonding area and a bonding pad area, and the pin areas and the bonding pad area are arranged in a one-to-one correspondence manner; a first through hole penetrating through the second resin substrate is formed in the bonding pad area; the light-emitting unit is fixed on the die bonding area; a packaging adhesive layer; a middle circuit layer is arranged on the back surface of the second resin substrate, and the middle circuit layer comprises a bonding pad heat dissipation area; the bonding pad heat dissipation area and the pin area are correspondingly arranged, and a second through hole penetrating through the first resin substrate is formed in the pin area; the first through hole and the second through hole are filled with first conductive copper, and the pin area and the bonding pad area are electrically connected through the first conductive copper. According to the LED lamp bead, the air tightness and the reliability of the LED lamp bead can be improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor photoelectric devices, in particular to a LED lamp bead with high air tightness. Background Art

[0002] The existing CHIP-LED device adopts a single-layer board of a flat BT substrate, and sets a front line and a back line on the front and back of the board respectively. The front line is used to bind the light-emitting chip and realize electrical interconnection, and the back line is used to weld with the LED display module PCB. The front and back lines are connected and conducted through the through holes set at the four corners of the BT substrate (see Figure 1 ). A portion of the copper layer is usually electroplated in the through hole 1a, and then filled with ink 1b. However, in actual use, water vapor can still easily enter the device through the through hole, causing the small-pitch CHIP-LED device to fail easily, resulting in poor display effects such as caterpillars on the small-pitch LED screen, affecting the viewing effect. In addition, the existing CHIP-LED device has relatively poor heat dissipation capacity, which also causes the device to age quickly and have a short service life. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a highly airtight LED lamp bead, which can effectively reduce the entry of water vapor, enhance heat dissipation, improve the reliability of the lamp bead, and extend the service life.

[0004] In order to solve the above problems, the utility model discloses a highly airtight LED lamp bead, which comprises:

[0005] A first resin substrate, a back side of which is provided with a back side circuit layer, wherein the back side circuit layer includes at least two pin areas;

[0006] A second resin substrate is fixed on the first resin substrate, and a front circuit layer is provided on the front side thereof, wherein the front circuit layer comprises at least two mutually separated crystal bonding areas and at least two pad areas, wherein the pin areas are arranged in one-to-one correspondence with the pad areas; and a first through hole penetrating the second resin substrate is provided in the pad area;

[0007] A light-emitting unit, which is fixed on the solid crystal area;

[0008] An encapsulation adhesive layer, which wraps the light-emitting unit on the second resin substrate;

[0009] Among them, an intermediate circuit layer is provided on the back side of the second resin substrate, and the intermediate circuit layer includes at least two pad heat dissipation areas; the pad heat dissipation area is arranged corresponding to the pin area, and a second through hole penetrating the first resin substrate is provided in the pin area; the first through hole and the second through hole are both filled with first conductive copper, and the pin area and the pad area are electrically connected through the first conductive copper.

[0010] As an improvement of the above technical solution, the diameters of the first through holes and the second through holes are ≤0.05 mm.

[0011] As an improvement of the above technical solution, a third through hole penetrating the second resin substrate is provided in the solid crystal area, and the intermediate circuit layer also includes a solid crystal heat dissipation area arranged corresponding to the solid crystal area; the third through hole is filled with a second conductive copper, one end of which is connected to the solid crystal heat dissipation area, and the other end is connected to the solid crystal area.

[0012] As an improvement of the above technical solution, the diameters of the first through hole, the second through hole and the third through hole are ≤0.02 mm.

[0013] As an improvement of the above technical solution, the solid crystal region includes a first solid crystal region, a second solid crystal region and a third solid crystal region which are separated from each other;

[0014] The light-emitting unit includes a first light-emitting unit fixed to the first crystal-bonding area, a second light-emitting unit fixed to the second crystal-bonding area, and a third light-emitting unit fixed to the third crystal-bonding area;

[0015] The pad area includes a first cathode pad area, a second cathode pad area and a common anode pad area;

[0016] The pin area includes a first cathode pin area corresponding to the first cathode pad area, a second cathode pin area corresponding to the second cathode pad area, an anode pin area corresponding to the common anode pad area, and a third cathode pin area corresponding to the third crystal bonding area;

[0017] The pad heat dissipation area includes a first pad heat dissipation area corresponding to the first cathode pin area, a second pad heat dissipation area corresponding to the second cathode pin area, a third pad heat dissipation area corresponding to the anode pin area, and a fourth pad heat dissipation area corresponding to the third cathode pin area;

[0018] The crystal bonding heat dissipation area includes a first crystal bonding heat dissipation area corresponding to the first crystal bonding area, a second crystal bonding heat dissipation area corresponding to the second crystal bonding area, and a third crystal bonding heat dissipation area corresponding to the third crystal bonding area;

[0019] The third die-bonding heat dissipation area is interconnected with the fourth pad heat dissipation area, so that the first conductive copper in the first through hole of the fourth pad heat dissipation area is electrically connected to the second conductive copper in the third through hole of the third die-bonding heat dissipation area.

[0020] As an improvement of the above technical solution, the first light-emitting unit is connected to the first cathode pad area and the common anode pad area through bonding wires;

[0021] The second light emitting unit is connected to the second cathode pad area and the common anode pad area through bonding wires;

[0022] One end of the third light emitting unit is electrically connected to the third die-bonding area via a conductive adhesive, and the other end is connected to the common anode pad area via a bonding wire.

[0023] As an improvement of the above technical solution, the second die-bonding heat dissipation area, the third die-bonding heat dissipation area and the fourth pad heat dissipation area are connected into a sheet.

[0024] As an improvement of the above technical solution, the first die-bonding heat dissipation area and the third pad heat dissipation area are connected into a sheet.

[0025] As an improvement of the above technical solution, the first light-emitting unit is a blue light LED chip with a front-mounted structure, the second light-emitting unit is a green light LED chip with a front-mounted structure, and the third light-emitting unit is a red light LED chip with a vertical structure.

[0026] As an improvement of the above technical solution, the first resin substrate is made of BT resin and has a thickness of 0.1 to 0.2 mm;

[0027] The second resin substrate is made of BT resin and has a thickness of 0.1-0.2 mm.

[0028] The implementation of this utility model has the following beneficial effects:

[0029] The high-airtightness LED lamp bead of the utility model is provided with a first resin substrate and a second resin substrate, a back circuit layer is provided on the back of the first resin substrate, a front circuit layer is provided on the front of the second resin substrate, and an intermediate circuit layer is provided on the back of the second resin substrate; in addition, the utility model realizes the electrical connection between the pad area and the pin area through the first through hole provided in the front circuit layer and the back circuit layer, and the first conductive copper in the second through hole. This through hole structure avoids the opening of large-aperture through holes around the substrate, avoids the use of ink, reduces the water vapor channel, improves the airtightness, and improves the reliability of the lamp bead. In addition, the intermediate circuit layer of the utility model can greatly improve the heat dissipation performance of the LED lamp bead, slow down the aging of the lamp bead, and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the front structure of a CHIP LED lamp bead in the prior art;

[0031] Figure 2 It is a schematic diagram of the cross-sectional structure of a highly airtight CHIP LED lamp bead in one embodiment of the utility model;

[0032] Figure 3 This is a schematic diagram of the front structure of a highly airtight CHIP LED lamp bead in one embodiment of the utility model;

[0033] Figure 4 This is a schematic diagram of the back structure of a highly airtight CHIP LED lamp bead in one embodiment of the utility model;

[0034] Figure 5 It is a schematic diagram of the back structure of the second resin substrate in one embodiment of the utility model;

[0035] In the figure, 1a is a through hole, 1b is ink, 2a is a solid crystal area, 3a is an electroplated lead; 1 is a first resin substrate, 11 is a pin area, 111 is a first cathode pin area, 112 is a second cathode pin area, 113 is an anode pin area, 114 is a third cathode pin area, 12 is a second through hole, 13 is a pad heat dissipation area, 131 is a first pad heat dissipation area, 132 is a second pad heat dissipation area, 133 is a third pad heat dissipation area, 134 is a fourth pad heat dissipation area, 14 is a solid crystal heat dissipation area, 141 is a first solid crystal heat dissipation area, 142 is a second solid crystal heat dissipation area, 1 is a first die-bonding heat dissipation area, 143 is a third die-bonding heat dissipation area, 2 is a second resin substrate, 21 is a die-bonding area, 211 is a first die-bonding area, 212 is a second die-bonding area, 213 is a third die-bonding area, 22 is a pad area, 221 is a first cathode pad area, 222 is a second cathode pad area, 223 is a common anode pad area, 23 is a first through hole, 24 is a third through hole, 3 is a light-emitting unit, 31 is a first light-emitting unit, 32 is a second light-emitting unit, 33 is a third light-emitting unit, 4 is a packaging glue layer, 5 is a first conductive copper, 6 is a second conductive copper, and 7 is a bonding wire. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model is further described in detail below.

[0037] See also Figure 2 to Figure 5One embodiment of the utility model provides a highly airtight LED lamp bead, which includes a first resin substrate 1, a second resin substrate 2, a light-emitting unit 3 and a packaging glue layer 4. The back of the first resin substrate 1 is provided with a back circuit layer, which includes at least two pin areas 11. The front of the second resin substrate 2 is provided with a front circuit layer, which includes a solid crystal area 21 and a pad area 22, wherein the solid crystal area 21 is used to fix the light-emitting unit 3, and the pad area 22 and the pin area 11 are used together to form an electrical connection with the light-emitting unit 3. In order to form a stable electrical connection, the pad area 22 and the pin area 11 are arranged in a one-to-one correspondence. A first through hole 23 that penetrates the second resin substrate 2 is provided in the pin area 11, and the first through hole 23 is filled with a first conductive copper 5.

[0038] The back of the second resin substrate 2 is also provided with an intermediate circuit layer, which includes at least two pad heat dissipation areas 13, and the pad heat dissipation areas 13 are arranged corresponding to the pin areas 11. A second through hole 12 penetrating the first resin substrate 1 is provided in the pin area 11, and the second through hole 12 is filled with the first conductive copper 5.

[0039] Based on the above-mentioned high-airtightness LED lamp beads, on the one hand, through the position setting of the intermediate circuit layer, the pad area, the pin area, the first through hole, and the second through hole, a good electrical connection between the pad area and the pin area is achieved, avoiding the first through hole and the second through hole being set in the edge area of ​​the substrate, reducing the water vapor channel, and improving the airtightness. At the same time, due to the setting of the intermediate circuit layer corresponding to the pin area 11, the current can be well expanded, which also makes it possible to use the first through hole and the second through hole with a smaller aperture in the utility model, providing good conditions for further reducing the water vapor channel. Secondly, by setting the intermediate circuit layer, the heat dissipation performance of the LED lamp beads is enhanced, the aging of the lamp beads is slowed down, and the service life is extended.

[0040] Specifically, the first resin substrate is made of BT resin, and its thickness is 0.1-0.2 mm; the second resin substrate is made of BT resin, and its thickness is 0.1-0.2 mm.

[0041] Specifically, in the utility model, the aperture of the first through hole 23 and the second through hole 12 is ≤0.05mm. Due to the introduction of the intermediate circuit layer, the current distribution is optimized and the adverse effects of heat generation are reduced. Therefore, the aperture of the through hole can be reduced, and the water vapor channel is reduced. It should be noted that in traditional CHIP LED lamp beads, the aperture of the through hole located around the substrate is ≥0.2mm. Although ink is used to fill and block it later, more water vapor channels will still be formed, and the bonding performance between the ink and the packaging glue is relatively poor, which will also form water vapor channels.

[0042] Preferably, in one embodiment of the present invention, the apertures of the first through hole 23 and the second through hole 12 are ≤ 0.02 mm. Based on this aperture, a solid first conductive copper 5 can be obtained by a copper deposition process, further optimizing air tightness. More preferably, the apertures of the first through hole 23 and the second through hole 12 are 0.01 to 0.02 mm. If the aperture is too small, the amount of the first conductive copper 5 is too small, and the electrical connection performance is weakened.

[0043] Preferably, in one embodiment of the utility model, the middle circuit layer also includes a solid crystal heat dissipation area 14, which is arranged corresponding to the solid crystal area 21, and the solid crystal heat dissipation area 14 can further enhance the heat dissipation performance of the lamp bead. Specifically, the solid crystal area 21 is also provided with a third through hole 24 that penetrates the second resin substrate 2, and the third through hole 24 is filled with a second conductive copper 6, one end of which is connected to the solid crystal heat dissipation area 14, and the other end is connected to the solid crystal area 21 to enhance heat conduction. At the same time, electrical connection between some special types of light-emitting units 3 and the pin area 11 can also be achieved.

[0044] Specifically, the aperture of the third through hole 24 is ≤0.05 mm, preferably, ≤0.02 mm, so as to obtain a solid second conductive copper 6 through the copper deposition process, further optimizing air tightness. More preferably, the aperture of the third through hole 24 is 0.01-0.02 mm.

[0045] The highly airtight CHIP LED lamp bead includes three light-emitting units 3, namely, a first light-emitting unit 31, a second light-emitting unit 32, and a third light-emitting unit 33. Correspondingly, the solid crystal area 21 includes a first solid crystal area 211 for fixing the first light-emitting unit 31, a second solid crystal area 212 for fixing the second light-emitting unit 32, and a third solid crystal area 213 for fixing the third light-emitting unit 33. The pad area 22 includes a first cathode pad area 221, a second cathode pad area 222 and a common anode pad area 223; the pin area 11 includes a first cathode pin area 111 corresponding to the first cathode pad area 221, a second cathode pin area 112 corresponding to the second cathode pad area 222, an anode pin area 113 corresponding to the common anode pad area 223, and a third cathode pin area 114 corresponding to the third solid crystal area 213; the pad heat dissipation area 13 includes a first pad heat dissipation area 131 corresponding to the first cathode pin area 111, a second pad heat dissipation area 132 corresponding to the second cathode pin area 112, and a third cathode pin area 114 corresponding to the third solid crystal area 213. 3, and a fourth solder pad heat dissipation area 114 corresponding to the third cathode pin area 114; the die-bonding heat dissipation area 14 includes a first die-bonding heat dissipation area 141 corresponding to the first die-bonding area 211, a second die-bonding heat dissipation area 142 corresponding to the second die-bonding area 212, and a third die-bonding heat dissipation area 143 corresponding to the third die-bonding area 213; the third die-bonding heat dissipation area 143 is interconnected with the fourth solder pad heat dissipation area 134, so that the first conductive copper 5 located in the first through hole 12 of the fourth solder pad heat dissipation area 134 and the second conductive copper 6 located in the third through hole 24 of the third die-bonding heat dissipation area 143 are electrically connected. Based on the above structure, the blue LED, green LED in the horizontal structure and the red LED in the vertical direction can be combined to form a small-pitch CHIP LED white light lamp bead with strong reliability.

[0046] Specifically, the first light-emitting unit 31 is connected to the first cathode pad area 221 and the common anode pad area 223 through the bonding wire 7; the second light-emitting unit 32 is connected to the second cathode pad area 222 and the common anode pad area 223 through the bonding wire 7; one end of the third light-emitting unit 33 is electrically connected to the third solid crystal area 213 through a conductive glue, and the other end is connected to the common anode pad area 223 through the bonding wire 7.

[0047] Specifically, the first solid crystal area 211, the second solid crystal area 212, and the third solid crystal area 213 are separately arranged. Based on the above arrangement scheme, the mixing of glue used for fixing during the packaging process can be reduced, the color rendering performance of the lamp beads can be optimized, and the yield rate can be improved. It should be noted that, see Figure 1In the prior art, due to the need to use electroplating technology, protruding electroplating leads are often set on the front circuit layer, and the solid crystal areas of multiple LED chips are connected together. Since blue LEDs and green LEDs are generally fixed in the solid crystal area by insulating glue, and red LEDs are fixed in the solid crystal area by conductive silver glue, different glues are easily mixed with each other during the glue dispensing process, which not only reduces the yield, but also may affect the color rendering performance of the lamp beads. The utility model greatly reduces the aperture of the through hole by setting the intermediate circuit layer, the first through hole, the second through hole, etc., and uses the copper deposition process to form the first conductive copper and the second conductive copper, so there is no need for protruding electroplating leads, and the solid crystal areas of different light-emitting units are set separately.

[0048] Preferably, in an embodiment of the present invention, the second die-bonding heat dissipation area 142, the third die-bonding heat dissipation area 143 and the fourth pad heat dissipation area 134 are connected into a sheet; the first die-bonding heat dissipation area 141 and the third pad heat dissipation area 133 are connected into a sheet. Based on the above solution, the heat dissipation performance can be further improved.

[0049] In summary, the highly airtight LED lamp beads in the utility model are provided with a first resin substrate and a second resin substrate, a back circuit layer is provided on the back of the first resin substrate, a front circuit layer is provided on the front of the second resin substrate, and an intermediate circuit layer is provided on the front of the first resin substrate or the front of the second resin substrate; in addition, the utility model realizes the electrical connection between the pad area and the pin area through the first through hole provided in the front circuit layer and the back circuit layer, and the first conductive copper in the second through hole. This through hole structure avoids the opening of large-aperture through holes around the substrate, avoids the use of ink, reduces the water vapor channel, improves the airtightness, and improves the reliability of the lamp beads. In addition, the intermediate circuit layer of the utility model can greatly improve the heat dissipation performance of the LED lamp beads, slow down the aging of the lamp beads, and extend the service life.

[0050] The above is a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications are also considered to be within the scope of protection of the utility model.

Claims

1. A highly airtight LED lamp bead, characterized in that: include: A first resin substrate, a back side of which is provided with a back side circuit layer, wherein the back side circuit layer includes at least two pin areas; A second resin substrate is fixed on the first resin substrate, and a front circuit layer is provided on the front side thereof, wherein the front circuit layer comprises at least two mutually separated crystal bonding areas and at least two pad areas, wherein the pin areas are arranged in one-to-one correspondence with the pad areas; and a first through hole penetrating the second resin substrate is provided in the pad area; A light-emitting unit, which is fixed on the solid crystal area; An encapsulation adhesive layer, which wraps the light-emitting unit on the second resin substrate; Among them, an intermediate circuit layer is provided on the back side of the second resin substrate, and the intermediate circuit layer includes at least two pad heat dissipation areas; the pad heat dissipation area is arranged corresponding to the pin area, and a second through hole penetrating the first resin substrate is provided in the pin area; the first through hole and the second through hole are both filled with first conductive copper, and the pin area and the pad area are electrically connected through the first conductive copper.

2. The highly airtight LED lamp bead according to claim 1, characterized in that: The diameters of the first through hole and the second through hole are ≤0.05 mm.

3. The highly airtight LED lamp bead as claimed in claim 2, characterized in that: A third through hole penetrating the second resin substrate is provided in the solid crystal area, and the intermediate circuit layer also includes a solid crystal heat dissipation area corresponding to the solid crystal area; the third through hole is filled with second conductive copper, one end of which is connected to the solid crystal heat dissipation area, and the other end is connected to the solid crystal area.

4. The highly airtight LED lamp bead as claimed in claim 3, characterized in that: The diameters of the first through hole, the second through hole and the third through hole are ≤0.02 mm.

5. The highly airtight LED lamp bead as claimed in claim 3 or 4, characterized in that: The crystal-bonding region includes a first crystal-bonding region, a second crystal-bonding region and a third crystal-bonding region separated from each other; The light-emitting unit includes a first light-emitting unit fixed to the first crystal-bonding area, a second light-emitting unit fixed to the second crystal-bonding area, and a third light-emitting unit fixed to the third crystal-bonding area; The pad area includes a first cathode pad area, a second cathode pad area and a common anode pad area; The pin area includes a first cathode pin area corresponding to the first cathode pad area, a second cathode pin area corresponding to the second cathode pad area, an anode pin area corresponding to the common anode pad area, and a third cathode pin area corresponding to the third crystal bonding area; The pad heat dissipation area includes a first pad heat dissipation area corresponding to the first cathode pin area, a second pad heat dissipation area corresponding to the second cathode pin area, a third pad heat dissipation area corresponding to the anode pin area, and a fourth pad heat dissipation area corresponding to the third cathode pin area; The crystal bonding heat dissipation area includes a first crystal bonding heat dissipation area corresponding to the first crystal bonding area, a second crystal bonding heat dissipation area corresponding to the second crystal bonding area, and a third crystal bonding heat dissipation area corresponding to the third crystal bonding area; The third die-bonding heat dissipation area is interconnected with the fourth pad heat dissipation area, so that the first conductive copper in the first through hole of the fourth pad heat dissipation area is electrically connected to the second conductive copper in the third through hole of the third die-bonding heat dissipation area.

6. The highly airtight LED lamp bead as claimed in claim 5, characterized in that: The first light emitting unit is connected to the first cathode pad area and the common anode pad area through bonding wires; The second light emitting unit is connected to the second cathode pad area and the common anode pad area through bonding wires; One end of the third light emitting unit is electrically connected to the third die-bonding area via a conductive adhesive, and the other end is connected to the common anode pad area via a bonding wire.

7. The highly airtight LED lamp bead as claimed in claim 5, characterized in that: The second die-bonding heat dissipation area, the third die-bonding heat dissipation area and the fourth pad heat dissipation area are connected into a sheet.

8. The highly airtight LED lamp bead as claimed in claim 5, characterized in that: The first die-bonding heat dissipation area and the third pad heat dissipation area are connected into a sheet.

9. The highly airtight LED lamp bead as claimed in claim 5, characterized in that: The first light emitting unit is a blue LED chip with a front-mounted structure, the second light emitting unit is a green LED chip with a front-mounted structure, and the third light emitting unit is a red LED chip with a vertical structure.

10. The highly airtight LED lamp bead according to claim 1, characterized in that: The first resin substrate is made of BT resin and has a thickness of 0.1 to 0.2 mm; The second resin substrate is made of BT resin and has a thickness of 0.1-0.2 mm.

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