TW202105765A - Active rgb led display carrier - Google Patents

Abstract

An active RGB LED display carrier includes a substrate, a circuit layer, multiple transistor chips, a solder resist layer and multiple LED chips. The circuit layer includes a gate circuit, a source circuit and a drain circuit. The transistor chips each has a gate terminal, a source terminal and a drain terminal. The gate terminal and the source terminal are mounted on the gate circuit and the source circuit, respectively. The solder resist layer covers the substrate, the circuit layer and the transistor chips. The solder resist layer has multiple first via holes and multiple second via holes, both are formed with copper therein. Each LED chip has an N-contact and a P-contact. The copper in the first via holes are electrically communicated between the drain terminals and the N-contacts, respectively. The copper in the second via holes are electrically communicated between the drain circuit and the P-contacts, respectively.

Description

Active RGB light-emitting diode display carrier board

The invention relates to a light-emitting diode display carrier board, in particular to an active light-emitting diode display carrier board.

With the gradual development of mini LED technology, the development prospects of LED displays are highly anticipated.

Among them, light-emitting diode displays can be divided into passive driving and active driving according to the difference in driving methods. The passive driving method needs to arrange row and column matrix scan electrodes and data electrodes on the substrate, and directly use the scan signals to drive the light-emitting diode chips in each frame, but because the scan electrodes and data electrodes are arranged in a row and column matrix, The circuit configuration is complicated, and the number of layers of the passive light-emitting diode display carrier usually reaches six, eight or more layers of circuits, resulting in an increase in processing costs.

On the other hand, the active driving method is to form multiple thin film transistors directly on the glass or polyimide (PI) substrate by sputtering, and the light-emitting diode wafers in each pixel can be individually controlled. Although the active light-emitting diode display reduces the number of layers of the substrate by arranging thin-film transistors, the cost of the process of forming thin-film transistors by sputtering is still relatively high, and the glass substrate is fragile. The cost of the imide substrate is relatively high, so that although the existing active light-emitting diode display is relatively thin and light, it still has other disadvantages such as relatively high cost.

In view of this, the main purpose of the present invention is to provide an active light emitting diode display carrier with a lower manufacturing cost and a smaller number of carrier layers than a passive light emitting diode display.

In order to achieve the above and other objectives, the present invention provides an active RGB light emitting diode display carrier board, which includes a substrate, a circuit layer, a plurality of transistor chips, a solder mask and a plurality of light emitting diode chips. The circuit layer is formed on the substrate and includes a gate circuit, a source circuit, and a drain circuit. Each transistor chip has a gate terminal, a source terminal, and a drain terminal. The gate terminals of the transistor chips and The source terminal is respectively mounted on the gate circuit and the source circuit of the circuit layer to form electrical connections. The solder mask layer covers the substrate, the circuit layer and the transistor chip, and the solder mask layer has a plurality of first via holes and a plurality of The second via holes, the first and second via holes are formed with via copper. Each light-emitting diode chip has an N-pole electrical contact and a P-pole electrical contact. The light-emitting diode chips are mounted on the solder mask, and the copper holes of the first via holes are electrically connected to each other. Between the drain terminals of the transistor chips and the N-pole electrical contacts of the light-emitting diode chips, the copper holes of the second via holes are electrically connected to the drain circuit and the light-emitting diodes, respectively Between the P pole electrical contacts of the bulk wafer.

In order to achieve the above and other objectives, the present invention provides an active RGB light emitting diode display carrier board, which includes a substrate, a circuit layer, a plurality of transistor chips, a solder mask and a plurality of light emitting diode chips. The circuit layer is formed on the substrate and includes a gate circuit, a source circuit, and a drain circuit. Each transistor chip has a gate terminal, a source terminal, and a drain terminal. The gate terminals of the transistor chips and The source terminal is respectively mounted on the gate circuit and the source circuit of the circuit layer to form electrical connections. The solder mask layer covers the substrate, the circuit layer and the transistor chip, and the solder mask layer has a plurality of first via holes and a plurality of The second via holes, the first and second via holes are formed with via copper. Each light-emitting diode chip has a P-pole electrical contact and an N-pole electrical contact. The light-emitting diode chips are mounted on the solder mask, and the copper holes of the first via holes are electrically connected to each other. Between the drain terminals of the transistor chips and the P electrode electrical contacts of the light emitting diode chips, the copper holes of the second via holes are electrically connected to the drain circuit and the light emitting diodes, respectively Between the N-pole electrical contacts of the bulk chip.

The present invention not only realizes the RGB light-emitting diodes, by embedding the transistor chip in the solder mask layer, and then using the through holes to electrically connect the two poles mounted on the surface of the solder mask layer to the transistor chip and the drain electrode, respectively. The active drive design of the display, the number of layers is lower than that of traditional passive light-emitting diode displays, and the cost is lower than that of existing active light-emitting diode displays using thin film transistors, which can satisfy the industry’s demand for light-emitting diodes. The need for lighter and thinner and lower cost of the diode display carrier board.

Please refer to Figures 1 and 2, the one shown is an embodiment of an active RGB light emitting diode display carrier, which includes a substrate 10, a circuit layer 20, a plurality of transistor chips 30, and a solder mask. Layer 40 and a plurality of light emitting diode chips 50.

The substrate 10 can be made of a substrate material commonly used in general circuit boards, such as FR-4 grade epoxy resin.

The circuit layer 20 is formed on the substrate 10, and the circuit layer 20 includes a gate electrode circuit 21, a source electrode circuit 22 and a drain electrode circuit 23. The transistor chip 30 has three electrical contacts: a gate terminal 31, a source terminal 32, and a drain terminal 33. The gate terminal 31 and the source terminal 32 are respectively mounted on the gate circuit 21 and the source circuit of the circuit layer 20. 22 and form electrical connections respectively. The gate terminal 31 and the gate circuit 21 may be electrically connected through conductive glue or solder balls, and the source terminal 31 and the source circuit 22 are also electrically connected. In this embodiment, the circuit layer is an example of a single-layer structure. In other possible implementations, the circuit layer can also be a multilayer structure, which allows it to have a higher degree of design freedom and can be used to design more complicated circuits. However, compared with a passive light emitting diode display, the number of layers in the structure of the present invention is still lower.

The solder resist layer 40 covers the substrate 10, the circuit layer 20, and the transistor chips 30, and the solder resist layer has a plurality of first vias 41 and a plurality of second vias 42, the first and second vias 41, Copper holes 43 and 44 are respectively formed in 42. The first and second via holes are formed by laser perforation or mechanical drilling, for example.

The light-emitting diode chip 50 has an N-pole electrical contact 51 and a P-pole electrical contact 52 respectively. It can be a flip-chip light-emitting diode chip, and the light-emitting diode chip 50 is mounted on the solder mask 40 Above, the hole copper 43 of the first through hole 41 is electrically connected between the drain terminal 33 of the transistor chip 30 and the N-pole electrical contact 51 of the light emitting diode chip 50, and the hole copper 44 of the second through hole 42 Then, they are electrically connected between the drain circuit 23 and the P-pole electrical contact 52 of the light-emitting diode chip 50, respectively. In order to increase the reliability of the placement of the N-pole electrical contact 51 and the P-pole electrical contact 52, a first electroplating layer 45 can be formed on the top surface of the copper 43 of the first via 41, and the hole of the second via 42 A second electroplating layer 46 is formed on the top surface of the copper 44, so that the N-pole electrical contact 51 and the P-pole electrical contact 52 are attached to the first and electroplated layers 45 and 46, respectively. As an RGB light-emitting diode display, the mounted light-emitting diode chips are used to emit red, green and blue light respectively. Three light-emitting diode chips that emit red, green and blue light respectively form a pixel. Each RGB light emitting diode display has a plurality of said pixels.

In this embodiment, the transistor chip 30 is a PNP type transistor, that is, when the gate terminal 31 is in the selected state (open), current will flow through the source circuit 22, the source terminal 32 of the transistor chip 30 and then It flows to the drain terminal 33, and finally enters the N-pole electrical contact 51 and drives the light-emitting diode chip 50 to emit light.

As shown in Figure 3, in other possible implementations, the transistor chip may be an NPN type transistor, that is, when the gate terminal 31 is in the selected state (open), the current flows from the drain circuit 23 through the second The copper 44 in the via 42 enters the N-pole electrical contact 51 and drives the light-emitting diode chip 50 to emit light, and then through the P-pole electrical contact 52, the copper 43 of the first via 41 flows through the drain terminal 33 in sequence. And the source terminal 32, and then enter the source circuit 22. Therefore, in this embodiment, the copper hole 43 of the first via 41 is electrically connected between the drain terminal 33 and the P electrode electrical contact 52, and the copper hole 44 of the second via 42 is electrically connected to the drain circuit 23. Between the N-pole electrical contact 51, the P-pole electrical contact 52 and the N-pole electrical contact 51 are mounted on the first and second electroplating layers 45, 46, respectively.

In the third embodiment shown in Figure 4, the P and N pole electrical contacts 51, 52 are not directly facing the first and second via holes 41, 42, but are mounted on the first and second vias. The tops of the holes 41 and 42 extend and are formed on the light-emitting diode pads 47 and 48 on the top surface of the solder mask 40.

In summary, the present invention embeds the transistor chip in the solder mask layer, and uses the via holes to electrically connect the two poles mounted on the surface of the solder mask layer to the transistor chip and the drain electrode, thereby not only realizing RGB light emission The active driving design of the diode display, and the number of layers is lower than that of the traditional passive light emitting diode display. Because the cost of the transistor chip is low, the cost is higher than that of the existing active light emitting diode using thin film transistors. The volume display is lower, so as to meet the industry's demand for light-emitting diode display substrates to be thinner and lower in cost.

10: substrate 20: circuit layer 21: Gate circuit 22: Source circuit 23: Drain circuit 30: Transistor wafer 31: gate extreme 32: Source extreme 33: Extremity 40: Solder mask 41: The first via 42: second via 43, 44: hole copper 45: The first electroplating layer 46: The second plating layer 47, 48: LED pads 50: LED chip 51: N pole electric contact 52: P pole electric contact

FIG. 1 is a partial exploded perspective view of one embodiment of the active RGB light-emitting diode display carrier of the present invention.

FIG. 2 is a schematic cross-sectional view of one embodiment of the active RGB light-emitting diode display carrier of the present invention.

10: substrate

20: circuit layer

21: Gate circuit

22: Source circuit

23: Drain circuit

30: Transistor wafer

31: gate extreme

32: Source extreme

33: Extremity

40: Solder mask

41: The first via

42: second via

43, 44: hole copper

45: The first electroplating layer

46: The second plating layer

50: LED chip

51: N pole electric contact

52: P pole electric contact

Claims (5)

An active RGB light-emitting diode display carrier board, including: A substrate; A circuit layer formed on the substrate, the circuit layer including a gate circuit, a source circuit and a drain circuit; A plurality of transistor chips, each having a gate terminal, a source terminal, and a drain terminal, the gate terminal and source terminal of the transistor chips are respectively mounted on the gate circuit and the source circuit of the circuit layer And respectively form electrical connections; A solder mask layer covering the substrate, the circuit layer and the transistor chips, the solder mask layer has a plurality of first via holes and a plurality of second via holes, and the first and second via holes are respectively formed Perforated copper; and A plurality of light-emitting diode chips, each having an N-pole electrical contact and a P-pole electrical contact, the light-emitting diode chips are mounted on the solder mask, and the holes of the first via holes are copper Are respectively electrically connected between the drain terminals of the transistor chips and the N-pole electrical contacts of the light emitting diode chips, and the copper holes of the second via holes are respectively electrically connected to the drain circuit And the P-pole electrical contacts of the light-emitting diode chips. The active RGB light emitting diode display carrier board according to claim 1, wherein the copper top surfaces of the first via holes are respectively formed with a plurality of first electroplating layers, and the copper top surfaces of the second via holes A plurality of second electroplating layers are respectively formed on the surfaces, and the N-pole electrical contacts and the P-pole electrical contacts of the light-emitting diode chips are respectively attached to the first electroplating layers and the second electroplating layers. Plating. An active RGB light-emitting diode display carrier board, including: A substrate; A circuit layer formed on the substrate, the circuit layer including a gate circuit, a source circuit and a drain circuit; A plurality of transistor chips, each having a gate terminal, a source terminal, and a drain terminal, the gate terminal and source terminal of the transistor chips are respectively mounted on the gate circuit and the source circuit of the circuit layer And respectively form electrical connections; A solder mask layer covering the substrate, the circuit layer and the transistor chips, the solder mask layer has a plurality of first via holes and a plurality of second via holes, and the first and second via holes are respectively formed Perforated copper; and A plurality of light-emitting diode chips, each having a P-pole electric contact and an N-pole electric contact, the light-emitting diode chips are mounted on the solder mask, and the holes of the first via holes are copper Are respectively electrically connected between the drain terminals of the transistor chips and the P electrode electrical contacts of the light emitting diode chips, and the copper holes of the second via holes are respectively electrically connected to the drain circuit And the N-pole electrical contacts of the light-emitting diode chips. The active RGB light emitting diode display carrier board according to claim 3, wherein the copper top surfaces of the first via holes are respectively formed with a plurality of first electroplating layers, and the copper top surfaces of the second via holes A plurality of second electroplating layers are respectively formed on the surface, and the P-electrode electrical contacts and the N-electrode electrical contacts of the light-emitting diode chips are respectively mounted on the first electroplating layers and the second electroplating layers. Plating. The active RGB light-emitting diode display carrier board according to any one of claims 1 to 4, wherein the light-emitting diode chips are flip-chip light-emitting diode chips.

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