TW202215636A - Grain structure of miniature light emitting diode display including a package carrier, at least one light emitting diode component, at least one metal-oxide-semiconductor field effect transistor (MOSFET) and a connecting line - Google Patents

Abstract

This invention relates to a grain structure of a miniature light emitting diode display, which includes a package carrier, at least one light emitting diode component, at least one metal-oxide-semiconductor field effect transistor (MOSFET) and a connecting line, wherein the at least one light emitting diode component and the at least one MOSFET are located on the package carrier. The at least one MOSFET has a source in copolar connection with an input voltage, a gate connected to a master control circuit and a drain. One end of the at least one light emitting diode component is connected with the at least one drain by the connecting line, and the other end of the at least one light emitting diode component is independently connected with a source drive circuit. Therefore, according to this invention, the at least one MOSFET is disposed on the package carrier and is integrated in the grain structure, so as to achieve a better heat radiation effect and to suit use demands for use of high density and high brightness.

Description

Grain structure of a miniature light-emitting diode display

The present invention relates to a micro light emitting diode display, and in particular, to a crystal grain structure of the micro light emitting diode display.

Micro Light Emitting Diode (Micro LED) displays, such as US Bulletin No. US10062675B2, etc. Each micro-light-emitting diode is a single entity, and can be regarded as an independent light-emitting module. Because of its self-luminous display characteristics, its structure is quite simple, there is no backlight element, and it has the characteristics of low energy consumption and high brightness, which can solve the problem of current display The problem of power consumption and brightness is very promising.

Please refer to "Fig. 1" and "Fig. 2" again. The driving circuit of the MLED can be roughly divided into two types: common cathode driving (as shown in Fig. 1) and common anode driving (as shown in Fig. 2). kind. In the common cathode driving method shown in Figure 1, after the miniature light-emitting diodes are formed into a light-emitting diode array 1 (LED array), light-emitting diodes of different colors (usually one each of R, G, and B) are adjacent to each other. The polar body is used as the same pixel 2, and the common electrode is connected to an N-channel MOSFET (NMOS) 3. The N-channel MOSFET 3 can control whether the current passes through, while the light-emitting diodes of the same pixel 2 are driven by different sources (Source). Drive) IC 4 controls the passing current (electron flow) of the light-emitting diodes of different colors to control the luminous brightness of the light-emitting diodes of different colors, so that the pixels can be displayed in full color through the light mixing method. In the common anode driving method shown in FIG. 2, a pixel 2 is connected to a P-channel MOSFET (PMOS) 5 in common, and the P-channel MOSFET 5 can control whether the current passes through, and the light-emitting diodes of different colors are also driven by different sources. The source drive IC 4 controls the amount of current (electron flow) passing through the light emitting diodes of different colors.

In the above-mentioned driving structure, the N-channel MOSFET 3 or the P-channel MOSFET 5 that controls whether the current passes through is integrated into a gate driver IC, and the gate driver IC is an integrated circuit. When high brightness is required, the gate driver IC needs to carry a high current, that is to say, the gate driver IC needs a larger die size. The number of channels) should not be too large, otherwise there will be problems of heat dissipation and yield, which will result in the need for multiple gate driver ICs, resulting in high cost.

Therefore, the main purpose of the present invention is to disclose a die structure suitable for high-density and high-brightness miniature light-emitting diodes.

The present invention is a chip structure of a miniature light emitting diode display for connecting an input voltage, a main control circuit and a source drive circuit, which comprises a loading board, at least one light emitting diode element , at least one metal oxide semiconductor field effect transistor (MOSFET) and a connecting line.

Wherein, the at least one light-emitting diode element is located on the package carrier, the at least one MOSFET is located on the package carrier, and the at least one MOSFET has a source, a The gate electrode and a drain electrode are connected to the input voltage at the common electrode of the at least one source electrode, and the at least one gate electrode is connected to the main control circuit. One end of the at least one light-emitting diode element is connected to the at least one drain electrode through the connection line, and the other end of the at least one light-emitting diode element is independently connected to the source driving circuit.

Accordingly, the present invention integrates a metal oxide semiconductor field effect transistor (MOSFET) in the die structure, and controls the switching of the MOSFET through the main control circuit, thereby saving the cost of the gate driver IC. In addition, the traditional integrated MOSFET circuit is dispersed into each die, and the MOSFET in each die only needs to carry the current required by the light-emitting diode element in a single die, that is, the MOSFET in each die multiplies The current carried is relatively small, and heat can be dissipated through the package board, so the heat dissipation is good, which can meet the needs of high density and high brightness of micro light-emitting diodes.

In order to make your members have a more in-depth understanding and recognition of the features, purposes and effects of the present invention, hereby enumerates a preferred embodiment and cooperates with the drawings to describe as follows:

Please refer to "FIG. 3", "FIG. 4A" and "FIG. 4B", the present invention is a chip structure of a miniature light emitting diode display for connecting an input voltage 20, a main control circuit 30 and a source electrode The source drive circuit 40 includes a loading board 50 , at least one light emitting diode element 60 , at least one metal oxide semiconductor field effect transistor 70 (MOSFET) and a connecting line 80 . As shown in FIG. 3 , the at least one MOSFET 70 is one, and the at least one light-emitting diode element 60 is three, and the red (R) diodes, the green The light (G) diode and the blue light (B) diode are used as examples to illustrate. In actual implementation, the at least one light-emitting diode element 60 can be a single or single color or a specific color, depending on the actual use determined by needs.

Wherein, the at least one light-emitting diode element 60 is located on the package carrier 50, and the at least one MOSFET 70 is located on the package carrier 50, and the at least one MOSFET 70 is respectively It has a source electrode 71 , a gate electrode 72 and a drain electrode 73 , the at least one source electrode 71 is connected to the input voltage 20 in common, and the at least one gate electrode 72 is connected to the main control circuit 30 . One end of the at least one light-emitting diode element 60 is connected to the at least one drain electrode 73 through the connection line 80 , and the other end of the at least one light-emitting diode element 60 is independently connected to the source driving circuit 40 . In actual implementation, each of the light-emitting diode elements 60 can be independently connected to the source driving circuit 40 through a first connection circuit 81 ; and each of the gate electrodes 72 can be independently connected through a second connection circuit 82 is connected to the main control circuit 30 .

In actual structure, as shown in FIG. 4A and FIG. 4B in one embodiment, the at least one light-emitting diode element 60 and the at least one MOSFET 70 can be flip-chip connected to the package carrier 50, and the connecting line 80 is made by an electroplating copper process. More specifically, the connecting line 80 can replace the traditional wire bonding process by an electroplating copper process, so as to be rapidly mass-produced. The contacts and lines required to connect the input voltage 20 , the main control circuit 30 and the source drive circuit 40 are disposed on the package carrier board 50 and are part of the packaging process. Not much to describe. In addition, in order to individually protect each of the at least one light-emitting diode element 60 from being damaged by static electricity, in the circuit structure shown in FIG. 3 , an electrostatic protection diode can be connected between the gate electrode 72 and the source electrode 71 The body 90 can reduce the influence of parasitic capacitance and improve image quality, optimize brightness and power consumption speed, and improve power usage efficiency.

Please refer to FIG. 5 , which is a schematic diagram of another chip structure circuit of the present invention. The at least one light-emitting diode element 60 can be plural and have different colors and are grouped to form plural pixels 91 , and the plural pixels 91 are arranged in an A×B matrix (as shown in FIG. 5 , a 2×2 matrix) , and the at least one MOSFET 70 has A pieces, and the LED elements 60 in the same row are connected to the drain 73 of the same MOSFET 70 . That is to say, the LED elements 60 in the same row use the same MOSFET 70 in common, so as to save the usage cost. In other embodiments, the light-emitting diode elements 60 in the same row can also be designed to use the same MOSFET 70 in common, or a specific number of the light-emitting diode elements 60 arranged in a matrix, such as 2 The light-emitting diode elements 60 in the ×2 matrix or the 3×3 matrix use the same MOSFET 70 in common. It can be achieved by simply changing the circuit wiring design. Likewise, an electrostatic protection diode 90 is connected between the gate electrode 72 and the source electrode 71 of each of the MOSFETs 70 to reduce the influence of parasitic capacitance.

Several feasible embodiments of the present invention are listed below, and these embodiments are only part of the embodiments of the present invention and do not limit the embodiments of the present invention.

Please refer to FIG. 6 , which is a schematic circuit diagram of the first embodiment of the present invention. In this embodiment, it is a common-cathode driving mode. The at least one light-emitting diode element 60 is a plurality of pixels with different colors and is grouped to form a plurality of pixels arranged in a matrix, and the at least one MOSFET 70 uses an N-channel MOSFET, and the at least one MOSFET The number of the semi-field effect transistors 70 is the same as the number of the at least one light-emitting diode element 60 , and the plurality of light-emitting diode elements 60 are connected to the corresponding metal-oxide semi-field effect transistors 70 one-to-one.

Please refer to FIG. 7 , which is a schematic circuit diagram of a second embodiment of the present invention. In this embodiment, it is similar to the first embodiment, but is changed to a common anode driving mode. Similarly, the at least one light-emitting diode element 60 is a plurality of pixels with different colors and is grouped to form a plurality of pixels arranged in a matrix, and the at least one metal oxide semiconductor field effect transistor 70A uses a P-channel MOSFET, and the at least one The number of one MOSFET 70A is the same as the number of the at least one light emitting diode element 60 , and the plurality of light emitting diode elements 60 are one-to-one connected to the corresponding MOSFET 70A.

Please refer to FIG. 8 , which is a schematic circuit diagram of a third embodiment of the present invention. In this embodiment, based on the first embodiment, a common-cathode driving method is added, and electrostatic discharge (ESD) is added. Protect. An electrostatic protection diode 90 is connected between the first electrical connection line 81 and a ground terminal 93 .

Please refer to FIG. 9 , which is a schematic circuit diagram of a fourth embodiment of the present invention. In this embodiment, based on the first embodiment, a common-cathode driving method is added, and electrostatic discharge (ESD) is added. Protect. Each of the light-emitting diode elements 60 is connected in parallel with an electrostatic protection diode 90 .

Please refer to FIG. 10 , which is a schematic circuit diagram of a fifth embodiment of the present invention, which is a common-cathode driving method. The at least one light-emitting diode element 60 is a plurality of pixels 91 with different colors and grouped to form a plurality of matrix arrays, and the number of the at least one MOSFET 70 is the same as the number of the plurality of pixels 91 The plurality of light emitting diode elements 60 of the same pixel 91 are connected to the MOSFET 70 corresponding to the pixel 91 .

Please refer to FIG. 11 , which is a schematic circuit diagram of a sixth embodiment of the present invention. In this embodiment, based on the fifth embodiment, a common-cathode driving method is added, and electrostatic discharge (ESD) is added. Protect. An electrostatic protection diode 90 is connected between the gate electrode 72 and the source electrode 71 of each of the MOSFETs 70 .

Please refer to FIG. 12 , which is a schematic circuit diagram of a seventh embodiment of the present invention. In this embodiment, based on the fifth embodiment, a common-cathode driving method is added, and electrostatic discharge (ESD) is added. Protect. An electrostatic protection diode 90 is connected between the second electrical connection line 82 and a ground terminal 93 .

As mentioned above, the features of the present invention include at least:

1. The at least one MOSFET is arranged on the package carrier board and dispersed in each die structure, and the MOSFET in each die only needs to carry the light-emitting diode element in a single die The required current, that is, the current carried by the MOSFET in each die is relatively small, and the heat can be dissipated through the package board, so the heat dissipation is good, which can meet the requirements of high density of micro light-emitting diodes (Dot pitch <0.5mm) or High brightness (>1000 nits) usage requirements.

2. Integrating the electrostatic protection diode into the die structure can reduce the influence of parasitic capacitance and improve the image quality, optimize the brightness and power consumption speed, and improve the efficiency of power usage.

3. No traditional gate driver IC is needed, and the main control circuit can be used to control the gate switch to save costs.

4. The copper electroplating process can be used to reduce costs, speed up production, improve reliability, and does not require wire bonding or copper pillar components.

acquaintance 1: LED array 2: Pixels 3: N-channel MOSFET 4: Source driver IC 5: P-channel MOSFET this invention 20: Input voltage 30: Main control circuit 40: Source driver circuit 50: Package carrier board 60: Light Emitting Diode Elements 70, 70A: metal oxide semi-field effect transistor 71: source 72: Gate 73: Drain 80: Connection line 81: The first connection line 82: The second connection line 90: Electrostatic protection diode 91: Pixel 93: ground terminal

FIG. 1 is a schematic circuit diagram of a conventional common-cathode driving method. FIG. 2 is a schematic circuit diagram of a conventional common anode driving method. FIG. 3 is a schematic diagram of the die structure circuit of the present invention. FIG. 4A is a schematic top view of the crystal grain structure of the present invention. FIG. 4B is a schematic side view of the grain structure of the present invention. FIG. 5 is a schematic diagram of another die structure circuit of the present invention. FIG. 6 is a schematic circuit diagram of the first embodiment. FIG. 7 is a schematic circuit diagram of the second embodiment. FIG. 8 is a schematic circuit diagram of the third embodiment. FIG. 9 is a schematic circuit diagram of the fourth embodiment. FIG. 10 is a schematic circuit diagram of the fifth embodiment. FIG. 11 is a schematic circuit diagram of the sixth embodiment. FIG. 12 is a schematic circuit diagram of the seventh embodiment.

20: Input voltage

30: Main control circuit

40: Source driver circuit

60: Light Emitting Diode Elements

70: metal oxide half field effect transistor

71: source

72: Gate

73: Drain

80: Connection line

81: The first connection line

82: The second connection line

90: Electrostatic protection diode

Claims (14)

A crystal grain structure of a miniature light-emitting diode display for connecting an input voltage, a main control circuit and a source drive circuit, comprising: a loading plate; at least one light emitting diode element, the at least one light emitting diode element is located on the package carrier board; At least one MOSFET, the at least one MOSFET is located on the package carrier, and the at least one MOSFET has a source connected to the input voltage in common, a source connected to a gate and a drain of the main control circuit; and A connecting line, one end of the at least one light emitting diode element is connected to the at least one drain electrode through the connecting line, and the other end of the at least one light emitting diode element is independently connected to the source driving circuit. The grain structure of claim 1, wherein the at least one MOSFET is one. The die structure of claim 2, wherein an electrostatic protection diode is connected between the gate electrode and the source electrode. The die structure of claim 2, wherein the at least one light-emitting diode element is three and is a red light diode, a green light diode, and a blue light diode, respectively. The die structure of claim 4, wherein an electrostatic protection diode is connected between the gate electrode and the source electrode. The die structure as claimed in claim 1, wherein the at least one light-emitting diode element and the at least one MOSFET are flip-chip connected to the package carrier, and the connection lines are made by a copper electroplating process . The die structure of claim 1, wherein the at least one light-emitting diode element is a plurality of different colors and is grouped to form a plurality of pixels, the plurality of pixels are arranged in an A×B matrix, and the at least one There are A MOSFETs, and the light-emitting diode elements in the same row are connected to the drain of the same MOSFET. The die structure of claim 7, wherein an electrostatic protection diode is connected between the gate and the source of each of the MOSFETs. The die structure of claim 1, wherein the at least one light-emitting diode element is a plurality of different colors and is grouped to form a plurality of pixels arranged in a matrix, and the number of the at least one MOSFET is The number of the at least one light emitting diode element is the same as that of the at least one light emitting diode element, and the plurality of light emitting diode elements are one-to-one connected to the corresponding MOSFET. The die structure of claim 9, wherein each light-emitting diode element is independently connected to the source driver circuit through a first connection circuit, and a first connection circuit and a ground terminal are connected with a Electrostatic protection diode. The die structure of claim 9, wherein each light-emitting diode element is connected in parallel with an electrostatic protection diode. The die structure of claim 1, wherein the at least one light-emitting diode element is a plurality of different colors and is grouped to form a plurality of pixels arranged in a matrix, and the number of the at least one MOSFET is The number of the plurality of light emitting diode elements is the same as that of the plurality of pixels, and the plurality of light emitting diode elements of the same pixel are connected to the MOSFET corresponding to the pixel. The die structure of claim 12, wherein an electrostatic protection diode is connected between the gate and the source of each of the MOSFETs. The die structure of claim 12, wherein each of the gates is connected to the main control circuit through a second connection circuit, and an electrostatic protection device is connected between the second connection circuit and a ground terminal polar body.

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