Double-chip silicon-based OLED display module and display device

Abstract

The utility model discloses a double-chip silicon-based OLED display module and a display device, and belongs to the OLED technical field, the display module comprises a substrate, a display driving chip and a pixel driving chip, the substrate is provided with a redistribution layer and a plurality of substrate bonding pads, the display driving chip and the pixel driving chip are respectively electrically connected with the substrate bonding pads, and the display driving chip and the pixel driving chip are electrically connected with the substrate bonding pads. The redistribution layer is connected with the corresponding substrate bonding pad so that the display driving chip and the pixel driving chip are electrically conducted; the display device comprises the display module. The pixel driving chip and the display driving chip are integrated on the common substrate with the wiring connection scheme, so that the area of the pixel driving chip can be reduced, and the cost of the display module and the display device is further reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of OLED, and particularly relates to a dual-chip silicon-based OLED display module and a display device. Background Art

[0002] Silicon-based OLED has become the best choice for VR / AR display terminals due to its advantages such as high brightness, high resolution, and high picture quality. Apple Vision Pro uses a 1.42-inch silicon-based OLED display screen as its display screen selection scheme. The traditional silicon-based OLED micro-display screen adopts a single-chip scheme in which a display driver integrated circuit (DDIC) and a pixel driver integrated circuit (BPIC) are integrated together. With the improvement of screen resolution and the requirement of high-immersion VR products for increasing the display screen size. On the one hand, for the display driver integrated circuit, high data processing capabilities require it to be designed and taped out using a process node below 40nm. On the other hand, with the improvement of screen resolution, the requirements for the taped-out process node of the pixel driver integrated circuit do not increase accordingly. Generally, a 90nm process can meet the requirements. If the single-chip driving scheme is continued to be used, the pixel driver integrated circuit and the display driver integrated circuit will need to be taped out using the same process node such as 40nm, which greatly increases the cost of the pixel driver integrated circuit. The dual-chip scheme of separately designing and taping out the display driver integrated circuit and the pixel driver integrated circuit is considered to be one of the effective solutions for silicon-based OLED to reduce costs.

[0003] Currently, the dual-chip scheme adopted needs to package the display driver integrated circuit 3 and the pixel driver integrated circuit 1 together using a Flip-chip (flip chip) packaging scheme, as Figure 1 shown. When designing the pixel driver integrated circuit 1, it is necessary to increase the area of the pixel driver integrated circuit 1 to form a packaging area for the display driver integrated circuit 3 in the non-light-emitting area. In addition, heat is generated when the display driver integrated circuit 3 works. Since silicon has a good thermal conductivity coefficient, the heat will be transferred to the light-emitting element 2. For OLED materials, too high a temperature may cause irreversible effects on the OLED materials, resulting in a reduction in the lifespan of the OLED device. The current solution is to keep a certain distance between the display driver integrated circuit 3 and the light-emitting element 2, which also increases the area requirement for the pixel driver integrated circuit 1. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a dual-chip silicon-based OLED display module and a display device, which can reduce the area of the pixel driver integrated circuit, and thus can reduce the costs of the display module and the display device.

[0005] To solve the above technical problems, the technical solution of the utility model is:

[0006] A dual-chip silicon-based OLED display module includes a substrate, a display driving chip, and a pixel driving chip. A redistribution layer and a plurality of substrate pads are provided on the substrate. The display driving chip and the pixel driving chip are respectively electrically connected to the substrate pads, and the redistribution layer is connected to the corresponding substrate pads to electrically conduct the display driving chip and the pixel driving chip.

[0007] Further, the display driving chip and the pixel driving chip are spaced apart.

[0008] Further, the substrate is any one of a silicon wafer, a glass plate, a printed circuit board, and a flexible printed circuit board.

[0009] Further, when the substrate is a silicon wafer, the distance between the display driving chip and the pixel driving chip is greater than 1.8 mm.

[0010] Further, the pixel driving chip includes a light-emitting element and a glass cover plate disposed on the surface of the light-emitting element. The light-emitting element includes a first silicon wafer and a CMOS circuit, a pixel anode, an isolation layer, a light-emitting layer, and a packaging film sequentially disposed on the first silicon wafer.

[0011] Further, a plurality of through-silicon vias are provided on the first silicon wafer, and a plurality of first pads are provided on the back surface of the first silicon wafer and located on the periphery of the through-silicon vias. The CMOS circuit is connected to the first pads through connection lines disposed in the through-silicon vias, and first gold bumps are formed on the first pads.

[0012] Further, the display driving chip includes a second silicon wafer and a control circuit disposed on the second silicon wafer. The display driving chip is provided with a plurality of second pads electrically connected to the control circuit, and second gold bumps are formed on the second pads.

[0013] Further, the first gold bumps and the corresponding substrate pads and the second gold bumps and the corresponding substrate pads are bonded by metal eutectic bonding or anisotropic conductive adhesive bonding.

[0014] Further, a flexible printed circuit board is provided on one side edge of the substrate away from the pixel driving chip, and the flexible printed circuit board is connected to the substrate pads through anisotropic conductive adhesive.

[0015] A display device, characterized in that it includes the above display module.

[0016] After adopting the above technical solution, the beneficial effects of the present utility model are:

[0017] Since the dual-chip silicon-based OLED display module of the present utility model includes a substrate, a display driving chip, and a pixel driving chip, a redistribution layer and a plurality of substrate pads are provided on the substrate, the display driving chip and the pixel driving chip are electrically connected to the substrate pads respectively, and the redistribution layer connects the corresponding substrate pads to electrically conduct the display driving chip and the pixel driving chip. The pixel driving chip and the display driving chip are integrated on a common substrate with a wiring connection scheme, which can reduce the area of the pixel driving chip and further reduce the cost of the display module.

[0018] Since the display device of the present utility model includes the above-mentioned display module, the production cost can be reduced and the industrial profit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a dual-chip silicon-based OLED display module in the prior art;

[0020] Figure 2 is a schematic structural diagram of the dual-chip silicon-based OLED display module of the present application;

[0021] In the figure, 1 - pixel driving chip, 11 - light-emitting element, 12 - connecting wire, 13 - first gold bump, 14 - glass cover plate, 2 - display driving chip, 21 - second gold bump, 3 - flexible circuit board, 4 - substrate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present utility model will be further described below in conjunction with the drawings and embodiments. The preferred embodiments of the present utility model are shown in the drawings. The role of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but it should not be construed as a limitation on the protection scope of the present utility model.

[0023] Embodiment 1:

[0024] As Figure 2 shown, a dual-chip silicon-based OLED display module includes a substrate 4, a display driving chip 2 (DDIC), and a pixel driving chip 1 (BPIC). A redistribution layer (RDL) and a plurality of substrate pads (Bonding Pad) are provided on the substrate 4. The display driving chip 2 and the pixel driving chip 1 are electrically connected to the substrate pads on the substrate 4 respectively, and the redistribution layer connects the corresponding substrate pads to electrically conduct the display driving chip 2 and the pixel driving chip 1. The pixel driving chip 1 and the display driving chip 2 adopt the Chiplet packaging method and are integrated on a common substrate 4 with a wiring connection scheme, which can reduce the area of the pixel driving chip 1, further reduce the chip cost, and improve the yield.

[0025] Preferably, to reduce the thermal influence of the display driving chip 2 on the pixel driving chip 1 and avoid affecting its service life, the display driving chip 2 and the pixel driving chip 1 are arranged at intervals, and the specific dimensions can be set according to the material of the substrate 4.

[0026] Furthermore, the substrate 4 can be any one of a silicon wafer, a glass plate, a printed circuit board, and a flexible printed circuit board. When the substrate 4 is a silicon wafer, since the silicon wafer has good thermal conductivity, the distance between the display driving chip 2 and the pixel driving chip 1 needs to be set to be greater than 1.8 mm. When the substrate 4 is a substrate 4 with poor thermal conductivity such as a glass plate, a printed circuit board (PCB), or a flexible printed circuit board (FPC) as a substrate, the distance between the display driving chip 2 and the pixel driving chip 1 can be set to be smaller than that when using a silicon wafer as the substrate 4.

[0027] As Figure 2 shown, the pixel driving chip 1 specifically includes a light-emitting element 11 (Si-OLED) and a glass cover plate 14 arranged on the surface of the light-emitting element 11. The light-emitting element 11 includes a first silicon wafer and a CMOS circuit, a pixel anode, an isolation layer (PDL), a light-emitting layer, and a packaging film (TFE) sequentially arranged on the first silicon wafer.

[0028] Among them, the first silicon wafer is provided with a plurality of through-silicon vias (TSVs), and the back surface of the first silicon wafer is provided with a plurality of first pads respectively located on the periphery of the through-silicon vias. The CMOS circuit is connected to the first pads through connection lines 12 arranged in the through-silicon vias, and first gold bumps 13 are formed on the first pads.

[0029] The display driving chip 2 includes a second silicon wafer and a control circuit arranged on the second silicon wafer. The display driving chip 2 is provided with a plurality of second pads electrically connected to the control circuit, and second gold bumps 21 are formed on the second pads.

[0030] The first gold bumps 13 and the corresponding substrate pads, and the second gold bumps 21 and the corresponding substrate 4 pads are bonded by a metal eutectic bond, that is, soldering is used; alternatively, the first gold bumps 13 and the corresponding substrate pads, and the second gold bumps 21 and the corresponding substrate pads are bonded by an anisotropic conductive film (ACF). The conductive film conducts electricity unidirectionally (vertically conducts, horizontally does not conduct), and can realize the gluing and fixing between the display driving chip 2 and the pixel driving chip 1 and the substrate 4.

[0031] A flexible printed circuit board 3 is arranged on the edge of the side of the substrate 4 away from the pixel driving chip 1, and the flexible printed circuit board 3 is connected to the substrate pads through an anisotropic conductive film.

[0032] The steps of the manufacturing method of the dual-chip silicon-based OLED display module of the present application are as follows:

[0033] a) Fabricate a silicon-based CMOS circuit on a silicon wafer through a mature CMOS process. The CMOS circuit leads the connection line 12 to the back of the first silicon wafer through a through-silicon via (TSV).

[0034] b) Successively complete the manufacturing processes such as anode, isolation layer (PDL), OLED evaporation, thin film (TFE) encapsulation, and glass cover attachment on the silicon wafer on which the CMOS circuit has been completed.

[0035] c) Thinning the back of the silicon wafer by chemical mechanical polishing (CMP) process until the designed through-silicon via is exposed, and set the first pad at the through-silicon via opening. Generally, it needs to be thinned to about 200μm.

[0036] d) Use electroplating process to fabricate gold bumps on the first pad. The height of the gold bumps is generally 12 - 15μm.

[0037] e) Use a cutting device to cut the structure formed by the silicon wafer and the glass cover into small pieces to form a small pixel driving chip 1 (BPIC).

[0038] f) Design and fabricate a display driving chip 2 (DDIC) through a process node below 40nm, and fabricate a control circuit on the second silicon wafer.

[0039] g) The display driving chip 2 grows gold bumps on the second pad by Bump manufacturing process, thins and cuts into small chips.

[0040] h) Fabricate a substrate 4 with a wiring connection scheme using any one of silicon wafer, glass, PCB, and FPC materials, and complete the fabrication of the ultra-fine redistribution layer (RDL) and the substrate pad on the substrate 4.

[0041] i) Adopt a flip-chip packaging scheme to bond the display driving chip 2 and the pixel driving chip 1 on the substrate 4 through metal eutectic bonding or anisotropic conductive film (ACF) bonding to achieve electrical conduction between chips.

[0042] j) Complete the processes such as conductive film bonding of the subsequent module flexible printed circuit board 3 (FPC).

[0043] Example Two:

[0044] A display device includes the display module described in Example One, which can reduce production costs and increase industrial profits.

[0045] The dual-chip silicon-based OLED display module and display device of the present utility model achieve electrical conduction between the display driving chip and the pixel driving chip through the redistribution layer and substrate pads on the substrate. The pixel driving chip and the display driving chip are integrated on a common substrate with a wiring connection scheme, which can reduce the area of the pixel driving chip, thereby further reducing the cost of the display module and the display device.

[0046] In the description of this specification, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features.

[0047] In the description of this specification, unless otherwise clearly defined, words such as "set", "installed", and "connected" should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0048] Although the specific implementation manners of the present utility model have been described above, those skilled in the art should understand that the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. These are only examples for illustration, and the protection scope of the present utility model is defined by the claims. Without departing from the principles and essence of the present utility model and without any creative work, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present utility model.

Claims

1. A dual-chip silicon-based OLED display module, characterized in that It includes a substrate, a display driver chip, and a pixel driver chip. A redistribution layer and a plurality of substrate pads are provided on the substrate. The display driver chip and the pixel driver chip are electrically connected to the substrate pads respectively, and the redistribution layer is connected to the corresponding substrate pads to electrically conduct the display driver chip and the pixel driver chip.

2. The dual-chip silicon-based OLED display module according to claim 1, characterized in that, The display driver chip and the pixel driver chip are arranged at intervals.

3. The dual-chip silicon-based OLED display module according to claim 2, wherein The substrate is any one of a silicon wafer, a glass plate, a printed circuit board, and a flexible printed circuit board.

4. The dual-chip silicon-based OLED display module according to claim 3, wherein, When the substrate is a silicon wafer, the distance between the display driver chip and the pixel driver chip is greater than 1.8 mm.

5. The dual-chip silicon-based OLED display module according to claim 1, wherein, The pixel driver chip includes a light-emitting element and a glass cover plate arranged on the surface of the light-emitting element. The light-emitting element includes a first silicon wafer and a CMOS circuit, a pixel anode, an isolation layer, a light-emitting layer, and a packaging film sequentially arranged on the first silicon wafer.

6. The dual-chip silicon-based OLED display module according to claim 5, wherein The first silicon wafer is provided with a plurality of through-silicon vias. A plurality of first pads are arranged on the back surface of the first silicon wafer and are respectively located on the periphery of the through-silicon vias. The CMOS circuit is connected to the first pads through connection lines arranged in the through-silicon vias, and first gold bumps are formed on the first pads.

7. The dual-chip silicon-based OLED display module according to claim 6, wherein, The display driver chip includes a second silicon wafer and a control circuit arranged on the second silicon wafer. The display driver chip is provided with a plurality of second pads electrically connected to the control circuit, and second gold bumps are formed on the second pads.

8. The dual-chip silicon-based OLED display module according to claim 7, wherein The first gold bumps and the corresponding substrate pads, and the second gold bumps and the corresponding substrate pads are bonded by metal eutectic bonding or anisotropic conductive adhesive bonding.

9. The dual-chip silicon-based OLED display module according to any one of claims 1 to 8, characterized in that, A flexible printed circuit board is arranged on one side edge of the substrate away from the pixel driver chip, and the flexible printed circuit board is connected to the substrate pads through anisotropic conductive adhesive.

10. A display device, characterized in that, It includes a display module according to any one of claims 1 to 9.

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