CN115666158A

CN115666158A - Display module and display device

Info

Publication number: CN115666158A
Application number: CN202211300653.2A
Authority: CN
Inventors: 王奉献; 汤强; 毕先磊
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2023-01-31
Also published as: CN110600522A

Abstract

The invention discloses a display module and a display device. Wherein the display module assembly includes: the flexible display panel comprises a non-bending area, a bending area and a binding area which are sequentially connected, and after the flexible display panel is reversely folded, the binding area is positioned on the back of the non-bending area; one end of the chip on film is connected with the binding area of the flexible display panel; the integrated circuit is fixed on one surface of the chip on film, which faces to the non-bending area; the printed circuit board is connected with the other end of the chip on film and is provided with a slot for accommodating the integrated circuit, and the depth of the slot is greater than the thickness of the integrated circuit. The display module and the display device can avoid bulge at the joint of the chip on film and the integrated circuit, reduce the thickness of the display module and the display device and are more beneficial to the realization of an ultrathin display device.

Description

Display module and display device

Technical Field

The present invention relates to the field of display technologies, and in particular, to a display module and a display device.

Background

With the development of Organic Light-Emitting Diode (OLED) display technology and the pursuit of new designs by consumers, OLED product morphology is gradually changing from rigid to flexible. Currently, flexible OLED display modules are widely used in various electronic products as display components of electronic devices, and the design of narrow bezel and ultra-thin Module (MDL) is more and more favored by terminal manufacturers and consumers. The narrow frame scheme is realized mainly by Chip On Flex (COF for short) and Pad Bending (Pad bonding) technologies.

The inventor of the present invention finds that no matter which scheme is adopted to realize the narrow frame, after the reverse-folded display Panel (Panel) is attached, an integrated circuit (IC for short) protrudes, that is, a bulge is formed at a connection position of the chip on film and the integrated circuit, which may increase the thickness of the whole MDL, and meanwhile, when the chip on film is reversely folded, a certain risk of fracture may be caused by the bulge.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a display module and a display device, which can avoid forming a bump at a connection between a flip chip film and an integrated circuit, reduce the thickness of the display module and the display device, reduce a fracture risk caused by the bump when the flip chip film is folded back, and are more beneficial to the realization of an ultra-thin display device.

In view of the above, a first aspect of the embodiments of the present invention provides a display module, including:

the flexible display panel comprises a non-bending area, a bending area and a binding area which are sequentially connected, and after the flexible display panel is folded reversely, the binding area is positioned on the back of the non-bending area;

one end of the chip on film is connected with the binding region of the flexible display panel;

the integrated circuit is fixed on one surface of the chip on film, which faces to the non-bending area;

the printed circuit board is connected with the other end of the chip on film, arranged between the non-bending area and the chip on film and provided with a slot for accommodating the integrated circuit, the projection of the slot in the non-bending area is positioned inside the projection of the chip on film in the non-bending area, and the depth of the slot is greater than the thickness of the integrated circuit.

Optionally, the thickness of the printed circuit board is 0.25mm-0.7mm.

Optionally, the slot is a slot penetrating through the printed circuit board.

Optionally, the method further includes:

a first base film disposed on a back surface of the non-bending region;

a second base film disposed in the bonding region; and (c) a second step of,

and the shock insulator is arranged between the first base film and the second base film.

Optionally, the distance from the top end of the integrated circuit far away from the chip on film to the top end of the printed circuit board far away from the chip on film has a gap, and the distance from the top end of the integrated circuit far away from the chip on film to one side of the first bottom film close to the chip on film has a gap.

Optionally, the spacer has a side close to the bending region and a side far away from the bending region, and a gap is formed between the side far away from the bending region and the side of the printed circuit board close to the bending region.

Optionally, the chip on film is arranged in parallel with the non-bending region.

Optionally, the thickness of the bonding layer is 0.035mm-0.3mm.

Optionally, the method further includes:

and the micro coating layer is arranged on the outer side of the bending area and comprises MCL glue.

A second aspect of an embodiment of the present invention provides a display device, including the display module described in any one of the above embodiments.

As can be seen from the above, according to the display module and the display device provided by the present invention, the groove is designed on the printed circuit board, and the integrated circuit is fixed in the area where the groove depth is greater than the thickness of the grooved integrated circuit through the flip chip, so that the groove can completely accommodate the integrated circuit without forming the bulge, which can reduce the thickness of the display module, facilitate the realization of the design of the ultra-thin display device, and simultaneously reduce the risk of fracture caused by the bulge when the flip chip is folded backwards. Because the depth of the slot is greater than the thickness of the integrated circuit, the integrated circuit is suspended and fixed in the slot, so that the heat dissipation capability of the chip on film and the integrated circuit can be greatly improved, the heat dissipation requirement of the chip on film and the integrated circuit can be met without additionally arranging a heat dissipation adhesive layer (IC Tape), the thickness of the display module is further reduced, and the realization of the ultrathin display device is facilitated.

Drawings

FIG. 1 is a side view of a conventional display module structure;

fig. 2 is a top view of a display module according to an embodiment of the invention;

fig. 3 is a side view of a display module structure according to an embodiment of the invention;

fig. 4 is a schematic structural diagram of a flexible display panel according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a slotted structure of a printed circuit board according to an embodiment of the present invention;

fig. 6 is a schematic structural view of a dual-layer printed wiring board according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments and the accompanying drawings.

It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are used for distinguishing two entities with the same name but different names or different parameters, and it should be noted that "first" and "second" are merely for convenience of description and should not be construed as limitations of the embodiments of the present invention, and they are not described in any more detail in the following embodiments.

In the prior art, an integrated Circuit 94 (IC) is fixed between a Flexible Printed Circuit (FPC) 93 and a display Panel 91 (Panel) through a Chip On Film (COF) 95 (COF), a connection between the integrated Circuit 94 (IC) and the Chip On Film (COF) 95 is subjected to a bump design, as shown in fig. 1, a side view of the existing display module structure is shown, and meanwhile, a SCF layer 92 (Super Clean Foam) needs to be attached to the back of both the rigid display Panel and the Flexible display Panel to achieve buffering, light shielding and heat dissipation effects on the display Panel, wherein the SCF layer 92 includes an EMBO layer 921, a Foam layer 922, and a Cu & Graphite layer, which are sequentially disposed. The inventor of the present invention analyzes the structure of the existing display module, and finds that: the thickness of the conventional flexible circuit board of the display device is about 0.13mm, the thickness of the integrated circuit IC is larger than that of the conventional flexible circuit board, and the integrated circuit IC needs to be fixed against the SCF layer, so that the bulge design cannot be avoided, and the avoiding space of the whole display device can be increased by the design, which is not beneficial to realizing the ultra-thin design of the display device.

Therefore, the inventors of the present invention considered to avoid the protrusion of the integrated circuit 94 (IC) by properly arranging the mounting positions of the chip on film 95 (COF), the integrated circuit 94 (IC), and the flexible circuit board 93.

In view of the above, a first aspect of the embodiments of the present invention provides a display module, as shown in fig. 2, which is a top view of a structure of the display module according to the embodiments of the present invention, as shown in fig. 3, which is a side view of the structure of the display module according to the embodiments of the present invention, the display module includes: flexible display panel 1, chip on film 2, integrated circuit 3 and printed circuit board 4.

Referring to fig. 4, which is a schematic structural diagram of the flexible display panel 1 according to an embodiment of the present invention, the flexible display panel 1 includes a non-bending region 11, a bending region 12, and a binding region 13 that are sequentially connected, after the flexible display panel 1 is folded back, the binding region 13 is located on the back side of the non-bending region 11 and is parallel to the non-bending region 11, the front side of the flexible display panel 1 is a display surface, and the non-bending region 11 includes an effective display region 14.

One end of the chip on film 2 is bound and connected with the binding region 13 of the flexible display panel 1, and specifically, one surface of the chip on film 2 facing the non-bending region 11 of the flexible display panel 1 is connected with the display surface of the binding region 13.

The integrated circuit 3 is fixed on the surface of the chip on film 2 facing the non-bending region 11, so that the integrated circuit 3 is fixed between the non-bending region 11 and the chip on film 2.

The printed circuit board 4 is connected to the other end of the chip on film 2, as shown in fig. 5, a schematic view of a slot structure of the printed circuit board 4 is shown, a slot 41 for accommodating the integrated circuit 3 is formed in the printed circuit board 4, and the depth of the slot 41 is greater than the thickness of the integrated circuit 3, so that the integrated circuit 3 is not bulged due to too high height when being fixed. Optionally, the printed circuit board 4 is fixed on a surface of the flip-chip film 2 facing the non-bending region 11, so that the printed circuit board 4 is also fixed between the non-bending region 11 and the flip-chip film 2, thereby reducing the thickness of the display module.

According to the display module provided by the embodiment of the invention, the groove design is carried out on the printed circuit board 4, and the integrated circuit 3 is fixed in the area with the groove depth larger than the thickness of the integrated circuit 3 of the groove 41 through the chip on film 2, so that the groove 41 can completely contain the integrated circuit 3 without forming bulge, the thickness of the display module can be reduced, the realization of the design of an ultrathin display device is facilitated, and meanwhile, the fracture risk caused by bulge when the chip on film 2 is folded reversely can be reduced. In order to improve the heat dissipation capability of the chip on film 2 and the integrated circuit 3, as shown in fig. 1, a heat dissipation adhesive layer 96 (IC Tape) with a conventional thickness of 0.05mm needs to be additionally disposed on the outer side of the chip on film 95 (COF). In this embodiment, since the depth of the slot 41 is greater than the thickness of the integrated circuit 3, the integrated circuit 3 is suspended and fixed in the slot 41, and the heat exchange between the integrated circuit 3 and the air is increased, which can greatly improve the heat dissipation capability of the chip on film 2 and the integrated circuit 3, and the heat dissipation requirement of the chip on film 2 and the integrated circuit 3 can be satisfied without additionally arranging a heat dissipation adhesive layer (IC Tape), so as to further reduce the thickness of the display module, and facilitate the realization of the ultra-thin display device.

In some alternative embodiments, the Printed Circuit board 4 in the display module is a rib-Flex Printed Circuit (RFPC) board, and the area where the slot 41 is located, i.e. the Bonding area, is configured as a Rigid Printed Circuit board, and the device area is still configured as a flexible Printed Circuit board. Rigidity printed wiring board is higher than the roughness of flexible printed wiring board and components and parts department does not need the reinforcement, and this makes its attached effect when attached with flexible display panel 1 better, and rigidity printed wiring board also has fine guard action to flexible display panel 1 simultaneously, consequently designs into the rigidity with the regional design of binding of printed wiring board 4 and has better technological effect, and the device district of printed wiring board 4 still is set to the normal realization that the flexible printed wiring board then can guarantee current function.

Optionally, the printed circuit board 4 may be one of a double-layer printed circuit board, a three-layer printed circuit board, a four-layer printed circuit board, a five-layer printed circuit board, a six-layer printed circuit board, a seven-layer printed circuit board, an eight-layer printed circuit board, and the like, and the thickness of the printed circuit board is 0.25mm to 0.7mm. Wherein, the common double-layer printed circuit board is selected conventionally, and the thickness of the double-layer printed circuit board is about 0.25mm. The selection of the double-layer printed circuit board can ensure that the integrated circuit 3 is not bulged when being fixed in the slot 41 on one hand, and the circuit laying requirement required by the display device is also met on the other hand.

The structure of the region where the groove of the printed wiring board 4 is located includes: a substrate layer; a copper layer attached to the surface of the base material layer; the adhesive layer is attached to the surface of the copper layer and comprises a prepreg; and the protective film is attached to the surface of the adhesive layer.

As shown in fig. 6, which is a schematic structural diagram of a dual-layer printed circuit board, taking the dual-layer printed circuit board as an example, the structure of the region where the slot 41 is located in this embodiment includes a substrate layer, two copper layers, two glue layers, and two protective films:

the substrate layer 401 may be made of a polyimide polymer film. Two

copper layers

4021 and 4022 are attached to both surfaces of the base material layer 401. The two

glue layers

4031 and 4032 are respectively attached to the two surfaces, far away from the substrate layer 401, of the two

copper layers

4021 and 4022, and the two

glue layers

4031 and 4032 are made of FPC (flexible printed circuit) hardened glue. During lamination, epoxy resin (AD glue) of the prepregs melts, flows and solidifies to bond all layers of circuits together to form a reliable insulating layer, and the cured PrePreg hardens. Two

protective films

4041, 4042 are respectively attached to the surfaces of the two

glue layers

4031, 4032 facing away from the substrate layer 401 to protect the internal structure of the double-layer printed wiring board.

Optionally, the flip chip 2 and the non-bending region 11 are arranged in parallel, and the extending direction of the surface of the flip chip 2 is flat without bulge, so that the situation that the thickness of the whole display module is increased due to the space occupied by the bulge can be avoided, and the risk of breaking the flip chip 2 when the flexible display panel 1 is folded back can be reduced.

Optionally, the slot 41 may be a slot penetrating through the printed circuit board 4, so that the process difficulty of slotting the printed circuit board 4 can be reduced, and a little more space is reserved for the suspended installation of the integrated circuit 3, thereby ensuring the heat dissipation effect.

In the existing design shown in fig. 1, a layer of SCF (Super Clean Foam) layer 92 heat dissipation material needs to be attached to the back of the flexible display Panel, the SCF layer can implement buffering and light-shielding functions, and most importantly, can implement heat dissipation of the display module, and at the same time, the FPC of the flexible circuit board and the flexible display Panel are fixed after being folded back, and the conventional thickness of the SCF layer is 0.2mm.

In this embodiment, since the suspension design of the integrated circuit 3 can already meet the heat dissipation requirement, it is not necessary to provide an SCF layer, but only to provide the adhesive layer 5 between the printed circuit board 4 and the flexible display panel 1, and connect the printed circuit board 4 and the flexible display panel 1 through the adhesive layer 5. Namely, the display device according to the embodiment of the present invention includes: a flexible display panel 1; one end of the flexible display panel is connected with the binding region 13 of the flexible display panel 1 in a binding manner; the integrated circuit 3 is fixed on one surface of the chip on film 2 facing the non-bending area 11 and is positioned in the slot 41 of the printed circuit board 4; the printed circuit board 4 connected with the other end of the flip chip 2 and the bonding layer 5 arranged between the printed circuit board 4 and the flexible display panel 1 are not required to be additionally provided with the SCF layer and the heat dissipation glue layer 96 to increase the heat dissipation of the whole display module, so that the structure of the display module is simplified, the bulge phenomenon cannot occur in the structure, the thickness of the display module is reduced, and the fracture risk caused by the bulge when the flip chip 2 is folded reversely is reduced; meanwhile, the attachment of the SCF layer and the IC Tape layer is reduced, the process flow is simplified, and the damage of static electricity to the display panel during the operation of personnel can be greatly reduced; in addition, the structure also saves the SCF membrane material and can reduce the cost of raw materials.

In the above embodiment, the adhesive layer 5 may be one of epoxy glue (AD glue), conductive glue and mesh glue (EMBO glue), and the thickness thereof may be 0.035mm to 0.3mm. The attachment OF the SCF layer is reduced during the manufacturing, the process flow OF the display module manufacturing is simplified, the damage OF static electricity to the flexible display panel 1 during the attachment operation OF personnel is reduced, the SCF film Material is saved, and the raw Material cost (Bill OF Material, BOM) can be reduced to a greater extent; the bonding layer 5 can be directly manufactured on the printed circuit board 4, the thickness of the bonding layer 5 can be properly adjusted according to the viscosity requirement of the printed circuit board 4, and the conventionally selected AD adhesive can be 0.05mm.

Optionally, as shown in fig. 3, the display module further includes: a first base film 61 disposed on the back of the non-bending region 11; a second carrier film 62 disposed at the bonding area 13; and a spacer 7 disposed between the first base film 61 and the second base film 62. Wherein, at first attach the basement membrane at the back of flexible display panel 1 during the preparation, get rid of the basement membrane at the back of bending zone 12 and form first basement membrane 61 and second basement membrane 62, buckle flexible display panel 1 again for bending takes place for bending in bending zone 1 of flexible display panel 1, makes the back of non-bending zone 11 of buckling to the district 13 of binding of flexible display panel 1, and the printed wiring board 4 of being connected with binding zone 13 like this can be located the back of flexible display panel 1. The spacer 7 is used for supporting the non-bending region 11 of the flexible display panel 1 and preventing the bending region 12 from being broken.

Optionally, the display module further includes a micro-coating layer 8 disposed outside the bending region 12, wherein the micro-coating layer 8 may be MCL glue for protecting the bending region 12 of the flexible display panel 1.

A second aspect of an embodiment of the present invention provides a display device, including the display module according to any one of the above embodiments. Optionally, the display device may further include a touch panel disposed on the display module.

In this embodiment, the display device is a flexible display device.

In this embodiment, the display device includes a narrow-bezel display device or a frameless display device.

In this embodiment, the display device may be applied to any product or component having a display function, such as a mobile phone, a display, a tablet computer, a television, a notebook computer, a digital photo frame, and a navigator.

As shown in fig. 1, in the structure of the conventional display module, the thickness of the conventional flexible printed circuit FPC is about 0.13mm, the thickness of the integrated circuit IC is generally greater than that of the flexible printed circuit FPC, because one end of the integrated circuit IC is required to be supported on the SCF layer, and the thickness of the integrated circuit IC is greater than that of the flexible printed circuit FPC, the connection between the chip on film COF and the integrated circuit IC is subject to swelling; meanwhile, in order to improve heat dissipation, it is necessary to attach a layer of SCF heat dissipation material between the display panel and the flexible circuit board FPC, whereas the conventional SCF layer has a thickness of 0.2mm. In addition, a layer of IC Tape is required to be added outside the COF to further increase the heat dissipation of the IC, the thickness of the conventional IC Tape is about 0.05mm, in this case, the sum of the thicknesses of the SCF layer, the flexible printed circuit FPC, and the IC Tape is about 0.38mm, and the total thickness is higher than 0.38mm due to the bulge at the IC of the IC.

In the display module and the display device of the embodiment of the invention, the structure of the groove design on the printed circuit board 4 is adopted, the thickness of the conventionally selected double-layer printed circuit board is generally 0.25mm, the thickness of the conventionally selected adhesive layer 5 for replacing the SCF layer is 0.05mm, the total thickness is only 0.3mm, and no bulge occurs, which is far less than the thickness of the existing display module, thereby being more beneficial to the realization of an ultrathin display device; meanwhile, the attachment of the SCF layer and the IC Tape layer is reduced, the process flow is simplified, and the damage of static electricity to the display panel during the operation of personnel can be greatly reduced; in addition, the structure also saves the SCF membrane material and can reduce the cost of raw materials.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, equivalents, improvements, and the like that may be made without departing from the spirit or scope of the present invention are intended to be included within the scope of the present invention.

Claims

1. A display module, comprising:

2. The display module of claim 1, wherein the printed circuit board has a thickness of 0.25mm to 0.7mm.

3. The display module of claim 1, wherein the slot is a slot through the printed wiring board.

4. The display module according to claim 1, further comprising:

a first base film disposed on a back surface of the non-bending region;

a second base film disposed in the bonding region; and the number of the first and second groups,

5. The display module of claim 4, wherein the top of the IC away from the COF has a gap from the top of the PCB away from the COF, and the top of the IC away from the COF has a gap from the side of the first film close to the COF.

6. The display module according to claim 4, wherein the spacer has a side close to the bending region and a side far from the bending region, and the side far from the bending region has a gap from the side of the printed circuit board close to the bending region.

7. The display module of claim 1, wherein the flip-chip film is disposed parallel to the non-bending region.

8. The display module of claim 1, wherein the bonding layer has a thickness of 0.035mm to 0.3mm.

9. The display module according to claim 1, further comprising:

10. A display device comprising a display module according to any one of claims 1 to 9.