阅读说明：本技术 显示装置及其制造方法 (Display device and method for manufacturing the same ) 是由 阮丞禾 曾建洲 侯智元 于 2021-08-20 设计创作，主要内容包括：一种显示装置,包括软性基底、接合垫、发光二极管、封装胶以及支撑结构。接合垫以及发光二极管位于软性基底上。封装胶包覆发光二极管。支撑结构横向地位于发光二极管与接合垫之间。支撑结构具有斜面,且支撑结构靠近发光二极管的厚度大于支撑结构靠近接合垫的厚度。(A display device comprises a flexible substrate, a bonding pad, a light emitting diode, packaging glue and a supporting structure. The bonding pad and the light emitting diode are positioned on the flexible substrate. The packaging adhesive covers the light emitting diode. The support structure is laterally located between the light emitting diode and the bonding pad. The support structure is provided with an inclined surface, and the thickness of the support structure close to the light-emitting diode is larger than that of the support structure close to the bonding pad.)

1. A display device, comprising:

a flexible substrate;

a bonding pad on the flexible substrate;

a light emitting diode on the flexible substrate;

a packaging adhesive for coating the light emitting diode; and

and a support structure transversely located between the light emitting diode and the bonding pad, wherein the support structure has an inclined surface, and the thickness of the support structure close to the light emitting diode is greater than that of the support structure close to the bonding pad.

2. The display device of claim 1, wherein the support structure is located between the bonding pad and the light emitting diode in a first direction, and a width of the support structure in the first direction is greater than a maximum thickness of the support structure.

3. The display device of claim 1, further comprising:

and the retaining wall surrounds the packaging adhesive, and is positioned between the supporting structure and the packaging adhesive.

4. The display apparatus as claimed in claim 3, wherein the retaining wall is integrally formed with the support structure.

5. The display apparatus as claimed in claim 3, wherein the dam is formed separately from the supporting structure, and the dam is in direct contact with the supporting structure.

6. The display device according to claim 3, wherein an angle between the inclined surface of the supporting structure and a bottom surface of the supporting structure is greater than 0 degree to less than or equal to 30 degrees.

7. The display device according to claim 3, wherein the thickness of the dam is approximately equal to the maximum thickness of the support structure, and the thickness of the dam is greater than the thickness of the encapsulant.

8. A method of manufacturing a display device, comprising:

providing a pixel circuit on a rigid carrier, the pixel circuit comprising:

a flexible substrate;

a bonding pad on the flexible substrate; and

a light emitting diode on the flexible substrate;

forming a packaging adhesive material on the pixel circuit to coat the light emitting diode;

curing the packaging adhesive material to form a packaging adhesive;

forming a support structure material over the pixel circuit, wherein the support structure material is laterally between the light emitting diode and the bonding pad;

curing the support structure material to form a support structure, wherein the support structure has an inclined surface, and the thickness of the support structure near the light emitting diode is greater than the thickness of the support structure near the bonding pad;

providing a protective layer on the inclined plane of the supporting structure and the packaging adhesive;

removing the hard carrier plate; and

the pixel circuit is attached to a soft carrier.

9. The method for manufacturing a display device according to claim 8, wherein the adhesive property of the supporting structure material is greater than the adhesive property of the encapsulating material.

10. The method of manufacturing a display device according to claim 8, further comprising:

the protective layer is removed.

11. The method of manufacturing a display device according to claim 8, further comprising:

forming a retaining wall on the pixel circuit; and

and forming the packaging adhesive material in the region surrounded by the retaining wall.

12. The method of claim 8, wherein the step of forming the support structure material over the pixel circuit comprises a doctor blade process.

Technical Field

The present invention relates to a display device, and more particularly, to a display device including a light emitting diode and a method of manufacturing the same.

Background

The light emitting diode is an electroluminescent semiconductor element and has the advantages of high efficiency, long service life, difficult damage, high reaction speed, high reliability and the like. With the investment of a great deal of time and money, the size of the light emitting diode is reduced year by year. In order to protect these tiny leds, the leds are usually encapsulated with an encapsulant by using an encapsulation technique. The encapsulating material of the light emitting diode includes, for example, a silicone gel. Generally, the encapsulant should have a sufficient thickness to ensure that the encapsulant completely encapsulates the led.

Disclosure of Invention

The invention provides a display device, which can improve the problem of bubbles in the display device.

The invention provides a method for manufacturing a display device, which can solve the problem of bubbles in the display device.

At least one embodiment of the present invention provides a display device. The display device comprises a flexible substrate, a bonding pad, a light emitting diode, packaging glue and a supporting structure. The bonding pad and the light emitting diode are positioned on the flexible substrate. The packaging adhesive covers the light emitting diode. The support structure is laterally located between the light emitting diode and the bonding pad. The support structure is provided with an inclined surface, and the thickness of the support structure close to the light-emitting diode is larger than that of the support structure close to the bonding pad.

At least one embodiment of the present invention provides a method of manufacturing a display device, including: providing a pixel circuit on the hard carrier plate, wherein the pixel circuit comprises a flexible substrate, and a bonding pad and a light-emitting diode which are positioned on the flexible substrate; forming an encapsulation adhesive material on the pixel circuit to coat the light emitting diode; curing the packaging adhesive material to form packaging adhesive; forming a support structure material over the pixel circuit, wherein the support structure material is laterally between the light emitting diode and the bonding pad; curing the support structure material to form a support structure, wherein the support structure has a slope and the thickness of the support structure near the light emitting diode is greater than the thickness of the support structure near the bonding pad; providing a protective layer on the inclined plane of the supporting structure and the packaging adhesive; removing the hard carrier plate; and attaching the pixel circuit to the soft carrier plate.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

Fig. 1A to 1L are schematic cross-sectional views illustrating a method for manufacturing a display device according to an embodiment of the invention.

Fig. 2 is a schematic top view of a display device according to an embodiment of the invention.

Fig. 3 is a schematic cross-sectional view of a display device according to an embodiment of the invention.

Fig. 4 is a schematic top view of a display device according to an embodiment of the invention.

Wherein, the reference numbers:

1. 2 display device

10 pixel circuit

100 flexible substrate

110 first insulating layer

120: signal line

122 routing

124 electrode

126 switching electrode

130 second insulating layer

140 third insulating layer

150 bonding pad

160 connecting structure

162 first layer

164 second layer

170 light emitting diode

210. 210a retaining wall

220 packaging adhesive material

220' packaging adhesive

230 support structure material

230', 230a support structure

232. 232', 232a inclined plane

234' bottom surface

A-A', B-B

D1 first direction

H1, H2, H3 thickness

HD height difference

LS laser

PF protective layer

RL1, RL2 rollers

SB1 hard carrier plate

SB2 Soft Carrier plate

TH1 first through hole

TH2 second through hole

TH3 third through hole

TH4 fourth through hole

TP scraper

W3 width

Angle of theta

Detailed Description

The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:

fig. 1A to 1L are schematic cross-sectional views illustrating a method for manufacturing a display device according to an embodiment of the invention. FIG. 2 is a schematic top view of a display device according to an embodiment of the invention, wherein FIG. 1L corresponds to the position of line A-A' in FIG. 2.

Referring to fig. 1A to fig. 1C, a pixel circuit 10 is provided on a rigid carrier SB1, the pixel circuit 10 includes a flexible substrate 100, and a bonding pad 150 and a light emitting diode 170 on the flexible substrate 100. In the present embodiment, the pixel circuit 10 further includes a first insulating layer 110, a signal line 120, a second insulating layer 130, and a third insulating layer 140.

Referring to fig. 1A, the flexible substrate 100 is formed on a rigid carrier SB 1. The rigid carrier SB1 includes, for example, a glass substrate, a sapphire substrate, a metal substrate, a wafer, a ceramic or other suitable substrate. Examples of the material of the flexible substrate 100 include Polyamide (PA), Polyimide (PI), polymethyl methacrylate (PMMA), Polyethylene naphthalate (PEN), Polyethylene terephthalate (PET), Fiberglass Reinforced Plastics (FRP), Polyetheretherketone (PEEK), epoxy resin, or other suitable materials, or a combination of at least two of the foregoing, but the embodiment is not limited thereto.

The first insulating layer 110 is formed on the flexible substrate 100. The material of the first insulating layer 110 includes an inorganic material (e.g., silicon oxide, silicon nitride, silicon oxynitride, other suitable materials, or stacked layers of at least two of the above materials), an organic material, or other suitable materials, or a combination thereof.

The signal line 120 is formed on the first insulating layer 110. The signal line 120 has a single-layer or multi-layer structure. In the present embodiment, the signal line 120 is a multi-layer structure and includes a trace 122, an electrode 124 and a via electrode 126, wherein the electrode 124 and the via electrode 126 are formed on the trace 122. In the embodiment, the second insulating layer 130 is formed on the trace 122 and has a first through hole TH1 and a second through hole TH2 overlapping the trace 122. The electrode 124 and the via electrode 126 are formed on the second insulating layer 130, and are connected to the trace 122 through the first through hole TH1 and the second through hole TH2, respectively.

The material of the second insulating layer 130 includes an inorganic material (e.g., silicon oxide, silicon nitride, silicon oxynitride, other suitable materials, or stacked layers of at least two of the above materials), an organic material, or other suitable materials, or a combination thereof.

The materials of the trace 122, the electrode 124, and the via electrode 126 include metals, nitrides of metal materials, oxides of metal materials, oxynitrides of metal materials, or other suitable conductive materials, or stacked layers of metal materials and other conductive materials.

In the present embodiment, the trace 122 includes a Fanout line (Fanout line), for example. In some embodiments, the structure of the signal line 120 is not limited to the structure of fig. 1A. For example, the traces 122 of the signal lines 120 may be discontinuous structures, and the discontinuous traces 122 are electrically connected to each other by other bridge structures (not shown). The trace 122 can cross other lines with different directions by the design of the bridge structure.

The third insulating layer 140 is formed on the signal line 120 and the second insulating layer 130, and has a third through hole TH3 and a fourth through hole TH4 respectively overlapping the electrode 124 and the via electrode 126. The material of the third insulating layer 140 includes an inorganic material (e.g., silicon oxide, silicon nitride, silicon oxynitride, other suitable materials, or stacked layers of at least two of the above materials), an organic material, or other suitable materials, or a combination thereof.

The bonding pad 150 is formed on the third insulating layer 140 and connected to the via electrode 126 through the fourth through hole TH 4. The material of the bonding pad 150 includes indium tin oxide, but the invention is not limited thereto. In some embodiments, the material of the bonding pad 150 includes a metal, a nitride of a metal material, an oxide of a metal material, an oxynitride of a metal material, or other suitable conductive material, or stacked layers of a metal material and other conductive materials.

Referring to fig. 1B, a connection structure 160 is selectively formed on the electrode 124. The connection structure 160 is a single-layer or multi-layer structure. In the present embodiment, the connection structure 160 is a multi-layer structure and includes at least a first layer 162 and a second layer 164. In some embodiments, the manner of forming the connection structure 160 includes Electroless Nickel Immersion Gold (ENIG), Electroless Nickel Immersion Gold (enipig), Electroless Nickel Immersion Gold (ENEPIG), or other suitable methods, but the invention is not limited thereto.

Referring to fig. 1C, the light emitting diode 170 is electrically connected to the electrode 124. In some embodiments, a low melting point metal (e.g., tin, indium, bismuth, mixed tin-bismuth metal, mixed tin-indium metal, mixed tin-copper metal, mixed tin-silver metal, mixed tin-antimony metal, mixed tin-zinc metal, mixed tin-silver-copper-bismuth metal, or a combination or stack of the foregoing) is formed on the light emitting diode 170 or on the connection structure 160. The light emitting diode 170 is eutectic-bonded to the connection structure 160 by heating the low melting point metal. The heating of the low melting point metal includes, for example, a hot pressing process, a laser process, or other suitable processes. In other embodiments, the led 170 is electrically connected to the electrode 124 through Anisotropic Conductive Film (ACF). In other words, the connection structure 160 may also be anisotropic conductive adhesive.

Fig. 1A to 1L and fig. 2 only show that the light emitting diode 170 is electrically connected to a bonding pad 150 through a signal line 120, but the invention is not limited thereto. Each of the light emitting diodes 170 includes two bonding pads, and the two bonding pads of each of the light emitting diodes 170 respectively correspond to a cathode and an anode of the light emitting diode 170. The cathode and the anode of the led 170 are electrically connected to different signal lines 120, respectively, and are electrically connected to different bonding pads 150 through different signal lines 120. In some embodiments, the light emitting diodes 170 are horizontal light emitting diodes or vertical light emitting diodes. In some embodiments, the bonding pads of the led 170 are located on a side of the led 170 opposite to the signal lines 120, and thus, the bonding pads are electrically connected to the corresponding signal lines 120 by forming other conductive structures on the led 170.

Referring to fig. 1D, a dam 210 is formed on the pixel circuit 10. In the present embodiment, the dam 210 is formed on the third insulating layer 140, and the dam 210 surrounds the plurality of light emitting diodes 170 (see fig. 2). The material of the retaining wall 210 includes, for example, an organic material (e.g., poly (methyl methacrylate)), a ceramic material, or other suitable materials. In some embodiments, a dam paste having a viscosity of 200000cps to 500000cps is formed on the pixel circuit 10, and then the dam paste is cured to obtain the dam 210. In the embodiment, the top surface of the retaining wall 210 is higher than the top surface of the light emitting diode 170, and the thickness H1 of the retaining wall 210 is, for example, 300 to 150 micrometers.

Referring to fig. 1E, an encapsulating material 220 is formed on the pixel circuit 10 to encapsulate the light emitting diode 170. In the present embodiment, the encapsulating material 220 is formed in the region surrounded by the retaining wall 210. The encapsulating material 220 comprises, for example, silica gel (Silicone), and the silica gel may comprise methyl and/or phenyl. In some embodiments, the viscosity of the encapsulant 220 is less than 10000cps, such as 5000cps to 10000cps, so that the encapsulant 220 can be easily filled into the small gap to prevent bubbles from occurring around the led 170.

Referring to fig. 1F, the encapsulant 220 is cured to form an encapsulant 220 ', wherein the encapsulant 220' encapsulates the light emitting diode 170. The refractive index of the encapsulant 220' is about 1.4 to 1.5. In some embodiments, the thickness H2 of the encapsulant 220' is 150 to 350 microns. In the embodiment, the retaining wall 210 surrounds the packaging adhesive 220 ', and the thickness H1 of the retaining wall 210 is greater than, equal to, or less than the thickness H2 of the packaging adhesive 220'. In the embodiment, the top surface of the retaining wall 210 is higher than the top surface of the package adhesive 220 ', and the top surface of the retaining wall 210 and the top surface of the package adhesive 220' have a height difference HD. In some embodiments, curing the encapsulating material 220 causes the solvent in the encapsulating material 220 to evaporate, so that the thickness of the encapsulating material 220' is slightly less than the thickness of the encapsulating material 220.

Referring to fig. 1G, a support structure material 230 is formed on the pixel circuit 10, wherein the support structure material 230 is laterally located between the light emitting diode 170 and the bonding pad 150. In some embodiments, the method of forming the support structure material 230 on the pixel circuit 10 includes a doctor blade molding method. The doctor blade forming method is, for example, to form the inclined surface 232 of the support structure material 230 by sliding the doctor blade TP over the support structure material 230. In some embodiments, the adhesive properties of the support structure material 230 are greater than the adhesive properties of the encapsulating adhesive material 220. Therefore, the support structure material 230 does not have difficulty forming the slope 232 because of too high fluidity. In some embodiments, the support structure material 230 has a viscosity greater than 300000cps, such as 300000cps to 500000 cps.

In some embodiments, the material of the support structure material 230 includes an organic material (e.g., poly (methyl methacrylate)), a ceramic material, or other suitable material. In some embodiments, the support structure material 230 comprises the same material as the retaining wall glue, for example.

Referring to fig. 1H, the support structure material 230 is cured to form a support structure 230 ', wherein the support structure 230 ' has a bevel 232 '. The retaining wall 210 is located between the supporting structure 230 'and the packaging adhesive 220'. In this embodiment, the retaining wall 210 is in direct contact with the supporting structure 230'. In the present embodiment, the retaining wall 210 and the supporting structure 230 'are formed separately, and an interface is formed between the retaining wall 210 and the supporting structure 230'.

In the present embodiment, by the inclined surface 232 ', the thickness of the supporting structure 230 ' near the led 170 is greater than the thickness of the supporting structure 230 ' near the bonding pad 150. In the present embodiment, the maximum thickness H3 of the support structure 230' is 150 to 350 microns. The thickness H1 of wall 210 is approximately equal to the maximum thickness H3 of support structure 230'. In this embodiment, the top surface of the retaining wall 210 is connected to the inclined surface 232 'of the supporting structure 230'.

In the present embodiment, the supporting structure 230 ' is located between the bonding pads 150 and the light emitting diodes 170 in the first direction D1, and the width W3 of the supporting structure 230 ' in the first direction D1 is greater than the maximum thickness H3 of the supporting structure 230 '. In the present embodiment, the width W3 of the support structure 230' is 1500 to 3000 microns. The width W3 of the support structure 230' is, for example, ten times or more the thickness H3.

In the present embodiment, an included angle θ between the inclined surface 232 'of the supporting structure 230' and the bottom surface 234 'of the supporting structure 230' is greater than 0 degree and less than or equal to 30 degrees, and the included angle θ is preferably greater than or equal to 5 degrees and less than or equal to 10 degrees.

In the present embodiment, the display device 1 includes a pixel circuit 10, an encapsulant 210, a dam 220 'and a support structure 230'.

Referring to fig. 1I, a protection layer PF is attached to the display device 1. In the present embodiment, a protection layer PF is provided on the inclined surface 232 ' of the support structure 230 ' and on the packaging adhesive 220 '. In the present embodiment, the protection layer PF covers the retaining wall 210, the packaging adhesive 220 ', the inclined surface 232 ' of the support structure 230 ', and the bonding pads 150. The protection layer PF is attached to the retaining wall 210, the molding compound 220 ', the inclined surface 232 ' of the support structure 230 ' and the bonding pads 150 by a roller RL1, for example.

The top surfaces of the retaining walls 210 are not flush with the top surface of the pixel circuit 10, and therefore, if the supporting structure 230' is not provided, a gap is easily formed between the protective layer PF and the pixel circuit 10 due to a step between the top surfaces of the retaining walls 210 and the top surface of the pixel circuit 10. In other words, in the present embodiment, the supporting structure 230' is disposed to prevent a gap from being formed between the protection layer PF and the pixel circuit 10.

The protective layer PF is, for example, an adhesive tape, and the material thereof includes Polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), Polycarbonate (PC), Cyclic Olefin Copolymer (COC), Cellulose Triacetate (TAC), Fiber-reinforced plastic (FRP), or other similar materials. The adhesive surface of the protective layer PF faces the display device 1.

Referring to fig. 1J, the rigid carrier SB1 is removed. In the present embodiment, the pixel circuits 10 are irradiated with the laser LS from the bottom surface of the hard carrier SB1, whereby the hard carrier SB1 is separated from the pixel circuits 10.

Referring to fig. 1K, a flexible carrier SB2 is attached to the display device 1. In the present embodiment, a flexible carrier SB2 is provided on the flexible substrate 100. In the present embodiment, the flexible carrier SB2 covers the bottom surface of the flexible substrate 100. The flexible carrier SB2 is attached to the bottom surface of the flexible substrate 100 by a roller RL 2. In some embodiments, the flexible carrier SB2 is, for example, a tape, and the material thereof includes Polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), Polycarbonate (PC), Cyclic Olefin Copolymer (COC), Cellulose Triacetate (TAC), fiberglass-reinforced plastic (FRP), or other similar materials.

In the embodiment, since the supporting structure 230' reduces the gap between the protection layer PF and the pixel circuit 10, when the flexible carrier SB2 is attached to the flexible substrate 100, the flexible substrate 100 is not deformed by the gap between the protection layer PF and the pixel circuit 10, and the gap between the flexible carrier SB2 and the flexible substrate 100 is further prevented.

Referring to fig. 1L and fig. 2, the protection layer PF is removed. In some embodiments, the adhesion of the soft carrier SB2 to the display device 1 is greater than the adhesion of the protective layer PF to the display device 1, so that the display device 1 remains on the soft carrier SB2 when the protective layer PF is removed.

Fig. 3 is a schematic cross-sectional view of a display device according to an embodiment of the invention. Fig. 4 is a schematic top view of a display device according to an embodiment of the invention, wherein fig. 3 corresponds to the position of line B-B' in fig. 4.

It should be noted that the embodiment of fig. 3 and 4 follows the element numbers and part of the contents of the embodiment of fig. 1A to 2, wherein the same or similar elements are denoted by the same or similar reference numbers, and the description of the same technical contents is omitted. For the description of the omitted parts, reference may be made to the foregoing embodiments, which are not repeated herein.

The display device 2 of fig. 3 and 4 differs from the display device 1 of fig. 1L and 2 in that: the retaining wall 210a of the display device 2 is integrally formed with the support structure 230 a.

In this embodiment, the retaining wall 210a and the supporting structure 230a are formed at the same time, and then the packaging adhesive 220' is formed in the region surrounded by the retaining wall 210 a.

In the present embodiment, the supporting structure 230a is laterally located between the light emitting diode 170 and the bonding pad 150. The support structure 230a has a slope 232a, and the thickness of the support structure 230a near the led 170 is greater than the thickness of the support structure 230a near the bonding pad 150.

In the present embodiment, the supporting structure 230a is located between the bonding pad 150 and the light emitting diode 170 in the first direction D1, and the width W3 of the supporting structure 230a in the first direction D1 is greater than the maximum thickness H3 of the supporting structure 230 a. In the present embodiment, the width W3 of the support structure 230a is 1500 to 3000 microns. The width W3 of the support structure 230a is, for example, ten times or more the thickness H3. The width W3 of the supporting structure 230a is substantially equal to the width of the inclined plane 232a vertically projected on the flexible carrier SB 2.

In the present embodiment, an included angle θ between the inclined surface 232a of the supporting structure 230a and the bottom surface 234a of the supporting structure 230a is greater than 0 degrees and less than or equal to 30 degrees, and the included angle θ is preferably greater than or equal to 5 degrees to less than or equal to 10 degrees.

In the present embodiment, the supporting structure 230a is disposed to prevent a gap from being formed between the flexible carrier SB2 and the flexible substrate 100.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.