TWI884665B - Panel structure - Google Patents

Abstract

A panel structure including a first substrate, a first electricity-connecting pad, a second substrate, a second electricity-connecting pad, an insulating adhesive layer and a conducting layer is provided. The first substrate includes a first surface. The first electricity-connecting pad is disposed on the first surface. The second substrate includes a second surface. The second electricity-connecting pad is disposed on the second surface. The insulating adhesive layer is disposed between the first substrate and the second substrate. The first surface faces the insulating adhesive layer, and the second surface of the second substrate is disposed away from the insulating adhesive layer. A vertical projection of the conducting layer on the first substrate overlaps vertical projections of the first electricity-connecting pad, the insulating adhesive layer and the second electricity-connecting pad on the first substrate.

Description

Panel structure

The present invention relates to an electrical connection assembly, and in particular to a panel structure.

The manufacturing process of the chip on film (COF) package for the electrical connection of the hyperbolic display panel needs to be carried out on a rigid substrate. Specifically, the electrical connection pads on the COF are oriented toward the electrical connection pads on the hyperbolic display panel, and hot pressing is performed to complete the electrical connection assembly (electricity-connecting bond) between the hyperbolic display panel and the COF. The above-mentioned rigid substrate provides support for the hot pressing process. However, in the process of removing the assembled hyperbolic display panel from the rigid substrate, the heterogeneous step difference in the electrical connection assembly will affect the yield of the hyperbolic display panel.

In order to avoid the yield reduction problem caused by the above-mentioned assembly first and then removal, the hyperbolic display panel that has not been electrically connected will be removed from the hard substrate first, and then the electrical connection assembly between the hyperbolic display panel and the COF will be performed. However, the hyperbolic display panel will be deformed after being removed, which will cause the pitch of multiple electrical connection pads on the hyperbolic display panel to be mismatched with the pitch of multiple electrical connection pads on the COF.

The present invention provides a panel structure with high process freedom, which can be applied to various hard, soft and curved display panels.

According to an embodiment of the present invention, a panel structure is provided, including a first substrate, a first electrical connection pad, a second substrate, a second electrical connection pad, an insulating adhesive layer and a conductive layer. The first substrate includes a first surface. The first electrical connection pad is arranged on the first surface. The second substrate includes a second surface. The second electrical connection pad is arranged on the second surface. The insulating adhesive layer is arranged between the first substrate and the second substrate. The first surface faces the insulating adhesive layer, and the second surface of the second substrate is away from the insulating adhesive layer. The vertical projection of the conductive layer on the first substrate overlaps the vertical projection of the first electrical connection pad, the insulating adhesive layer and the second electrical connection pad on the first substrate.

Based on the above, the panel structure provided by the embodiment of the present invention is a universal electrical connection assembly, which is not limited to display panels and can be completed by printing/coating, photolithography or wire bonding technology. The assembly position is not limited to the spacing between multiple first electrical connection pads and whether the spacing between multiple second electrical connection pads matches, which greatly improves the degree of freedom of the process. In addition, the first substrate is not limited to a hard display panel, but can also be a curved and/or soft display panel. The curved and/or soft display panel is no longer limited by the requirement of electrical connection assembly on a hard substrate, thereby avoiding the problem of reduced display panel yield due to heterogeneous step differences in the electrical connection assembly.

In order to make the above features and advantages of the present invention more clearly understood, embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

1A, 1B and 1C, the panel structure 100 according to the embodiment of the present invention includes a first substrate 101, a plurality of first electrical connection pads 201, a second substrate 102, a plurality of second electrical connection pads 202, an insulating adhesive layer 300, a conductive layer 400 and an insulating protective layer 500. The first substrate 101 includes a first surface S1. The plurality of first electrical connection pads 201 are disposed on the first surface S1. The second substrate 102 includes a second surface S2. The plurality of second electrical connection pads 202 are disposed on the second surface S2. The conductive layer 400 includes a plurality of patterned wires 401.

In some embodiments, the first substrate 101 is a flat display panel or a curved display panel, and the first surface S1 can be the front, back or side of the display panel. The second substrate 102 is a component that drives and/or controls the display panel 101, such as an integrated circuit (IC), a chip-on-film package (COF), a flexible circuit board (FPC) and a printed circuit board (PCB), but is not limited thereto.

Please refer to FIG. 3 , where the first substrate 101 is a hyperbolic display panel and the second substrate 102 is a chip-on-film package (COF). In some comparative examples based on the prior art, the process of electrically connecting the hyperbolic display panel 101 to the chip-on-film package 102 needs to be performed on a rigid substrate, specifically, the second surface S2 of the chip-on-film package 102 is facing the first surface S1 of the hyperbolic display panel 101 and is hot-pressed to electrically connect the plurality of first electrical connection pads 201 on the hyperbolic display panel 101 and the plurality of second electrical connection pads 202 on the chip-on-film package 102, so as to complete the electrical connection structure (electricity-connecting bond) between the hyperbolic display panel 101 and the chip-on-film package 102. The above-mentioned rigid substrate is used to provide the support required in the hot-pressing process. However, in the process of removing the assembled hyperbolic display panel 101 from the rigid substrate, the heterogeneous step difference in the electrical connection assembly will affect the yield of the hyperbolic display panel 101. In some other comparative examples, in order to avoid the yield reduction problem caused by the above-mentioned assembly first and then removal, the hyperbolic display panel 101 that has not been electrically connected is first removed from the rigid substrate, and then the electrical connection assembly between the hyperbolic display panel 101 and the chip on film package 102 is performed. However, the hyperbolic display panel 101 will be deformed after being removed, thereby causing the problem that the pitch of the multiple first electrical connection pads 201 of the hyperbolic display panel 101 and the pitch of the multiple second electrical connection pads 202 of the chip on film package 102 do not match.

In order to avoid the various limitations and problems of the above-mentioned thermal compression process, the panel structure 100 provided in the embodiment of the present invention uses precision printing/coating or photolithography to perform electrical connection assembly between the first substrate 101 and the second substrate 102. Specifically, referring to FIG. 1A and FIG. 1B, the second substrate 102 is first fixed on the first substrate 101 by the insulating adhesive layer 300, wherein the first surface S1 of the first substrate 101 faces the insulating adhesive layer 300, and the second surface S2 of the second substrate 102 is away from (facing away from) the insulating adhesive layer 300. Then, a plurality of wires 401 are arranged to electrically connect the plurality of first electrical connection pads 201 on the first substrate 101 and the plurality of second electrical connection pads 202 on the second substrate 102 , respectively, thereby completing the electrical connection structure between the first substrate 101 and the second substrate 102 .

It should be noted that even if the first substrate 101 in the panel structure 100 according to the embodiment of the present invention is an embodiment of a hyperbolic display panel or other soft display panel, and the spacing between the multiple first electrical connection pads 201 changes during the process of removing the first substrate 101 from the hard substrate, and thus does not match the spacing between the multiple second electrical connection pads 202, multiple wires 401 can still be arranged between the multiple first electrical connection pads 201 and the corresponding multiple second electrical connection pads 202 by precision printing/coating or yellow light lithography and other technologies to complete the electrical connection assembly between the first substrate 101 and the second substrate 102.

In the embodiment shown in FIG. 1A and FIG. 1B , the vertical projection of the conductive layer 400 on the first substrate 101 overlaps the vertical projections of the first electrical connection pad 201, the insulating adhesive layer 300, and the second electrical connection pad 202 on the first substrate 101. This is because the insulating adhesive layer 300 protrudes from the second substrate 102 from the overlapping portion of the first substrate 101 and the second substrate 102. In other words, the vertical projection of the edge of the second substrate 102 on the first substrate 101 falls within the vertical projection of the insulating adhesive layer 300 on the first substrate 101. Accordingly, the contact area between the insulating adhesive layer 300 and the first substrate 101 can be increased, and the structural strength of the electrical connection assembly can be improved.

Please refer to FIG. 1A and FIG. 1C at the same time. Since the insulating adhesive layer 300 protrudes from the second substrate 102 from the overlapping portion of the first substrate 101 and the second substrate 102, the conductive layer 400 contacts the insulating adhesive layer 300. In some embodiments, the insulating adhesive layer 300 may have a plurality of grooves 300L on the surface S3 away from the first surface S1 to prevent the conductive lines 401 from overflowing and causing short circuits when formed. Therefore, the conductive lines 401 formed may be at least partially located in the grooves 300L, as shown in FIG. 1C.

Referring to FIG. 1D , a schematic diagram of various patterned wires 401 according to some embodiments of the present invention is shown. The patterned wires 401 have multiple curved portions, thereby improving the tensile properties and the tensile strength of the panel structure 100. In some alternative embodiments, the patterned wires 401 may be PEDOT:PSS wires, silver nanowires or carbon nanotubes, which have good ductility.

In the embodiment shown in FIG1B , the edge of the first substrate 101 below the second substrate 102 is aligned with the insulating adhesive layer 300. Thus, the contact area between the insulating adhesive layer 300 and the first substrate 101 and the second substrate 102 can be increased, the structural strength of the electrical connection assembly can be improved, and the process of disposing the backing glue of the second substrate 102 between the second substrate 102 and the edge of the first substrate 101 below it in the conventional technology can be omitted.

Referring to FIG. 1B , the insulating adhesive layer 300 is adjacent to the first electrical connection pad 201 , and there is no gap between the two, thereby enhancing the structural strength of the electrical connection assembly. Moreover, the conductive layer 400 does not need to overcome the step difference between the insulating adhesive layer 300 and the first substrate 101 , thereby improving the manufacturing yield of the panel structure 100 . However, the present invention is not limited thereto. Referring to FIG. 2A and FIG. 2B , the panel structure 200 according to an embodiment of the present invention includes a first substrate 101 , a plurality of first electrical connection pads 201 , a second substrate 102 , a plurality of second electrical connection pads 202 , an insulating adhesive layer 300 , and a conductive layer 600 . The conductive layer 600 includes a plurality of wires 601 .

Different from the panel structure 100, the insulating adhesive layer 300 in the panel structure 200 can partially cover the first electrical connection pad 201, and the first electrical connection pad 201 is exposed through the through hole 300H of the insulating adhesive layer 300, and the wire 601 is passed through the through hole 300H by a wire bonding process to electrically connect the first electrical connection pad 201 and the second electrical connection pad 202.

It should be noted that, for embodiments in which the first substrate 101 is a hyperbolic display panel or other soft display panel, even if the spacing between the plurality of first electrical connection pads 201 changes during the process of removing the first substrate 101 from the hard substrate and thus does not match the spacing between the plurality of second electrical connection pads 202, a plurality of wires 601 can still be arranged between the plurality of first electrical connection pads 201 and the corresponding plurality of second electrical connection pads 202 through a wire bonding process to complete the electrical connection assembly between the first substrate 101 and the second substrate 102.

In summary, the panel structure provided by the embodiment of the present invention is a universal electrical connection assembly, which is not limited to display panels and can be completed by printing/coating, photolithography or wire bonding technology. The electrical connection assembly is not limited to the problem of whether the spacing between multiple first electrical connection pads and the spacing between multiple second electrical connection pads match, which greatly improves the degree of freedom of the process. In addition, the first substrate is not limited to a hard display panel, but can also be a curved and/or soft display panel. The limitation that curved and/or soft display panels must be electrically connected and assembled on a hard substrate is avoided, thereby avoiding the problem of reduced yield due to heterogeneous step differences in the electrical connection assembly.

100, 200: Panel structure 101: First substrate 102: Second substrate 201: First electrical connection pad 202: Second electrical connection pad 300: Insulating adhesive layer 300L: Groove 300H: Through hole 400, 600: Conductive layer 401, 601: Wire 500: Insulating protective layer S1: First surface S2: Second surface X, Y, Z: Direction

FIG. 1A schematically shows a perspective view of a panel structure according to an embodiment of the present invention. FIG. 1B is a schematic cross-sectional view of the panel structure of FIG. 1A. FIG. 1C is a partial schematic view of the panel structure of FIG. 1A. FIG. 1D is a schematic view of a conductive layer according to an embodiment of the present invention. FIG. 2A is a schematic view of a panel structure according to an embodiment of the present invention. FIG. 2B is a schematic cross-sectional view of the panel structure of FIG. 2A. FIG. 3 is a schematic view of a panel structure according to an embodiment of the present invention.

100: Panel structure

101: First substrate

102: Second substrate

201: First electrical connection pad

202: Second electrical connection pad

300: Insulating adhesive layer

400: Conductive layer

401: Conductor

500: Insulation protection layer

S1: First surface

S2: Second surface

X, Y, Z: direction

Claims (10)

A panel structure includes: A first substrate including a first surface; A first electrical connection pad disposed on the first surface; A second substrate including a second surface and a third surface, the second surface being opposite to the third surface; A second electrical connection pad disposed on the second surface; An insulating adhesive layer disposed between the first substrate and the second substrate, wherein the first surface faces the insulating adhesive layer; and A conductive layer, wherein the third surface faces the insulating adhesive layer, and the vertical projection of the conductive layer on the first substrate overlaps the vertical projections of the first electrical connection pad, the insulating adhesive layer, and the second electrical connection pad on the first substrate. A panel structure as described in claim 1, wherein a vertical projection of an edge of the second substrate on the first substrate falls within a vertical projection of the insulating adhesive layer on the first substrate. A panel structure as described in claim 1, wherein the insulating adhesive layer is adjacent to the first electrical connection pad. A panel structure as described in claim 1, wherein the insulating adhesive layer is aligned with an edge of the first substrate. A panel structure as described in claim 1, wherein there is a gap between the conductive layer and the insulating adhesive layer. A panel structure as described in claim 1, wherein the conductive layer contacts the insulating adhesive layer. The panel structure as described in claim 1, wherein the insulating adhesive layer is arranged between the first electrical connection pad and the conductive layer, and the conductive layer is electrically connected to the first electrical connection pad through a through hole of the insulating adhesive layer. A panel structure as described in claim 1, wherein the conductive layer includes a plurality of patterned wires, the insulating adhesive layer has a plurality of grooves on a surface away from the first surface, and the plurality of patterned wires are respectively at least partially located in the plurality of grooves. A panel structure as described in claim 1, wherein the conductive layer includes a plurality of patterned wires, each of the patterned wires is non-straight. A panel structure as described in claim 1, wherein the conductive layer includes PEDOT:PSS wires, silver nanowires or carbon nanotubes.

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