JP2009098451A - Display panel and laminate type display element equipped with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display panel connected to a circuit board by wire bonding, and a laminate type display element equipped with the same such that a transparent electrode can be prevented from being damaged as a bonding wire is connected to the transparent electrode. <P>SOLUTION: The display panel comprises a transparent electrode 5 formed on a substrate 1, a hole portion 1a bored in the substrate 1, a fixed portion 15 fixed while embedded in the hole portion 1a, a contact portion 17 coming into contact with the transparent electrode 5, and a bonding portion 18 to which the bonding wire 13 is bonded, and is characterized in having a connection terminal portion 11 which is formed of a conductive member and electrically connects the transparent electrode 5 to the bonding wire 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display panel connected to a circuit board by wire bonding and a multilayer display element including the display panel.

2. Description of the Related Art Conventionally, a display panel that selectively reflects light of a specific wavelength and a laminated display element in which the display panels are laminated are known. The multilayer display element has a structure in which a terminal portion formed on a display panel and a terminal portion formed on a circuit board for driving the display panel are connected by a relay substrate (for example, Patent Document 1). reference).
FIG. 4 is a perspective view showing a multilayer display element 400 in which three reflective liquid crystal display panels 300B, 300G, and 300R are stacked. Each display panel 300B, 300G, and 300R is connected to a circuit board (not shown) by a relay board 213 through an anisotropic conductive sheet. In this display element 400, each relay substrate 213 is connected to a terminal portion of each display panel 300B, 300G, 300R. These terminal portions are formed by extending transparent electrodes (not shown) from the display regions of the resin film substrates of the respective display panels 300B, 300G, and 300R to the panel edge portions, and are formed of a transparent metal.

  In addition, a display element is known in which each display panel and a circuit board are connected by a wire bonding method without using a relay substrate in order to narrow the display element. FIG. 5 is a cross-sectional view showing a display element 500 by a wire bonding method. As shown in FIG. 5, the display element 500 includes three reflective liquid crystal display panels 400B, 400G, and 400R that are stacked. The ball portion 13a formed at the tip of the bonding wire 13 is joined to the panel edge of each display panel 400B, 400G, 400R.

FIG. 6 is a cross-sectional view of the display panel 400B. As shown in FIG. 6, in the display panel 400B, a substrate 401 on which a transparent electrode 405 is formed and a substrate 403 on which a transparent electrode 406 is formed are arranged with the transparent electrodes 405 and 406 facing each other. Between the pair of substrates 401 and 403, the outer periphery is covered with a sealing agent 409, and liquid crystal is sealed to form a display region D. The transparent electrode 405 extends to the panel edge to form an electrode end 405a. A metal film 419 is laminated on the electrode end portion 405a. Thereby, the ball portion 13 a of the bonding wire 13 is connected to the electrode end portion 405 a of the transparent electrode 405 through the metal film 419.
WO 06/100711 pamphlet

However, in the above conventional technique, the transparent electrode 405 is usually formed with a thickness of 1000 to 1500 mm. In addition, the transparent electrode 405 has low adhesion to the substrate 401 and has low strength against the application of stress due to bending of the bonded bonding wire or the like. For this reason, the transparent electrode 405 has a problem that when a stress is applied to the electrode end portion 405a, as shown in FIG.
Further, as shown in FIG. 7B, there is a problem that the bonding region portion of the electrode end portion 405 a with the bonding wire 13 is peeled off from the substrate 401 together with the metal film 419 and the bonding wire 13.
Even if the bonding strength between the electrode end portion 405a and the bonding wire 13 is improved by stacking another metal plating on the transparent electrode, these problems occur due to connection stress such as ultrasonic waves.

  An object of the present invention is to provide a display panel capable of preventing damage to a transparent electrode caused by connecting a bonding wire to the transparent electrode, and a multilayer display element including the display panel.

  The object is to provide a transparent electrode formed on the substrate, a hole formed in the substrate, a fixed portion that is embedded and fixed in the hole, a contact portion that contacts the transparent electrode, and a bonding wire. And a connection terminal portion that is formed of a conductive member and electrically connects the transparent electrode and the bonding wire.

  The object is a multilayer display element in which a plurality of display panels are laminated, wherein the display panel is the display panel of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the display panel which can prevent the damage of a transparent electrode by having connected the bonding wire to the transparent electrode, and a laminated display element provided with the same are realizable.

[First Embodiment]
A display panel according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a display panel according to the present embodiment.
The display panel 100 according to the present embodiment is mounted on a display element or the like that displays an image. As shown in FIG. 1, the display panel 100 includes a substrate 1 on which a plurality of transparent electrodes 5 are formed on a substrate surface, and a substrate on which a plurality of transparent electrodes 6 (see FIG. 2B) are formed on the substrate surface. 3 is provided. These substrates 1 and 3 are resin film substrates having transparency.
The plurality of transparent electrodes 5 and 6 are arranged along the substrate surfaces of the substrates 1 and 3, respectively. The substrates 1 and 3 are overlapped with the transparent electrode 5 and the transparent electrode 6 facing each other. The transparent electrodes 5 and 6 are arranged so as to cross each other. Between the pair of substrates 1 and 3 and the transparent electrodes 5 and 6, the outer periphery is covered with a sealant 9 (see FIG. 2B), and liquid crystal is sealed in a region covered with the sealant 9. This liquid crystal is a cholesteric liquid crystal that forms a cholesteric phase. The display panel 100 can display an image in the image display region D by applying a voltage to the liquid crystal via the transparent electrodes 5 and 6.

  A connection structure 7 for electrically connecting the transparent electrodes 5 and 6 and the drive circuit board for driving the display panel 100 by bonding wires 13 is provided in the terminal region T at the edge of each substrate 1 and 3. Yes. Hereinafter, although the connection structure 7 provided in the board | substrate 1 is demonstrated, the connection structure 7 provided in the board | substrate 2 is also equipped with the same structure. The connection structure 7 is provided for each transparent electrode 5.

FIG. 2A is a top view illustrating a part of the display panel, and FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. As shown in FIGS. 2A and 2B, the connection structure 7 includes an electrode end portion 5 a, a connection terminal portion 11, and a hole portion 1 a formed in the substrate 1.
The electrode end 5 a is formed by extending the transparent electrode 5 to the terminal region T at the edge of the substrate 1. The transparent electrode 5 on which the electrode end 5a is formed is formed in a straight line from the image display region D to the terminal region T with substantially the same width W. In the present embodiment, the width W of the transparent electrode 5, that is, the width W of the electrode end portion 5a is 75 μm.

  The hole 1a is formed at the approximate center in the width W direction at each electrode end 5a. The hole 1a formed in the substrate 1 and the electrode end 5a is formed in a circular shape when viewed in the normal direction of the substrate surface. As shown in FIG. 2B, the hole 1a is formed so as to penetrate the electrode end 5a and the substrate 1 in a direction substantially perpendicular to the substrate surface. The hole 1a is formed by machining with a drill or the like, a short wavelength laser, or the like. The diameter d1 of the hole 1a is determined by the diameter of the bonding wire 13 and bonding conditions, and is about 2 to 5 times the diameter of the bonding wire 13. In this embodiment, the diameter d1 of the hole 1a is smaller than the width W of the electrode end 5a, and the diameter d1 of the hole 1a is 50 μm. Here, the thickness t1 of the substrate 1 including the transparent electrode 5 in the present embodiment is 100 to 200 μm.

  The connection terminal portion 11 is provided on the electrode end portion 5a of each transparent electrode 5 and at the approximate center in the width W direction of the electrode end portion 5a. The connection terminal portion 11 is made of a conductive material, and includes a fixing portion 15, a contact portion 17, and a joint portion 18. The connection terminal portion 11 is formed by patterning by plating or photolithography.

  The fixing portion 15 is embedded and fixed in the hole 1a. The fixing portion 15 is formed by filling the hole 1a with a metal or conductive paste by plating or the like and solidifying it. That is, the fixing portion 15 embedded in the circular hole 1a has a columnar shape having the same diameter d1 as the hole 1a. The fixed portion 15 penetrates the hole 1a, and the tip 15a of the fixed portion 15 that penetrates protrudes from the substrate surface on the back side of the substrate 1 on which the transparent electrode 5 is not formed. A protruding portion 15 b that protrudes along the substrate surface on the back surface side of the substrate 1 is formed at the tip 15 a of the fixing portion 15. The projecting portion 15 b is in contact with the substrate surface of the substrate 1. Thereby, the fixing | fixed part 15 is prevented from falling out from the side to which the bonding wire 13 of the board | substrate 1 is joined. Therefore, the fixing portion 15 functions as an anchor for fixing the connection terminal portion 11 to the substrate 1.

  The contact portion 17 is formed on the electrode end portion 5a. The contact portion 17 protrudes along the substrate surface of the substrate 1 and extends in a disc shape, and is formed in a thin disc shape integrally with the joining portion 18 so as to be substantially coaxial with the columnar fixing portion 15. The contact portion 17 has a contact surface 17a in contact with the electrode end portion 5a on the substrate 1 side. The thickness t2 of the contact portion 17 in this embodiment is 1 μm in the normal direction of the substrate surface of the substrate 1. Further, the diameter d2 of the contact portion 17 is formed larger than the diameter d1 of the fixed portion 15, and the diameter d2 of the contact portion 17 in the present embodiment is 110 μm. The contact portion 17 sandwiches the electrode end portion 5 a of the transparent electrode 5 between the contact surface 17 a and the substrate 1 by contacting the electrode end portion 5 a in the normal direction of the substrate surface of the substrate 1.

  The joint portion 18 is formed on the back side of the contact surface 17 a of the contact portion 17, that is, on the upper end of the connection terminal portion 11. The joint portion 18 has a joint surface to which the ball portion 13 a formed at the joint end of the bonding wire 13 is joined. The ball portion 13a is melted at the time of joining and formed into a spherical shape by surface tension. The bonding surface is formed substantially parallel to the substrate surface of the substrate 1. The bonding wire 13 bonded to the bonding portion 18 is formed such that the diameter d3 of the ball portion 13a of the bonding wire 13 is smaller than the diameter d1 of the hole portion 1a or the fixing portion 15 at the time of bonding. That is, the diameter d1 of the hole portion 1a or the fixing portion 15 is provided to be equal to or larger than the diameter d3 of the ball portion 13a of the bonding wire 13. Here, the diameter d3 of the ball portion 13a of the bonding wire 13 in this embodiment is 40 μm.

  On the joint surface of the joint 18, a metal film 19 such as gold is formed by a plating method or a sputtering method. That is, the joint portion 18 and the ball portion 13 a of the bonding wire 13 are joined via the metal film 19 formed on the joint portion 18. Thereby, the bonding wire 13 and the electrode end part 5a are electrically connected.

  The bonding wire 13 that is electrically connected to the transparent electrode 5 extends from the outside toward the connection terminal portion 11 in the terminal region T along the direction in which the transparent electrode 5 formed in a straight line extends. In the bonding wire 13, the ball portion 13 a is bonded to the approximate center of the bonding portion 18 when viewed in the normal direction of the substrate surface of the substrate 1.

Hereinafter, a method for manufacturing the display panel 100 will be described.
To manufacture the display panel 100, first, a plurality of transparent electrodes 5 are formed on the substrate 1 by patterning.

  Next, a hole 1a penetrating the electrode end 5a of each transparent electrode 5 is formed in the substrate 1 by machining with a drill or the like, a short wavelength laser, or the like.

  Next, for example, Cu (copper) paste is filled in the hole 1 a of the substrate 1 using screen printing to form the connection terminal portion 11. At this time, the fixed portion 15 of the connection terminal portion 11 has a tip 15 a protruding from the substrate surface on the back surface side of the substrate 1, and a protruding portion 15 b protruding along the substrate surface on the back surface side of the substrate 1 is formed.

  Next, a resist is applied and patterned on the terminal region T at the edge of the substrate 1, and a region to be a bonding surface of the bonding portion 18 of the connection terminal portion 11 is opened.

  Next, a metal film 19 made of, for example, gold is formed on the bonding surface of the bonding portion 18 by a plating method, and the resist is removed. Thus, the connection structure 7 is completed on the substrate 1. The connection structure 7 is completed on the substrate 3 by the same method.

  Next, the substrate 1 and the substrate 3 are bonded together.

  Next, liquid crystal is injected between the substrate 1 and the substrate 3. Thereby, the display panel 100 is completed.

  Next, the connection structure 7 and the drive circuit board are joined by the bonding wire 13. Thereby, the display element is completed.

  As described above, according to the first embodiment, the display panel 100 includes the transparent electrode 5 formed on the substrate 1, and the hole 1a formed through the substrate 1 and the transparent electrode 5. A fixed portion 15 that is embedded and fixed in the hole portion 1a, a contact portion 18 that contacts the electrode end portion 5a of the transparent electrode 5, and a bonding portion 18 to which the bonding wire 13 is bonded, and a conductive member. And a connection terminal portion that electrically connects the transparent electrode 5 and the bonding wire 13. Thereby, the bonding wire 13 is electrically connected to the transparent substrate 5 through the connection terminal portion 11 fixed to the substrate 1, and even if stress is applied to the connection terminal portion 11 due to the bending of the bonding wire 13, This stress is difficult to be transmitted to the transparent electrode 5. For this reason, it is possible to prevent stress from being applied due to the bonding wire 13 being connected to the transparent electrode 5 and damage to the transparent electrode 5 due to ultrasonic waves or the like.

  Further, the display panel 100 has the contact end 17 a of the contact portion 17 of the connection terminal portion 11 in contact with the normal direction of the substrate surface of the substrate 1, so that the electrode end 5 a of the transparent electrode 5 is interposed between the display panel 100 and the substrate 1. It is sandwiched. Thereby, the adhesiveness of the transparent electrode 5 and the board | substrate 1 improves, and since the transparent electrode 5 cannot peel easily, the reliability of the connection using a wire bonding method can be improved.

  Furthermore, since the display panel 100 includes the connection terminal portion 11, connection using the wire bonding method can be easily performed without considering damage such as peeling of the transparent electrode 5. Therefore, it is possible to easily narrow the terminal region T of the display panel 100 and narrow the frame.

[Second Embodiment]
A display panel according to a second embodiment of the present invention will be described with reference to FIGS. 3A is a top view illustrating a part of the display panel, FIG. 3B is a cross-sectional view taken along the line BB ′ of FIG. 3A, and FIG. It is the side view of the display panel seen in the arrow C direction shown to (a).
The display panel 200 according to the present embodiment has substantially the same configuration as the display panel 100 according to the first embodiment. Hereinafter, common parts are denoted by the same reference numerals, and description thereof is omitted. The display panel 200 is manufactured by the same manufacturing method as the display panel 100 according to the first embodiment.

  As shown in FIGS. 3A to 3C, the display panel 200 includes a substrate 101 having a plurality of transparent electrodes 105 formed on the substrate surface and a plurality of transparent electrodes 106 similarly formed on the substrate surface. And a substrate 103. In the terminal region T at the edge of each of the substrates 101 and 103, a connection structure 107 for electrically connecting the transparent electrode 105 and the drive circuit substrate for driving the display panel 200 by the bonding wire 13 is provided. Hereinafter, although the connection structure 107 provided on the substrate 101 will be described, the substrate 103 is also provided with the connection structure 107 having the same configuration. The connection structure 107 is provided for each transparent electrode 105. As shown in FIG. 3A, the connection structure 107 includes an electrode end portion 105 a, a connection terminal portion 111, and a pair of hole portions 101 a formed in the substrate 101.

  The pair of hole portions 101 a is formed in the substrate 101 for each electrode end portion 105 a across the electrode end portion 105 a of the transparent electrode 105. The pair of holes 101a are arranged with the electrode end 105a interposed therebetween. The holes 101a are formed so as to penetrate only the substrate 101, respectively. These holes 101a are formed by machining with a drill or the like, a short wavelength laser, or the like. The diameter of the hole 101a is determined by the diameter of the bonding wire 13 and bonding conditions, and is approximately 2 to 5 times the diameter of the bonding wire 13.

  The connection terminal portion 111 is formed of a conductive material, and includes a pair of fixing portions 115, a contact portion 117, and a joint portion 118. The connection terminal portion 111 is formed by patterning by plating or photolithography.

  The pair of fixing portions 115 are embedded and fixed in the pair of hole portions 101a, respectively. These fixing portions 115 are formed by filling the hole 101a with a metal or conductive paste by plating or the like and solidifying it. That is, the fixing portion 115 embedded in the hole 101a formed in a circular shape has a columnar shape having the same diameter as the hole 101a. The fixing part 115 penetrates the hole part 101a, and the tip 115a of the penetrating fixing part 115 protrudes from the substrate surface on the back side of the substrate 101 where the transparent electrode 105 is not formed. A protruding portion 115 b that protrudes along the substrate surface on the back surface side of the substrate 101 is formed at the tip 115 a of the fixing portion 115. These projecting portions 115 b are in contact with the substrate surface of the substrate 101. As a result, the fixing portion 115 is prevented from coming off to the side where the bonding wire 13 of the substrate 101 is bonded. Accordingly, the fixing portion 115 functions as an anchor that fixes the connection terminal portion 111 to the substrate 101.

  The contact portion 117 is formed on the electrode end portion 105a. The contact portion 117 is formed so as to span the pair of fixing portions 115 along the substrate surface of the substrate 101. The contact portion 117 has a contact surface 117 a that contacts the electrode end portion 105 a on the substrate 101 side between the pair of fixing portions 115. The contact portion 117 sandwiches the electrode end portion 105 a of the transparent electrode 105 between the contact surface 117 a and the substrate 101 by contacting the electrode end portion 105 a in the normal direction of the substrate surface of the substrate 101.

  The joint portion 118 is formed on the back side of the contact surface 117 a of the contact portion 117, that is, on the upper end of the connection terminal portion 111. The joint portion 118 has a joint surface to which the ball portion 13 a formed at the joint end of the bonding wire 13 is joined. The ball portion 13a is melted at the time of joining and formed into a spherical shape by surface tension. The bonding surface is formed substantially parallel to the substrate surface of the substrate 101.

  A metal film 119 such as gold is formed on the bonding surface of the bonding portion 118 by a plating method or a sputtering method. That is, the bonding portion 118 and the ball portion 13 a of the bonding wire 13 are bonded via the metal film 119 formed on the bonding portion 118. Thereby, the bonding wire 13 and the electrode end part 105a are electrically connected.

  The bonding wire 13 electrically connected to the transparent electrode 105 extends from the outside toward the connection terminal portion 111 in the terminal region T along the direction in which the transparent electrode 105 formed in a straight line extends. In the bonding wire 13, the ball portion 13 a is bonded to the approximate center of the bonding portion 118, that is, the back surface side of the contact portion 117 when viewed in the normal direction of the substrate surface of the substrate 101.

Also with the display panel 200 according to the second embodiment, the same effect as the display panel 100 according to the first embodiment can be obtained.
In addition, since the display panel 200 can provide the connection terminal portion 111 without forming a hole in the electrode end portion 105a of the transparent electrode 105, the strength of the electrode end portion 105a due to the formation of the hole portion is reduced. Can be prevented. Furthermore, compared to the case where the hole is formed, the area of the surface where the transparent electrode 105 and the substrate 101 are in close contact with each other is increased by the opening area of the hole. For this reason, the adhesion between the transparent electrode 105 and the substrate 101 is further improved.

As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and various modifications are possible.
In the above embodiment, the holes 1a and 101a formed in the substrates 1 and 101 are formed through the substrates 1 and 101, but the present invention is not limited to this. As long as the fixing portions 15 and 115 can be fixed, the holes 1a and 101a formed in the substrates 1 and 101 may be formed so as not to penetrate the substrates 1 and 101 and have a bottom portion.

  Moreover, in the said embodiment, although the junction parts 18 and 118 and the ball | bowl part 13a of the bonding wire 13 are connected via the metal films 19 and 119 formed on the junction parts 18 and 118, this invention. Is not limited to this. As long as the joint portions 18 and 118 are formed of a material having high bondability, the joint portions 18 and 118 and the ball portion 13a of the bonding wire 13 may be joined without the metal films 19 and 119 interposed therebetween.

  Furthermore, in the above-described embodiment, a single display panel 100 used for a display element is described. However, the present invention is not limited to this, and a plurality of display panels 100 of different colors such as red, green, and blue are provided. The present invention may be applied to a multilayer display element capable of color display by stacking.

The display panel according to the present embodiment described above and the multilayer display element including the display panel are summarized as follows.
(Appendix 1)
A transparent electrode formed on the substrate;
A hole formed in the substrate;
A fixing portion that is embedded and fixed in the hole, a contact portion that contacts the transparent electrode, and a bonding portion to which a bonding wire is bonded, and is formed of a conductive member and is bonded to the transparent electrode and the bonding A display panel comprising a connection terminal portion for electrically connecting a wire.

(Appendix 2)
In the display panel described in Appendix 1,
The said hole part penetrates the said transparent electrode, and is formed in the diameter smaller than the width | variety of the said transparent electrode.

(Appendix 3)
In the display panel according to appendix 1 or 2,
The display panel, wherein the hole portion penetrates the substrate.

(Appendix 4)
In the display panel described in Appendix 3,
The display panel according to claim 1, wherein a front end of the fixing portion protrudes from the substrate through the hole portion.

(Appendix 5)
In the display panel according to any one of appendices 1 to 4,
The display panel further comprising a metal film formed on the joint.

(Appendix 6)
In the display panel according to any one of appendices 1 to 5,
The diameter of the hole is formed to be equal to or larger than the diameter of the ball formed at the tip of the bonding wire during bonding.

(Appendix 7)
In the display panel according to any one of appendices 1 to 6,
A pair of said hole parts are formed in the said board | substrate on both sides of the said transparent electrode, The said fixing | fixed part is being fixed to each of a pair of said said hole parts.

(Appendix 8)
In the display panel according to any one of appendices 1 to 7,
The display panel, wherein the contact portion is formed so as to protrude along a substrate surface of the substrate, and the transparent electrode is sandwiched between the contact portion and the substrate.

(Appendix 9)
In the display panel according to appendix 4 or 5,
The display panel according to claim 1, wherein a protrusion that protrudes along a substrate surface of the substrate is formed at the tip of the fixing portion, and the protrusion hits the substrate surface.

(Appendix 10)
A laminated display element in which a plurality of display panels are laminated,
The multilayer display element, wherein the display panel is a display panel according to any one of appendices 1 to 9.

1 is a perspective view showing a display panel according to a first embodiment of the present invention. FIG. 2A is a top view illustrating a part of the display panel according to the first embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line AA ′ of FIG. . FIG. 3A is a top view showing a part of the display panel according to the second embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along the line BB ′ of FIG. FIG. 3C is a side view of the display panel viewed in the direction of arrow C shown in FIG. It is a perspective view which shows the display element by a prior art. It is a perspective view which shows the display element by the wire bonding method by a prior art. It is sectional drawing which shows the display panel by a prior art. FIG. 7A and FIG. 7B are diagrams for explaining problems of the display panel according to the prior art.

Explanation of symbols

1, 3, 101, 103 Substrate 1a, 101a Hole part 5, 6, 105, 106 Transparent electrode 11, 111 Connection terminal part 13 Bonding wire 13a Ball part 15, 115 Fixed part 15a, 115a Tip 15b, 115b Protrusion part 17, 117 Contact portion 18, 118 Joint portion 19, 119 Metal film 100, 200 Display panel

Claims (6)

A transparent electrode formed on the substrate;
A hole formed in the substrate;
A fixing portion that is embedded and fixed in the hole, a contact portion that contacts the transparent electrode, and a bonding portion to which a bonding wire is bonded, and is formed of a conductive member and is bonded to the transparent electrode and the bonding A display panel comprising a connection terminal portion for electrically connecting a wire. The display panel according to claim 1,
The said hole part penetrates the said transparent electrode, and is formed in the diameter smaller than the width | variety of the said transparent electrode. The display panel according to claim 1 or 2,
The display panel, wherein the hole portion penetrates the substrate. The display panel according to claim 3,
The display panel according to claim 1, wherein a front end of the fixing portion protrudes from the substrate through the hole portion. The display panel according to any one of claims 1 to 4,
The display panel further comprising a metal film formed on the joint. A laminated display element in which a plurality of display panels are laminated,
The display panel according to claim 1, wherein the display panel is a display panel according to claim 1.

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