Patent Application
20110175841
The present invention relates to a touch-input-function added protective panel for an electronic instrument display window which is used for a portable information terminal such as a PDA (personal digital assistance) or a handy terminal, an OA (office automation) instrument such as a copying machine or a facsimile, a smart phone, a portable telephone, a portable game instrument, an electronic dictionary, a car navigation system, a small-sized PC (personal computer), any one of various home electrical appliances, or the like, and is excellent in reliability of its FPC connection region.
A casing in an electronic instrument, such as a portable telephone or a smart phone, is generally made of a combination of a front surface casing and a rear surface casing each made of a synthetic resin. Specifically, a protective panel is fixed onto the front surface of the front casing by melt-bonding or the like to protect a liquid crystal display window. As this protective panel, conventionally, a panel made of a transparent and colorless resin has been hitherto used. However, as electronic instruments have been made decorative, a decoration, such as trimming, has been applied thereto by printing.
In recent years, about portable telephones, a protective panel 101 having an input device function, as illustrated in
About the touch-input-function added protective panel 101 for an electronic instrument display window, a description will be made in more detail, using an exploded view of
On the inside surface of the upper electrode sheet 102a and that of the lower electrode panel 103, ITO (indium tin oxide) pieces, or the like are formed by sputtering or vacuum vapor deposition in a rectangular form as the transparent electrodes 104 and 105, respectively. On the upper electrode sheet 102a are formed band-form bus bars 106a and 106b, wherein a silver paste is used, which are connected to the transparent electrode 104 and are in parallel to each other. On the lower electrode panel 103 are formed band-form bus bars 107a and 107b, wherein a silver paste is used, which are extended in a direction orthogonal to the bus bars 106a and 10106b and are connected to the transparent electrode 105. About the individual bus bars 106a, 106b, 107a and 107b, their circuits are extended to a connection section 108 located at an edge region of the upper electrode sheet 102a, and then collected at the section, which is a single region.
The decorative sheet 102b is adhered onto the whole of the front surface (outside surface) of the upper electrode sheet 102a (hereinafter, a laminated film of the upper electrode sheet 102a and the decorative sheet 102b will be called a movable sheet 102) . When the surface of the decorative sheet 102b is pressed with a finger, a pen, or the like, the movable sheet 102 is, in an integrated manner, bent down so that the respective transparent electrodes 104 and 105 formed on the inside surfaces of the upper electrode sheet 102a and the lower electrode panel 103, are brought into contact with each other. In this way, the input position is detected.
In
In the pin-attached FPC 110 described in Patent document 2, at the connection side end 110a of the FPC 110, metallic pin fixing holes 110g are made in each of a film substrate 110f, and a circuit 110c as an electrically conductive section. Into the metallic pin fixing holes 110g are inserted the metallic pins 111 to 114, which each have a pin shaft portion and a head portion formed to have a larger diameter than the outside diameter of this pin shaft portion, from the circuit 110c side. A coverlay film 110b is adhered and bonded onto the circuit 110c and the film substrate 110f so as to cover the head portions (for example, reference number 114a in
Reference number 116 in
Patent document 1: International Publication 2005/064451 pamphlet
Patent document 2: International Publication 2006/077784 pamphlet
However, when the electroconductive adhesive 115 is injected from the connection hole 121 in each of the electrode ends 106c, 107c, 106d, and 107d, an issue is caused. Specifically, in the connection hole 121, which is a hollow region in the adhesive layer 116, naturally, a void (air gap) is made between the movable sheet 102 and the lower electrode panel 103 (see
The electroconductive adhesive 115 is cured by heating and drying, or curing at normal temperature (moisture curing, anaerobic curing, or two-component curing); thus, when the electroconductive adhesive 115 is cured in the state that the movable sheet 102 over the individual connection holes 121 are depressed as described above so that the electroconductive adhesive 115 cannot be sufficiently injected therein, the depressions in the movable sheet 102 are maintained. As a result, the external appearance quality of the touch-input-function added protective panel 101 becomes low for the following reason: about the protective panel 101, the whole of the front surface of the movable sheet 102 is to be an outer package of an electronic instrument, so that the depressions in the movable sheet 102 are to exist.
Even in a case where no depression is generated at the time of the injection of the electroconductive adhesive 115, the electroconductive adhesive 115 shrinks when heated and dried or cured at normal temperature, thereby generating depressions in the movable sheet 102 to decline the external appearance quality of the protective panel 101.
An object of the present invention is to resolve the issues as described above in the prior art, and provide a touch-input-function added protective panel for an electronic instrument display window which is excellent in connection reliability of its FPC, or the external appearance quality.
In order to attain the object, the present invention is constructed as follows:
According to a first aspect of the present invention, there is provided a touch-input-function added protective panel for an electronic instrument display window, comprising:
a lower electrode panel having, on an upper surface of a nonflexible protective panel body, a lower transparent electrode and a lower circuit located around the lower transparent electrode;
an upper electrode sheet arranged on an upper side of the lower electrode panel, having, on a lower surface of a flexible and transparent insulating film, an upper transparent electrode located at a position opposite to the lower transparent electrode and an upper circuit located around the upper transparent electrode, and further bonded, at its peripheral edge region, to the lower electrode panel through an adhesive layer so as to form an inter-electrode gap between the upper transparent electrode and the lower transparent electrode;
a decorative sheet arranged on an upper side of the upper electrode sheet, having, in at least one surface of a flexible and transparent insulating film, a decorative layer that hides the lower circuit and the upper circuit and forms a transparent window section, and further adhered onto an upper surface of the upper electrode sheet; and
an FPC that takes out an electrical signal through a pin inserted into a through hole made in the lower electrode panel,
wherein the adhesive layer has a connection hole connected to the through hole, plural spacers are fixed and arranged in the connection hole and between the upper surface, at the peripheral edge of the through hole, of the lower electrode panel and the upper electrode sheet, so as to be separated from one another, and an electroconductive adhesive is filled from the through hole into the connection hole, a gap interval of an inside of which is maintained by the spacers.
According to a second aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to the first aspect, wherein the spacers are dot spacers, and dots of the dot spacers are each fixed and bonded to at least one of the lower electrode panel and the upper electrode sheet.
According to a third aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to the first aspect, wherein the spacers are dot spacers, and dots of the dot spacers are each a particle fixed and bonded to at least one of the lower electrode panel and the upper electrode sheet.
According to a fourth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to the third aspect, wherein the particle is fixed and bonded by fixing a supporting layer that fixes the particle, to at least one of the lower electrode panel and the upper electrode sheet.
According to a fifth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to the fourth aspect, wherein the supporting layer is a layer having electroconductivity.
According to a sixth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to anyone of the first to fifth aspects, wherein the spacers have electroconductivity.
According to a seventh aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to anyone of the third to fifth aspects, wherein the particle is spherical.
According to an eighth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to any one of the first to fifth aspects, wherein a height size of the spacers is larger than a gap interval size of the connection hole that is maintained, in the connection hole in the adhesive layer, by the spacers.
According to a ninth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to any one of the first to fourth aspects, wherein the spacers are arranged around a position of the upper surface of the lower electrode panel which corresponds to an inside of the through hole, so as to be in positions except the position, which corresponds to the inside of the through hole.
According to a tenth aspect of the present invention, there is provided the touch-input-function added protective panel for an electronic instrument display window according to the fourth or fifth aspect, wherein the supporting layer has a frame shape having, at a position of the upper surface of the lower electrode panel which corresponds to an inside of the through hole, a through hole, and the particles are fixed to regions of the supporting layer except the through hole in the supporting layer, whereby the particles are arranged around the position corresponding to the inside of the through hole.
In the touch-input-function added protective panel according to the present invention, between the upper surface, at the peripheral edge of a through hole, of its lower electrode panel and its upper electrode sheet and further in the connection hole in its adhesive layer, plural spacers are fixed and arranged so as to be separated from one another, and an electroconductive adhesive is filled from the through hole into the connection hole, the gap interval of which is maintained by the spacers. For this reason, the injection of the electroconductive adhesive can be filled smoothly into every portion of the connection hole made in the adhesive layer for bonding the lower electrode panel and the upper electrode sheet to each other. In other words, for example, the electroconductive adhesive is certainly filled into the connection hole to make it possible to connect the following electrically to one another with certainty: the electrode of the upper electrode sheet or the electrode of the lower electrode panel, which faces the connection hole; the electroconductive adhesive inside the connection hole; and a pin of the FPC inserted into the through hole connected to the connection hole. Thus, the reliability of electrical connection between the electrode(s) and the pin can be made high. Accordingly, the connection reliability of the pin-attached FPC, which depends on the filling degree of the electroconductive adhesive, is improved.
Furthermore, the protective panel has a structure wherein the electroconductive adhesive is filled from the through hole into the gap maintained by the spacers; thus, the injection of the electroconductive adhesive can be attained in the state that no depression is generated in the movable sheet, which is a laminated film of the upper electrode sheet and the decorative sheet. Thus, the external appearance quality of the protective panel is improved.
Also against the shrinkage of the electroconductive adhesive when the adhesive is heated and dried or cured at normal temperature, the spacers can resist the shrinkage stress. Thus, depressions in the movable sheet are decreased so that the external appearance quality of the protective panel is improved.
These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:
Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.
Hereinafter, the present invention will be described in detail on the basis of embodiments illustrated in the drawings.
In
The lower electrode panel 3 is constructed to have, on the upper surface of a nonflexible, transparent and rectangular protective panel body 3A, a rectangular lower transparent electrode 5 and band-form lower circuits 7a and 7b around the lower transparent electrode 5.
The upper electrode sheet 2a is constructed to have, on the lower surface of a flexible, rectangular and transparent insulating film, a rectangular upper transparent electrode 4 located at a position opposite to the lower transparent electrode 5, and band-form upper circuits 6a to 6d, 7c and 7d located around the upper transparent electrode 4. Of the upper circuits 6a to 6d, 7c and 7d, the circuits 6c and 6d are routing lines for giving outputs from the upper circuits 6a and 6b, respectively, to the outside. The circuits 7c and 7d are routing lines for connection to the lower circuits 7a and 7b, respectively.
The decorative sheet 2b is constructed to have, on a flexible, rectangular and transparent insulating film, a decorative layer 17 having a rectangular frame shape for hiding, by means of its pattern region, each of the lower circuits 7a and 7b of the lower electrode panel 3 and the upper circuits 6a to 6d, 7c and 7d of the upper electrode sheet 2a arranged at the peripheral edge region of the film, and defining a rectangular transparent window section 18.
The decorative sheet 2b is adhered onto the whole of the front surface (outside surface) of the upper electrode sheet 2a through a transparent adhesive layer 5d (see
Out of the above-mentioned constituents, main constituting members each have a rectangular shape. However, in the present invention, the shapes thereof are not limited to the rectangular shape.
The material of the nonflexible protective panel body 3A of the lower electrode panel 3 may be, for example, a glass plate; a plate of an engineering plastic such as a polycarbonate, polyamide, or polyetherketone plastic; or a plate of plastic such as an acrylic, polyethylene terephthalate, or polybutylene terephthalate; or the like. It is allowable to adhere, onto a surface of such a plate where the lower transparent electrode 5 is to be formed, a film of an engineering plastic such as a polycarbonate, polyamide, or polyetherketone plastic; an acrylic; polyethylene terephthalate; polybutylene terephthalate plastic; or the like, thereby forming the lower electrode panel 3.
The material of the flexible and transparent insulating film of the upper electrode sheet 2a may be, for example, a film of an engineering plastic such as a polycarbonate, polyamide, or polyetherketone plastic; an acrylic; polyethylene terephthalate; polybutylene terephthalate plastic; or the like.
The upper electrode sheet 2a and the lower electrode panel 3 are arranged oppositely to each other to make a gap 35 (see
On the upper electrode sheet 2a, the upper transparent electrode 4 is formed, and further band-form bus bars 6a and 6b are formed around the upper transparent electrode 4 to be partially parallel to each other; the bus bars 6a and 6b are connected to the upper transparent electrode 4 as the upper circuits 6a to 6d, 7c and 7d, and formed by use of a metal such as gold, silver, copper, or nickel, or an electroconductive paste of carbon or the like.
On the lower electrode panel 3, the lower transparent electrode 5 is formed, and band-form bus bars 7a and 7b extended in a direction orthogonal to the bus bars 6a and 6b are formed, as the lower circuits 7a and 7b, around the lower transparent electrode 5. The band-form bus bars 6a, 6b, 7a and 7b can each be formed by a printing method such as screen printing, offset printing, gravure printing, or flexography; a photoresist method; a brush printing method; or the like.
About the individual bus bars 6a, 6b, 7a and 7b, their circuits are extended to the connection region 8 located at one (the lower end edge in
Correspondingly to the electrode ends 6c, 7c, 6d and 7d in this connection region 8, the through holes 9a to 9d are made, respectively, in the lower electrode panel 3.
Furthermore, from these through holes 9a to 9d, electrical conductions to the electrode ends 6c, 7c, 6d and 7d are independently attained through the four metallic pins 11 to 14 of the FPC (flexible printed circuit board) 10 and the electroconductive adhesive 15 (see
The decorative sheet 2b, which has the rectangular transparent window 18, is adhered onto the front surface of the upper electrode sheet 2a. In the decorative sheet 2b, the decorative layer 17 is constituted by a pattern region on a single surface of a flexible and transparent insulating film and around the transparent window 18, in other words, the layer 17 is formed to hide the upper circuits 6a to 6d, 7c and 7d, or the lower circuits 7a and 7b, or so on; the insulating film may be, for example, a film of an engineering plastic such as a polycarbonate, polyamide, polyetherketone plastic; an acrylic; polyethylene terephthalate; or polybutylene terephthalate plastic; or the like.
It is advisable that for the decorative layer 17, a colored ink is used which contains a resin as a binder and a pigment or dye in an appropriate color as a colorant, with as the resin being used polyvinyl resins, polyamide resins, polyester resins, polyacrylic resins, polyurethane resins, polyvinyl acetal resins, polyester urethane resins, or alkyd resins. It is advisable to use, as the method for forming the decorative layer 17, an ordinary printing method such as screen printing, offset printing, gravure printing, or flexography. In order to perform multi-color printing or gradation display, offset printing or gravure printing is particularly suitable.
The decorative layer 17 maybe a metallic thin film layer, or a combination of a pattern printed layer with a metallic thin film layer. The metallic thin film layer is a layer for representing metallic luster as the decorative layer 17, and is formed by vacuum vapor deposition, sputtering, ion plating, or plating. In this case, the following may be used in accordance with the metallic luster color to be represented: a metal such as aluminum, nickel, gold, platinum, chromium iron, copper, tin, indium, silver, titanium, lead, or zinc; or an alloy or compound of any two or more of these metals. The film thickness of the metallic thin film layer is generally set to about 0.05 μm.
As described above, the decorative sheet 2b is adhered onto the whole of the front surface (outside surface) of the upper electrode sheet 2a through the adhesive layer 5d (see
The above has described the basic structure of the touch-input-function added protective panel 1 for an electronic instrument display window. The following will describe features of the embodiment of the present invention.
As described above,
As illustrated in
In
An example of the adhesive layer 16 is a double faced adhesive tape which has such a rectangular frame shape that regions for attaining inputs while a screen of the liquid crystal display device 20 or the like is seen through (the transparent window 18 in
By the particles 22, the size of each of the gaps in the individual connection holes 16a and between the lower electrode panel 3 upper surface at the peripheral edges of the through holes 9a to 9d and the movable sheet 2 is maintained (see
The filled electroconductive adhesive 15 is a product wherein electroconductive fillers are incorporated into a binder made of a silicone, epoxy, acrylic, or urethane resin. The electroconductive filler may be a powder of an electroconductive metal such as silver, gold, copper, nickel, platinum, or palladium; a filler wherein an inorganic insulator such as alumina or glass, an organic polymer such as polyethylene, polystyrene, or divinylbenzene, or the like is used as an electroconductive filler nucleus material, and any surface of the nucleus material is coated with an electroconductive layer of gold, nickel, or the like; or a filler wherein any surface of the nucleus material is coated with an electroconductive layer of carbon, graphite, or the like. The electroconductive adhesive 15 may be of either a thermosetting type or an ultraviolet curable type, and may be of either a one-component type or a two-component type. The electroconductive filler may be a filler in the form of flakes, spheres, short fibers, or the like. The method for painting the electroconductive adhesive 15 may be a dispenser method or the like.
The individual dots of the dot spacers 30, as an example of which the particles 22 function, may be formed, for example, by fixing and bonding the particles 22 onto the movable sheet 2 as illustrated in
The particle 22 is preferably made spherical. When the particle 22 is made spherical, the length sizes of the particle along the length and breadth directions thereof are substantially equal to the thickness size thereof; thus, in any state the particles 22 are fixed and bonded to the movable sheet 2, the size of the gaps between the lower electrode panel 3 upper surface at the peripheral edges of the through holes 9a to 9d and the movable sheet 2 and further in the individual connection holes 16a can be certainly kept at a predetermined value (for example, a size substantially equal to the particle diameter of the particle 22) (spacer function can be fulfilled). When the particle 22 is made into, for example, a flake form, the thickness size thereof is far smaller than the length sizes of the flake-form particles along the length and breadth directions (the thickness size is smaller than the gap size). Thus, depending on the state that the particles are fixed and bonded, the gap size may not be locally kept at the predetermined value.
When the thickness of the adhesive layer 16 is, for example, 50 μm, it is preferred to set the average particle diameter of the particles 22 into the range of 75±10 μm (65 to 85 μm). The distribution of the particles 22 is set into, for example, 10 particles/mm2.
The average particle diameter of the particles 22 is not always set into the range of 65 to 85 μm. When the thickness of the adhesive layer 16 is varied, the average particle diameter of the particles 22 is also varied. In other words, if the average particle diameter of the particles 22 is too small for the thickness of the adhesive layer 16, the movable sheet 2 cannot be supported. On the other hand, if the average particle diameter of the particles 22 is too large for the thickness of the adhesive layer 16, irregularities are generated in the surface of the movable sheet 2. In short, the matter that the average particle diameter of the particles 22 ranges from 75±10 μm (65 to 85 μm) is an example, and is a numerical example when the thickness of the adhesive layer 16 is 50 μm. Thus, for example, when the average particle diameter of the particles 22 relative to the thickness of the adhesive layer 16 is represented by the ratio therebetween (the average particle diameter of the particles/the thickness of the adhesive layer), the ratio is from 1.3 to 1.7. If this ratio is smaller than 1.3, the movable sheet 2 cannot be supported. On the other hand, if this ratio is more than 1.7, irregularities are generated in the surface of the movable sheet 2.
About the number of the particles, the following can be described: if the number of the particles is too large, the electroconductive adhesive 15 is not easily filled; on the other hand, if the number of the particles is too small, the movable sheet 2 cannot be supported. Thus, in an example, a density of 10 particles/mm2 is preferred.
The fixing and bonding of the particles 22, which has the spacer function, onto the movable sheet 2 can be attained by the supporting layer 21, which is, for example, rectangular (see
When the same silver paste is used for the supporting layer 21 and the electrode 7d, the compatibility between the two becomes good. Thus, the use is preferred for the connection reliability.
For example, the thickness of the supporting layer 21 is 20 μm, the diameter of the particles 22 is 75 μm, and the inside diameter of the through holes is 1.5 mm.
The necessity of the supporting layer 21 (that is, the necessity of fixing the particles 22) is described herein. If the particles 22 are not fixed onto the movable sheet 2 by means of the supporting layer 21 (that is, the particles 22 are not fixed onto the movable sheet 2), the following is unfavorably caused even when the particles 22 are evenly arranged at the peripheral edge of the through hole 9d as illustrated in
On the other hand, when the particles 22 are fixed onto positions at the peripheral edge of the through hole 9d by means of the supporting layer 21 (that is, the particles 22 are fixed onto the movable sheet 2), the following can be attained even when the electroconductive adhesive 15 is injected from the through hole 9d into the gaps of the individual connection holes 16a: by the electroconductive adhesive 15, the particles 22 are not shifted from the positions at the peripheral edge of the through hole 9d, so that the size of the gap of each of the connection holes 16a can be certainly kept at the predetermined value at the peripheral edge of the through hole 9d. Moreover, the electroconductive adhesive 15 can go around the particles 22, so that the space 37 does not remain between the electroconductive adhesive 15 and the adhesive layer 16. Thus, the connection reliability can be made high.
The shape of the supporting layer 21 is not limited to a rectangular shape, and may be any shape.
For example,
When an ink wherein the particles 22 are evenly dispersed in a binder is patterned to form the supporting layer 21A, the pattern shape is not limited to any rectangular frame shape, and may be any pattern shape as far as the pattern shape makes it possible that the particles 22 are not arranged in the central region thereof. For example, as illustrated in
The pattern shape is not limited to any pattern printed so as to exclude the central region of the supporting layer 21. For example, the following manner may be used: a manner of printing a rectangle with an ink wherein the particles 22 are evenly dispersed in a binder, so as to form the supporting layer 21, adding compressed air lightly to the central region of the supporting layer 21 before the ink is dried, so as to shift the ink not dried from the central region of the supporting layer 21 to the peripheral region thereof, thereby making the rectangular hole 21a.
When the supporting layer 21 is laid, it is preferred to render the supporting layer 21 an electroconductive layer. Specifically, besides the particles 22, which have the spacer function, many fine electroconductive fillers are incorporated into the binder, which constitutes the supporting layer 21, inside the supporting layer 21, thereby giving electroconductivity to the supporting layer 21 itself. Under such a condition, the filler-incorporated mixture is painted into a predetermined area of the movable sheet 2. When the supporting layer 21 is not electroconductive, the individual electrode ends 6c, 7c, 6d and 7d of the movable sheet 2 cannot attain electrical connection in their regions covered with the supporting layer 21. Thus, about the size of the area where the supporting layer 21 is formed, design flexibility is small. On the other hand, when the supporting layer 21 is electroconductive, the design flexibility about the size of the area where the supporting layer 21 is formed is increased so that the production of the particles 22 becomes easy. The electroconductive filler may be a powder of an electroconductive metal such as silver, gold, copper, nickel, platinum, or palladium; a filler wherein an inorganic insulator such as alumina or glass, an organic polymer such as polyethylene, polystyrene, or divinylbenzene, or the like is used as a nucleus material, and any surface of the nucleus material is coated with an electroconductive layer of gold, nickel, or the like; or a filler wherein any surface of the nucleus material is coated with carbon, graphite, or the like. The electroconductive filler may be a filler in the form of flakes, spheres, short fibers, or the like.
It is more preferred to render the particles 22, which have the spacer function, electroconductive particles for the following reason: when the particles 22, which have the spacer function, are rendered electroconductive particles, the electroconductivity of the insides of the individual connection holes 16a becomes good. The electroconductive particles may be a powder of an electroconductive metal such as silver, gold, copper, nickel, platinum, or palladium; a filler wherein an inorganic insulator such as alumina or glass, an organic polymer such as polyethylene, polystyrene, or divinylbenzene, or the like is used as an electroconductive particle nucleus material, and any surface of the nucleus material is coated with an electroconductive layer of gold, nickel, or the like; a filler wherein any surface of the nucleus material is coated with an electroconductive layer of carbon, graphite, or the like; or other particles.
When both of the supporting layer 21 and the particles 22 have electroconductivity, the connection performance between the region 7f extended from the bus bar 7b of the lower electrode panel 3 and the electrode end 7d of the movable sheet 2 is stabilized for the following reason: even when the heating/drying shrinkage or normal-temperature-curing shrinkage of the electroconductive adhesive 15 causes a gap to be generated between the electroconductive adhesive 15 and the extended region 7f or electrode end 7d, electrical connection is attained through the supporting layer 21 and the particles 22 between the upper and lower circuits.
Incidentally, the present invention is not limited to any embodiment wherein the particles 22 are fixed onto the lower surface side of the movable sheet 2 as illustrated in
For example, as illustrated in
However, in a case where the supporting layer 21 to which the particles 22 are attached is fixed onto the upper surface side of the lower electrode panel 3 and then the lower electrode panel 3 and the supporting layer 21 are punched out to make the through hole 9d, wastes may be generated when the supporting layer 21 and the particles 22 are removed while the through hole is made.
In order to prevent this, for example, as illustrated in
Apart from the above, as illustrated in
As illustrated in
When the individual particles 22 are each formed to have a size permitting the member opposite to the member onto which the particles 22 are fixed and bonded to be pressed, an anchor effect is obtained. For example, when the particles 22 sink slightly into the lower electrode panel 3, physical connection between the movable sheet 2 onto which the particles 22 are fixed and bonded, and the lower electrode panel 3 opposite thereto is stabilized. Furthermore, when the particles 22 fixed and bonded onto the movable sheet 2 sink slightly into the lower electrode panel 3, physical connection of the circuits (the lower circuit 7f in
The present invention is not limited to any product wherein the supporting layer 21 is arranged for each of the upper circuits 7d, 6d, 7c and 6d. The present invention may be a product wherein a single supporting layer 21, 21A, 21B or 21C is arranged for the plural upper circuits 7d, 6d, 7c and 6d.
For example, as illustrated in
As illustrated in
The spacers 30 are not limited to the particles 22, and may be prismatic spacers, or columnar spacers as described below, or the like. In other words, the spacers 30 may have any shape as far as the spacers can exhibit each of a function of permitting gaps between regions at the peripheral edges of the through holes 9a to 9d to be kept to such a degree that depressions in the movable sheet are decreased, and a function of not hindering the electroconductive adhesive 15 injected from the through holes 9a to 9d from being filled into the connection holes 16a. The material thereof is preferably electroconductive in the same manner as the particles 22.
As an example thereof, the following will describe the prismatic spacers, giving examples thereof.
In
According to the embodiment, the plural spacers 30 are fixed and arranged between the upper surface, at the peripheral edges of the through holes 9a to 9d, of the lower electrode panel 3 of the touch-input-function added protective panel 1 and the upper electrode sheet 2a and further in the individual connection holes 16a in the adhesive layer 16, so as to be separated from one another. From the through holes 9a to 9d, the electroconductive adhesive 15 is filled into the connection holes 16a, the gap interval of which is maintained by the spacers 30. For this reason, the injection of the electroconductive adhesive 15 can be smoothly filled into every portion of each of the connection holes 16a in the adhesive layer 16 for bonding the lower electrode panel 3 and the upper electrode sheet 2a. In other words, for example, the electroconductive adhesive 15 is certainly filled into the connection holes 16a, and further the following can be electrically connected to one another with certainty: the electrodes 6c, 7c, 6d and 7d of the upper electrode sheet 2a, or the electrodes 7e and 7f of the lower electrode panel 3, which face the connection holes 16a; the electroconductive adhesive 15 in the connection holes 16a; and the pins 11, 12, 13 and 14 of the FPC 10, which are inserted into the through holes 9a to 9d connected to the connection holes 16a. Thus, it is possible to heighten the reliability of electrical conduction between the electrodes 6c, 7c, 6d, 7d, 7e and 7f and the pins 11, 12, 13 and 14. Accordingly, the connection reliability of the pin-attached FPC 10, which depends on the filling degree of the electroconductive adhesive 15, is improved.
Furthermore, the electroconductive adhesive 15 is filled from the through holes 9a to 9d into the connection holes 16a, the gap interval of which is maintained by the spacers 30, so that the injection of the electroconductive adhesive 15 can be attained in the state that no depression is generated in the movable sheet 2, which is a laminated film of the upper electrode sheet 2a and the decorative sheet 2b. Thus, the external appearance quality of the protective panel 1 is improved.
Also against the shrinkage of the electroconductive adhesive 15 when the adhesive is heated and dried or cured at normal temperature, the spacers 30 can resist the shrinkage stress. Thus, depressions in the movable sheet 2 are decreased so that the external appearance quality of the protective panel 1 is improved.
The following will describe working examples which are actual examples of the embodiments. In the description on the working examples, the reference numbers of the individual constituting elements of the embodiments are used in order to make corresponding relationship between the working examples and the embodiments easily understandable. However, this does not mean that the individual constituting elements are limited to those in the following working examples.
An ITO film of 20 nm thickness was formed on the whole of a surface of a PET film of 0.1 mm thickness as a lower transparent electrode forming substrate by sputtering, and the peripheral edge region of the ITO film was removed to prepare a lower transparent electrode 5 in the form of a rectangle having a large width. Bus bars 7a and 7b arranged to two sides of the lower transparent electrode 5 that were opposite to each other along the traverse direction thereof, and routing lines 7e and 7f for giving outputs from the respective bus bars to the outside were each formed by screen printing using a silver paste. A substrate-free transparent adhesive of 0.025 mm thickness was used to adhere an acrylic plate having the same length and width as the PET film and a thickness of 0.7 mm, as a protective panel body 3A, onto the surface of the PET film opposite to the surface thereof on which the lower transparent electrode 5 was formed. Thereafter, in the edge region thereof were made by drilling four through holes 9a, 9b, 9c and 9d of 1.5 mm inside diameter wherein metallic pins 11 to 14 of a pin-attached FPC 10, which will be described later, were to be inserted. In this way, a lower electrode panel 3 was yielded.
A PET film having the same length and width as the lower electrode panel 3 and a thickness of 125 μm was used, and an ITO film of 20 nm thickness was formed on the whole of a surface thereof by sputtering. The peripheral edge region of the ITO film was removed to prepare an upper transparent electrode 4 in the form of a rectangle having a large width. Bus bars 6a and 6b arranged to two sides of the upper transparent electrode 4 that were opposite to each other along the lengthwise direction thereof, and routing lines 6c and 6d (thickness: 35 μm) for giving outputs from the respective bus bars 6a and 6b to the outside were each formed by screen-printing a silver paste wherein many electroconductive fillers made of a silver powder (diameter: 10 μm) in the form of fine flakes were incorporated into a binder made of a polyester resin. In this way, an upper electrode sheet 2a was yielded.
Furthermore, a hard coat film of a PET substrate having the same length and width as the lower electrode panel 3 and a thickness of 0.075 mm was used, and a decorative layer 17 having a transparent window section 18 was formed onto its surface opposite to its hard coat surface by gravure printing, so as to yield a decorative sheet 2b. Thereafter, the decorative layer side surface of the decorative sheet 2b was adhered onto the surface of the upper electrode sheet 2a opposite to the transparent electrode side surface thereof through a substrate-free transparent adhesive 5d of 0.025 mm thickness. In this way, a movable sheet 2 was yielded.
Next, on the upper electrode sheet 2a in the movable sheet 2, plural dot spacers 30 were formed and arranged at positions opposite to regions, at the peripheral edges of the through holes 9a to 9d, of the upper surface of the lower electrode panel 3, so as to be separated from one another. Specifically, many electroconductive fillers made of a silver powder (diameter: 10 μm) in the form of fine flakes were incorporated into a binder made of a polyester resin to prepare a silver paste, and then to the silver paste were further added particles 22 having a spacer function and made of a nickel powder (particle diameter: 75 μm). The resultant was painted by a dispenser method. In this way, the nickel particles 22 were fixed by a supporting layer 21 made of the silver paste, so as to turn to individual dots of the dot spacers 30. The thickness of the supporting layer 21 itself, which was made of the silver paste, was 35 μm, and the portions to which the nickel particles 22 were fixed and bonded were projected by 40 μm.
Next, the lower electrode panel 3 and the movable sheet 2 were arranged to be opposite to each other in such a manner that the electrodes 5 and 4 formed on the elements 3 and 2, respectively, were made apart from each other. These were adhered onto each other through a frame-form double faced adhesive tape (thickness: 50 μm) (adhesive layer 16) obtained by punching out a region of the transparent window 18 and the individual connection holes 16. The resultant was then cut along the inside circumference edge of the decorative layer 17. By the adhesion, a gap having a thickness of 50 μm was made between the upper surface of the lower electrode panel 3 at the peripheral edges of the through holes 9a to 9d and the upper electrode sheet 2a. This gap was maintained by the plural dot spacers 30. The dot spacers 30 were 25 μm larger than the distance between the lower electrode panel 3 and the movable sheet 2; thus, the particles 22 constituting the dot spacers 30 pressed the lower electrode panel 3 so that an anchor effect for the lower electrode panel 3 was exhibited.
In the meantime, in a connection side end 10a of an FPC 10 wherein a silver paste was used to form a circuit, as an electroconductive section, on a surface of a polyimide film of 0.075 mm thickness, four metallic-pin-fixing holes of 2.0 mm inside diameter were made by drilling. Therein were inserted metallic pins 11 to 14 each having a pin shaft of 1.8 mm diameter and 1 mm length and a pin head portion of 2.8 mm diameter from the circuit side surface of the FPC 10. Furthermore, a polyimide film (coverlay film 10b) of 0.05 mm thickness was adhered thereto so as to cover the circuit of the FPC 10 and the head portions of the metallic pins 11 to 14 (for example, reference number 14a in the metallic pin 14). In this way, the pin-attached FPC 10 was yielded.
Thereafter, an ink of the electroconductive adhesive 15 was injected into the through holes 9a to 9d made in the lower electrode panel 3 by a dispenser, and then the metallic pins 11 to 14 of the pin-attached FPC 10 were inserted into the through holes 9a to 9d from the inlets thereof. This electroconductive adhesive 15 was an agent wherein a flake-form silver powder having a particle diameter of 10 μm was incorporated into a binder made of a silicone resin.
Finally, while an ultrasonic inserting machine was used to apply ultrasonic vibration and pressure onto the head portions of the metallic pins 11 to 14, the shaft portions of the metallic pins 11 to 14 were inserted into the through holes 9a to 9d under the pressure. Thus, while the resin constituting the wall surfaces of the through holes 9a to 9d made in the lower electrode panel 3 was melted, the individual shaft portions of the metallic pins 11 to 14 were inserted thereinto. In this way, a touch-input-function added protective panel 1 for an electronic instrument display window was yielded.
The same process as in Working Example 1 was carried out except that the dot spacers 30 were not formed on the upper electrode sheet 2a side but were formed on the upper surface of the lower electrode panel 3 at the peripheral edges of the through holes 9a to 9d.
The same process as in Working Example 1 was carried out except that in Working Example 2, the dot spacers 30 were further formed on the upper surface of the lower electrode panel 3 at the peripheral edges of the through holes 9a to 9d. Specifically, Working Example 3 was an example wherein as illustrated in
In each of the touch-input-function added protective panels 1 of Working Examples 1 to 3, the plural dot spacers 30 were fixed and arranged between the upper surface of the lower electrode panel 3 at the peripheral edges of the through holes 9a to 9d and the upper electrode sheet 2, so as to be separated from one another. From the through holes 9a to 9d, the electroconductive adhesive 15 was filled into the gap maintained by the dot spacers 30. Thus, the protective panel 1 was excellent in the connection reliability of the FPC 10 and the external appearance quality thereof.
By properly combining arbitrary embodiment(s) or modification(s) or aspect(s) of the aforementioned various embodiments or modifications or aspects, the effects owned by each of them can be made effectual.
The touch-input-function added protective panel for an electronic instrument display window according to the present invention is excellent in reliability of its FPC connection region, and is useful for a portable information terminal such as a PDA (personal digital assistance) or a handy terminal, an OA (office automation) instrument such as a copying machine or a facsimile, a smart phone, a portable telephone, a portable game instrument, an electronic dictionary, a car navigation system, a small-sized PC (personal computer), any one of various home electrical appliances, or the like.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2009/063178 | 7/23/2009 | WO | 00 | 3/24/2011 |
