TWI476800B - A method for manufacturing thin film circuit of two-layer type membrane keyboard and structure thereof - Google Patents

Description

Thin film circuit manufacturing method and structure of two-layer membrane keyboard

The invention relates to a membrane keyboard, in particular to a method and a structure for manufacturing a two-layer membrane circuit of a membrane keyboard.

It is known that notebook computers have the function of being easy to carry around and communicating on the Internet. Since the buttons of the membrane keyboard of the current notebook computer adopt a thin button structure, mainly a bridge supporting structure is assembled between the key cap and the bottom plate, and a film printed circuit is also included. After the key cap is pressed, the bridging type support structure is interlocked, so that the key cap is smoothly pressed on the thin film printing circuit, so that the contact pads on the thin film printed circuit are in contact with each other, and the contact telecommunications is transmitted to the contact. On the computer, input the input signal to complete the operation interface.

A conventional thin film printed circuit requires three layers of an upper film layer, a middle film layer, and a lower film layer. In the manufacturing process, a conductive circuit layer is printed on the upper film layer and the lower film layer in a silver paste, and after the conductive circuit layer is printed, the waterproof glue is printed on both sides of the conductive circuit layer. When the upper film layer is bonded to the lower film layer, the intermediate film layer is adhered between the upper and lower film layers and bonded by a waterproof glue. After the upper film layer, the middle film layer and the lower film layer are bonded, not only has a waterproof effect, but also has an air passage to prevent air-tightness between the upper, middle and lower layers of the film layer. At the same time, the middle film layer can prevent short circuit between the conductive circuit layer of the upper film layer and the conductive circuit layer of the lower film layer.

Since the conventional thin film printed circuit has a three-layer structure design, problems such as air passage, waterproof and short circuit are considered in the manufacturing process, so that the three-layer thin film printed circuit step is difficult to be produced, resulting in an increase in manufacturing cost.

Therefore, the main object of the present invention is to solve the conventional defect and avoid the existence of the missing. The present invention proposes to manufacture a two-layer thin film circuit by using two layers of thin film layers, which makes the steps of fabricating the thin film circuit simpler and easier, and also reduces the manufacturing cost and material saving. It also makes the thickness of the thin film circuit thinner.

To achieve the above objective, the present invention provides a method for fabricating a thin film circuit of a two-layer membrane keyboard, comprising: first having a first film layer and a second film layer; respectively, the first film layer and the second film layer respectively Forming a first conductive layer and a second conductive layer; forming a protective layer and a plurality of spacer pads on the first conductive layer and the second conductive layer; and the first film layer and the second film layer along The first conductive layer and the second conductive layer, the protective layer and the first film layer adjacent to the spacer and the second film layer are coated with a waterproof layer; the waterproof layer is bonded to the first film layer and the a second film layer, the spacer forms an air flow passage between the first film layer and the second film layer, and prevents external moisture from entering between the first film layer and the second film layer.

The first film layer and the second film layer have a plurality of through holes of different shapes.

Wherein, the first film layer and the second film layer are transparent polyethylene terephthalate.

The first film layer and the second film layer have a thickness of 0.075 mm.

The first conductive layer includes a plurality of first contact pads and a plurality of first lines connecting the plurality of first contact pads, and the first conductive layer on the periphery of the first contact pads is printed with a plurality of a bump, the plurality of first bump loops are disposed on a periphery of the first contact pad.

The second conductive layer includes a plurality of second contact pads in contact with the first contact pads and a plurality of second lines connecting the plurality of second contact pads, on the periphery of the second contact pads. The second conductive layer is printed with a plurality of second bumps, and the plurality of second bump loops are disposed on the second contact pads.

The material of the first conductive layer and the second conductive layer is a silver paste.

The protective layer is formed on the first line of the first conductive layer and the second line of the second conductive layer, and the thickness of the protective layer is 7-14 um.

Wherein, when the protective layer is formed, a first gasket and a second gasket are formed on the first bump and the second bump in synchronization.

The first gasket and the second gasket have a thickness of 12 to 25 um.

Wherein the protective layer, the first gasket and the second gasket are formed on the first film layer and the second film layer along the first line, the second line path and the first line and A plurality of spacers are formed on the path of the second line.

Wherein, the protective layer, the first gasket, the second gasket and the spacer are ultraviolet curing resin (uv).

Wherein the waterproof layer is coated on the edge of the through hole of the first film layer and the second film layer and adjacent to the first line, the second line, the protective layer, the first gasket, the second gasket and the spacer The position of the first film layer and the second film layer.

The waterproof layer is a waterproof glue and has a thickness of 10 to 22 um.

In order to achieve the above object, the present invention provides a thin film circuit structure of a two-layer membrane keyboard, comprising: a first film layer having a first conductive layer thereon; a second film layer having a second conductive layer thereon; a protective layer disposed on the first conductive layer and the second conductive layer; a plurality of spacers disposed on the first film layer and the first On the second film layer; a waterproof layer is disposed on the first film layer and the second film layer; wherein the first film layer and the second film layer are bonded by the waterproof layer, the plurality of spacers enable the An air flow passage is formed between the first film layer and the second film layer, and the waterproof layer prevents external moisture from entering between the first film layer and the second film layer.

The first film layer and the second film layer have a plurality of through holes of different shapes.

The first conductive layer includes a plurality of first contact pads and a plurality of first lines connecting the plurality of first contact pads, and the first conductive layer on the periphery of the first contact pads has a plurality of first protrusions The first bump ring is disposed on a periphery of the first contact pad.

The second conductive layer includes a plurality of second contact pads in contact with the first contact pads and a plurality of second lines connecting the plurality of second contact pads, on the periphery of the second contact pads. The second conductive layer has a plurality of second bumps disposed on the second contact pad.

The first conductive layer and the second conductive layer are silver paste and have a thickness of 3-8 um.

Wherein, the first film layer and the second film layer are transparent polyethylene terephthalate materials having a thickness of 0.075 mm.

The protective layer is disposed on a surface of the first line of the first conductive layer and the second line of the second conductive layer, and the protective layer has a thickness of 7-14 um.

The protective layer further includes a first gasket and a second gasket disposed on the surfaces of the first bump and the second bump.

The first gasket and the second gasket have a thickness of 12 to 25 um.

Wherein, the protective layer is an ultraviolet curing resin (uv).

The plurality of spacer pads are disposed on the first line, the second line path, and the path of the first line and the second line of the first film layer and the second film layer.

Wherein, the spacer is an ultraviolet curing resin (uv).

Wherein, the waterproof layer is disposed at an edge of the through hole of the first film layer and the second film layer and along the first line, the second line, the protective layer, the first gasket, the second gasket, and the spacer The positions of the adjacent first film layer and the second film layer.

The waterproof layer is a waterproof glue and has a thickness of 10 to 22 um.

100~108‧‧‧Steps

1‧‧‧First film layer

11‧‧‧through hole

12‧‧‧First conductive layer

121‧‧‧First contact pad

121‧‧‧First contact pad

122‧‧‧First line

123‧‧‧First bump

2‧‧‧Second film layer

21‧‧‧through hole

22‧‧‧Second conductive layer

221‧‧‧Second contact pad

222‧‧‧second line

223‧‧‧second bump

3‧‧‧Protective layer

31‧‧‧First washer

32‧‧‧Second washer

4‧‧‧ spacer

5‧‧‧Waterproof layer

The first figure is a schematic diagram of the production process of the present invention.

The second figure is a schematic diagram of a thin film circuit of the membrane keyboard of the present invention.

The third figure is a partial enlarged view of the second figure.

The fourth figure is an exploded view of the third figure.

The fifth figure is a cross-sectional view of the second figure at the position of 5-5.

The technical content and detailed description of the present invention are described below with reference to the following drawings: Please refer to the first drawing, which is a schematic diagram of the manufacturing process of the present invention; and the structural diagrams of the second to fifth figures are also referred to. As shown in the figure: a method for fabricating a thin film circuit 10 of a two-layer membrane keyboard of the present invention, first, a step 100 is provided with a first film layer 1 and a second film layer 2, and the first film layer 1 and the first film layer The second film layer 2 has a plurality of through holes 11, 21 of different shapes. In the present drawing, the first film layer 1 and the second film layer 2 are transparent PET plastic materials (Polyethylene terephthalate polyethylene terephthalate) having a thickness of 0.075 mm.

Step 102, coating (printing) the formed conductive line, forming a first conductive layer 12 and a second conductive layer 22 on the first film layer 1 and the second film layer 2, and having a thickness of 3-8 μm. The first conductive layer 12 includes a plurality of first contact pads 121 and a plurality of first lines 122 connecting the plurality of first contact pads 121, and a first conductive layer 12 on the periphery of the first contact pads 121. A plurality of first bumps 123 are printed on the periphery, and the plurality of first bumps 123 are disposed on the periphery of the first contact pad 121. The first The second conductive layer 22 includes a plurality of second contact pads 221 electrically connected to the first contact pads 121 and a plurality of second lines 222 connecting the plurality of second contact pads 221, the second contacts The second conductive layer 22 on the periphery of the pad 221 is printed with a plurality of second bumps 223 , and the plurality of second bumps 223 are annularly disposed on the second contact pads 221 . The aforementioned first and second bumps 123, 223 balance the force of the depression. In the present drawing, the material of the first conductive layer 12 and the second conductive layer 22 is a silver paste.

In step 104, a protective layer, a gasket and a spacer are formed. After the first conductive layer 12 and the second conductive layer 22 are formed, a protective layer 3 is coated on the first line 122 and the second line 222. The protective layer 3 has a thickness of 7 to 14 um, and the protective layer 3 does not cause a short circuit between the first line 122 and the second line 222. In addition, when the protective layer 3 is printed, a first gasket 31 and a second gasket 32 are printed on the first bump 123 and the second bump 223, and the first gasket 31 and the second gasket are printed on the first bump 123 and the second bump 223. The thickness of 32 is 12~25um, and the first washer 31 and the second washer 32 mainly serve to balance the steady-state airflow when the first contact pad 121 is pressed into contact with the second contact pad 221, so that the first A gas-tight phenomenon does not occur between the film layer 1 and the second film layer 2. Moreover, when the protective layer 3, the first gasket 31 and the second gasket 32 are printed, the first film layer 1 and the second film layer 2 are also synchronized along the first line 122 and the second line 222. A plurality of spacers 4 are printed on the path and the path without the first line 122 and the second line 222. In the present drawing, the protective layer 3, the first gasket 31, the second gasket 32, and the spacer 4 are ultraviolet curable resins (uv).

Step 106, preparing a waterproof layer, at the edges of the through holes 11, 21 of the first film layer 1 and the second film layer 2, along the first line 122, the second line 222, the protective layer 3, the first gasket 31, The waterproof layer 5 is applied to the positions of the first film layer 1 and the second film layer 2 adjacent to the second gasket 32 and the spacer 4. In the figure, the waterproof layer 5 is a waterproof glue.

Step 108, bonding the first film layer 1 and the second film layer 2 with the waterproof layer 5, and after the bonding, the spacer 4 forms an air flow channel between the first film layer 1 and the second film layer 2 When the first contact pad 121 is pressed into contact with the second contact pad 221, the airflow is circulated, so that a gas-tight phenomenon is less likely to occur between the first film layer 1 and the second film layer 2, and the waterproof layer 5 can be External moisture is prevented from entering between the first film layer 1 and the second film layer 2.

Referring to the second to fifth figures, the two-layer thin film circuit of the membrane keyboard completed by the above manufacturing method comprises: a first film layer 1, a second film layer 2, a protective layer 3, and a plurality of spacer pads. 4 and a waterproof layer 5.

The first film layer 1 has a plurality of different shapes of through holes 11 and a first conductive layer 12. The first conductive layer 12 includes a plurality of first contact pads 121 and a plurality of first lines 122 connecting the plurality of first contact pads 121, and a first conductive layer 12 on the periphery of the first contact pads 121. A plurality of first bumps 123 are printed on the plurality of first bumps 123. The first bumps 123 are disposed on the periphery of the first contact pads 121. The first bumps 123 balance the force of the pressing. In the present drawing, the first film layer 1 is a transparent PET plastic material (Polyethylene terephthalate polyethylene terephthalate) having a thickness of 0.075 mm. The first conductive layer 12 is a silver paste having a thickness of 3 to 8 um.

The second film layer 2 has a plurality of through holes 21 and a second conductive layer 22 of different shapes. The second conductive layer 22 includes a plurality of second contact pads 221 electrically connected to the first contact pads 121 and a plurality of second lines 222 connecting the plurality of second contact pads 221. The second conductive layer 22 on the periphery of the contact pad 221 is printed with a plurality of second bumps 223 A plurality of the second bumps 223 are disposed on the second contact pad 221, and the second bumps 223 balance the force of the pressing. In the present drawing, the second film layer 2 is a transparent PET plastic material (Polyethylene terephthalate polyethylene terephthalate) having a thickness of 0.075 mm. The second conductive layer 22 is a silver paste having a thickness of 3 to 8 um.

The protective layer 3 is disposed on the first line 122 and the second line 22 The protective layer 3 has a thickness of 7 to 14 um on the surface of the second layer. The protective layer 3 does not cause a short circuit between the first line 122 and the second line 222. In addition, when the protective layer 3 is printed, a first gasket 31 and a second gasket 32 are provided on the surfaces of the first bump 123 and the second bump 223, and the first gasket 31 and the second gasket The thickness of the washer 32 is 12-25 μm, and the first washer 31 and the second washer 32 mainly serve to balance the steady-state airflow when the first contact pad 121 is pressed into contact with the second contact pad 221. No gas-tight phenomenon occurs between the first film layer 1 and the second film layer 2. In the present drawing, the protective layer 3 is an ultraviolet curable resin (uv).

The plurality of spacers 4 are disposed on the first line 122 of the first film layer 1 and the second film layer 2, the path of the second line 222, and the path of the first line 122 and the second line 222. When the first film layer 1 is adhered to the second film layer 2, the spacer 4 forms an air flow passage between the first film layer 1 and the second film layer 2, and the first contact pad 121 is When the contact with the second contact pad 221 is pressed, the airflow is caused to flow, and a gas-tight phenomenon is unlikely to occur between the first film layer 1 and the second film layer 2. In the present drawing, the spacer 4 is an ultraviolet curable resin (uv).

The waterproof layer 5 is disposed at the edge of the through holes 11 and 21 of the first film layer 1 and the second film layer 2 along the first line 122, the second line 222, the protective layer 3, and the first gasket. 31. The second gasket 32 and the first film layer 1 and the second film layer 2 adjacent to the spacer 4 are disposed, and the waterproof layer 5 is provided to bond the first film layer 1 and the second film layer 2 In addition, the waterproof layer 5 prevents external moisture from entering between the first film layer 1 and the second film layer 2. In the figure, the waterproof layer 5 is a waterproof glue and has a thickness of 10 to 22 um.

After the film circuit of the film type keyboard is fabricated by using the two-layer first film layer 1 and the second film layer 2, not only the film keyboard is made easier, but also the material and the manufacturing cost are saved, and the film keyboard is saved. The thinner thickness has been produced in line with the current trend that electronic products tend to be light, thin and short.

The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. That is, the equivalent changes and modifications made by the scope of the patent application of the present invention are covered by the scope of the invention.

100~118‧‧‧Steps

Claims (22)

A method for fabricating a thin film circuit of a two-layer membrane keyboard, comprising: a) preparing a first film layer and a second film layer, wherein the first film layer and the second film layer have a plurality of through holes of different shapes And forming a first conductive layer and a second conductive layer on the first film layer and the second film layer, the first conductive layer comprising a plurality of first contact pads and a plurality of connecting plurality of a first line of the first contact pad, and a plurality of first bumps printed on the first conductive layer on the periphery of the first contact pad, the plurality of first bump rings being disposed on the periphery of the first contact pad The second conductive layer includes a plurality of second contact pads in contact with the first contact pads and a plurality of second lines connecting the plurality of second contact pads, and the second periphery of the second contact pads The second conductive layer is printed with a plurality of second bumps, wherein the plurality of second bump loops are disposed on the second contact pad; c), the first line of the first conductive layer and the second conductive layer Forming a protective layer and a plurality of spacer pads on the second line; d), in the first thin The layer and the second film layer are coated with a waterproof layer at a position of the first film layer and the second film layer adjacent to the first conductive layer and the second conductive layer, the protective layer and the spacer; e) The waterproof layer is bonded between the first film layer and the second film layer, the spacer forms an air flow passage between the first film layer and the second film layer, and prevents external moisture from entering the Between the first film layer and the second film layer. The method for fabricating a thin film circuit according to claim 1, wherein the first film layer and the second film layer are transparent polyethylene terephthalate. The method for fabricating a thin film circuit according to claim 2, wherein the first film layer and the second film layer have a thickness of 0.075 mm. The method for fabricating a thin film circuit according to claim 3, wherein the material of the first conductive layer and the second conductive layer is a silver paste. The method for fabricating a thin film circuit according to claim 4, wherein the protective layer has a thickness of 7 to 14 um. The method of fabricating a thin film circuit according to claim 5, wherein the step c is formed by simultaneously forming a first gasket and a second gasket on the first bump and the second bump when the protective layer is formed. The method for fabricating a thin film circuit according to claim 6, wherein the first gasket and the second gasket have a thickness of 12 to 25 um. The method of fabricating a thin film circuit according to claim 7, wherein the step c is synchronously forming the protective layer, the first gasket and the second gasket along the first film layer and the second film layer along the first A plurality of spacers are formed on a line, a second line path, and a path without the first line and the second line. The method for fabricating a thin film circuit according to claim 8, wherein the protective layer, the first gasket, the second gasket, and the spacer are ultraviolet curing resins (uv). The method for fabricating a thin film circuit according to the eighth aspect of the invention, wherein the waterproof layer of the step d is coated on the edge of the through hole of the first film layer and the second film layer and along the first line and the second line, a protective layer, a first gasket, a second gasket, and a position of the first film layer adjacent to the spacer and the second film layer. The method for fabricating a film circuit according to claim 10, wherein the waterproof layer is a waterproof glue and has a thickness of 10 to 22 um. A thin film circuit structure of a two-layer membrane keyboard, comprising: a first film layer having a first conductive layer thereon, the first film layer having a plurality of different shapes of through holes, the first conductive layer comprising a plurality of a first contact pad and a plurality of first lines connecting the plurality of first contact pads, and a plurality of first bumps on the first conductive layer on the periphery of the first contact pad, the first bump ring being disposed on a second film layer having a second conductive layer thereon, the second film layer having a plurality of different shapes of through holes, the second conductive layer comprising a plurality of a contact pad contacting the conductive second contact pad and a plurality of second lines connecting the plurality of the second contact pads, and having a plurality of second bumps on the second conductive layer on the periphery of the second contact pad, a second bump ring is disposed on the second contact pad; a protective layer is disposed on the first line of the first conductive layer and the second line of the second conductive layer; a plurality of spacers are disposed on the first film layer and the second film layer; The layer is disposed between the first film layer and the second film layer; wherein the first film layer and the second film layer are bonded by the waterproof layer, the plurality of spacers make the first film layer and An air flow passage is formed between the second film layers, and the waterproof layer prevents external moisture from entering between the first film layer and the second film layer. The thin film circuit structure of claim 12, wherein the first conductive layer and the second conductive layer are silver paste, and the thickness thereof is 3-8 um. The film circuit structure of claim 13, wherein the first film layer and the second film layer are transparent polyethylene terephthalate materials having a thickness of 0.075 mm. The thin film circuit structure of claim 14, wherein the protective layer has a thickness of 7 to 14 um. The film circuit structure of claim 15, wherein the protective layer further comprises a first gasket and a second gasket disposed on the surface of the first bump and the second bump. The film circuit structure of claim 16, wherein the first gasket and the second gasket have a thickness of 12 to 25 um. The film circuit structure of claim 17, wherein the protective layer is a UV curable resin (uv). The thin film circuit structure of claim 18, wherein the plurality of spacers are disposed on the first line and the second line of the first film layer and the second film layer, and the first line and the first line On the path of the two lines. The film circuit structure of claim 19, wherein the spacer is an ultraviolet curing resin (uv). The thin film circuit structure of claim 20, wherein the waterproof layer is disposed at an edge of the through hole of the first film layer and the second film layer and along the first line and the second line, The protective layer, the first gasket, the second gasket, and the first film layer adjacent to the spacer and the position of the second film layer. The film circuit structure of claim 21, wherein the waterproof layer is a waterproof glue and has a thickness of 10 to 22 um.