CN116744547A

CN116744547A - Film circuit structure

Info

Publication number: CN116744547A
Application number: CN202210193601.3A
Authority: CN
Inventors: 蔡磊龙; 张胜帆; 潘锦松
Original assignee: Primax Electronics Ltd
Current assignee: Primax Electronics Ltd
Priority date: 2022-03-01
Filing date: 2022-03-01
Publication date: 2023-09-12

Abstract

The invention provides a thin film circuit structure which is provided with a plurality of switch areas and comprises a first thin film, a second thin film, a spacing layer and a third thin film. The second film is positioned below the first film, and the lower surface of the second film is provided with a conductive pattern in at least one of the switch areas. The spacer layer is located between the first film and the second film. The third film is positioned below the second film, the upper surface of the third film is provided with a first trigger part and a second trigger part which are separated from each other at the at least one of the switch areas, and the conductive pattern can contact the first trigger part and the second trigger part to enable the first trigger part and the second trigger part to be conducted with each other.

Description

Film circuit structure

Technical Field

The present invention relates to a thin film circuit structure, and more particularly, to a thin film circuit structure without jumper wires.

Background

Because of the large number of mechanism holes (or film perforations) in the existing film circuit structure, the space for circuit layout is limited, and therefore, a plurality of jumpers are needed to realize the circuit layout. Please refer to fig. 1, which is a schematic diagram of a conventional thin film circuit layout. The thin film circuit layout has a plurality of mechanism holes 10m, and the wires 11 are provided with jumpers 20 at intersections with the plurality of wires 12 to electrically insulate the wires 11 from the plurality of wires 12. However, the manufacturing process of the jumper 20 is complicated, and if the quality of the insulating layer (which is used to electrically insulate the upper and lower circuits) between the upper and lower circuits is poor, a short circuit phenomenon occurs between the circuits. In addition, the jumper 20 may cause a local thickness of the thin film line structure to increase, so that the thickness of the thin film line structure is not uniform. Thus, there is a need for a thin film circuit structure that does not include jumpers.

On the other hand, referring to fig. 1, generally, a waterproof adhesive (not shown) is disposed around the periphery of the mechanism hole 10m, so that the thin film circuit structure has good waterproof performance. However, since the number of the lines 11, 12 is large and a plurality of jumpers 20 are used, the distributable range (i.e., the distributable area or the distributable width) of the waterproof adhesive is small, so that the thin film line structure does not have enough waterproof performance.

Disclosure of Invention

In some embodiments, the thin film wire structure does not include jumpers.

In some embodiments, the lower surface of the first film is provided with an upper trigger portion at the other of the switching regions, the upper surface of the second film is provided with a lower trigger portion at the other of the switching regions, the spacer layer has a through hole, and the upper trigger portions can be conducted to each other by contacting the lower trigger portions through the through hole.

In some embodiments, the thin film circuit structure further comprises: the anisotropic conductive material is arranged in the first opening and the second opening, and the first circuit and the second circuit are electrically connected through the anisotropic conductive material.

In some embodiments, the thin film circuit structure further comprises: the upper surface of the second film is provided with a third circuit in the circuit connecting area, the spacing layer is provided with a third opening separated from the first opening, the other anisotropic conductive material is positioned in the third opening, and the first circuit and the third circuit are electrically connected through the other anisotropic conductive material.

In some embodiments, the first trigger is a first U-shaped pattern.

In some embodiments, the second trigger is a second U-shaped pattern.

In some embodiments, the trailing end of the first U-shaped pattern is inserted into the opening of the second U-shaped pattern.

In some embodiments, an edge of the conductive pattern is offset from an edge of the first trigger portion closest to the edge of the conductive pattern, and another edge of the conductive pattern is offset from an edge of the second trigger portion closest to the other edge of the conductive pattern.

In some embodiments, a sum of the width of the first trigger portion and the width of the second trigger portion is greater than the width of the conductive pattern.

Drawings

The aspects of the invention will be best understood from the following description when read in conjunction with the accompanying drawings. It will be appreciated, however, that in accordance with common practice in the industry, various features are not necessarily drawn to scale. Indeed, the shape of the various features may be suitably adapted for clarity, and the dimensions of the various features may be arbitrarily increased or reduced.

FIG. 1 is a schematic diagram of a conventional thin film circuit layout.

Fig. 2 is a schematic cross-sectional view of a thin film circuit structure according to an embodiment of the invention.

Fig. 3 is a schematic top view of a switching region according to an embodiment of the present invention.

Wherein reference numerals are as follows:

10m, 100m: mechanism hole

11. 12: circuit arrangement

20: jumper wire

110: first film

111t: upper trigger part

113. 113a, 113b: first circuit

120: second film

120p: a second opening

121t: lower trigger part

122: conductive pattern

123. 123a, 123b: third line

130: third film

131t: first trigger part

132t: second trigger part

133. 133a, 133b: second circuit

140: spacer layer

140h: through hole

140p: a first opening

140q: a third opening

152. 154: anisotropic conductive material

CR: line connection area

SR1, SR2: switch area

Detailed Description

The advantages and features of the present invention and the manner in which the same are accomplished will be more readily understood by reference to the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Spatially relative terms, such as "lower" and "upper" herein, may be used for convenience in describing the relative relationship between one element or feature and another element or feature in the drawings. The true meaning of these spatially relative terms encompasses other orientations. For example, when the drawing is turned over 180 degrees up and down, the relationship between one element and another element may be changed from "down" to "up". The spatially relative terms used herein should be interpreted as such.

As described in the prior art, the existing thin film circuit structure is complicated in manufacturing process due to the jumper design, and the thin film circuit structure has the problems of inconsistent thickness, insufficient waterproof performance and the like. There is therefore a need for a thin film wiring structure that does not include jumpers. Accordingly, the present invention provides a thin film circuit structure that does not include jumpers, so as to solve the above-mentioned problems. Various embodiments of the thin film wire structure of the present invention are described in detail below.

The thin film circuit structure of the invention can be applied to keyboard structures, such as keyboard structures of notebook computers. The thin film circuit structure is provided with a plurality of switch areas, and each switch area can correspond to one key structure. Fig. 2 is a schematic cross-sectional view of a thin film circuit structure according to an embodiment of the invention. Fig. 2 illustrates two switching zones. As shown in fig. 2, the thin film circuit structure has switching regions SR1, SR2.

With continued reference to fig. 2, the thin film circuit structure includes a first thin film 110, a second thin film 120, a third thin film 130, and a spacer layer 140. The first film 110, the second film 120, the third film 130, and the spacer layer 140 may be made of plastic materials, such as Polycarbonate (PC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyurethane (PU), or Polyimide (PI). The film made of plastic material has the characteristics of insulation, heat resistance, bending property, high resilience and the like, so that the manufactured film circuit structure has flexibility and is similar to the existing flexible printed circuit board (flexible printed circuit, FPC).

With continued reference to fig. 2, the second film 120 is substantially parallel to the first film 110 and is located below the first film 110. The lower surface of the second film 120 is provided with a conductive pattern 122 at least one of the switching regions (i.e., switching region SR 1). The conductive pattern 122 may be formed by printing conductive silver paste, but the present invention is not limited thereto.

The spacer layer 140 is substantially parallel to the first film 110 and the second film 120 and is positioned (or may be referred to as sandwiched) between the first film 110 and the second film 120. In some embodiments, the thickness of the spacer layer 140 is less than the thickness of the first film 110 and the thickness of the second film 120.

The third film 130 is substantially parallel to the second film 120 and the first film 110, and is located under the second film 120. The upper surface of the third film 130 is provided with a first trigger portion (or first contact) 131t and a second trigger portion (or second contact) 132t, which are separated from each other, at the at least one of the switching regions (i.e., switching region SR 1). The first trigger part 131t, the second trigger part 132t and the connection lines thereof may be formed by printing conductive silver paste, but the present invention is not limited thereto.

The conductive pattern 122 can contact the first trigger portion 131t and the second trigger portion 132t, and turn on the first trigger portion 131t and the second trigger portion 132t. In detail, when the user does not press the key, the first triggering portion 131t and the second triggering portion 132t are separated from the conductive pattern 122 (as shown in fig. 2); when the user presses the key, the second film 120 is pressed to deform (e.g., protrude downward), so that the conductive pattern 122 contacts the first triggering portion 131t and the second triggering portion 132t, and the first triggering portion 131t and the second triggering portion 132t are electrically connected to each other through the conductive pattern 122. In some embodiments, one or more switching regions among the thin film wire structures may employ the structure of switching region SR1 as shown in fig. 2.

In some embodiments, the lower surface of the first film 110 is provided with an upper trigger (or upper contact) 111t at the other of the switch regions (i.e., switch region SR 2), and the upper surface of the second film 120 is provided with a lower trigger (or lower contact) 121t at the other of the switch regions (i.e., switch region SR 2), the spacer layer 140 has a through hole 140h, and the upper trigger 111t can be electrically connected to each other by contacting the lower trigger 121t through the through hole 140 b. In detail, when the user does not press the key, the upper trigger 111t and the lower trigger 121t are separated from each other (as shown in fig. 2); when the user presses the key, the first film 110 is pressed to deform (e.g., protrude downward) so that the upper trigger 111t contacts the lower trigger 121t, and the upper trigger 111t and the lower trigger 121t are electrically connected to each other. In some embodiments, one or more switching regions among the thin film wire structures may employ the structure of switching region SR2 as shown in fig. 2.

It should be noted that, in practical applications, the design of the switching region SR1 can be used to replace the switching region (i.e. the switching region requiring the jumper) related to the jumper position in the existing thin film circuit layout (i.e. the thin film circuit layout with the jumper). That is, the design of the switch region SR1 of the present invention can be applied to various existing thin film circuit layouts with jumpers, and the thin film circuit layout with jumpers can be converted into the thin film circuit layout without jumpers without spending much labor and time.

On the other hand, since one or more switch regions in the film circuit structure can adopt the structure of the switch region SR1 shown in fig. 2, the circuit disposed on the first film 110 and the circuit disposed on the second film 120 can be reduced in addition to the jumper wire, so that the distribution range of the waterproof glue disposed around the mechanism hole is larger, and the film circuit structure of the present invention has good waterproof performance.

In some embodiments, as shown in fig. 2, an edge of the conductive pattern 122 is offset from an edge of the first trigger portion 131t closest to the edge of the conductive pattern 122, and another edge of the conductive pattern 122 is offset from an edge of the second trigger portion 132t closest to the other edge of the conductive pattern 122. However, the present invention is not limited to the above embodiment, and the setting positions of the conductive pattern 122, the first triggering portion 131t and the second triggering portion 132t can be adjusted appropriately according to the actual requirements.

In some embodiments, as shown in fig. 2, the sum of the width of the first triggering portion 131t and the width of the second triggering portion 132t is greater than the width of the conductive pattern 122. However, the present invention is not limited to the above embodiment, and the dimensions of the conductive pattern 122, the first triggering portion 131t and the second triggering portion 132t can be adjusted appropriately according to the actual requirements.

In some embodiments, as shown in fig. 2, the thin film wire structure further has a wire connection region CR adjacent to one of the switching regions (e.g., switching region SR 1). In some embodiments, the thin film circuit structure further includes anisotropic conductive material 152 disposed to electrically connect the circuits located at different levels to each other.

For example, as shown in fig. 2, the lower surface of the first film 110 is provided with one or more first lines 113 (two first lines 113a and 113b are taken as an example in fig. 2), and the upper surface of the third film 130 is provided with one or more second lines 133 (two second lines 133a and 133b are taken as an example in fig. 2). The spacer layer 140 has a first opening 140p and the second film 120 has a second opening 120p that is generally aligned with the first opening 140 p. The anisotropic conductive material 152 is disposed in the first opening 140p and the second opening 120p, and the first circuit 113 and the second circuit 133 are electrically connected through the anisotropic conductive material 152. In detail, the first line 113a is electrically connected to the second line 133a through the anisotropic conductive material 152, and the first line 113b is electrically connected to the second line 133b through the anisotropic conductive material 152.

It should be noted that fig. 2 is an illustration of two first lines 113a and 113b, but fig. 2 is a cross-sectional view, so two portions of the first line 113a and two portions of the first line 113b are shown. In some embodiments, the upper surface of the second film 120 is provided with one or more third lines 123 (two third lines 123a, 123b are illustrated in fig. 2 as an example) in the line connecting region CR. The spacer layer 140 has a third opening 140q that is separate from the first opening 140 p. The anisotropic conductive material 154 is disposed in the third opening 140q, and the first circuit 113 and the third circuit 123 are electrically connected through the anisotropic conductive material 154. In detail, the first line 113a is electrically connected to the third line 123a through the anisotropic conductive material 154, and the first line 113b is electrically connected to the third line 123b through the anisotropic conductive material 154.

As can be seen from the above, the second circuit 133a is electrically connected to the third circuit 123a through the anisotropic conductive material 152, the first circuit 113a and the anisotropic conductive material 154; the second line 133b is electrically connected to the third line 123b through the anisotropic conductive material 152, the first line 113b, and the anisotropic conductive material 154. That is, the second wires 133a, 133b may exit the third wires 123a, 132b through the wire bonding shown in fig. 2, and then may be electrically connected to the connectors of the system side.

Fig. 3 is a schematic top view of a switching region according to an embodiment of the present invention. As shown in fig. 3, a switch region SR1 is disposed between the two mechanism holes 100m, and in some embodiments, the first triggering portion 131t is a first U-shaped pattern. In some embodiments, the second trigger portion 132t is a second U-shaped pattern. In some embodiments, the trailing end of the first U-shaped pattern is inserted into the opening of the second U-shaped pattern. However, the present invention is not limited to the above embodiment, and the shapes of the first triggering portion 131t and the second triggering portion 132t can be adjusted appropriately according to the actual requirements.

However, the foregoing description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the invention, i.e., the invention is defined by the appended claims and their description, but rather by the following claims. Furthermore, not all of the objects, advantages, or features of the disclosure are required to be achieved by any one embodiment or claim of the present invention. Furthermore, the abstract sections and headings are for use only in assisting patent document searching and are not intended to limit the scope of the claims.

Claims

1. A thin film circuit structure having a plurality of switching regions, the thin film circuit structure comprising:

a first film;

a second film under the first film, a lower surface of the second film having a conductive pattern on at least one of the switching regions;

a spacer layer between the first film and the second film; and

the third film is positioned below the second film, a first triggering part and a second triggering part which are separated from each other are arranged on the upper surface of the third film at least one of the switch areas, and the conductive pattern can contact the first triggering part and the second triggering part so as to lead the first triggering part and the second triggering part to be conducted with each other.

2. The thin film wire structure of claim 1, wherein the thin film wire structure does not include a jumper.

3. The thin film circuit structure as claimed in claim 1, wherein a lower surface of the first thin film is provided with an upper trigger portion at the other of the switching regions, an upper surface of the second thin film is provided with a lower trigger portion at the other of the switching regions, the spacer layer has a through hole, and the upper trigger portions can be conducted to each other by contacting the lower trigger portion through the through hole.

4. The thin film wire structure of claim 1, further comprising:

the first film is provided with a first circuit in the circuit connection area, the upper surface of the third film is provided with a second circuit in the circuit connection area, the spacing layer is provided with a first opening, the second film is provided with a second opening which is approximately aligned with the first opening, the anisotropic conductive material is positioned in the first opening and the second opening, and the first circuit and the second circuit are electrically connected through the anisotropic conductive material.

5. The thin film wire structure of claim 4, further comprising:

the first circuit and the second circuit are electrically connected through the other anisotropic conductive material.

6. The thin film circuit structure of claim 1, wherein the first trigger portion is a first U-shaped pattern.

7. The thin film circuit structure of claim 6, wherein the second trigger portion is a second U-shaped pattern.

8. The thin film wire structure of claim 7, wherein a tail end of the first U-shaped pattern is inserted into an opening of the second U-shaped pattern.

9. The thin film wire structure of claim 1, wherein an edge of the conductive pattern is offset from an edge of the first trigger portion closest to the edge of the conductive pattern, and another edge of the conductive pattern is offset from an edge of the second trigger portion closest to the other edge of the conductive pattern.

10. The thin film circuit structure of claim 1, wherein a sum of a width of the first trigger portion and a width of the second trigger portion is greater than a width of the conductive pattern.