JP2019153429A - Switch module - Google Patents

Abstract

To provide a narrow and thin switch module with a high sealing performance.SOLUTION: A switch module according to one embodiment comprises: a wiring board where a fixed contact is provided on its first surface; a movable contact arranged on the first surface of the wiring board so as to be contactable with the fixed contact; a sheet member that has a first portion covering the first surface of the wiring board, a second portion extending from the first portion and covering a first lateral face of the wiring board, a third portion extending from the second portion and covering a part of a second surface of the wiring board, a fourth portion extending from the first portion and covering a second lateral face opposed to the first lateral face of the wiring board, and a fifth portion extending from the fourth portion and covering a part of the second surface of the wiring board; and an adhesive layer provided between the wiring board and the sheet member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a switch module.

  In recent years, narrow and thin switch modules have been sought as side switches for smartphones and tablet terminals, and as operation switches for thin frameless TVs. In addition, in a smartphone or the like, a high sealing property may be required for the switch module for dust prevention and waterproofing.

  Conventionally, as a narrow and thin switch module, FPC (Flexible Printed Circuits) having a fixed contact, a dome-shaped movable contact provided on the surface of the FPC, and a sheet member attached to the surface of the FPC with an adhesive tape, The thing equipped with, is known. In this switch module, high sealing performance can be obtained by widening the adhesive margin of the adhesive tape.

JP 2017-117593 A

  However, the conventional switch module described above has a limit in narrowing because it is necessary to secure a margin for attaching the adhesive tape.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a narrow and thin switch module having high hermeticity.

  A switch module according to an embodiment includes a wiring board having a fixed contact on a first surface, a movable contact disposed on the first surface of the wiring board so as to be in contact with the fixed contact, and the wiring board A first portion covering the first surface, a second portion extending from the first portion and covering the first side surface of the wiring substrate, and extending from the second portion and covering a part of the second surface of the wiring substrate A third portion; a fourth portion extending from the first portion and covering a second side surface facing the first side surface of the wiring substrate; and a first portion extending from the fourth portion and extending from the second surface of the wiring substrate. And a pressure-sensitive adhesive layer provided between the wiring board and the sheet member.

  According to each embodiment of the present invention, a narrow and thin switch module having high hermeticity can be realized.

The top view which shows an example of a switch module. AA line sectional view of the switch module of FIG. The disassembled perspective view of the switch module of FIG. The figure which shows the modification of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, regarding the description of the specification and the drawings according to each embodiment, constituent elements having substantially the same functional configuration are denoted by the same reference numerals and overlapping description is omitted.

  A switch module 100 according to an embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing an example of the switch module 100. FIG. 2 is a cross-sectional view of the switch module 100 of FIG. FIG. 3 is an exploded perspective view of the switch module 100 of FIG. FIG. 4 is a diagram showing a modification of FIG.

  As shown in FIGS. 1 to 3, the switch module 100 includes a wiring board 1, a movable contact 2, a sheet member 3, and an adhesive layer 4. Hereinafter, for convenience, the first surface (upper surface in FIG. 2) of the wiring board 1 will be referred to as the front surface, and the second surface (lower surface in FIG. 2) will be referred to as the back surface. The reverse may be possible.

  The wiring substrate 1 is a thin substrate having a wiring pattern (not shown) formed on the surface 11. The wiring pattern can also be formed on the back surface 12 or inside of the wiring substrate 1. Although the wiring board 1 is FPC, for example, it is not restricted to this. In the example of FIG. 1, the planar view shape of the wiring board 1 is a rectangle having a long side and a short side. The length of the short side of the wiring board 1 corresponds to the width W of the wiring board 1. The width W is, for example, 5 mm or less. Of the two side surfaces corresponding to the long side of the wiring substrate 1, one side surface (left side surface in FIG. 2) is the first side surface 13, and the other side surface facing the first side surface 13 (right side surface in FIG. 2). Is referred to as a second side surface 14. The height H (the thickness of the wiring board 1) of the first side surface 13 and the second side surface 14 is, for example, 1 mm or less. In addition, the planar view shape of the wiring board 1 is not restricted to a rectangle, It can be set as the arbitrary shapes which have the narrow part whose width W is 5 mm or less. The wiring board 1 has a fixed contact 15.

  The fixed contact 15 is a contact formed on the surface 11 of the wiring board 1 with a conductor such as metal or carbon, and is connected to the wiring pattern. The fixed contact 15 includes a central contact 15a disposed at a position where the movable contact 2 can be contacted / separated and an outer contact 15b that is always in contact with the movable contact 2 (see FIG. 3). The contact 15b is not electrically connected. In the switch module 100, the electrical connection state between the central contact 15a and the outer contact 15b is switched according to the contact state between the central contact 15a and the movable contact 2, and outputs an ON signal and an OFF signal. The switch module 100 outputs an OFF signal via the wiring pattern when the central contact 15a is separated from the movable contact 2, and turns on via the wiring pattern when the movable contact 2 is in contact with the central contact 15a. Output a signal.

  The movable contact 2 is a dome-shaped contact formed of a conductor such as metal or carbon, and is disposed on the surface 11 of the wiring board 1. The movable contact 2 is arranged such that the outer edge portion is always in contact with the outer contact 15b. The movable contact 2 is arranged so as to cover the center contact 15a so as to be able to contact the center contact 15a when pressed by the user. When the movable contact 2 is pressed by the user, the movable contact 2 reverses, and the back surface of the top of the dome-shaped portion contacts the surface of the central contact 15a. When the user stops pressing the movable contact 2 while the movable contact 2 is in contact with the central contact 15a, the movable contact 2 performs a restoring operation and is separated from the central contact 15a.

  The movable contact 2 is preferably larger in plan view. In other words, the distance between the movable contact 2 and the long side (the first side surface 13 and the second side surface 14) of the wiring board 1 is preferably smaller. A portion between the movable contact 2 and the long side of the wiring board 1 corresponds to a pasting amount of the sheet member 3. The minimum distance L1 between the movable contact 2 and one long side (first side surface 13) of the wiring board 1 is, for example, 1 mm or less. Further, the minimum distance L2 between the movable contact 2 and the other long side (second side surface 14) of the wiring board 1 is, for example, 1 mm or less. Thus, by increasing the planar view shape of the movable contact 2, the amount of movement of the movable contact 2 in the vertical direction when pressed by the user can be increased, and the operational feeling of the movable contact 2 can be improved. Further, the operation durability can be improved.

  In the example of FIG. 1, the planar view shape of the movable contact 2 is a side cut shape. As shown in FIG. 1, the side cut shape here is a shape obtained by linearly removing opposing ends (upper and lower ends in the example of FIG. 1) from a circle, and two opposing arc portions. And two opposing straight portions. The movable contact 2 having a side cut shape is arranged so that the straight line portion is parallel to the long sides (first side surface 13 and second side surface 14) of the wiring board 1. In this case, the distance between the first side surface 13 and the straight line portion of the movable contact 2 closer to the first side surface 13 corresponds to the distance L1. Further, the distance between the second side surface 14 and the straight line portion of the movable contact 2 closer to the second side surface 14 corresponds to the distance L2.

  With such a configuration, the planar view shape of the movable contact 2 can be made larger than when the planar view shape of the movable contact 2 is circular. That is, it is possible to obtain the same effect as that of arranging the circular movable contact whose radius dimension is larger than the width dimension (short side dimension) of the wiring board 1. As a result, the amount of movement of the movable contact 2 in the vertical direction when the user presses down can be increased, and the operational feeling of the movable contact 2 can be improved. In addition, the planar view shape of the movable contact 2 is not limited to the side cut shape, and may be an arbitrary shape such as a circle or an ellipse.

  The sheet member 3 is a member that covers the wiring substrate 1 and the movable contact 2 and seals the inside of the switch module 100. The sheet member 3 is formed by folding back both sides of the insulating sheet disposed on the surface of the wiring board 1 toward the back surface of the wiring board 1. The sheet member 3 is, for example, a PET (Polyethylene Terephthalate) sheet, but is not limited thereto. As shown in FIG. 2, the sheet member 3 includes a first portion 31, a second portion 32, a third portion 33, a fourth portion 34, and a fifth portion 35.

  The first portion 31 is a portion that covers the surface 11 of the wiring board 1. The movable contact 2 is fixed on the surface 11 of the wiring board 1 by being covered with the first portion 31. The first portion 31 is attached to the surface 11 of the wiring board 1 by the adhesive layer 4 provided at the pasting margin of the surface 11 of the wiring board 1 (the portion between the movable contact 2 and the long side of the wiring board 1). Is done.

  The second portion 32 is a portion that covers the first side surface 13 of the wiring board 1 and extends from one end of the first portion 31 (the left end of the first portion 31 in the example of FIG. 2). The second portion 32 is affixed to the first side face 13 by the adhesive layer 4 provided on the first side face 13 of the wiring board 1.

  The third portion 33 is a portion that covers a part of the back surface 12 of the wiring board 1 and extends from the second portion 32 (the lower end of the second portion 32 in the example of FIG. 2). The third portion 33 is attached to the back surface 12 of the wiring board 1 by the adhesive layer 4 provided on the back surface 12 of the wiring board 1.

  The fourth portion 34 is a portion that covers the second side surface 14 of the wiring board 1, and extends from the other end of the first portion 31 (in the example of FIG. 2, the right end of the first portion 31). The fourth portion 34 is affixed to the second side surface 14 by the adhesive layer 4 provided on the second side surface 14 of the wiring board 1.

  The fifth portion 35 is a portion that covers a part of the back surface 12 of the wiring board 1 and extends from the fourth portion 34 (the lower end of the fourth portion 34 in the example of FIG. 2). The fifth portion 35 is attached to the back surface 12 of the wiring board 1 by the adhesive layer 4 provided on the back surface 12 of the wiring board 1.

  As can be seen from FIG. 2, the second portion 32 is bent with respect to the first portion 31 and the third portion 33. Similarly, the fourth portion 34 is bent with respect to the first portion 31 and the fifth portion 35. Moreover, since the wiring board 1 is narrow, the contact area between the second part 32 to the fifth part 35 and the adhesive layer 4 is small. For this reason, the sheet member 3 is easily peeled off from the wiring board 1 due to the repulsive force (force to return to flat) generated in the second portion 32 and the fourth portion 34.

  Therefore, in the present embodiment, the second portion 32 is preferably formed thinner than the first portion 31 and the third portion 33 in order to suppress the repulsive force generated in the second portion 32. Similarly, in order to suppress the repulsive force generated in the fourth portion 34, the fourth portion 34 is preferably formed thinner than the first portion 31 and the fifth portion 35.

  In the present embodiment, in order to suppress the repulsive force generated in the second portion 32, the second portion 32 has a plurality of recesses 36 parallel to the first side surface 13 (long side of the wiring board 1) on the surface. Preferably it is done. Similarly, in order to suppress the repulsive force generated in the fourth portion 34, the fourth portion 34 is formed with a plurality of recesses 37 parallel to the second side surface 14 (long side of the wiring board 1) on the surface. preferable.

  The thinning of the second portion 32 and the fourth portion 34 and the formation of the concave portions 36 and 37 can be realized by cutting the surfaces of the second portion 32 and the fourth portion 34 by laser processing or blast processing. The thinning of the second portion 32 and the fourth portion 34 and the formation of the recesses 36 and 37 may be performed after the sheet member 3 is affixed to the wiring substrate 1 or before the sheet member 3 is affixed to the wiring substrate 1. It may be performed in advance.

  Since the second portion 32 and the fourth portion 34 are formed by sticking the sheet member 3 to the wiring board 1, they are not yet formed before the sheet member 3 is stuck. Therefore, when thinning is performed before the sheet member 3 is attached, the portions corresponding to the second portion 32 and the fourth portion 34 in the sheet member 3 may be thinned. At this time, it is preferable to thin a range wider than portions corresponding to the second portion 32 and the fourth portion 34 in the sheet member 3. As a result, even if a positional shift occurs when the sheet member 3 is attached to the wiring board 1, the thinned portions can be used as the second portion 32 and the fourth portion 34.

  Similarly, when the recesses 36 and 37 are formed before the sheet member 3 is attached, the recesses 36 and 37 may be formed in portions corresponding to the second portion 32 and the fourth portion 34 in the sheet member 3. At this time, it is preferable that the concave portions 36 and 37 are formed in a wider range than portions corresponding to the second portion 32 and the fourth portion 34 in the sheet member 3. As a result, even when a positional shift occurs when the sheet member 3 is attached to the wiring board 1, the portions where the recesses 36 and 37 are formed can be used as the second portion 32 and the fourth portion 34. .

  In addition, since the demand for narrowing is high recently, there is a possibility that there is almost no pasting allowance in the short side direction of the wiring board 1 as in the example of FIG. Therefore, the movable contact 2 has a side cut shape, and the minimum distance L1 between the movable contact 2 and one long side (first side surface 13) of the wiring board 1 and the other of the movable contact 2 and the wiring board 1 are the same. When the minimum distance L2 between the long side (second side surface 14) is 1 mm or less (almost 0 mm), it is thinned to a range corresponding to a part of the upper surface of the dome-shaped portion of the movable contact 2. Is preferred.

  As can be seen from FIG. 3, the linear portion of the movable contact 2 has a high central portion and a low end portion. For this reason, when the sheet member 3 is affixed to the movable contact 2, there is a risk that the operation feel of the movable contact 2 may be deteriorated due to wrinkles in the straight portion. As described above, the sheet member 3 is thinned to a range corresponding to a part of the upper surface of the dome-shaped portion of the movable contact 2, so that wrinkles are less likely to occur at the straight portion of the movable contact 2. Deterioration of the operation feeling can be suppressed.

  A gap C is preferably formed between the third portion 33 and the fifth portion 35. In other words, it is preferable that the third portion 33 and the fifth portion 35 do not overlap. Thereby, it is possible to prevent the switch module 100 from becoming thick due to the overlap between the third portion 33 and the fifth portion 35.

  The pressure-sensitive adhesive layer 4 is a pressure-sensitive adhesive layer provided between the wiring board 1 and the sheet member 3. Specifically, the pressure-sensitive adhesive layer 4 includes a gap between the surface 11 and the first portion 31, a space between the first side surface 13 and the second portion 32, a part of the back surface 12, and a third portion 33. And between the second side surface 14 and the fourth portion 34 and between the part of the back surface 12 and the fifth portion 35.

  The pressure-sensitive adhesive layer 4 may be formed by applying a pressure-sensitive adhesive to the wiring board 1 or the sheet member 3, or formed by sticking a double-sided pressure-sensitive adhesive tape that does not include a base material to the wiring board 1 or the sheet member 3. May be. In any case, the adhesive layer 4 does not include a substrate such as PET. Thereby, since the repulsive force which arises with a base material is lose | eliminated, the adhesiveness of the adhesive layer 4 and the wiring board 1 can be improved. As a result, the sheet member 3 can be made difficult to peel off, and the sealing performance of the switch module 100 can be improved.

  Moreover, the adhesive layer 4 is provided with an opening 41 through which the movable contact 2 is inserted, as shown in FIG. That is, the pressure-sensitive adhesive layer 4 is not provided on the surface of the movable contact 2. Thereby, the interference to the operation | movement of the movable contact 2 by the adhesive layer 4 and the deterioration of an operation feeling can be suppressed.

  With the configuration as described above, according to the present embodiment, a narrow and thin switch module 100 having high hermeticity can be realized. The reason is as follows.

  In the conventional switch module, the sheet member is attached only to the surface of the wiring board. For this reason, when the wiring board is narrowed and the minimum distance between the movable contact and the wiring board is reduced, the contact area between the sheet member and the adhesive layer around the movable contact is reduced. As a result, the sheet member affixed around the movable contact is easily peeled off, and the sealing performance of the switch module is lowered. In particular, when the minimum distance between the movable contact and the wiring board is 1 mm or less, the adhesive force of the sheet member attached to the pasting portion between the movable contact and the wiring board cannot be obtained sufficiently, and the switch module It was difficult to seal.

  On the other hand, according to the present embodiment, the sheet member 3 is folded and attached to the wiring board 1. Specifically, the first portion 31 is attached to the front surface 11, the second portion 32 is attached to the first side surface 13, the third portion 33 is attached to the back surface 12, and the fourth portion 34 is attached to the second side surface 14. The fifth portion 35 is pasted on the back surface 12. Thereby, even if the wiring board 1 becomes narrow and the minimum distances L1 and L2 between the movable contact 2 and the wiring board 1 become small, the sheet member 3 and the adhesive layer around the movable contact 2 A sufficient contact area with 4 can be secured. Thereby, even if the wiring board 1 is narrow, the sheet member 3 attached around the movable contact 2 is less likely to be peeled off, so that the sealing performance of the switch module 100 can be improved.

  Further, according to the present embodiment, the second portion 32 and the fourth portion 34 of the sheet member 3 are made thinner than the other portions of the sheet member 3 and provided with the recesses 36 and 37. Thereby, the repulsive force produced by bending the sheet | seat member 3 is suppressed, and it can suppress that the sheet | seat member 3 peels from the adhesive layer 4. FIG.

  Moreover, according to this embodiment, since the adhesive layer 4 does not include a base material, no repulsive force is generated even if the adhesive layer 4 is bent and attached to the wiring board 1. Thereby, while being able to suppress that the adhesive layer 4 peels from the wiring board 1, the adhesiveness of the wiring board 1 and the adhesive layer 4 can be improved, and the sealing performance of the switch module 100 can be improved.

  Moreover, according to this embodiment, even if it is a case where the movable contact 2 which has a side cut shape is employ | adopted like the example of FIGS. 1-4, the sealing performance of the switch module 100 can be maintained. In general, the movable contact 2 having a side cut shape has a straight portion that is higher than the surface 11 of the wiring board 1, and therefore the sheet member 3 tends to float from the surface 11 of the wiring substrate 1 around the straight portion. That is, the contact area between the sheet member 3 and the pressure-sensitive adhesive layer 4 around the movable contact 2 tends to be small. For this reason, when the movable contact which has a side cut shape is employ | adopted with the conventional switch module, the sealing performance of a switch module will fall further. On the other hand, according to the present embodiment, the contact area between the sheet member 3 and the pressure-sensitive adhesive layer 4 is secured by the first side surface 13, the second side surface 14, and the back surface 12 of the wiring substrate 1. Even when the contact area of the sheet member 3 with respect to the surface 11 of the wiring board 1 is reduced, the contact area between the sheet member 3 and the pressure-sensitive adhesive layer 4 can be ensured and the sealing performance of the switch module 100 can be maintained. By adopting the movable contact 2 having a side cut shape, the amount of movement of the movable contact 2 in the vertical direction when the user presses down can be increased, and the operational feeling of the movable contact 2 can be improved.

  As described above, the switch module 100 according to the present embodiment has high hermeticity and is narrow and thin. Therefore, the switch module 100 can be suitably used as a side key of a smartphone or a tablet terminal or an operation switch of a thin frameless TV. .

  It should be noted that the present invention is not limited to the configuration shown here, such as a combination with other elements in the configuration described in the above embodiment. These points can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

1: wiring board 2: movable contact 3: sheet member 4: adhesive layer 11: front surface 12: back surface 13: first side surface 14: second side surface 15: fixed contact 31: first portion 32: second portion 33: first 3 part 34: 4th part 35: 5th part 36: recessed part 37: recessed part 41: opening

Claims (6)

A wiring board having a fixed contact on the first surface;
A movable contact disposed on the first surface of the wiring board so as to be in contact with the fixed contact;
A first portion that covers the first surface of the wiring substrate; a second portion that extends from the first portion and that covers a first side surface of the wiring substrate; and a second surface of the wiring substrate that extends from the second portion. A third portion that covers a portion of the wiring board, a fourth portion that extends from the first portion and that covers a second side surface that faces the first side surface of the wiring board, and extends from the fourth portion, and A sheet member having a fifth part covering a part of the second surface;
An adhesive layer provided between the wiring board and the sheet member;
A switch module comprising: The switch module according to claim 1, wherein the second part and the fourth part are thinner than the first part. The second portion has a recess parallel to the first side surface,
The switch module according to claim 1, wherein the fourth portion has a recess parallel to the second side surface. The switch module according to any one of claims 1 to 3, wherein the movable contact has a linear portion parallel to the first side surface and the second side surface. A minimum distance between the movable contact and the first side surface is 1 mm or less;
The switch module according to any one of claims 1 to 4, wherein a minimum distance between the movable contact and the second side surface is 1 mm or less. The switch module according to any one of claims 1 to 5, wherein a gap is formed between the third portion and the fifth portion.

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