JP6029106B2 - Push switch - Google Patents

Description

  The present invention relates to a push switch, and more particularly to a push switch that is surface-mounted on a printed wiring board for electronic equipment.

  A surface mounting technology that melts and joins solder by printing solder paste (which includes flux and having an appropriate viscosity) on a printed wiring board, and then placing the components on top of it and applying heat. SMT) is widely used. The flux is used to chemically remove the oxide film on the surface of the metal to be soldered to form a solderable metal surface, and is necessary for improving the bondability. In many cases, the surface mount push switch is pressed from the upper side perpendicular to the substrate surface of the printed wiring board, and it is preferable that the housing immediately below the contact portion to be pressed contacts the substrate surface. For this reason, Patent Document 1 describes that the bottom surface of the housing around the soldering terminal is raised one step higher to form a solder accommodating portion.

  FIG. 9A is a plan view of the pushbutton switch 100 of Patent Document 1. FIG. FIG. 9B is a cross-sectional view taken along the line IX-IX in FIG. FIG. 10A is an enlarged view around the connection terminal in the XX cross section of FIG. FIG. 10B is an explanatory diagram showing a state where the pushbutton switch 100 is mounted on the substrate.

  As shown in FIG. 9, the pushbutton switch 100 is a metal having a substantially circular center contact portion 121 a that is processed into a convex shape as a contact portion on a concave housing 110 that is formed of an insulating resin and has a concave upper opening. A center fixed contact 121 made of a plate is provided. And the outer side stationary contact 122 made from a metal plate which has the substantially rectangular outer side contact part 122a processed into convex shape is provided in the symmetrical position on both sides of this.

  Further, as shown in FIG. 9, the center fixed contact 121 includes a connection piece 121 c that is connected to the center contact portion 121 a and extends to both sides of the housing 110. The outer fixed contact 122 includes a connection piece 122c that is connected to the outer contact portion 122a and extends to both sides of the housing 110. The center fixed contact 121 and the outer fixed contact 122 are insert-molded and fixed by exposing the above-described center contact portion 121a and outer contact portion 122a on the inner bottom surface of the housing 110. At both ends of the connection pieces 121c and 122c, connection terminals 123 protruding from the corners 111 at the four corners of the lower surface 112 of the housing 110 are provided.

  As shown in FIG. 10A, the housing 110 is provided with a step 113 protruding below the lower surface 123 b of the connection terminal 123 at a portion other than the corner portion 111 of the lower surface 112. By providing such a step 113, the cream solder accommodating portion 114 is formed below the connection terminal 123 relatively. By forming the cream solder accommodating portion 114, the cream solder 150 is accommodated in the cream solder accommodating portion 114 when the pushbutton switch 100 is temporarily fixed to the cream solder 150 on the substrate 160. As a result, the push button switch 100 is not disposed above the predetermined position by the cream solder 150, and the lower surface 112 of the housing 110 comes into contact with the substrate 160 as shown in FIG. 10B. The arrangement state of the push button switch 100 is stabilized.

JP 2004-158349 A

  However, when trying to increase the area of the connection terminal 123 to be soldered, when soldering, the path for moving the flux contained in the solder to the outside becomes long, and remains at the interface portion between the terminal and the housing. It is possible that Then, there is a concern that the residual flux may enter the housing through the interface between the terminal and the housing and enter the contact portion. In the push switch, since the flux causes a contact failure of the contact portion, it is required to prevent a phenomenon in which the residual flux enters the contact portion.

  The present invention solves the above-described problems, and an object of the present invention is to provide a push switch that can avoid a flux residue from entering a contact portion during soldering.

  The present invention includes a movable contact member, a housing provided with a fixed contact member that has a stationary contact portion that is open at one side and accommodates the movable contact member, and has a fixed contact portion that contacts and separates from the movable contact member, A cover member covering the opening, and the fixed contact member is provided with a soldering portion for soldering to a printed wiring board, and the soldering portion is closer to the cover member than the bottom surface of the housing. In the push switch that is exposed and disposed on the step surface located at a position on the outer side of the housing, the soldering portion has a width direction that intersects the direction toward the fixed contact portion on the step surface. The second soldering surface has a wide first soldering surface and a second soldering surface narrower than the first soldering surface on the fixed contact portion side. Characterized the wall that connects said bottom surface and said step surface, and the stepped surface, that are disposed to the boundary portion.

  According to this structure, since the soldering part for soldering is arrange | positioned with respect to the bottom face of the housing which contact | abuts a printed wiring board in the level | step difference surface which has a level | step difference, while ensuring soldering, pressing operation is carried out. It can be stabilized. Furthermore, by providing the second soldering surface with a narrow soldering portion to the boundary with the bottom surface of the housing, the solder reaches the boundary, the flux is moved outward by the solder, and the flux is a terminal. It is possible to reduce remaining in the vicinity of the interface between the housing and the housing. Therefore, it is possible to provide a push switch that can prevent the residual flux from entering the contact portion during soldering.

  Further, in the push switch of the present invention, the second soldering surface is continuously extended toward the fixed contact portion side at an intermediate position from both ends in the width direction of the first soldering surface. It is characterized by.

  According to this configuration, by providing the second soldering surface that is narrow from the middle position of the first soldering surface that is wide, the first soldering surface that is wider than the second soldering surface is provided on both sides. Solder that has been arranged to extend and flowed through the first soldering surface will flow into the second soldering surface with a narrow width from both sides, and the solder is less biased than when flowing from one side. Since it flows, it becomes difficult for flux to remain at the boundary.

  The push switch according to the present invention is embedded on the side of the first soldering surface that is connected to the second soldering surface and bent from both ends in the width direction of the first soldering surface to the housing side. A buried portion is provided.

  According to this configuration, by disposing the embedded portion at a position different from the second soldering surface, an anchor portion that improves the adhesion between the terminal and the housing can be formed without increasing the width.

  According to the present invention, the housing has the first soldering surface whose width on the outer side of the housing is wider than the width on the fixed contact portion side, and the second soldering surface having a narrow width. The surface is arranged up to the boundary between the wall surface and the step surface connecting the bottom surface and the step surface. By providing the second soldering surface with a narrow soldering part to the boundary with the bottom of the housing, the solder reaches the boundary, the flux is moved outward by the solder, and the flux is transferred to the terminal and the housing. It is possible to reduce remaining in the vicinity of the interface. Therefore, it is possible to provide a push switch that can prevent the residual flux from entering the contact portion during soldering.

It is a perspective view which shows the push switch of embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view which shows the push switch of embodiment of this invention, (a) is a top view, (b) is a front view. It is explanatory drawing which shows the push switch of embodiment of this invention, (a) is a disassembled perspective view, (c) is a bottom view. It is sectional drawing cut | disconnected by the IV-IV line of Fig.2 (a). It is explanatory drawing which shows a fixed contact member, (a) is a perspective view, (b) is a top view. It is an enlarged view of the A section of FIG.3 (b). It is an enlarged view of the B section of FIG. It is explanatory drawing of the mounting state which mounts a push switch in a printed wiring board. It is explanatory drawing which shows the conventional pushbutton switch, (a) is a top view, (b) is AA sectional drawing of (a). It is an enlarged view of the periphery of the connection terminal in the BB cross section of Fig.9 (a), (b) is explanatory drawing showing the mounting state to the board | substrate of the conventional pushbutton switch.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For easy understanding, the dimensions of the drawings are appropriately changed.

  FIG. 1 is a perspective view showing a push switch 1 according to an embodiment of the present invention. 2A and 2B are external views showing the push switch 1, in which FIG. 2A is a plan view and FIG. 2B is a front view. 3A and 3B are explanatory views showing the push switch 1, in which FIG. 3A is an exploded perspective view and FIG. 3B is a bottom view. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an explanatory view showing a fixed contact member, FIG. 5 (a) is a perspective view, and FIG. 5 (b) is a plan view. FIG. 6 is an enlarged view of a portion A in FIG. FIG. 7 is an enlarged view of a portion B in FIG. FIG. 8 is an explanatory diagram of a mounting state in which the push switch 1 is mounted on the printed wiring board 60.

  As shown in FIG. 1, the push switch 1 of this embodiment includes a housing 10 provided with a soldering portion 23 and a cover member 40 that covers the housing 10. A flexible cover member 40 is provided on the Z1 side of the push switch 1, and the pressing portion 50 protrudes as shown in FIG. On the Z2 side of the push switch 1, as shown in FIG. 2B, the soldering portion 23 is disposed on the step surface 10 b located on the cover member 40 side (Z1 side) with respect to the bottom surface 10 a of the housing 10. Yes.

  The pressing part 50 is an operated part for performing a switch operation by pressing. As shown in FIGS. 3A and 4, the pressing portion 50 is configured to be able to press the apex portion 30 a of the movable contact member 30 via the pressing member 35 and the cover member 40.

  The movable contact member 30 is a metal elastic member having a dome-shaped bulge. When the apex portion 30a of the movable contact member 30 is pressed, the apex portion 30a moves downward and reverses, and when released from the pressed state, the original state is restored by the elastic restoring force. When the movable contact member 30 and the fixed contact portion 21 come into contact with each other when the push switch 1 is pressed, an electrically conducting switching operation is operated.

  The pressing member 35 is made of synthetic resin and is formed with relatively high rigidity.

  The housing 10 is an insulating member made of synthetic resin. As shown in FIG. 3A, the housing 10 has an accommodating portion 5 that is open at one end and accommodates the movable contact member 30. The housing 10 is provided with a fixed contact member 20 having a fixed contact portion 21 protruding into the housing portion 5. On the Z2 side of the housing 10, as shown in FIGS. 2B and 3B, a bottom surface 10a, a step surface 10b, a wall surface 10c that connects the bottom surface 10a and the step surface 10b, and a protrusion 10e are provided. Yes. The soldering portion 23 is exposed and disposed on the step surface 10b.

  The cover member 40 is bonded to the Z1 side of the housing 10 so as to cover the opening of the accommodating portion 5 that accommodates the movable contact member 30 and the pressing member 35. The cover member 40 is a flexible synthetic resin sheet, and is previously formed into the shape shown in FIGS. The material constituting the cover member 40 may be a rubber material such as silicone rubber.

  The fixed contact member 20 is a metal member. As shown in FIGS. 3 to 4, the fixed contact member 20 and the housing 10 are integrally formed by insert molding. The fixed contact member 20 is provided with a fixed contact portion 21 protruding into the housing portion 5 of the housing 10, a terminal 22 embedded in the housing 10, and a soldering portion 23 exposed on the Z2 side of the housing 10. ing. The soldering part 23 is a connection terminal for soldering to the printed wiring board 60. As shown in FIG. 5, the fixed contact portion 21, the terminal 22, and the soldering portion 23 are extended to the fixed contact side member 20 a, and the movable contact side member 20 b that is not connected to the fixed contact portion 21. , Are arranged insulated. The movable contact side member 20b is provided so as to be in constant contact with the movable contact member 30 for conduction. The fixed contact side member 20a is switched by moving the movable contact member 30 to and away from the fixed contact portion 21. In this specification, these electrical contact portions are referred to as contact portions.

  As shown in FIG. 5, the fixed contact member 20 is embedded in a bent manner extending upward (Z1 side) separately from the terminal 22 extending from the soldering portion 23 toward the fixed contact portion 21 side. A portion 25 is provided. The embedded portion 25 and the terminal 22 are embedded in the housing 10 by insert molding and integrated with the housing 10.

  As shown in FIG. 6, the soldering portion 23 viewed from the Z2 side has a first soldering surface 23a and a second soldering surface 23b. The first soldering surface 23 a protrudes outward of the housing 10. The 2nd soldering surface 23b is distribute | arranged to the boundary part 10d of the wall surface 10c which connects the bottom face 10a and the level | step difference surface 10b, and the level | step difference surface 10b. The first soldering surface 23a is a portion having a wide width (with a width W1) on the outer side of the housing 10 with the width direction being a direction crossing the direction toward the fixed contact portion 21 in the step surface 10b. The second soldering surface 23b is a portion having a narrower width (with a width W2) than the first soldering surface 23a on the fixed contact portion 21 side.

  As shown in FIG. 6, the second soldering surface 23b is continuously extended toward the fixed contact portion 21 side at the intermediate position from both ends in the width direction of the first soldering surface 23a. In other words, by providing the second soldering surface 23b having a small width in the direction from the intermediate position of the first soldering surface 23a having a large width toward the fixed contact portion 21, the width is larger than that of the second soldering surface 23b. It arrange | positions so that the 1st soldering surface 23a may extend on both sides.

  5 is formed near both ends of the first soldering surface 23a shown in FIG. 6 in the width direction (Y1-Y2 direction). Since the embedded portion 25 is embedded in the housing 10 by insert molding, it acts as an anchor portion that improves the adhesion with the housing 10. In this manner, by arranging the embedded portion 25 at a position different from the second soldering surface 23a, an anchor portion that improves the adhesion between the terminal 22 and the housing 10 without further increasing the width is formed. Can do.

  As shown in FIGS. 6 and 7, the soldering portion 23 is arranged up to the boundary portion 10 d with the wall surface 10 c connected to the bottom surface 10 a of the housing 10. The soldering portion 23 is exposed on the step surface 10b located on the cover member 40 side with respect to the bottom surface 10a of the housing 10, and the surface on the Z2 side of the soldering portion 23 in FIG. 7 is flush with the step surface 10b. ing. That is, the second soldering surface 23b of the soldering portion 23 is arranged up to the boundary portion 10d between the wall surface 10c that connects the bottom surface 10a and the step surface 10b and the step surface 10b.

  As shown in FIG. 8, in a mounting state where the bottom surface 10a of the housing 10 is in contact with the printed wiring board 60, the solder paste 70 that is adjusted to an appropriate viscosity containing flux is printed on the soldering portion 23 and the printed wiring. It is accommodated between the substrate 60. The solder paste 70 is printed in an area that does not overlap the bottom surface 10a in plan view so as not to adhere to the bottom surface 10a of the housing 10. The printed wiring board 60 includes an insulating substrate and a wiring pattern, but details are omitted in FIG. As shown in FIGS. 1 to 4, the housing 10 is provided with a protrusion 10 e that protrudes toward the Z <b> 2 side. The protrusion 10 e is inserted into a through hole formed in the printed wiring board 60 so as not to prevent the bottom surface 10 a of the housing 10 from coming into contact with the printed wiring board 60 when mounted on the printed wiring board 60. Since the bottom surface 10a of the housing 10 contacts the printed wiring board 60, the pressing operation can be stabilized. In addition, it is possible to accurately position the push switch 1 with respect to the printed wiring board 60 by inserting the protrusions 10 e into the through holes of the printed wiring board 60.

  In this embodiment, since the soldering part 23 is arrange | positioned at the level | step difference surface 10b of the housing 10, the solder paste 70 printed on the printed wiring board 60 is accommodated appropriately, and soldering is ensured. In addition, compared with the printing area of the solder paste 70, the printed thickness is very thin. For example, the printing area of the solder paste 70 is 1 mm × 3 mm, and the thickness of the solder paste 70 is 0.1 mm. Further, the soldering portion 23 has, for example, a width W1 of 3 mm and a width W2 of 1 mm.

  When the solder is melted by applying heat, the flux contained in the solder paste 70 flows and spreads over the entire surface of the soldering portion 23. Soldering is performed by alloying the solder with the metal to be connected.

  Although there is a space where the solder does not easily spread between the printed region of the solder paste 70 and the bottom surface 10a of the housing 10, in the present embodiment, the second soldering surface 23b connects the bottom surface 10a and the step surface 10b. It arrange | positions even to the boundary part 10d of the wall surface 10c and the level | step difference surface 10b. For this reason, the solder reaches the wall surface 10c connecting the bottom surface 10a and the step surface 10b and the boundary portion 10d between the step surface 10b, and the flux is outward along the wall surface 10c connecting the bottom surface 10a and the step surface 10b by the solder. Moved to. Then, the solder spread over the entire surface of the second soldering surface 23b reaches the bottom surface 10a of the housing 10 so as to close the space. In this way, by providing the second soldering surface 23b having a narrow soldering portion up to the boundary portion 10d of the portion forming the stepped surface 10b of the housing 10, the solder reaches the boundary portion 10d, and the flux is generated. Remaining in the vicinity of the interface between the terminal 22 and the housing 10 can be reduced. For this reason, it is difficult for the flux to remain in the vicinity of the boundary portion 10d.

  Furthermore, when the area of the soldering part 23 is large, the path | route for moving the flux of the center part away from the outer peripheral part of the soldering part 23 to an outward becomes long. In this embodiment, as shown in FIG. 6, even if the area of the soldering portion 23 is large, the soldering portion 23 has a second soldering surface 23b that is narrower than the first soldering surface 23a. Therefore, the path | route for the flux of a center part to move outside is shortened. In particular, since the narrow second soldering surface 23b extends toward the fixed contact portion 21 side, flux remains in the vicinity of the boundary portion 10d on the fixed contact portion 21 side of the second soldering surface 23b. It has become difficult.

  Moreover, in this embodiment, by providing the 2nd soldering surface 23b with a narrow width | variety from the intermediate position of the 1st soldering surface 23a with a wide width, as shown in FIG. 6, with respect to the 2nd soldering surface 23b, The wide first soldering surface 23a is arranged to extend on both sides. For this reason, the molten solder that has flowed through the first soldering surface 23a flows from both sides into the narrow second soldering surface 23b, and is less biased than when flowing from one side. Since the solder flows, it is difficult for the flux to remain in the boundary portion 10d.

  Hereinafter, the effect by having set it as this embodiment is demonstrated.

  In the push switch 1 of the present embodiment, the soldering portion 23 has the width W1 on the outer side of the housing 10 as the width direction that intersects the direction toward the fixed contact portion 21 on the stepped surface 10b. The first soldering surface 23a is wider than the width W2 on the side, and the second soldering surface 23b is narrower than the soldering portion 23. The second soldering surface 23b has a bottom surface 10a and a step surface 10b. It arrange | positions to the boundary part 10d of the wall surface 10c to connect, and the level | step difference surface 10b.

  According to this structure, since the soldering part 23 for soldering is arrange | positioned with respect to the bottom face 10a of the housing 10 contact | abutted to the printed wiring board 60 on the level | step difference surface 10b which has a level | step difference, soldering is ensured. In addition, the pressing operation can be stabilized. Further, by providing the second soldering surface 23b having a narrow soldering portion up to the boundary portion 10d of the portion forming the stepped surface 10b of the housing 10, the solder reaches the boundary portion 10d, and the flux is caused by the solder. It is possible to reduce the fact that the flux is moved outward and the flux remains in the vicinity of the interface between the terminal 22 and the housing 10.

  Further, in the push switch 1 of the present embodiment, the second soldering surface 23b is continuously extended toward the fixed contact portion 21 side at an intermediate position from both ends in the width direction of the first soldering surface 23a. Yes.

  According to this configuration, the first soldering surface that is wider than the second soldering surface 23b is provided by providing the second soldering surface 23b that is narrow from the middle position of the first soldering surface 23a that is wide. 23a is arranged so as to extend on both sides, and the solder that has flowed through the first soldering surface 23a flows into the second soldering surface 23b with a narrow width from both sides, compared with the case where it flows from one side. Since the solder flows with little bias, the flux is less likely to remain at the boundary portion 10d. The second soldering surface 23b is preferably the center of the same distance from both ends in the width direction of the first soldering surface 23a. However, the second soldering surface 23b may be provided near the center even if the distance is not equal.

  Further, the push switch 1 according to the present embodiment is bent to the housing 10 side from both ends in the width direction of the first soldering surface 23a on the side connected to the second soldering surface 23b of the first soldering surface 23a. A buried portion 25 is provided.

  According to this configuration, by arranging the embedded portion 25 at a position different from the second soldering surface 23a, it is possible to form an anchor portion that improves the adhesion between the terminal 22 and the housing 10 without increasing the width. it can. If the adhesion between the terminal 22 and the housing 10 is poor, the residual flux easily enters the contact portion. However, in this embodiment, the adhesiveness can be improved, so the residual flux enters the contact portion. Can be suppressed.

  Therefore, according to the present embodiment, it is possible to provide the push switch 1 that can prevent the residual flux from entering the contact portion during soldering.

  As described above, the push switch 1 according to the embodiment of the present invention has been specifically described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Is possible. For example, the present invention can be modified as follows, and these also belong to the technical scope of the present invention.

  (1) In the present embodiment, the movable contact member 30 may be formed of a plurality of metal plates. Compared to a single metal plate having the same elasticity, when it is formed from a plurality of metal plates, the failure due to metal fatigue is reduced.

  (2) In this embodiment, the pressing part 50 protrudes and becomes easy to press through the pressing member 35, but is not limited to this structure. For example, the pressing member 35 may be arranged in a flatter shape without disposing the pressing member 35 in the pressing portion 50. Further, the housing 10 may not be provided with the protrusion 10e. If the protrusions on the Z1 side and Z2 side are reduced in this way to form a flatter shape, the residual flux can be prevented from entering the contact portion without impairing the effect as a push switch. Thinning is possible.

DESCRIPTION OF SYMBOLS 1 Push switch 5 Housing | casing part 10 Housing 10a Bottom surface 10b Step surface 10c Wall surface 10d Boundary part 10e Protrusion part 20 Fixed contact member 20a Fixed contact side member 20b Movable contact side member 21 Fixed contact part 22 Terminal 23 Soldering part 23a 1st soldering Surface 23b Second soldering surface 25 Buried portion 30 Movable contact member 30a Vertex portion 35 Pressing member 40 Cover member 50 Pressing portion 60 Printed wiring board 70 Solder paste

Claims (3)

A movable contact member, a housing having one open opening and containing the movable contact member, a fixed contact member having a fixed contact portion contacting and separating from the movable contact member, and an opening in the receiving portion The fixed contact member is provided with a soldering portion for soldering to a printed wiring board, and the soldering portion is closer to the cover member than the bottom surface of the housing. In the push switch that is exposed to the stepped surface,
The soldering portion has a width direction that intersects the direction toward the fixed contact portion on the stepped surface, and a wide first soldering surface on the outer side of the housing, and the fixed contact portion side. A second soldering surface that is narrower than the first soldering surface, and the second soldering surface is arranged up to the boundary between the bottom surface and the step surface and the step surface. A push switch characterized by   The said 2nd soldering surface is continuously extended toward the said fixed contact part side in the intermediate position from the both ends of the width direction of the said 1st soldering surface. Push switch. An embedded portion that is bent and embedded in the housing side from both ends in the width direction of the first soldering surface on the side connected to the second soldering surface of the first soldering surface is provided. The push switch according to claim 2, wherein the push switch is provided.

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