JP4097638B2 - Push button switch - Google Patents

Description

  The present invention relates to a push button switch that presses and reverses a movable contact to make contact with and away from a fixed contact, and particularly relates to a push button switch suitable for mounting on a thin electronic device.

A conventional pushbutton switch has a fixed housing and a movable contact housed in a resin housing having a box-shaped housing, and the switch can be switched by pressing and reversing the movable contact from the outside to be connected to the fixed contact. Is to be done.
The fixed contact of such a pushbutton switch is formed by embedding a metal terminal material in the bottom portion of the resin housing by insert molding and projecting one end thereof into the housing portion.

  In the insert molding of the fixed contact into the housing, the molten resin is allowed to flow into the mold with the mold pin slightly opposed to the back surface of the metal terminal material to be the fixed contact. The fixed contact was positioned by pressing the opposite surface of the metal terminal material against the opposing mold with resin pressure. As a result, the entire bottom surface of the fixed contact is covered with resin to prevent flux intrusion during soldering (see, for example, Patent Document 1).

Japanese Patent Publication No. 64965

  However, in the conventional pushbutton switch described above, the fixed contact is positioned in the mold by using the molding resin pressure, and therefore it is necessary to ensure a corresponding resin wall thickness on the lower surface of the metal terminal material on which the fixed contact is formed. Therefore, there is a problem that the housing cannot be thinned.

  Accordingly, an object of the present invention is to solve the above-described problems and to provide a push button switch with an adhesive sheet that can be reduced in thickness.

In order to solve the above-mentioned problem, in the present invention, as a first solving means, a resin-made housing having a box-shaped accommodation part opened on one side, and one end projecting into the accommodation part and fixed in the bottom of the housing A metal terminal material that forms a contact; an external terminal connected to the other end of the metal terminal material so as to be surface-mountable; and a movable contact disposed in the housing portion so as to face the fixed contact And an adhesive sheet that covers the periphery of the opening, and is a push button switch that is individually housed in an embossed tape housing portion that is housed during transportation and mounting , and a bottom plate portion of the housing includes a lower surface of the metal terminal material, provided with a hole communicating, on the outside of the opening, said forming the higher projection than the thickness of the adhesive sheet on the outer periphery of the joining surface of the adhesive sheet, bonded to the adhesive sheet on the inner side of the projection Attached, and with the pressure-sensitive adhesive sheet by the upper surface facing the push button switch provided sealed with cover tape the housing portion configured.

  As described above, the pushbutton switch of the present invention includes a resin-made housing having a box-shaped accommodation portion that is open on one side, and a metal terminal material that is embedded in the bottom of the housing and has one end protruding into the accommodation portion to form a fixed contact. An external terminal that is connected to the other end of the metal terminal material and led out of the housing so as to be surface-mountable, a movable contact that is disposed in the housing portion so as to face the fixed contact, and an adhesive sheet that covers the periphery of the opening A hole that communicates with the lower surface of the metal terminal material is formed in the bottom plate portion of the housing, a protrusion higher than the thickness of the adhesive sheet is formed outside the opening, and the adhesive sheet is attached to the inside of the protrusion The adhesive sheet can prevent foreign matter from entering the housing from the opening, and the lower surface of the terminal material of the fixed contact can be pressed directly with the pressing pin during molding, making the housing thinner. Since a protrusion higher than the thickness of the adhesive sheet is formed on the outside of the opening, even if the adhesive protrudes from the end face of the adhesive sheet, it does not adhere to the supply material of the pushbutton switch, and can be removed smoothly during mounting. Can be supplied.

In addition, the pushbutton switch of the present invention is individually housed in the embossed tape housing portion that is housed during transportation and mounting, and the housing portion is sealed with a cover tape so as to face the upper surface of the pushbutton switch provided with the adhesive sheet. , Even if the adhesive material protrudes from the end face of the adhesive sheet during transportation with embossed tape, it does not adhere to the cover tape, and can be removed smoothly from the embossed tape when mounted on a circuit board, enabling reliable supply Become.

  Embodiments of the present invention are shown in FIGS. 1 is a plan view of a pushbutton switch according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the pushbutton switch shown in FIG. 1, and FIG. 3 is an explanatory diagram for explaining a molding state of the housing of the pushbutton switch according to the embodiment of the present invention. FIG. 4 and FIG. 4 are explanatory views showing the transport state of the pushbutton switch according to the embodiment of the present invention.

  The housing 2 of the pushbutton switch 1 is formed in an insulating material such as synthetic resin in a substantially rectangular shape in plan view, and has a box shape in which an upper portion is opened by a side wall 2b that surrounds the outer periphery of the rectangular bottom plate portion 2a in an annular shape. The accommodating part 3 is formed. The side wall 2b has a flat upper surface adjacent to the opening of the housing portion 3 and is provided with an adhesive surface 2c for an adhesive sheet 8 to be described later. Further, a plurality of protrusions 2d are provided on the outer periphery of the adhesive surface 2c. Is formed.

  A pair of terminal members 5 and 5 made of a conductive metal material are insert-molded in the bottom plate portion 2 a of the housing 2, and one end thereof is bent in the bottom plate portion 2 a so as to enter the housing portion 3. A central fixed contact 6a is formed so as to protrude. Further, one end of the other terminal material is bifurcated in the bottom plate portion 2a, and each of them protrudes with the central fixed contact 6a interposed in the accommodating portion 3, and a pair of peripheral fixed contacts 6b are provided.

  The central fixed contact 6a is located at the approximate center of the housing part 3 of the housing 2, and the amount of protrusion from the bottom plate 2a to the housing part 3 is such that the peripheral fixed contact 6b is slightly higher than the central fixed contact 6a. Is formed. The other end portion of the terminal material connected to the central fixed contact 6a is led out of the housing 2 and bent along the side wall 2b to form an external terminal 5a having a surface mounting soldering portion. Similarly, an external terminal 5b having a surface mounting soldering portion is formed at the other end of the terminal material connected to the peripheral fixed contact 6b.

The housing 2 in which the terminal material 5 is embedded is manufactured by the following steps. (1) A metal sheet cut into a predetermined shape is press-molded to prepare a terminal material 5 in which a center fixed contact 6a and a peripheral fixed contact 6b are bent.
(2) Next, the terminal material 5 is disposed between the first mold 10 and the second mold 11 which are opened and clamped to form a columnar shape provided in the second mold. The pin 11a is brought into contact with the back side of the terminal material 5 on which the peripheral fixed contact 6b is formed, and the opposing surface of the terminal material 5 is pressed against the first mold for positioning.
(3) Thereafter, the molten resin is injected into the mold and allowed to flow, solidified, and then taken out from the mold, thereby completing the housing 2 having a predetermined shape in which the terminal material 5 is embedded.

  At this time, the pin 11a provided on the second mold is also pulled out from the bottom plate portion 2a of the molded housing 2, so that the bottom plate portion 2a of the housing 2 has a lower surface of the terminal material 5 on which the peripheral fixed contact 6b is formed. A hole 2e communicating with is formed. Depending on the shape of the extracted pin 11 a, the hole 2 e has a substantially straight inner wall or a tapered or hemispherical shape in which the lower surface side of the terminal material 5 is smaller than the lower surface side of the bottom plate portion 2 a of the housing 2. Since the terminal material 5 is directly clamped and positioned in the mold by the mold pins as described above, the resin thickness on the lower surface of the terminal material 5 can be set thin, and the housing 2 can be thinned. Further, the fixed contact can be formed in the housing 2 with higher accuracy.

  The terminal member 5 in contact with the hole 2e has a narrow portion 5c whose width is set slightly larger than the inner diameter of the hole 2e and whose end face position is close to the inner wall of the hole 2e, and a wider portion 5d larger than this. And are formed. The terminal material 5 embedded in the housing 2 has a slight gap between the terminal material 5 and the resin due to the shrinkage of the molded resin. However, by providing the narrow portion 5c, the gap in contact with the narrow portion 5c is reduced. The airway 9 through which air can enter and exit is formed by communicating the accommodating portion 3 and the hole 2e. Further, by providing the wide portion 5d, it is possible to reliably hold the terminal material 5 to the resin in the vicinity of the hole 2e. In addition to forming the hole 2e on the peripheral fixed contact 6b side, the mold pin 11b may be pressed against the back side of the terminal material 5 on which the central fixed contact 6a is formed to form the hole 2f. good.

The movable contact 7 is formed by punching a conductive metal thin plate made of phosphor bronze, stainless steel or the like, which has been subjected to a surface treatment such as silver plating on one side, into a substantially disk shape, and the outer peripheral edge with the surface treated side as a lower surface. A skirt portion 7b that rises at a predetermined angle from the portion 7a toward the center portion and a top portion 7c that bulges continuously in a dome shape from the skirt portion 7b are integrally formed with high precision by a press die. The movable contact 7 is accommodated in the concave accommodating portion 3 of the housing 2, the outer peripheral edge portion 7a is placed on the peripheral fixed contact 6b and is always in contact, and the back surface of the top portion 7c is the central fixed contact. The movable contact portion is formed on the 6a so as to face and separate from each other.
The movable contact 7 is press-molded so as to bulge out from the substantially circular outer peripheral edge 7a toward the center without providing the skirt 1b, and constitutes a reversing spring having a top 7c. Also good. Furthermore, it is not always necessary to use one sheet, and the operation force and click may be adjusted by arranging a plurality of sheets.

  In order to prevent deformation due to reflow heat during surface mounting of the pushbutton switch 1, the pressure-sensitive adhesive sheet 8 uses a heat-resistant resin as a base material, and a back surface of which a pressure-sensitive adhesive material is applied and punched into a predetermined shape. May be. Such a substrate is preferably formed of a fluororesin having good heat resistance and elongation such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-per-fluoroalkyl vinyl ether copolymer). Thus, since the opening of the accommodating portion 3 is covered with the pressure-sensitive adhesive sheet 8, it is possible to prevent gas and dust from entering the movable contact 7 from the outside.

  As described above, a plurality of protrusions 2 d that protrude in the height direction from the thickness of the pressure-sensitive adhesive sheet 8 are provided on the outer periphery of the sticking surface 2 c outside the opening of the box-shaped housing portion 3 of the housing 2. Therefore, as shown in FIG. 4, when the push button switch 1 is stored and transported in the embossed tape 22 in which the bathtub-shaped storage portion 20 is formed and the upper portion is sealed with the cover tape 21, The sticking position of the adhesive sheet 8 is regulated by the projection 2d so that the end of the outer shape does not protrude from the four sides of the housing 2. Also, as shown in FIG. Even if it is inclined, the protrusion 2d abuts against the cover tape 21 to prevent the adhesive tape 8 from abutting against the cover tape 21, so that the adhesive that protrudes from the end face of the outer shape of the adhesive sheet 8 is Not adhere to bar tape 21, at the time of mounting on a circuit board, since the push-button switch 1 can be taken out smoothly from the inside of the embossed tape 22, reliable supply is possible.

  The pushbutton switch 1 configured as described above prints cream solder on the circuit board pattern, and places and places the external terminals 5a and 5b of the pushbutton switch 1 on the cream solder for reflow. Surface mounting on a circuit board is performed by passing it through a soldering device.

  Next, the switching operation of the push button switch configured as described above will be described. When the movable contact 7 of the pushbutton switch 1 is not pressed, the center fixed contact 6a is separated from the back surface of the top 7c of the movable contact by the spring force of the movable contact 7, and the peripheral fixed contact 6b is electrically connected. The switch is in a non-conductive state, and the switch is maintained in the off state.

From such a switch-off state, when the top portion 7c of the movable contact 7 is pressed against the spring force by a key top disposed on a decorative panel of an electronic device (not shown), the adhesive sheet 8 is bent. However, the movable contact 7 buckles and reverses to create a click feeling, and the central fixed contact 6a and the back surface of the top 7c of the movable contact 7 come into contact with each other, and the state is electrically switched between the peripheral fixed contact 6b. . That is, the switch is turned on, and a signal is sent to the electronic device through the external terminals 5a and 5b.
Although the air in the bulging portion of the movable contact 7 moves outward by the buckling reversal of the movable contact 7, the reversing operation of the movable contact 7 is not affected by the extension of the flexible sheet 8.

  Thereafter, when the pressing force to the movable contact 7 is released, the movable contact 7 is self-returned to the state before reversal by the accumulated spring force, and thereby the position of the top 7c of the movable contact 7 is raised to the initial state. Is restored.

  In addition, this invention is not limited to the structure of the said Example, You may make it hold | maintain an adhesive sheet closely to a housing via another members, such as an attachment frame. Alternatively, the movable contact may be attached to the adhesive sheet in advance and integrated, and then attached to the housing. Furthermore, a thin plate-like stem may be disposed above the movable contact, and this stem may also be hermetically sealed with an adhesive sheet in the accommodating portion.

  According to the above-described embodiment of the present invention, the adhesive sheet 8 covering the periphery of the opening of the housing 2 is provided, the hole 2e communicating with the lower surface of the metal terminal material 5 is provided in the bottom plate portion of the housing 2, and the housing 2 Since the protrusion 2d higher than the thickness of the pressure-sensitive adhesive sheet 8 is formed on the outer side of the opening and the pressure-sensitive adhesive sheet 8 is attached to the inner side of the protrusion 2d, the pressure-sensitive adhesive sheet 8 prevents foreign matter from entering the housing portion 3 from the opening. Since the lower surface of the terminal material 5 of the fixed contacts 6a and 6b can be pressed directly with a pressing pin at the time of molding, the housing 2 can be thinned, and the protrusion 2d higher than the thickness of the adhesive sheet 8 on the outside of the opening. The adhesive material that protrudes from the end face of the adhesive sheet 8 does not adhere to the supply material of the push button switch 1 and can be taken out smoothly during mounting and supplied reliably. It has become a thing that can be.

It is a top view of the pushbutton switch which concerns on the Example of this invention. It is sectional drawing of the pushbutton switch which concerns on the Example of this invention. It is explanatory drawing explaining the molding state of the housing of the pushbutton switch which concerns on the Example of this invention. It is explanatory drawing which shows the conveyance state of the pushbutton switch which concerns on the Example of this invention.

Explanation of symbols

1: Pushbutton switch 2: Housing 2a: Bottom plate portion 2b: Side wall 2c: Adhering surface 2d: Protrusion 2e: Hole 2f: Hole 3: Housing portion 5: Terminal material 5a: External terminal 5b: External terminal 5c: Narrow portion 5d: wide portions 6a: central fixed contact 6b: peripheral fixed contact 7: movable contact 7a: an outer peripheral edge portion 7b: skirt portion 7c: the top 8: adhesive sheet
9 : Airway 10: First mold 11: Second mold 11a: Pin 11b: Pin 20: Storage part 21: Cover tape 22: Embossed tape

Claims (1)

A resin-made housing having a box-shaped housing part open on one side, a metal terminal material embedded in the bottom of the housing and projecting into the housing part to form a fixed contact, and on the other end of the metal terminal material An external terminal connected to the housing so as to be surface-mountable, a movable contact disposed opposite to the fixed contact in the housing portion, and an adhesive sheet covering the periphery of the opening, and carrying and mounting A pushbutton switch individually stored in an embossed tape storage portion that is sometimes stored, and provided with a hole communicating with the lower surface of the metal terminal material in the bottom plate portion of the housing, and on the outside of the opening , higher projection than the thickness of the adhesive sheet on the outer periphery of the application surface bonded to form, paste the adhesive sheet on the inner side of the projection, the top surface and a pair of push button switch the adhesive sheet is provided Push button switch, wherein the closed with cover tape the housing portion by.

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