JPH08934U - Small electronic components - Google Patents

Abstract

(57) An object of the present invention is to provide a relatively high strength, the cover sheet is easily broken when moving the movable part, and a mark for the movable part is provided to facilitate automatic adjustment. A case (2) has a movable part (8) inside and at least one surface is an opening. Providing a cover sheet 10 such as a resin film that covers and seals the opening,
A cover member 11 having a through hole 11a is provided at a predetermined position on the cover sheet 10 while closely contacting and reinforcing the cover sheet 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a small electronic component in which electronic components such as a variable resistor are hermetically sealed and which can be soldered by a flow solder.

[0002]

[Prior art]

 Conventionally, for example, in a variable resistor, a flow solder can be used when soldering the variable resistor to a circuit board, as disclosed in JP-A-61-287103 and JP-A-62-28404. In some cases, the opening of the variable resistor case is covered with a cover sheet and sealed. This cover sheet is located above the rotating body with which the driver or the like engages in order to adjust the resistance value of the variable resistor later, and can be easily broken by the driver or the like during the adjustment.

Further, Japanese Utility Model Laid-Open No. 62-28404 discloses a cover sheet on which a positioning mark is displayed.

[0004]

[Problems to be solved by the device]

 In the case of the above conventional technique, it is necessary to securely adhere the cover sheet and the opening of the case of the variable resistor to prevent the solder from entering the case, and the cover sheet itself is being worked or transported. It must be something that will not be torn. Therefore, when breaking the cover sheet and adjusting the resistance value, a relatively large force is required to break the cover sheet, and conversely, if the cover sheet is weakened to solve this, soldering may occur. There was a conflicting problem that it would break before it could function.

In addition, the positioning mark disclosed in Japanese Utility Model Laid-Open No. 62-28404 has only a coating material for the mark applied to the central portion, and does not have a function of reinforcing the cover sheet. Further, as disclosed in Japanese Utility Model Laid-Open No. 61-144606, there is a cap integrally formed with a thin-walled portion on the radiation. In this case, molding of the thin-walled portion is difficult and fragile. It was difficult to make it very thin.

The present invention has been made in view of the above-mentioned conventional problems, and has relatively high strength, and the cover sheet is easily broken when moving the movable portion, and further, It is an object of the present invention to provide a small electronic component that has a mark and is easy to adjust automatically.

[0007]

[Means for Solving the Problems]

 This invention relates to a small electronic component having a movable part inside, which has a case in which at least one surface is an opening and the movable part is arranged inside, and a cover such as a resin film which covers and seals the opening. It is a small electronic component that is provided with a sheet and closely adheres to and reinforces the cover sheet, and also has a covering member having through holes formed at predetermined positions on the cover sheet.

[0008]

[Action]

 The small electronic component of the present invention covers the opening of the case with a cover sheet and seals it so as to prevent the inflow of solder and the like, and further covers the cover sheet with a cover member to prevent the cover sheet from breaking. This is a small electronic component in which a through hole is formed at the position so that the portion of the cover sheet exposed by this through hole can be easily broken when adjusting the movable member inside.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention, in which a variable resistor 1 has a current collecting electrode terminal 3 projectingly provided on a bottom surface of a case 2 whose upper surface is an opening. A lead terminal 4 integrated with the collector electrode terminal 3 is provided along the bottom surface of the case 2, a part of which is exposed to the outside of the bottom surface of the case 2 and formed flush with the surface thereof. A resistor substrate 6 having a fitting hole 5 formed in the center is fitted into the collecting electrode terminal 3, and a slider 7 and a rotating body 8 are fitted therein. The resistor substrate 6 is fixed to the bottom surface of the case 2, and a resistor 9 is printed on the top surface of the resistor substrate 6. The contacts 7a of the slider 7 are in sliding contact with the base ends of the lead terminals 12 and 13 at both ends thereof. Is soldered. The slider 7 and the rotating body 8 are integrally formed by crimping and are rotatable with respect to the collecting electrode terminal 3. Further, the rotating body 8 is formed with an engaging portion 8a with which an adjusting jig such as a driver is engaged.

As shown in FIGS. 2 and 3, the rotating body 8 is located at the uppermost part in the opening of the case 1, and the cover is opposed to the rotating body 8 and covers the entire opening. The seat 10 is attached. This cover sheet 10 seals the opening of the case 2 to prevent solder and solvent from entering the case 2, and is thin and relatively thin such as synthetic resin film, metal foil or laminated film of these. It is made of fragile material. Further, a cover member 11 made of vinyl resin or the like is provided on the outer surface of the cover sheet 10. The covering member 11 can withstand immersion in molten solder and is formed on the surface of the cover sheet 10 by screen printing. The covering member 11 is formed such that the portion corresponding to the engaging portion 8a of the rotating body 8 is the through hole 11a, and this through hole 11a serves as a mark of the engaging portion 8a of the rotating body 8.

To mount the variable resistor 1 of this embodiment on a circuit board (not shown), the variable resistor 1 is bonded to a predetermined position of the circuit board and soldered by a flow solder. Then, the flux is washed with a solvent to complete the installation.

Next, to adjust the resistance value, the through hole 11a of the covering member 11 is pressed by an adjusting jig such as a screwdriver, the cover sheet 10 is broken, and the engaging portion 8a of the rotating body 8 is adjusted and adjusted. The tool is engaged and the rotating body 8 is rotated to adjust the resistance value.

According to the variable resistor 1 of this embodiment, since the opening of the case 2 is sealed by the cover sheet 10, the solder does not enter the case 2 even when soldering with the flow solder. The cover sheet 10 is covered by the covering member 11 leaving only a small number of through holes 11a, and can sufficiently withstand the heat generated by the molten solder. Moreover, when the resistance value is adjusted, the cover sheet 10 exposed in the through hole 11a can be easily broken by the adjustment jig, and the adjustment work can be easily performed.

Further, the through hole 11a is provided only in the central portion of the cover sheet 10 and has a strong mechanical strength because it is reinforced by the covering member 11, so that the circuit can be automatically strengthened by an automatic machine. The cover sheet 10 will not be broken even when it is attached to a substrate. Further, since the covering member 11 can be formed by printing, it can be inexpensively and easily provided.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. Here, the same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, a covering member 14 made of a thin synthetic resin film covering the outer surface of the cover sheet 10 and the side surface of the case 2 is provided. The synthetic resin film may be one that adheres to the variable resistor 1 to reinforce the cover sheet 10, and may be a heat-shrinkable film that covers the variable resistor 1 and then heats and adheres it. good. A circular through hole 14a is formed in the central portion of the covering member 14 at a position corresponding to the engaging portion 8a of the rotating body 8.

As a result, also in this embodiment, the cover sheet 10 is reinforced by the covering member 14 of the synthetic resin film, and the through hole 14a is provided in the portion corresponding to the engaging portion 8a of the rotating body 8. It can be easily broken with an adjustment jig. Particularly, in this embodiment, the side surface of the variable resistor 1 is covered with the covering member 14 of the synthetic resin film, so that the protection is more sufficiently performed.

In addition to the variable resistor, the present invention can be used for all small electronic parts having movable parts such as variable-capacity chip capacitors and switches, which are soldered to a circuit board or the like. is there. Further, the shape of the through hole in the covering member can be variously modified, and it is sufficient that the covering member is provided corresponding to the movable portion.

[0018]

[Effect of device]

 According to this invention, the opening of the case of the small electronic component is covered with a cover sheet, and the cover sheet is further covered with a covering member to reinforce it, and a through hole is formed at a predetermined position of the covering member. When the movable part is moved, the cover sheet exposed from the through hole can be easily torn, and the movable part can be easily adjusted.

Moreover, since the cover sheet seals the opening of the case, solder and various cleaning solvents do not enter the case. Furthermore, since the cover member also improves the mechanical strength, the cover sheet will not be broken during transportation, and the sealing property of the cover sheet will be impaired even when this small electronic component is mounted on a circuit board etc. by an automatic machine. Nor.

Further, since the through hole of the covering member serves as a mark of the position of the movable portion in the case, the through hole can be optically easily detected even when the moving portion is adjusted by an automatic machine. This also contributes greatly to the automation of electronic device assembly.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

2 is a sectional view taken along the line AA of FIG. 1 of the present invention.

FIG. 3 is a plan view of the variable resistor according to the embodiment of the present invention before the cover sheet is attached.

FIG. 4 is a perspective view of a covering member according to a second embodiment of the present invention.

FIG. 5 is a vertical sectional view of a second embodiment of the present invention.

[Explanation of symbols]

 2 Case 7 Slider (movable part) 8 Rotating body (movable part) 10 Cover sheet 11, 14 Covering member 11a, 14a Through hole

Claims (1)

[Scope of utility model registration request] 1. A case having a movable part capable of mechanical movement with an electric action, the movable part being housed inside, at least one surface of which is an opening, and the opening. A small electronic device comprising: a thin cover sheet which is covered and hermetically sealed; and a covering member which covers and reinforces the cover sheet and has a through hole formed in a portion corresponding to a predetermined position on the cover sheet. parts.