JPH0314038Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is based on a case in which a rotating mechanism including a rotor is built into a case. The present invention relates to a double-sided adjustable trimmer capacitor provided in each of the above, and particularly relates to an improvement in the sealed structure of the double-sided adjustable trimmer capacitor.

2. Description of the Related Art A trimmer capacitor is configured such that a rotating mechanism including a rotor is housed in a case. In such a trimmer capacitor, the capacitance can be changed by rotating the rotor. Therefore, in order to change the capacity and make desired adjustments by external operation, the case is provided with an opening, through which the rotor can be rotated. In a double-sided adjustable trimmer capacitor, openings are formed on opposite sides of the case, and the rotor can be rotated through either opening.

By the way, in general, when electronic components are mounted on a printed circuit board or the like, flux during soldering enters through an opening provided in a case and adversely affects various characteristics of the electronic component. Furthermore, in order to improve workability and reduce mass production costs, it is desired that a plurality of electronic components can be soldered at once by passing the entire electronic component into a molten solder tank. However, in the case of so-called electronic mechanical parts such as trimmer capacitors that have a rotating mechanism, solder enters through the opening provided in the case, which has an adverse effect on the rotor, etc. As a result, for example, the rotor There were times when it became impossible to rotate. Therefore, it was necessary to separately solder only the electronic mechanical components such as the trimmer capacitor later.

Therefore, we pasted a cover sheet to close the opening of the case and avoided flux during soldering.
A so-called sealed electronic mechanism component has also been proposed that prevents solder from entering when using a molten solder bath. In this conventional example, a heat-resistant cover sheet is adhered to the outer surface of the case using a heat-resistant adhesive so as to close the opening of the case. Therefore, in such sealed electronic mechanical parts, flux is prevented from entering during soldering, and even when immersed in a molten solder bath, solder is prevented from entering the case, and other It becomes possible to carry out soldering in a simultaneous process with electronic components.

Note that the cover sheet is made of a material that is thick and strong enough to be easily torn with a screwdriver, etc., so if it becomes necessary to rotate the rotor of the trimmer capacitor, tear the cover sheet with a screwdriver, etc. However, the rotor can be rotated using a screwdriver or the like.

However, in the case of the above-mentioned conventional technology, since the cover sheet is attached to the outer surface of the case, the force of rubbing against the outer surface of the case, which is often applied when handling the trimmer capacitor, is not applied to the bond between the cover sheet and the case. This made it easy for the cover sheet to peel off. Also,
The end surface of the opening periphery of the case to which the cover sheet is attached does not always have a width that is wide enough to attach the cover sheet with sufficient strength. For example, when the case is made thin, it may be difficult to attach the cover sheet to the end face of the opening periphery with sufficient strength. Also, in one case, if the wall thickness is not uniform, etc.
The width of the end face of the opening periphery may not be uniform.
In this case, there is an imbalance in the adhesion force of the bar sheet to the case when it is stuck to the end face of the opening periphery of the case, and the cover sheet tends to peel off when contractile force is applied to the cover sheet.
Further, the thickness or height of the trimmer capacitor is increased by the amount of the cover sheet attached, and such an increase in size is not desirable, especially for a small trimmer capacitor. The above-mentioned problems will be doubled if the double-sided adjustment type is used.

Problems to be solved by the invention Therefore, this invention aims to solve the problems of the conventional example as described above. It is an object of the present invention to provide a double-sided adjustable trimmer capacitor provided with a cover sheet.

Means for Solving the Problems In this invention, a cover sheet is provided to close the openings formed on both sides of the case, and this cover sheet is glued to the inner peripheral surface of each opening of the case. It is characterized by the fact that it is formed.

Function The cover sheet, which is a feature of this invention, can be produced efficiently by utilizing the change in the state of an appropriate resin from a molten state to a hardened state, as will become clear from the explanation of the examples described later. can. Moreover,
It becomes possible to provide the cover sheet in a manner that it does not substantially protrude from the outer surface of the case, which not only does not cause a substantial increase in the size of the trimmer capacitor, but also prevents the cover sheet from undesirably peeling off.

Note that by selecting the material, thickness, etc. of the cover sheet, the cover sheet does not become an obstacle when rotating the rotor. That is, the cover sheet is
The structure may be such that it is easily broken when the rotor is rotated. It may be configured to stretch, or it may be configured to be in an intermediate state, that is, to be partially broken while stretching.

Embodiment In the embodiment described below, this invention is applied to a double-sided adjustable chip trimmer capacitor.

FIG. 1 shows a longitudinal sectional view of an embodiment of this invention, and FIG. 2 is a plan view of the same. In explaining the chip trimmer capacitor 1 shown in FIGS. 1 and 2, each component constituting the chip trimmer capacitor 1 will first be described with reference to FIGS. 3 to 5.

As shown in the exploded view in FIG. 3, five main parts are prepared. That is, the driver grooved spring 2, the metal rotor 3, the dielectric plate 4, the case 5, and the center shaft 6. Especially case 5
are shown individually in a plan view in FIG. 4 and in a longitudinal sectional view in FIG. 5.

The driver grooved spring 2 has both the function of a spring that presses the metal rotor 3 in the direction of the dielectric plate 4 and the function of a driver grooved member for applying rotational operating force to the metal rotor 3. The driver grooved spring 2 is made of a metal with spring properties, and is formed into the shape shown in the figure by punching and drawing. That is, the disk-shaped portion 7 has 4
Notches are formed at 90 degree intervals, and the driver groove 8
It is said that The central part of the disc-shaped part 7 is constricted so as to bulge downward, and a through hole 10 is formed in the bottom wall 9.
will be provided. Further, four spring pieces 11 are formed to extend radially outward and diagonally downward from the bottom wall 9 at intervals of 90 degrees. In addition, each spring piece 11
are made of material cut out for forming each of the driver grooves 8 described above.

The metal rotor 3 has a disk shape as a whole and is made of metal. The upper surface of the metal rotor 3 has a recess 12 having a substantially cross-shaped planar shape.
is formed. When the spring piece 11 of the driver grooved spring 2 described above fits into this recess 12, the metal rotor 3 rotates together with the driver grooved spring 2.
A through hole 13 having a substantially square cross section is formed in the center of the metal rotor 3 . Further, on the lower surface of the metal rotor 3, a rotor electrode 14 is formed with a stepped portion having a substantially semicircular planar shape.
Although not shown in FIG. 3, a balance step 15 is formed on the lower surface of the metal rotor 3 on the side where the rotor electrode 14 is not provided, as shown in FIG.

The dielectric plate 4 has a shape of a rectangle and a semicircle connected together, and is made of an appropriate dielectric material. A circular through hole 16 is provided in the center thereof. On the lower surface of the dielectric plate 4, a stator electrode 17 having a shape as shown by a broken line, for example, is formed.

The case 5 is made of an insulating and heat-resistant resin as a whole. The upper opening 18 of the case 5 is
It has almost the same shape as the dielectric plate 4, and a space is formed inside the case 5 that extends to the bottom surface while maintaining the planar shape of the top opening 18. When the dielectric plate 4 is placed in this space, rotation of the dielectric plate 4 is prevented. In the center of the bottom wall 19 of the case 5,
A lower opening 20 is formed.

A rotor side terminal 21 is provided on the bottom wall 19 of the case 5.
and the stator side terminals 22 are shown embedded. The rotor-side terminals 21 and the stator-side terminals 22 are inserted into a mold when the case 5 is molded, and are thereby integrated with the case 5. The rotor side terminal 21 has a through hole 23 concentric with the lower opening 20 of the case 5, and the peripheral edge of the through hole 23 projects inward from the inner peripheral surface of the lower opening 20. . Also,
The stator side terminals 22 are partially exposed on the upper surface of the bottom wall 19 inside the case 5 . The rotor side terminals 21 and the stator side terminals 22 protrude laterally during the manufacturing stage, but when the final product is made as shown in FIG. It is said to have extended to . For this purpose, recesses 24 and 25 are formed on the lower surface of the case 5.

The central shaft 6 is made of metal and has a generally rivet-like shape. A head 26 having a relatively large diameter is formed at the lower end of the center shaft 6, and a driver groove 27 is formed at the lower end surface of the head 26. The upper half of the shank portion of the center shaft 6 has a square section 28, and the lower half has a circular section 29. Square cross section part 2
8 fits into the through hole 13 at the center of the metal rotor 2. This through hole 13 is connected to the center shaft 6.
engages the square cross-section portion 28 against rotational movement. The circular cross-sectional portion 29 is located within the through hole 16 of the dielectric plate 4 and the lower opening 20 of the case 5 .

Next, the assembled state of the chip trimmer capacitor 1 shown in FIGS. 1 and 2 will be explained.

First, the center shaft 6 is inserted into the lower opening 20 of the case 5 from below the case 5 . and,
Along this central shaft 6, a dielectric plate 4, a metal rotor 3, and a driver grooved spring 2 are sequentially arranged in a case 5. Then, the upper end of the center shaft 6 is caulked, and appropriate pressure is applied by the spring pieces 11 between the parts arranged along the center shaft 6, so that the parts do not come off. At this stage, as shown in Figure 1,
Cover sheets 30 and 31, which are the characteristics of this invention
are formed so as to close the upper surface opening 18 and the lower surface opening 20 of the case 5, respectively. Top opening 1
The cover sheet 30 covering the case 8 is shown as transparent in FIG. 2 so that the inside of the case 5 can be seen through. In addition, the cover sheets 30, 31
may actually be transparent, in which case the rotational positions of the driver grooves 8, 27, etc. can be easily seen from the outside of the case 5.

The cover sheets 30 and 31 have heat resistance that can withstand the melting temperature of solder (for example, they can withstand immersion in a molten solder bath at 270° C. for 20 seconds). It is preferable to use a thermosetting silicone adhesive with excellent adhesive strength. Note that the thermosetting resin is used in the cover sheet 3 described below.
This is to efficiently proceed with the formation process of 0 and 31. Furthermore, among thermosetting resins, thermosetting resins allow easier curing time control than room temperature curing types, resulting in less time loss.

Next, FIGS. 6 to 8 show a preferred example of a method for forming the cover sheets 30 and 31.
This will be explained with reference to FIGS. 9 to 11, respectively. 6 to 8 show the process of forming the cover sheet 30, and FIGS. 9 to 1
FIG. 1 shows the process of forming the cover sheet 31. As shown in FIG.

When forming the cover sheet 30, as shown in FIG. 6, a heat-curable silicone adhesive 35 with a viscosity of 50,000 to 100,000 cs is applied to the base plate 36 (flatness of 0.05 or less) to a uniform thickness. stretched out. This thickness is preferably about 0.1 to 0.3 mm. This is because the elongation and breaking strength of the film or sheet after curing are appropriate. The base plate 36 is preferably configured to have good releasability from the adhesive 35, and is made of, for example, Teflon (trade name) or coated with Teflon. Then, the intermediate product 1 at the above-mentioned manufacturing stage of the trimmer capacitor is placed so that the upper surface opening 18 faces the adhesive 35.
a is placed. This intermediate product 1a differs from the chip trimmer capacitor 1 as a final product in that the rotor side terminals 21 and the stator side terminals 22 are not bent.

Next, as shown in FIG. 7, pressure is applied between the intermediate product 1a and the base plate 36 to the extent that the peripheral edge defining the upper opening of the case 5 bites into the adhesive 35. At the same time, the adhesive 35 is heated. Heating conditions vary depending on the material constituting the adhesive 35, but are generally preferably 130 to 150°C. In addition, the pressure causes the adhesive 35 to protrude in a portion where the peripheral edge defining the upper surface opening 18 of the case 5 faces the base plate 36, thereby causing the adhesive 35 to protrude in this portion.
It is preferable that the pressure be such that no residue remains. Inside the case 5, at least a portion of the disc-shaped portion 7 of the driver grooved spring 2 is in contact with or buried in the adhesive 35. In order to realize this state, the upper surface of the driver grooved spring 2 is preferably positioned lower than the upper surface of the case 5 by about 0.05 to 0.1 mm.

Further, while maintaining the state shown in FIG. 7, the adhesive 35 begins to harden and becomes a sheet, and a state in which sufficient adhesive strength is not yet obtained, that is,
It is once cooled in a semi-hardened state. When a heat-curable silicone adhesive is used as the adhesive 35, this semi-cured state can be obtained, for example, at 130° C. for 4 minutes.

Next, as shown in FIG. 8, the intermediate product 1a is
It is separated from the base plate 36. Accordingly, since the adhesive 35 in contact with the outer peripheral surface of the case 5 still has insufficient adhesive strength, the adhesive 35 is easily attached to the case 5.
Only the adhesive 35a located away from the case 5 and within the upper opening 18 of the case 5 acts together with the intermediate product 1a.

Thereafter, the adhesive 35a is heated to completely cure it to form the cover sheet 30 shown in FIG. 1.

The cover sheet 31 formed on the lower opening 20 side of the case 5 is also obtained by substantially the same method.
9 to 11 respectively correspond to the aforementioned FIGS. 6 to 8, and the same or corresponding parts are given the same reference numerals.

To form the cover sheet 31, the case 5 is placed with the lower opening 20 facing the adhesive 35. As shown in FIGS. 10 and 11, the lower end of the center shaft 6 is coated with adhesive 35 as in the case of the driver grooved spring 2 described above.
Or it is made to touch or be buried in 35a. The other steps are the same as those shown in FIGS. 6 to 8, so their explanation will be omitted.

After both cover sheets 30, 31 are formed in this way, the rotor side terminals 21 and stator side terminals 22 are finally cut to appropriate lengths, as shown in FIGS. 1 and 2. It is bent and placed into the recesses 24 and 25.

When assembled as described above, the head 26 of the center shaft 6 engages with the rotor-side terminal 21 while also establishing electrical continuity. The central shaft 6 is electrically connected to the metal rotor 3 either directly or indirectly via the driver grooved spring 2. Note that the lower end surface of the center shaft 6 is located within the lower opening 20 of the case 5 and does not protrude from the lower opening 20.

Further, the stator side terminals 22 are in contact with the stator electrodes 17 formed on the lower surface of the dielectric plate 4 inside the case 5, and electrical continuity is established here.

In the embodiment described above, the cover sheet 30,
Since a silicone adhesive is used as the material constituting the cover sheets 31, the cover sheets 30, 31 themselves have stretch and do not become an obstacle to inserting a driver or the like into the driver groove 8 or 27. for example,
It can be inserted with a load of 50g or less.
When the driver grooved spring 2 or the center shaft 6 is rotated by this driver, the cover sheets 30, 31 are thin, 0.1 to 0.3 mm, so they are easily broken and do not require a large torque. For example, rupture is possible with a torque of 150 gcm or less.
Note that the place where the breakage occurs is in the cover sheet 3.
0, the disk-shaped portion 7 of the driver grooved spring 2
The most average position is approximately halfway between the outer peripheral edge of the case 5 and the inner peripheral surface defining the upper opening 18 of the case 5. Further, in the case of the cover sheet 31, the most average position is approximately halfway between the outer peripheral end of the head 26 of the center shaft 6 and the inner peripheral surface defining the lower opening 20. In this way, even if the cover sheets 30, 31 are broken, most of the cover sheets 30, 31 are retained by the disc-shaped portion 7 or the head 26, so
A complete gap does not occur, and therefore a dustproof effect can be expected after adjustment.

In the above explanation, the cover sheets 30 and 31 are broken by the adjustment operation, but the invention is not limited to this, and the cover sheets 30 and 31 may simply be stretched or only a portion may be broken. . Such changes in the cover sheets 30, 31 due to adjustment operations are determined by factors such as the material or thickness of the cover sheets.

Further, in the embodiment described above, the cover sheet 3
Since a heat-resistant resin is used as the material for 0, 31 and the case 5, it is possible to allow the solder to pass through the molten solder tank. For example, FIG. 12 shows a mounted state of the chip trimmer capacitor 1 obtained by performing such a soldering process.

As shown in FIG. 12, the chip trimmer capacitor 1 is mounted using solder 34 on a substrate 33 in which an adjustment hole 32 is provided. In FIG. 12, the chip trimmer capacitor 1 is mounted on each of the upper and lower sides of the board 33. In this way, according to the double-sided adjustable chip trimmer capacitor 1, the board 33
3 can be mounted on either side, and the direction of adjustment is also possible from either side.

In this invention, it is sufficient that the cover sheet is bonded to at least the inner peripheral surfaces of the upper opening and the lower opening of the case. Therefore, it is not limited to the case where the cover sheets 30 and 31 are bonded only to the inner peripheral surfaces of the upper opening 18 and the lower opening 20 as in the illustrated embodiment. For example, in the process shown in FIG. 7, if the pressure applied between the intermediate product 1a and the base plate 36 is insufficient, the adhesive 35 may be applied to the periphery of the upper surface opening 18 of the case 5 and the base plate 36. A slight amount may remain on the opposing parts. In this case, the material constituting the cover sheet 30 may be
Although a fraction of the thickness of the case 5 remains on the upper end surface of the case 5, it should be pointed out that such a case also falls within the scope of this invention.

In addition, this invention is characterized by a cover sheet being glued to the inner peripheral surface of each opening so as to close both openings of the case, and the structure of the double-sided adjustable trimmer capacitor itself is not limited to what is illustrated.

Effects of the invention According to this invention, a sealed double-sided adjustable trimmer capacitor can be obtained due to the presence of the cover sheet. In addition, since the cover sheet is formed in a state where it is adhered to each inner peripheral surface of both openings of the case, it is possible to provide the cover sheet in a manner that does not protrude from the outer surface of the case, and the thickness of the trimmer capacitor or It becomes possible to provide a cover sheet without substantially increasing the height. Further, since the cover sheet is formed in a state where it is adhered to the inner peripheral surface of the opening of the case, it is possible to prevent the cover sheet from undesirably peeling off when handling the trimmer capacitor. In addition, the adhesive force of the cover sheet to the case is controlled by the thickness of the cover sheet, so it is possible to obtain a stable adhesive state with constant strength regardless of the width of the case, especially around the opening. . Further, by selecting the material, thickness, etc. of the cover sheet, it is possible to prevent it from becoming an obstacle when rotating the rotor. Further, as is clear from the description of the above-mentioned embodiments, the formation of the cover sheet is as follows.
This can be carried out efficiently by utilizing the change in the state of an appropriate resin from a molten state to a hardened state.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of this invention. Figure 2 shows the chip trimmer capacitor 1 in Figure 1.
FIG. FIG. 3 is an exploded perspective view showing the parts constituting the chip trimmer capacitor 1. As shown in FIG. FIG. 4 is a plan view of the case 5 which is a part of the chip trimmer capacitor 1. FIG. 5 is a longitudinal sectional view of the case 5. 6 to 8 sequentially show steps for forming the cover sheet 30 (adhesive 35a). 9 to 11 sequentially show steps for forming the cover sheet 31 (adhesive 35a). FIG. 12 is a diagram showing an example of the mounting state of the chip trimmer capacitor 1. In the figure, 1 is a chip trimmer capacitor, 2
3 is the rotor (metal rotor), 5 is the case, 6 is the rotation mechanism (center shaft), 8 and 27 are the driver grooves, 18 is the opening (top opening), and 20 is the rotation mechanism part (spring with driver groove). Opening (bottom opening), 3
0 and 31 are cover sheets, and 35 and 35a are adhesives.

Claims (1)

[Claims for Utility Model Registration] (1) A rotating mechanism including a rotor is built into a case, and the case is provided with openings on opposite sides into which tools for rotating the rotor can be inserted. Further, in the double-sided adjustable trimmer capacitor, the cover sheet is formed in a state adhered to the inner peripheral surface of each opening so as to close both openings of the case. capacitor. (2) The double-sided adjustable trimmer capacitor according to claim (1), wherein the cover sheet is made of a stretchable material. (3) The double-sided adjustable trimmer capacitor according to claim 1 or 2, wherein the cover sheet is configured to be easily broken when the rotor is rotated.