JP3840962B2 - Method for manufacturing variable capacitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a variable capacitor.
[0002]
[Prior art]
In general, a variable capacitor changes an effective facing area between a stator electrode and a rotor electrode by rotation of the rotor with respect to the stator, thereby changing capacitance. Conventionally known as this type of variable capacitor is, for example, that described in Japanese Patent Laid-Open No. 2001-267178.
[0003]
In this variable capacitor, a stator provided with a stator electrode is fixed to an insulating case in which a rotor terminal and a stator terminal are insert-molded. Then, the central shaft portion of the rotor terminal is inserted into the hole of the rotor provided with the rotor electrode, and further inserted into the hole of the driver plate having a spring portion for elastically biasing the rotor toward the stator. is doing. The front end portion of the central shaft portion is caulked so that the rotor and the driver plate are rotatably attached to the central shaft portion.
[0004]
Here, since the rotor terminal and the stator terminal are soldered to a printed circuit board or the like, the entire surface is usually treated with a solder plating film or an Sn plating film in order to improve solderability. The reason why the whole is surface-treated with a solder plating film or the like is that the manufacturing cost is low compared with the case where only a part of the terminal is plated (masking work before plating is necessary). Moreover, it is because the corrosion resistance of a terminal can be improved by surface-treating the whole terminal with a solder plating film.
[0005]
FIG. 12 is a vertical sectional view showing a mounting structure of the driver plate 101 and the rotor terminal 110 of the conventional variable capacitor 100. The rotor terminal 110 has a cylindrical central shaft portion 111 and a lead portion 112. A surface treatment film 113 that melts at the soldering temperature is formed on the surface of the rotor terminal 110. For example, the surface treatment film 113 includes a primary (base) plating film 114 and a secondary plating film 115.
[0006]
The driver plate 101 is for rotating the rotor, and has a driver groove 102 for receiving the tip of the driver and a spring portion 103 for elastically biasing the rotor toward the stator. After the central shaft portion 111 of the rotor terminal 110 is inserted into the hole 104 of the driver plate 101, the tip end portion 111a of the central shaft portion 111 is caulked, and the driver plate 101 is rotatably attached to the central shaft portion 111.
[0007]
[Problems to be solved by the invention]
However, in the conventional variable capacitor 100, a surface treatment film (solder plating film, Sn plating film or the like) 113 that melts at the soldering temperature is interposed between the center shaft portion 111 and the caulking portion of the driver plate 101. Prior to soldering, as indicated by a circle A, torque is generated by friction generated by contact due to unevenness of the surface 113a of the surface treatment film 113. For this reason, when the variable capacitor 100 is soldered to a printed circuit board or the like, when the surface treatment film 113 is temporarily dissolved by heat, a part of the unevenness disappears and a large number of voids are generated in the vicinity of the surface 113a. It becomes like this. When the contact due to the unevenness of the surface 113a is reduced and the gap is increased, the torque due to the friction is reduced and the torque is reduced.
[0008]
In addition, the soft unevenness due to the surface treatment film 113 may cause the air gap to be crushed or the top of the convex portion of the surface 113a to be crushed by the residual stress after adjusting the capacitance by rotating the driver plate 101. easy. As a result, a gap is generated in the caulked portion between the central shaft portion 111 and the driver plate 101, the caulking is loosened, and the rotational torque of the driver plate 101 is reduced.
[0009]
Further, the loosening of the caulking causes a decrease in the spring load of the driver plate 101 holding the rotor, the contact force between the rotor and the stator is weakened, and a minute gap is generated at the interface between the rotor and the stator. For this reason, the capacitance is not stable, it becomes difficult to set the capacitance, and the setting drift (capacitance change after setting) increases. In particular, recently, the use of lead-free solder has progressed due to environmental problems, and the soldering temperature has risen from about 235 ° C. (in the case of lead-containing solder) to about 260 ° C., and the above problem has occurred remarkably. Yes.
[0010]
Accordingly, an object of the present invention is to provide a method for manufacturing a variable capacitor that can suppress loosening of a caulking portion of a central shaft portion due to heat at the time of soldering to a printed circuit board or the like.
[0011]
[Means and Actions for Solving the Problems]
  In order to achieve the above object, a variable capacitor manufacturing method according to the present invention includes:
  (A) A stator terminal and a rotor terminal having a central shaft portion on which a surface treatment film that melts at a soldering temperature is formed.,Forming an insulating case provided at the bottom;
  (B) a step of heat treating the surface treatment film provided at the surface of the central shaft portion, which is dissolved at the soldering temperature, and once dissolving;
  (C) In a state where the stator provided with the stator electrode is electrically connected to the stator terminal and the stator electrode,ProvideProcess,
  (D) inserting the central shaft portion of the rotor terminal into the hole of the rotor provided with the rotor electrode that forms a capacitance facing the stator electrode;
  (E) inserting the central shaft portion of the rotor terminal into the hole of the driver plate having a driver groove and a spring portion for elastically biasing the rotor toward the stator;
  (F)Shifting the angle between the driver plate and the rotor from the engagement angle so that the driver plate and the rotor inserted through the central shaft portion of the rotor terminal are in a non-engaged state;
  (G)Caulking the tip of the central shaft, and attaching the rotor and the driver plate to the central shaft in a rotatable manner;
  (H) After crimping the tip of the central shaft portion and rotatably mounting the rotor and driver plate to the central shaft portion, rotate the driver plate while sliding on the rotor, and adjust the angle between the driver plate and the rotor. Engaging the driver plate and the rotor at an engagement angle; and
  It is provided with. Here, examples of the “surface treatment film that dissolves at the soldering temperature” include a solder plating film and a Sn plating film.
[0012]
By the above method, since the surface treatment film that melts at the soldering temperature is once melted by heat treatment before the central shaft portion is caulked, the residual stress is released in the surface treatment film. Further, since the diffusion layer grows between the base material of the rotor terminal and the surface treatment film, the adhesion is greatly improved. As a result, the surface becomes difficult to break, and the surface of the surface-treated film after dissolution is not uneven but smooth. The surface-treated film once melted and dense in composition is less susceptible to heat during subsequent soldering to a printed circuit board or the like. Therefore, even when heat is applied when the variable capacitor is soldered to a printed circuit board or the like, the shape of the surface of the central shaft portion of the caulking portion hardly changes. Therefore, even when the electrostatic capacity is adjusted by rotating the driver plate, a gap is hardly generated between the central shaft portion and the driver plate, and loosening of the caulking portion can be suppressed.
[0014]
  Further, by the steps (f) and (h),The rotor and the driver plate are securely engaged without causing a positional shift. In this case, it is preferable that a convex portion is provided on the rotor side surface of the driver plate or the driver plate side surface of the rotor. This protrusion improves the slippage between the driver plate and the rotor until the rotor is engaged. Therefore, when the driver plate and the rotor are engaged with each other, it is possible to prevent the driver plate and the rotor from rotating together and not being engaged with each other.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a variable capacitor manufacturing method according to the present invention will be described below with reference to the accompanying drawings.
[0016]
As shown in FIGS. 1 and 2, the variable capacitor 1 includes a stator 2, a rotor 3, a driver plate 4, an insulating case 5, and a rotor terminal 6 and a stator terminal 7 provided on the insulating case 5. It consists of and.
[0017]
The rectangular stator 2 is made of a dielectric substrate 23 and has an insertion hole 21 at the center thereof. The diameter of the insertion hole 21 is set to be slightly larger than the outer diameter of the central shaft portion 62 of the rotor terminal 6 described later. A stator electrode 22 is formed on a substantially left half of the lower surface of the dielectric substrate 23 by a method such as printing.
[0018]
The substantially semicircular rotor 3 has an insertion hole 31 at the center of the string, and linear engagement wall surfaces 33a and 33b with the insertion hole 31 in between. The diameter of the insertion hole 31 is set to be slightly larger than the outer diameter of the central shaft portion 62 of the rotor terminal 6 described later. The rotor 3 is manufactured, for example, by etching or laser processing a conductive metal plate. The rotor 3 has a substantially semicircular rotor electrode 32 on its lower surface. The rotor electrode 32 forms a capacitance by facing the stator electrode 22 with the dielectric substrate 23 therebetween.
[0019]
The insulating case 5 made of resin or the like has an opening on the upper surface. The rotor terminal 6 and the stator terminal 7 are insert-molded at the bottom.
[0020]
The rotor terminal 6 has a lead portion 61 and a cylindrical central shaft portion 62. The lead portion 61 is led out from the right side wall of the insulating case 5 and wraps around the bottom surface (mounting surface) of the insulating case 5 along the side wall. The central shaft portion 62 is erected in the recess 51 of the insulating case 5. A surface treatment film (for example, a solder plating film or an Sn plating film) 63 that melts at the soldering temperature is formed on the entire surface of the rotor terminal 6.
[0021]
On the other hand, the stator terminal 7 has a lead portion 71 and a connection portion 72. The lead portion 71 is led out from the left side wall of the insulating case 5 and wraps around the bottom surface (mounting surface) of the insulating case 5 along the side wall. The connection portion 72 is exposed on the bottom wall of the recess 51 of the insulating case 5. A surface treatment film (for example, a solder plating film or a Sn plating film) 73 that melts at the soldering temperature is formed on the entire surface of the stator terminal 7.
[0022]
The surface treatment of the rotor terminal 6 and the stator terminal 7 will be described more specifically. For the base material of the terminals 6 and 7, a copper alloy plate (brass plate, white plate, etc.), a stainless plate (SUS plate), an iron plate, or the like is used. A primary (underlying) plating film of Ni or the like is formed on the entire surface of the base material for rust prevention in the state of the plate material before being cut into a terminal shape by pressing the base material. As the material of the primary (underlying) plating film, a material that does not dissolve at the soldering temperature is selected. However, the primary (underlying) plating film is not always necessary and may be omitted.
[0023]
Next, a secondary plating film is formed on the primary plating film. As the material of the secondary plating film, a material that melts at the soldering temperature (for example, solder or Sn) is selected. In this embodiment, Sn is used. The secondary plating films are formed as surface treatment films 63 and 73 which are formed on the surfaces of the terminals 6 and 7 and melt at the soldering temperature. Thereafter, the plate-like base material is pressed to cut out the terminals 6 and 7 from the plate-like base material.
[0024]
Next, the terminals 6 and 7 are heat-treated (reflowed) at a temperature at which the surface treatment films 63 and 73 are melted or soldered (at about 260 ° C.) or higher. As a result, the surface treatment films 63 and 73 are once dissolved and the residual stress is released. Further, since a diffusion layer grows between the base material of the terminals 6 and 7 and the surface treatment films 63 and 73, the adhesion is greatly improved. As a result, the surfaces of the surface treatment films 63 and 73 are less likely to be cracked, and the surfaces of the surface treatment films 63 and 73 after dissolution are not uneven, and are smooth. The surface treatment films 63 and 73 that have once been dissolved and have a dense composition are less susceptible to the effects of heat during subsequent soldering to a printed circuit board or the like.
[0025]
The driver plate 4 is for rotating the rotor 3, and is obtained from one metal plate through press working and bending. The driver plate 4 includes a driver groove 41 that receives the tip of the driver, a spring portion 47 that elastically biases the rotor 3 toward the stator 2, and a pair of engaging portions 48 that engage with the rotor 3. Have. The cross-shaped driver groove 41 is formed in the head 40 of the driver plate 4.
[0026]
As shown in FIGS. 3 and 4, the spring portion 47 includes a first folded portion 42 connected to the end portion of the head portion 40, a first plate portion 43 in contact with the lower surface of the head portion 40, and The second plate portion 44 is connected to the end portion of the first plate portion 43, the second plate portion 45 is disposed substantially parallel to the first plate portion 43, and the support portion 46.
[0027]
The head 40, the first plate portion 43, and the second plate portion 45 are provided with insertion holes 40 a, 43 a, 45 a (see FIG. 2) for inserting the central shaft portion 62 of the rotor terminal 6. These insertion holes 40a, 43a, and 45a are arranged coaxially so that when the driver plate 4 rotates around the central shaft portion 62, a stable posture and a stable torque are obtained. The diameter of the insertion hole 40 a is set to be approximately the same as the outer diameter of the central shaft portion 62 of the rotor terminal 6. The second plate portion 45 is a portion in pressure contact with the rotor 3. A long convex portion 49 is formed on the lower surface of the second plate portion 45. When the support portion 46 caulks the tip end portion of the central shaft portion 62, the support portion 46 comes into contact with the lower surface of the head portion 40, and by supporting it from below, the second folded portion 44 plastically deforms beyond the elastic limit. To prevent.
[0028]
The pair of engaging portions 48 extend from the left and right sides of the second plate portion 45, respectively, and the front end surfaces 48 a protrude from the lower surface of the second plate portion 45. The front end surface 48 a engages with the linear engagement wall surfaces 33 a and 33 b of the rotor 3.
[0029]
The above components are assembled as follows. That is, as shown in FIG. 5, the stator 2 is housed and fixed in the recess 51 of the insulating case 5 in which the rotor terminal 6 and the stator terminal 7 are insert-molded. The central shaft portion 62 of the rotor terminal 6 is inserted into the insertion hole 21 of the stator 2, and the stator electrode 22 is electrically connected to the connection portion 72 of the stator terminal 7 exposed at the bottom wall of the recess 51. Next, the rotor 3 is accommodated in the recess 51 of the insulating case 5 and disposed on the upper surface of the stator 2. A central shaft portion 62 is inserted into the insertion hole 31 of the rotor 3, and the rotor 3 is rotatable about the central shaft portion 62.
[0030]
Next, the driver plate 4 is accommodated in the recess 51 of the insulating case 5 and disposed on the upper surface of the rotor 3. The central shaft portion 62 is inserted through the insertion holes 40 a, 43 a, 45 a of the driver plate 4, and the driver plate 4 is rotatable about the central shaft portion 62. At this time, as shown in FIG. 6, the position of the driver plate 4 is such that the front end surfaces 48 a of the pair of engaging portions 48 of the driver plate 4 are engaged with the engaging wall surfaces 33 a and 33 b of the rotor 3. Is decided. However, FIG. 6 is a diagram showing an engaged state of the rotor 3 and the driver plate 4 as viewed from the bottom surface side.
[0031]
Thereafter, the tip end portion of the central shaft portion 62 is caulked as shown in FIG. 2, thereby preventing the stator 2, the rotor 3 and the driver plate 4 from falling off from the case 5, and by the driver plate 4. A spring action is exerted on the rotor 3.
[0032]
In the variable capacitor 1 thus obtained, the spring portion 47 of the driver plate 4 presses against the rotor 3 to urge the rotor 3 to elastically press the rotor 3 toward the stator 2. As a result, the rotor electrode 32 of the rotor 3 is in close contact with the stator 2.
[0033]
Further, when the tip of the driver is inserted into the driver groove 41 and the driver plate 4 is rotated, the distal end surface 48a of the engaging portion 48 is engaged with the engaging wall surfaces 33a and 33b. 3 and the rotor 3 is rotated. Due to the rotation of the rotor 3, the effective facing area between the rotor electrode 32 and the stator electrode 22 facing each other is changed, and the capacitance formed between the rotor electrode 32 and the stator electrode 22 is changed. Can be adjusted. The adjusted capacitance is taken out between the rotor terminal 6 electrically connected to the rotor electrode 32 and the stator terminal 7 electrically connected to the stator electrode 22. In this case, the rotor electrode 32 is electrically connected to the rotor terminal 6 via the rotor 3 and the driver plate 4.
[0034]
In the variable capacitor 1 having the above-described configuration, the surface treatment films 63 and 73 once melted to have a dense composition are affected by heat when the variable capacitor 1 is soldered to a printed circuit board or the like thereafter. It becomes difficult to receive. Therefore, even if heat is applied when soldering to a printed circuit board or the like, the shape of the surface of the central shaft portion 62 of the caulking portion hardly changes. As a result, even if the electrostatic capacity is adjusted by rotating the driver plate 4, a gap is hardly generated in the caulking portion between the central shaft portion 62 and the driver plate 4, and loosening of the caulking portion can be suppressed.
[0035]
Accordingly, it is possible to prevent a decrease in rotational torque of the driver plate 4. FIG. 7 shows the results of measuring the rotational torque before and after soldering of the variable capacitor 1 (see the solid line 81). For comparison, FIG. 7 also shows the rotational torque measurement results of a conventional variable capacitor that does not heat-treat terminals 6 and 7 (see dotted line 82).
[0036]
Furthermore, the variable capacitor 1 can suppress a decrease in the spring load of the driver plate 4 and can prevent a decrease in the adhesion between the stator 2 and the rotor 3. For this reason, the electrostatic capacity is stabilized, the electrostatic capacity is easily set, and the setting drift (capacitance change after setting) can be reduced.
[0037]
By the way, when the rotor 3 and the driver plate 4 are put into the insulating case 5 in the assembly process of the variable capacitor 1, if the arrangement of the two is set to be in an engaged state as shown in FIG. If the angular position of the rotor 3 or the driver plate 4 is shifted due to the cause and the both are not engaged, the relationship between the angular position of the rotor 3 and the angular position of the driver plate 4 is obtained by caulking the central shaft 62 as it is. No longer match. As a result, the relationship between the angular position of the driver plate 4 and the MAX position of the capacitance does not match.
[0038]
Further, the clearance Q (see FIG. 6) between the engagement wall surfaces 33a and 33b of the rotor 3 and the front end surface 48a of the engagement portion 48 of the driver plate 4 so that the rotor 3 and the driver plate 4 are easily engaged. ) Is increased, the play of the driver plate 4 is increased. Therefore, the angular region where the rotor 3 does not rotate even when the driver plate 4 is rotated becomes large, and the variable capacitor is difficult to adjust the capacitance.
[0039]
Therefore, when it is necessary to eliminate the above-mentioned problems, the following assembly process is adopted. That is, as shown in FIG. 8A, when the rotor 3 is put in the insulating case 5, the arrangement angle of the rotor 3 is previously shifted by a predetermined angle θ counterclockwise from the case shown in FIG. And accommodate. FIG. 8 is a diagram showing an arrangement relationship between the rotor 3 and the driver plate 4 as viewed from the bottom surface side. Therefore, in the drawing, it is described as being shifted by an angle θ in an apparent clockwise direction.
[0040]
Next, the driver plate 4 is put into the insulating case 5 at the same arrangement angle as that shown in FIG. As a result, the angle between the driver plate 4 and the rotor 3 deviates from the engagement angle, and the driver plate 4 and the rotor 3 are always disposed in the insulating case 5 in a non-engaged state. The engagement angle means an angle between the driver plate 4 and the rotor 3 when they are engaged. In the present embodiment, the engagement angle is set to approximately 0 degrees.
[0041]
Next, the tip end portion of the central shaft portion 62 of the rotor terminal 6 is caulked, and the rotor 3 and the driver plate 4 are rotatably attached to the central shaft portion 62. Thereafter, the tip of the driver is inserted into the driver groove 41 of the driver plate 4, and the driver plate 4 is rotated in the direction of the arrow K on the drawing (A) of FIG. As a result, the driver plate 4 slides on the rotor 3, and the front end surface 48a of the engaging portion 48 of the driver plate 4 is engaged with the engaging wall surfaces 33a and 33b of the rotor 3 as shown in FIG. Match. At this time, the convex portion 49 provided on the sliding surface of the driver plate 4 (the lower surface of the second plate 45) improves the sliding between the driver plate 4 and the rotor 3 until they are engaged.
[0042]
Here, the angle θ is set to a value larger than the variation in the angle between the rotor 3 and the driver plate 4 that occurs during the assembly work (the variation angle is α). Otherwise, the positional relationship as shown in FIG. 9A may occur due to the variation in the angle between the rotor 3 and the driver plate 4. At this time, when the driver plate 4 is rotated in the clockwise direction on the drawing (apparently), the drive plate 4 must be rotated nearly 360 degrees in order to engage the rotor 3 and the drive plate 4. Will become longer. In addition, the driver plate 4 is easily caught on the edge of the engagement wall surface 33b of the rotor 3, and a problem that the driver plate 4 is not engaged easily occurs.
[0043]
Further, as shown in FIG. 9B, when the driver plate 4 is provided with the convex portion 49, the angle θ is larger than the variation angle α and smaller than the arrangement angle β of the convex portion 49. Set to an angle. This is because if the angle θ is larger than the angle β, the convex portion 49 is caught on the edge of the engagement wall surface 33b of the rotor 3 and a problem that the engagement does not occur easily occurs.
[0044]
By adopting the assembly method as described above, the yield can be improved simply by setting the angle θ according to the angle variation that occurs during the assembly work. Can respond. Furthermore, since it is not necessary to match the angular position of the rotor 3 and the angular position of the driver plate 4 at the beginning, the rotor 3 and the driver plate 4 can be engaged without being affected by the deviation of the angular positions of the two. . Accordingly, since the clearance Q (see FIG. 6) between the engagement wall surfaces 33a and 33b of the rotor 3 and the tip surface 48a of the engagement portion 48 of the driver plate 4 can be reduced, the rotation play of the driver plate 4 can be reduced. Responsive capacitance can be adjusted in accordance with the rotation of the driver plate 4. Furthermore, the relationship between the angular position of the driver plate 4 and the MAX position of the capacitance can be matched.
[0045]
In addition, this invention is not limited to the said embodiment, It can change variously within the range of the summary. For example, in the above-described embodiment, the surface treatment films 63 and 73 of the rotor terminal 6 and the stator terminal 7 are formed before the terminal processing (press processing). ) Or after insert molding the insulating case 5. Further, the heat treatment of the surface treatment films 63 and 73 may be performed after insert molding in the insulating case 5.
[0046]
Further, as shown in FIG. 10, a plurality of short convex portions 49 a may be formed on the second plate 45 of the driver plate 4. Further, as shown in FIG. 11, a convex portion 35 may be formed on the surface of the rotor 3 on the driver plate side. The convex portion 35 extends in a long shape from the front to the back of the drawing.
[0047]
【The invention's effect】
As is clear from the above description, according to the present invention, the surface treatment film that melts at the soldering temperature is melted once by heat treatment before the central shaft portion is caulked, so that the surface is hardly cracked and dissolved. The surface of the subsequent surface treatment film does not become uneven and becomes smooth. The surface-treated film once melted and dense in composition is less susceptible to heat during subsequent soldering to a printed circuit board or the like. Therefore, even when heat is applied when the variable capacitor is soldered to a printed circuit board or the like, the shape of the surface of the central shaft portion of the caulking portion hardly changes. As a result, even when the electrostatic capacity is adjusted by rotating the driver plate, a gap is hardly generated between the central shaft portion and the driver plate, and loosening of the caulking portion can be suppressed.
[0048]
First, the angle between the driver plate and the rotor is shifted from the engagement angle so that the driver plate inserted into the central shaft portion of the rotor terminal and the rotor are in a non-engaged state. After the rotor and the driver plate are rotatably attached to the central shaft portion, the driver plate is rotated while sliding on the rotor, and the angle between the driver plate and the rotor is set to the engagement angle. By adopting a method for bringing the rotor into an engaged state, the rotor and the driver plate are securely engaged without causing any positional displacement. In this case, it is preferable that a convex portion is provided on the rotor side surface of the driver plate or the driver plate side surface of the rotor. This protrusion improves the slippage between the driver plate and the rotor until the rotor is engaged. Therefore, when the driver plate and the rotor are engaged with each other, it is possible to prevent the driver plate and the rotor from rotating together and not being engaged with each other.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a practical form of a variable capacitor according to the present invention.
FIG. 2 is a vertical sectional view of the variable capacitor shown in FIG.
3 is a front view of the driver plate and the rotor shown in FIG. 1. FIG.
4 is a right side view of the driver plate and the rotor shown in FIG. 1. FIG.
5 is a vertical sectional view of the insulating case, the stator, and the rotor shown in FIG.
FIG. 6 is an explanatory view showing a positional relationship when viewed from the bottom side of the rotor and the driver plate.
FIG. 7 is a graph showing a result of measuring a change in rotational torque of a driver plate before and after soldering.
FIG. 8 is an explanatory diagram showing an example of a method for assembling a variable capacitor.
FIG. 9 is an explanatory diagram for explaining the assembly method shown in FIG. 8;
FIG. 10 is a bottom view showing a modified example of the driver plate.
FIG. 11 is a partial cross-sectional view showing a modified example of the rotor.
FIG. 12 is an enlarged cross-sectional view of a main part for explaining a conventional variable capacitor.
[Explanation of symbols]
1 ... Variable capacitor
2 ... Stator
3 ... Rotor
4 ... Driver plate
5 ... Insulating case
6 ... Rotor terminal
7: Stator terminal
21 ... insertion hole
22 ... Stator electrode
32 ... Rotor electrode
31 ... Insertion hole
33a, 33b ... engaging wall surface
35 ... convex part
41 ... Driver groove
47 ... Spring part
48 ... engaging portion
48a ... tip surface
49 ... convex part
62 ... Center shaft
63, 73 ... Surface treatment film that melts at soldering temperature

Claims (2)

A step of forming an insulating case provided at the bottom with a stator terminal and a rotor terminal having a central shaft portion on which a surface treatment film that melts at a soldering temperature is formed;
A step of dissolving the surface treatment film, which is provided at the surface of the central shaft portion and melts at a soldering temperature, by heat treatment;
Providing a stator provided with a stator electrode in the insulating case in a state where the stator terminal and the stator electrode are electrically connected;
Inserting a central axis portion of the rotor terminal into a hole of a rotor provided with a rotor electrode that forms a capacitance facing the stator electrode;
Inserting a central shaft portion of the rotor terminal into a hole of a driver plate having a driver groove and a spring portion for elastically biasing the rotor toward the stator;
Shifting the angle between the driver plate and the rotor from the engagement angle so that the driver plate inserted through the central shaft portion of the rotor terminal and the rotor are in a disengaged state;
Caulking the tip of the central shaft, and attaching the rotor and the driver plate to the central shaft so as to be rotatable;
The front end portion of the central shaft portion is caulked, the rotor and the driver plate are rotatably attached to the central shaft portion, and then the driver plate is rotated while sliding on the rotor, so that the driver plate and the rotor An angle between the engagement plate and the driver plate and the rotor are engaged.
A method of manufacturing a variable capacitor, comprising: Method of manufacturing a variable capacitor of claim 1, wherein a convex portion is provided on one side at least one of the rotor-side surface and the surface of the driver plate side of the rotor of the driver plate.

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