JPH02126601A - Connecting structure of terminal and variable resistor provided with such connecting structure - Google Patents

Abstract

PURPOSE:To enable a terminal to be stably connected onto an electrode through simple work by solder-plating the surface of a terminal member beforehand, causing the terminal member to abut an electrode part, and heating them to electrically connect the terminal member and the electrode part. CONSTITUTION:A resistor 6, electrodes 6a, 6b, a collector electrode 7, and an elastic body 8 are formed on the surface of a substrate 1. Terminals 9, 10, 11 consist of a copper alloy, etc., and are connected to the electrodes 6a, 6b by solder-plating the extremities of the terminals 9, 10, 11 beforehand, and causing these solder-plated parts to abut on the electrodes 6a, 6b, 7, and fusing the plated layers through heating by Joule heat or a heater to carry out soldering. For the substrate 1, alumina is preferably used, and as the electrodes 6a, 6b, 7, silver or silver-palladium alloy is preferably used. Therefore, in soldering, the solder is not required to be supplied separately, so that the work is simplified, and is suitable for continuous production. Further, the adhered solder amount is made constant, so that the possibility that the excessive solder flows out to exert adverse influence upon the other parts is eliminated and stable connection to a thin film electrode can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a connection structure by soldering terminals, a variable resistor equipped with the connection structure, and particularly a slider to a substrate having a resistor on its surface. The present invention relates to a variable resistor having a rotor rotatably attached thereto.

- Previous Techniques and Their Titles Conventionally, in order to connect a terminal to an electrode provided on a board, the terminal was brought into contact with the electrode, and solder was applied and heated by applying solder thereto. However, this requires a device for supplying solder and a function to control the amount of solder supplied during assembly, making the equipment larger and more expensive.

In addition, it is difficult to adjust the amount of solder supplied, and if the amount supplied is too large, it may cause damage to other components, such as the rotor becoming unable to rotate.This problem is particularly important for small integrated circuit components. It was remarkable.

On the other hand, it is possible to weld the terminal to the electrode, but since the difference in thickness between the electrode and the terminal is too large, the characteristics lack stability and this is not suitable for mass production.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a structure that allows a terminal to be connected to an electrode with good stability by a simple operation.

Means and Function for Solving the Problems In order to solve the above problem, the terminal connection structure according to the present invention is provided by applying solder plating to the surface of the terminal material in advance, bringing the solder plating part into contact with the electrode part, and heating it. The present invention is characterized in that the terminal material and the electrode portion are electrically connected. The heating method is
For example, a method is employed in which an electrode of a heating device is brought into contact with the terminal and a current is supplied to the electrode to generate Joule heat, or a method in which a heat source such as a heater is brought into contact with the terminal. In this connection structure, the step of heating while supplying solder during assembly is omitted, and a stable electrical connection is obtained without excess solder flowing out to other parts.

Further, the variable resistor according to the present invention includes the terminal connection structure. That is, the surface of the terminal is solder-plated in advance, and the solder-plated part is brought into contact with an electrode or a collector electrode provided at the end of a resistor on a board and heated, and the terminal and the resistor or collector electrode are heated. It is characterized in that it is electrically connected to.

Embodiments of the variable resistor according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment, Figures 1 to 18] As schematically shown in Figures 12 and 13, this variable resistor includes a resistor board 1 with a terminal and a resistor 6 attached to a case 2. A rotor 3 having a slider 4 is rotatably held in this case 2, and lead terminals 9, 10 and a collector terminal 11 are drawn out from the case 2.

As shown in FIG. 1, a resistor 6, electrodes 6a, 6b, a collector electrode 7, and an elastic body 8 are formed on the surface of a substrate 1. The resistor 6 has a horseshoe shape, and a first lead terminal 9 is connected to one end thereof via an electrode 6a, and a second lead terminal 10 is connected to the other end by soldering via an electrode 6b.

The collector electrode 7 extends from the center of the substrate 1 to one end of the substrate 1, and a collector terminal 11 is connected to the end.

The terminals 9, 10.11 are made of copper alloy or the like, and the electrodes 6a.

For attachment to terminals 9, 10 .
Solder plating is applied to at least the tips of the electrodes 11, and the solder plated portions are brought into contact with the electrodes 6a, 6b, and 7, and the plating layer is melted by heating with Joule heat, heating with a heater, etc., and soldered. . In this case, it is preferable to use alumina for the substrate 1 and silver or a silver-palladium alloy for the electrodes 6a, 6b, and 7.

On the other hand, the elastic body 8 is fixed to the surface of the substrate 1 in an annular shape at a position facing a skirt portion 3c of the rotor 3, which will be described later. As the material of the elastic body 8, insulating silicone, last, etc., which can withstand the temperature of soldering and the solvents used in flux cleaning, etc., is used. Further, as a method for fixing it to the substrate 1, screen printing, drawing method, dipping, etc. can be adopted. Thereby, when slidingly contacting the rotor 3, internal airtightness can be obtained, and the torque can be increased and stabilized. Furthermore, when the board 1 and the case 2 are integrated by insert molding, a buffering effect is obtained, which prevents the problem of the board 1 from cracking, and also prevents the molded resin of the case 2 from flowing toward the resistor 6 side. It has the advantage of being suppressed. Note that this elastic body 8 may be fixed to the lower surface of the skirt portion 3c of the rotor 3.

Incidentally, the case 2 including the substrate 1 is manufactured by being held by a hoop material 3o processed into the shape shown in FIG. That is, the board 1 has the terminals 9, 10 . . . soldered as described above.
11 and dummy terminals 31 and 31, and in this state is insert molded into the case 2 (see FIGS. 3 and 5). Incidentally, the tie bar and dummy terminals 31 and 31 of the hoop material 30 are finally cut. Lead terminals 9, 10
A bifurcated branch terminal 9a is formed by forming slits 9' and 10' in the longitudinal direction.

It is divided into 9b, 10a, and 10b. This is to make it compatible with the standard 2.5 mm pitch and irregular 2.5 mm pitch mounting configurations described below.

As shown in FIGS. 3 to 6, the case 2 has a cylindrical body that opens upward, and has grooves 12a that can hold the terminals 9, 10, and 11 from the side to the bottom.

A plurality of 12b, 13a, 13b, and 14 have been formed. The upwardly opened cylindrical portion 2a has an inner diameter that can rotatably accommodate the rotor 3, and a ring-shaped protrusion 2b having a width necessary for heat bending is formed on the inner peripheral portion of the upper portion.

The grooves 12a, 12b, 13a, 13b, 14
are formed to match the widths of the lead terminals 9° 10 and the collector terminal 11, and the branch terminals 9a and 9a of the lead terminals 9 and 10
Grooves 12a and 13a correspond to 10a, and branch terminals 9b and 1
Grooves 12b and 13b correspond to 0b. This groove extends from the top edge of the case 2 through the side surface to the bottom surface side, and allows each terminal 9, 10, 11 protruding from the side surface of the case 2 to be taken out by bending at a required point on the side surface or bottom surface. It has become.

Furthermore, the spacing between the grooves is set to match the distance between the terminal insertion holes formed on the printed circuit board etc. on which the variable resistor is mounted, that is, the pitch. It is compatible with both pitch and irregular 2.5 mm pitch.

Furthermore, the edges 12c, 13c, and 14c of each groove protrude outward to facilitate processing for fixing each terminal 9, 10, and 11, that is, heat fusion, etc., and to improve stability when mounted on a printed circuit board. It also has a standoff effect that improves flux removal and improves soldering.

As the material for the case 2, it is preferable to use a thermoplastic resin having a heat deformation temperature equal to or lower than that of the rotor 3, such as PBT*.

As shown in FIGS. 7 to 9, the rotor 3 has a cross-shaped driver groove 38 formed on its upper surface, and an annular skirt portion 3c facing the elastic body 8 on the substrate 1 formed at its lower part. has been done. Further, the base plate portion 4a of the slider 4 is physically fixed to the lower portion by insert molding. The protrusions 3d and 3d protrude from the bottom side, and when the rotor 3 is rotated by a screwdriver to adjust the resistance value, when the protrusions 3d and 3d come into contact with the substrate 1, the rotor 3 may be damaged by the pressurizing force or may slide. This prevents the child 4 from being deformed. The material of the rotor 3 is as follows:
Thermosetting resins and thermoplastic resins with excellent heat resistance, such as P
PS resin or the like is used to prevent the ring protrusion 2b of the case 2 from being deformed or deteriorating in characteristics due to heat during heat bending.

As shown in FIGS. 10 and 11, the slider 4 is formed by pressing a single conductive metal plate, and includes a base plate 4a and a contact point located at the tip of an arm 4c. A pair of arm portions 4e located on the periphery, contact portions 4f located at the tips of 4e.

The substrate portion 4a is bent at the end portion 4b to form a double structure. The arm parts 4e, 4e extend in the circumferential direction, and as is clear from FIG. It is divided. Further, the arm parts 4e, 4e are bent toward the board 1 by straight lines B, which are parallel to the straight line A connecting the center of the board part 48 and the contact parts 4f, 4f, and the vicinity of the tips are bent in the opposite direction. and contact parts 4f, 4f
is formed. In this case, when the contact portions 4f, 4f are brought into contact with the resistor 6 and put into operation after all the bending processes are completed, they will be arranged in parallel on the straight line A.

By the way, the contact portions 4f, 4f are in the position indicated by the dashed dotted line in FIGS. 10 and 11 in a free state, and when mounted on the substrate 1, they are bent in the direction of the arrow and shifted to the position indicated by the solid line. That is, in this embodiment, since the arm portions 4e, 4e are bent along straight lines B, B parallel to the straight line A, the contact portions 4f, 4f move vertically in the direction indicated by the arrow. if,
If the arm parts 4e, 4e are bent at an angle with respect to the straight line A, the contact part 4 will be bent when attached to the board 1.
In order for f, 4f to exist at the solid line position, in the free state, the contact portions 4f, 4f should be closer to the arrow E than the two-dot chain line position.
It must exist shifted in the direction. When molding the rotor 3, a contact portion 4f is placed in a space of a mold (not shown).
4f and arm portion 4e.

4e, but if the contact part 4f.

If 4f is in a free state and is shifted in the direction of arrow E from the position of the two-dot chain line, then the contact parts 4f, 4f and the arm part 4
e, 4e cannot be accommodated in the space of the mold. That is, in this embodiment, straight line B parallel to straight line A
, bend the arm portions 4e, 4e at B, and connect the contact portions 4f, 4.
Since f is arranged to move vertically in the direction of the arrow, molding of the rotor 3 is possible.

Furthermore, in this embodiment, since the contact portions 4f, 4f are divided by a curved line including an arc shape, when the arm portions 4e, 4e are bent along a straight line B, the contact portion 4f is divided as shown in FIG.
A gap G is formed between the contact portions 4f, 4f, and mutual interference between the contact portions 4f and 4f is prevented, and the contact portions 4f and 4f can mutually operate freely following the resistor 6, thereby improving contact reliability. Moreover, the width dimension of the contact portions 4f, 4f can be increased, and the processing accuracy is also improved.

The slider 4 configured as described above has a rotor 3 attached to the case 2.
When assembled together, the contact portion 4d contacts the collector electrode 7, the contact portions 4f, 4f contact the resistor 6, and the contact between the terminals 9°11 and 10.11 changes depending on the rotation angle of the rotor 3. The resistance value is adjusted.

Next, regarding the assembly of this variable resistor, Fig. 12 and 1
This will be explained with reference to FIGS. 3 and 14. First, the tie bars 40 and 40 of the slider 4 are cut out and attached to the cylindrical part 2a of the case 2.
A single rotor 3 is accommodated. Next, the ring-shaped protrusion 2b of the case 2 is bent by heat caulking to prevent the rotor 3 from being pulled out. This bending process is performed using a thermal bonder, ultrasonic processing, etc., and the rotor 3 is rotatably held within the case 2.

A part of the protrusion 2b is formed high in advance (indicated by the reference numeral 2c in FIG. 5), so that it faces the upper surface of the rotor 3 during this bending process, and the protrusion 3b formed on the upper surface of the rotor 3 comes into contact with it. A stopper 2 that regulates the rotation angle of the rotor 3
Functions as c. A ring-shaped protrusion 2 is on the top of the case 2.
A plurality of scales 15 are formed on the outside of b. This scale 1
Reference numeral 5 is formed as a recess, located close to the driver groove 3a of the rotor 3, and serves as a guide for the rotation angle of the rotor 3 using the driver groove 3a as a so-called index.

Next, remove the tie bars of terminals 9, 10, and 11.
A variable resistor having lead terminals 9 and 10 and a collector terminal 11 protruding from the side surface of the case 2 is obtained.

By the way, these lead terminals 9, 10 and collector terminal 11 are arranged along the groove provided in the case 2, bent at a predetermined position, and projected outward to form a plurality of leads formed on the printed circuit board. insertion hole, i.e. standard 2.5mm
It is said that it can be adapted to both pitch and irregular pitch of 2.5 mm. As shown in FIGS. 15 and 16, a plurality of insertion holes 17 are formed in the printed circuit board 16 at a pitch of X, and this X is normally set to 2.5 mm. The standard 2.5 mm pitch means that the collector terminal 11 is inserted through the insertion hole 17a and the lead terminal 9 is inserted through the insertion hole 17a so that a right-angled isosceles triangle with a base of 2X and a height of X is formed as shown by the two-dot chain line in FIG. Insert the lead terminal 10 into the hole 17b.
The attachment that is inserted through C is called the form. Anomaly 2.5
The mm pitch means that the collector terminal 11 is inserted into the insertion hole 17a1, the lead terminal 9 is inserted into the insertion hole 1, and the collector terminal 11 is inserted into the insertion hole 17a1, and the lead terminal 9 is inserted into the insertion hole 1, in which an isosceles triangle with two sides of X is formed, as shown by the two-dot chain line in FIG.
7b, the attachment in which the lead terminals 10 are respectively inserted into the insertion holes 17c is referred to as a form.

Therefore, the lead terminals 9 and 10 and the collector terminal 1
1, the above two types of attachment are not limited to the side surface perpendicular to the driver groove 3a located on the top surface of the case 2 as shown in FIG. 17, but can also be taken out from the bottom surface side of the case 2. It can be taken out.

First, to explain the case of adapting to the standard 2.5 mm pitch (see the two-dot chain line Y1 in Fig. 17) when taking out from the side, first, the collector terminal 11 protruding from the side of the case 2 should be directed toward the bottom side. bend it and align it along the groove 14. Then, it is bent again at a predetermined point P1 to protrude perpendicularly to the side surface. Lead terminal 9
, 1o cut off the branch terminals 9b and 10b, respectively, and bend the remaining branch terminals 9a and 10a toward the upper surface side, and align them with the grooves 12a and 13a. Further, point P2, which is a predetermined position. Bend again at P3 and connect collector terminal 11
Protrude so that it is parallel to the As a result, the extraction position of a right-angled isosceles triangle having the collector terminal 11 as its apex can be determined.

Next, an irregular 2.5 mm pitch (double-dashed line Y2 in Fig. 17)
), first bend the collector terminal 11 toward the upper surface of the case 2 and align it with the groove 14.

Then, it is bent again at a predetermined point P4 to protrude perpendicularly to the side surface. The lead terminals 9 and 10 are
Cut out the branch terminals 9a and 10a, respectively, and bend the remaining branch terminals 9b and 10b toward the bottom side to form grooves 12b and 1.
Align it along 3b. Furthermore, point P5. which is a predetermined position. P6
It is bent again at , and is made to protrude in the same direction as the collector terminal 11 . Thereby, the extraction position of the isosceles triangle having the flexor terminal 11 as its apex can be determined.

On the other hand, when taking out each terminal 9, 10, 11 from the bottom side of case 2, each terminal 9, 10, 11 is removed from the bottom side of case 2 in accordance with the standard 2.5 mm pitch and irregular 2.5 mm pitch as described above. It is sufficient if they are made to protrude so as to form the conical shapes Yl and Y2 in FIG. 17. At the extraction position, the first
As shown in FIG. 8, for example, in the case of the bottom surface side, if the edge of the groove 12a is heated and crushed toward the branch terminal 98 side to form a caulked part, the branch terminal 9a is fixed and its lifting is prevented. Prevented.

[Second Embodiment, FIG. 19] In the second embodiment, the present invention is applied to a conventionally known configuration. The slider 40 is inserted into the hole and caulked on the back side to prevent it from being pulled out, allowing the slider 40 to rotate integrally with the rotor 45. A resistor 55 and a collector electrode 56 are formed on the substrate 50, and the ends of terminals 61, 62, 63 are soldered onto the electrodes 55a, 55b at both ends of the resistor 55 and the collector electrode 56. As described in the first embodiment, this soldering involves applying solder plating to the surfaces of the tips of the terminals 61, 62, and 63, and bringing the solder plated portions into contact with the electrodes 55a, 55b, and 56.
This is done by melting the plating layer by heating.

Heating is performed by generating Joule heat while supplying current to the heating electrode, or by pressing a heater chip against it. Further, the substrate 1 is made of alumina, and the electrodes 55a, 55b, 56
Silver or silver-palladium alloy is used for the solder plating layer, and a copper alloy is used for the solder plating layer.

Of course, it is also possible to select other materials as appropriate.

Effects of the Invention As is clear from the above explanation, according to the present invention, the solder plating layer provided in advance on the surface of the terminal is melted by heating and the terminal is connected to the electrode, so that soldering can be performed while supplying solder one by one. There is no need to do this, making the work easier and suitable for continuous production. In addition, the amount of solder adhered is constant, and there is no risk of excess solder flowing out and interfering with other components, making it ideal for small electronic components. Moreover, a stable electrical connection can be achieved between electrodes having a thin film thickness.

[Brief explanation of drawings]

FIGS. 1 to 18 show a first diagram of a variable resistor according to the present invention.
Embodiments are shown; Fig. 1 is a plan view of a resistor board with a terminal, Fig. 2 is a plan view of the terminal before assembly, Fig. 3 is a half-sectional plan view of the board inserted into a case, and Fig. 4 is a plan view of a resistor board with a terminal.
The figure is a side view of Fig. 3, Fig. 5 is a sectional view taken along the line I-I of Fig. 3, Fig. 6 is a bottom view of Fig. 3, and Fig. 7 is a plan view of the rotor with insert molded sliders. , Figure 8 is II of Figure 7.
- I line sectional view, FIG. 9 is a bottom view of FIG. 7, FIGS. 10 and 11 are explanatory diagrams showing the deflection of the contact portion of the slider, respectively,
FIG. 12 is a half-sectional plan view of the assembled variable resistor, FIG. 13 is a sectional view taken along the line ■-■ in FIG. 12, and FIG.
Fig. 15 is a plan view showing the standard pitch of the insertion holes provided in the printed circuit board, Fig. 16 is a plan view showing the irregular pitch of the insertion holes, and Fig. 17 is a plan view showing the standard pitch and irregular pitch of the insertion holes. side view of the case showing the protruding position of the terminal,
FIG. 18 is a perspective view showing the terminal in a bent state. FIG. 19 shows a second embodiment, and is a perspective view of a variable resistor with a part of the rotor cut away. 1... Resistance board, 2... Case, 3... Rotor,
4...Slider, 4d, 4f...Contact part, 6...
Resistor, 6a, 6b... Electrode, 7... Collector electrode, 9, 10.11... Terminal, 40... Slider, 4
5... Rotor, 50... Substrate, 55... Resistor,
55a, 55b---electrode, 56...-Ill rectifier electrode, 61.62.63...terminal. Patent applicant Murata Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A terminal connection structure characterized in that the surface of a terminal material is pre-plated with solder, the solder plated portion is brought into contact with an electrode portion and heated, and the terminal material and the electrode portion are electrically connected. 2. In a variable resistor in which a rotor with a slider is rotatably attached to a board with a resistor on its surface, the surface of the terminal is solder-plated in advance, and the solder-plated part is connected to the resistor on the board. 1. A variable resistor, characterized in that the terminal is electrically connected to the resistor or the collector electrode by contacting the electrode or the collector electrode provided at the end of the variable resistor and heating the resistor.