JP2000329790A - Conductive contact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower impedance and resistance of a coil spring shape conductive contact, increase the tolerance of alignment with contact body and improve the capability of soldering. SOLUTION: A conductive contact 1 consisting of a coil spring, having a pitch winding part in the middle of the axial direction and a cone shape contact needle 1b thinning toward the outside in both ends of the axial direction is formed. The wire 4 of the coil spring is reduced in diameter, the winding stem diameter at the end of the contact needle is reduced as small as possible and three layers of plating are provided to the wire. In the coil spring, an enlarged diameter part capable of elastically fitting in a penetration hole is provided. By this, the contact point against the contacter of the contact needle part can be made as close to the coil spring axis as possible, and the tolerance range of alignment with the contacter can be widened. Also for increase in resistance due to cross sectional area reduction of the wire, the resistance can be reduced by providing plating layers. Since coil spring can be stopped at the enlarged diameter part, soldering work is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact probe or probe card for inspecting a semiconductor device or a wafer, or an LGA (land grid array).
The present invention relates to a conductive contact suitable for use in a socket such as a BGA (Ball Grid Array), a CSP (Chip Side Package), a bare chip, or a connector.

[0002]

2. Description of the Related Art Conventionally, a contact probe for conducting an electrical inspection (open / short test, environmental test, burn-in test, etc.) of a conductor pattern or an electronic component of a printed wiring board, a wafer test or the like, or a semiconductor element. (LGA, BGA, CSP, bare chip) sockets (including those for products) and connectors have various types of conductive contacts.

For example, when used in the above-mentioned semiconductor device socket, the signal frequency used for the semiconductor device has been increased in recent years, and a signal frequency of several hundred MHz has been used. Therefore, a socket used for a semiconductor element operating at such a high speed is required to further promote lowering of inductance and lowering of resistance of a conductive contact which is a conductive portion thereof. As described in Japanese Patent Application No. 8-188199 filed by the applicant, a coil end of a coil spring is formed as a contact by being closely wound in a tapered conical shape, and the contact is formed with a compression coil spring. Are integrated to reduce inductance and resistance.

[0004]

One of the objects of the conductive contact is to reduce the inductance and the resistance. However, a plurality of conductive contacts are provided on a support member to allow simultaneous multipoint contact. When making contact, the positional accuracy of each contact with respect to a plurality of contacted objects becomes a problem.

According to the coil spring-like conductive contact as described above, low inductance and low resistance between the contact and the coil spring can be achieved, but since the coil end is closely wound in a conical shape, Also, the conical apex portion, which is the portion that comes into contact with the contacted body, has a circular shape. In the case of a coil spring, there is a height difference in the axial direction in one turn, and the end of the element wire comes into contact with the coil end that can come into contact with the contacted object. It is not on the line (the center as the conductive contact) and deviates from the axis of the coil spring by the radius of the winding diameter at the apex. Therefore, in the case of the multipoint simultaneous contact structure, there is a problem that the allowable range of the alignment with the contacted object is narrowed.

[0006]

Means for Solving the Problems To solve such problems and improve the low inductance and the low resistance, the allowable range of the alignment with the contacted object and the solderability are improved. In order to realize this, in the present invention, at least one coil end of the conductive coil spring is tightly wound in a conical shape tapering outward in the axial direction and is brought into elastic contact with the contacted object. In order to reduce the diameter of the winding at the tapered end of the electrode portion and bring the terminal of the electrode portion of the coil spring closer to the axis of the coil spring, the wire of the coil spring is reduced in diameter. In addition, a low-resistance plating layer is provided on the wire in order to reduce the resistance of the coil spring which is increased by reducing the diameter of the wire.

[0007] According to this, the diameter of the winding at the end of the electrode portion can be reduced by the wire having a reduced diameter, so that the end can be brought as close as possible to the axis of the coil spring, and the positioning with respect to the contacted object can be performed. Can be widened, and the resistance of the pitch wound portion that performs the spring action of the coil spring can be reduced, and the resistance as the conductive contact can be reduced. .

In addition, at least one coil end of the conductive coil spring is tightly wound in a conical shape tapering outward in the axial direction to form an electrode portion for resiliently contacting the contacted member. The other coil end opposite to the electrode portion of the conductive coil spring is soldered to a circuit terminal, thereby eliminating contact resistance,
The overall resistance can be reduced.

Further, since the other end of the coil is formed in a conical shape that tapers toward a portion to be soldered to the circuit terminal, the fixing portion can be formed into a tapered shape. It facilitates accumulation, prevents the solder from rising in the spiral groove formed by the coil spring, and secures the amount of solder required for fixing strength even when the amount of solder is small, and also when the amount of solder is large. Excessive rise can be prevented.

[0010] Alternatively, the other coil end is reduced in diameter so as to enter the inside of the outer winding part as it reaches the coil end, and is wound on a plane perpendicular to the axis of the coil spring. By doing so, the portion of the other coil end that is in contact with the circuit terminal is flattened, and the coil spring can be positioned at right angles to the surface of the circuit terminal in the state of contact with the circuit terminal. In addition, the soldering operation can be performed in a state where the coil spring is stable. Further, the solder easily enters the gap between the outer winding portion and the winding portion that has entered the inside, and the solder spreads over the entire coil end portion, so that cracks can be suitably prevented.

In addition, the conductive coil spring has a pitch winding portion acting as a spring, and the pitch winding portion is coaxial so that the pitch winding portion is guided by a through hole provided in the insulating support when expanding and contracting. By being received, the displacement of the electrode portion with respect to the axis of the coil spring can be reduced, and the position of the electrode portion is stabilized.

Further, the conductive coil spring is provided on at least one of a part of the portion of the conductive coil spring opposite to the electrode portion and received in the through hole and the through hole. It is preferable to provide a radial projection that can be inserted when inserting into the through-hole and that can be prevented from falling off after the insertion.

[0013] Thereby, when the conductive coil spring is incorporated into the insulating support, it can be prevented from falling out after being inserted into the through-hole, and, for example, a part of the conductive coil spring can be formed as a radially projecting portion from the inner diameter of the through-hole. By slightly increasing the diameter or providing an inward projection in the through-hole, the conductive coil spring can be elastically deformed and inserted into the through-hole, and after the insertion, is inserted into the inner peripheral surface of the through-hole. The spring can be elastically engaged or locked by an inward projection to prevent it from falling off.The conductive coil spring does not fall out of the through hole during the subsequent soldering work to the circuit terminal, so it is inserted. Restriction on soldering work can be eliminated, such as handling of the insulating support with the side opening facing downward, and assembling workability can be improved

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to specific examples shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a conductive contact 1 to which the present invention is applied. The present conductive contact 1 is formed by winding a conductive spring material in a coil shape, has a cylindrical shape at a middle portion in the axial direction of the coil spring, and is wound at a predetermined pitch. Each of the electrode portions 1b and 1c is wound in a conical and tightly wound shape that tapers outward in the axial direction at both ends in the axial direction of the pitch winding portion 1a. Coil end of lower electrode portion 1c in the drawing (lower end in the drawing)
Are soldered to the circuit terminals 2a formed on the substrate 2 by, for example, printed wiring.

In the conductive contact 1 implanted on the substrate 2 as described above, for example, an IC chip 3 as an object to be contacted is disposed above the upper electrode portion 1b in FIG. The chip 3 is moved downward in the drawing to bring the pad 3a provided on the chip 3 into contact with the electrode portion 1b, and the pitch winding portion 1a is further compressed and deformed. Thus, the tip of the electrode portion 1b can be brought into contact with the pad 3a with a load due to the elastic force, and the contact state between the electrode portion 1b and the pad 3a is secured with a sufficient contact pressure.

The conductive contact 1 is formed by winding the element wire of the conductive coil spring so that both coil ends taper in opposite directions to each other as described above. However, as shown in FIG.
Is formed by laminating three plating layers 5a, 5b and 5c on the surface of the wire 4 of the coil spring in the illustrated example. Therefore, for the diameter d1 of the wire 4 of the wire 3, the wire 3
The wire diameter d2 as a whole is large.

By doing so, the wire diameter d2 can be secured to a predetermined size, and the diameter d1 of the wire 4 can be reduced. The diameter of the winding (shown as radius R in FIG. 2) at the distal end of the electrode portion 1b can be made smaller than that of a wire having a larger diameter. Therefore, since the radial distance R from the axis C to the position of the most protruding end of the wire 3 is reduced, the position of the most protruding end of the wire 3 can be made as close as possible to the axis C of the coil spring. For example, if the diameter d1 of the wire 4 is 110 μm, it is difficult to wind the radius R smaller than 140 μm.
By setting 1 to 90 μm, the radius R could be reduced to 115 μm. Therefore, the terminal position (contact position) of the electrode portion 1b can be brought closer to the axis C by 25 μm, and that amount provides a margin for alignment.

As shown in FIG. 3, the positioning of the conductive contact with respect to the contacted body (3a) is performed with respect to the axis C of the conductive contact and the tip (projecting end) of the needle-like body 11. Coincides with the maximum, but the allowable range of the above alignment is maximized.However, when the conductive contact is formed only by the coil spring, the element wire is reduced so as to taper the coil end. If the winding is performed while the diameter is increased, the end of the wire cannot be aligned with the axis of the coil spring. In addition, machining the wire ends so as to finally coincide with the axis becomes a factor of increasing the manufacturing cost.

According to the present invention, as described above, the diameter d1 of the wire 4 can be reduced so that the diameter of the winding can be reduced. I try to make it bigger. The wire 4 is required to have a spring action at the same time as being a conductor, so that the material is also limited. When the cross-sectional area of the wire 4 is reduced, the resistance particularly at the pitch winding portion 1a increases.
Of the plating layers 5a, 5b,
5c is provided to achieve low resistance.

In the case of winding in a conical shape, if a gap is formed in the radial direction between adjacent strands, the wire will bend in the axial direction. Therefore, it is necessary to wind in a conical shape leaving a portion overlapping in the radial direction. is there. Therefore, if the diameter d1 of the wire 4 is reduced, a gap may be formed in the radial direction when the wire is wound with the same reduction ratio between the adjacent windings. When winding from the same pitch winding portion 1a and winding the tip portion to the same small diameter, the number of windings increases and the length of the electrode portion 1b in the axial direction increases. In that case, not only does it conflict with compactness, but also the length of the conductive path increases.

By providing the plating layer, it is possible to prevent the wire diameter d2 from becoming small. In addition, by increasing the thickness of the plating layers 5a, 5b, and 5c, the wire diameter d2 can be further increased, and winding can be easily performed without any gap in the radial direction.
Therefore, the end (tip) of the strand 3 is brought as close as possible to the axis C to widen the allowable alignment range, and the electrode portion 1b
Can be formed without increasing the axial length of the conductive contact 1.

When the lowermost plating layer 4a is made of silver or copper, the intermediate plating layer 5b is made of nickel to prevent the underlayer from diffusing. In this case, since high hardness can be obtained, durability is also improved, and there is also an effect of improving spring property. For the outermost plating layer 5c, a stable metal such as gold or rhodium may be selected depending on the purpose.

In the case of three-layer plating, the effect as in the above specific example is obtained. However, it is not always necessary to form a plurality of layers, and plating of only one layer may be used. Also,
Silver or copper, which has a lower specific resistance than gold and is inexpensive, is preferably plated with a thickness of several μm to several tens μm. The effects of such plating include reducing contact resistance, improving durability, and preventing oxidation. Further, plating was performed at the wire rod stage (the above embodiment).
Alternatively, plating may be performed after forming the coil spring (after forming the electrode portion). Alternatively, plating may be performed at both the wire stage and after the coil spring is formed.

FIG. 4 shows a case where plating is performed after the coil spring is formed.
Shown in As described above, in the case of plating after molding, since the electrode portions 1b and 1c are solidified by plating, the same stability as the conical cylindrical body can be obtained electrically.

In the present conductive contact 1, the electrode portion 1c is soldered to the circuit terminal 2a of the substrate 2 as described above. Thereby, the contact resistance (resistance generated at the connection part due to the contact) becomes zero and is fixed at the same time, so that there is no displacement, and in some cases, a new fixing means such as screwing becomes unnecessary.

As shown in FIG. 5, it is preferable to solder the conical electrode portion 1c to the circuit terminal 2a. As a result, the electrode portion 1c has a cup shape with a narrowed bottom, so that the cavity diameter of the fixed portion (near the circuit terminal 2a) is small,
Since the solder adhered to the wire 3 having a small winding diameter can be bonded together and the solder can be accumulated at the bottom, the electrode 1
The amount of solder that rises in the winding portion b is reduced. Alternatively, only the electrode portion 1b may be formed in a conical shape, and the electrode portion on the circuit terminal 2a side may be formed into a cylindrical straight coil winding shape. Also in this case, the cylindrical electrode portion is connected to the circuit terminal 2a.
The contact resistance can be eliminated by soldering.

Therefore, it is possible to obtain a strong fixing state to the circuit terminal 2a and to prevent the solder from rising to the pitch winding portion 1a and obstructing the spring action when the amount of solder is large. Although the amount of solder supplied in a reflow furnace or the like varies to some extent, even when the amount of solder is small, it is accumulated at the bottom as shown in FIG. Strength is ensured. Thus, it is easy to tolerate a certain variation in the amount of solder.

In the conductive contact according to the present invention, a housing may be formed by using an insulating substrate, and an example thereof is shown in FIG. In FIG. 7, two insulating plates 7 and 8 are laminated in two layers as an insulating support member. A through hole 9 penetrating in the thickness direction is formed in one insulating plate 7, and a through hole 10 similarly penetrating in the thickness direction is formed in the other insulating plate 8. The two insulating plates 7 and 8 are integrally connected to each other with through bolts or the like in a state where they are coaxially aligned. The conductive contact 1 formed coaxially in the same manner as described above is received in both through holes 9 and 10.

In the upper through hole 9 in the figure, a large-diameter hole portion 9a for receiving the conductive contact 1 having the above-mentioned shape coaxially and receiving the pitch winding portion 1a in a stretchable manner so as to prevent the contact from coming off. A small-diameter hole portion 9b smaller in diameter than the pitch winding portion 1a is formed. The pitch winding portion 1a side of one of the electrode portions 1b abuts on the tapered step 9c between the large-diameter hole portion 9a and the small-diameter hole portion 9b, and the upper electrode 9b is electrically conductive from the upper through hole 9 to the upper side in the drawing. The contact 1 is retained.

In the lower through hole 8 in the figure, a small-diameter hole 10a whose diameter is smaller than that of the large-diameter hole 9a on the side aligned with the large-diameter hole 9a, and a small-diameter hole 10a A tapered hole portion 10b that is continuous and has a trumpet-shaped diameter is formed. Since the small-diameter hole portion 10a is provided adjacent to the large-diameter hole portion 9a, the other electrode portion 1c is provided at the step between them.
The conductive contact 1 is prevented from coming off from the lower through hole 10 to the lower side in the figure.

The coil end (lower end in the figure) of the lower electrode portion 1c in the figure is soldered to the circuit terminal 2a of the substrate 2. As a result, the insulating plate 8 is pressed against the substrate 2 via the electrode portion 1c, so that the insulating plate 8 can be fixed to the substrate 2 without a separate fixing means such as screwing or bonding. Further, the opening area of the maximum diameter portion of the tapered hole portion 10b is preferably larger than the area of the circuit terminal 2a, so that a deviation between the two during the assembly can be tolerated, and the circuit terminal 2a is formed by the tapered hole portion 10a. Will not block part of the

Incidentally, the coupling structure between the insulating plate 8 and the substrate 2 may be fixed by screwing, bonding or fitting. And both insulating plates 7 and 8
And the substrate 2 are integrated, and the conductive contact 1 is also integrated. Although only one conductive contact 1 is shown in the figure, when it is used for a socket or the like, a plurality of conductive contacts 1 are provided according to the number of pins of a target chip.

The conductive contact 1 constructed as described above
7, the tapered end (upper end in the figure) of one of the electrode portions 1b is exposed above the insulating plate 7 by a predetermined amount, as shown in FIG. The axial length of the large-diameter hole 9a may be set so that an initial load is applied to the pitch winding portion 1a in this natural state.

FIG. 8 shows an example of the state of use of the conductive contact 1. As shown in FIG. 8, the pad 7a of the IC chip 7 is brought into contact with the tip of the exposed electrode portion 1b, and the insulating plate 7 (the insulating plate 8 and the substrate 2) and the IC chip 7 are fixed to each other by a predetermined amount. It is brought close to the interval and fixed by a fixing member (not shown) so as to maintain the state. This allows
The tip of the electrode portion 1b comes into contact with the pad 7a with a predetermined initial load of the conductive contact 1, and further comes into contact with the pad 7a with a resilient urging force against bending in the fixed state of the IC chip 7 shown in FIG. Since they come into contact with each other, a contact state between the electrode portion 1b and the pad 7a is ensured with a sufficient contact pressure.

Next, FIG. 9 shows a second example using a housing. Parts similar to those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 9, the through-hole 11 provided in the insulating plate 8 on the substrate 2 side has a small-diameter hole 10 a similar to that of FIG. 7, and a large-diameter hole larger than the small-diameter hole 10 a. 11a. This large-diameter hole 11
a is larger than the circuit terminal 2a, deviation during assembly can be tolerated, and the large-diameter hole 11a
Thereby, a part of the circuit terminal 2a is not blocked.
Further, the large-diameter hole portion 11a is formed as a straight hole, which has an advantage that processing is simple.

FIG. 10 shows a third example. In the same manner as above, the same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 10, the through hole 12 provided in the insulating plate 8 on the substrate 2 side is
Of the same diameter as the small-diameter hole portion 10a. Thereby, the mold structure for forming the through holes 12 in the insulating plate 8 can be simplified, and the manufacturing cost can be reduced.

FIG. 11 shows a fourth example. Like the above, the same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 11, one insulating plate 13 is used, and the insulating plate 13 is
Is to be combined. The insulating plate 13 has a small-diameter hole 9b similar to that shown in FIG. 7 and a large-diameter hole that is continuous with the small-diameter hole 9b via a tapered step 9c and that is enlarged in the same manner as the large-diameter hole 9a. 14a is provided.

Thus, only one insulating plate 13 constituting the housing for holding the conductive coil spring 1 can be provided, and the overall configuration can be simplified. As in FIG. 7, the conical electrode portion 1b resiliently strikes the tapered step portion 9c, and the axis of the conductive coil spring 1 naturally coincides with the axis C of the through hole. While the centering action works,
The protruding height of the electrode portion 1b is also constant.

FIG. 12 shows a fifth example. In the same manner as above, the same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 12, the insulating plate 15 is
The insulating plate 15 is bonded to the substrate 2. The through holes 16 provided in the insulating plate 15
And a small-diameter hole 16b formed on the substrate 2 side. The small-diameter hole 16b has a smaller diameter than the maximum diameter of the conical electrode portion 1c, and the large-diameter hole 16a and the small-diameter hole 16a have the same diameter.
b, a tapered step 16c is formed.

According to this, the electrode portion 1c is connected to the circuit terminal 2a.
By soldering, the electrode portion 1c is fixed to the substrate 2 in a state where the largest diameter portion of the electrode portion 1c is in contact with the tapered step portion 16c, so that the insulating plate 15 is also fixed to the substrate 2. Therefore, in addition to using only one insulating plate 15, without using another fixing means such as a screw or an adhesive,
The insulating plate 15 and the substrate 2 can be connected to each other, so that the number of parts and the number of assembling steps can be suitably reduced, and the manufacturing cost can be reduced.

FIG. 13 shows a sixth example. In the same manner as above, the same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 13, the insulating plate 17 is
The insulating plate 17 is joined to the substrate 2. The through hole 18 provided in the insulating plate 17 has a straight hole having the same diameter as the size capable of guiding the pitch winding portion 1 a so as to be able to expand and contract. Consists of According to this, in addition to using only one insulating plate 15, the mold structure can be most simplified, and the manufacturing cost can be reduced.

Next, FIG. 14 shows a seventh example based on the present invention. Also in this illustrated example, the same parts as those in FIG. 11 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example of FIG. 14, the electrode portion 1b that is brought into contact with the contact target (pad 3a) of the conductive coil spring 1 is
Tapered step 9c of through hole 14 provided in insulating plate 13
As a result, the pitch winding portion 1a is coaxially received in the large-diameter hole portion 14a.

In the electrode portion 1c formed of a coil end opposite to the electrode portion 1b, the diameter is reduced so as to enter the inside of the outer winding portion toward the coil end. The conductive coil spring 1 is wound on a plane perpendicular to the axis C. Thereby, the circuit terminal 2a of the electrode portion 1c
In the state where the electrode portion 1c is in contact with the circuit terminal 2a, the coil spring 1 can be in a state of standing upright at a right angle to the surface of the circuit terminal 2a. The soldering operation can be performed with the coil spring 1 in a stable state in which the coil spring 1 is prevented from falling down.

Further, in the electrode portion 1c, since the solder easily enters the gap between the outer winding portion and the reduced-diameter winding portion which has entered the inside, the solder W is applied to the entire coil end portion 1c. In this way, the solder wire W is spread over the entire circumference of the element wire, so that the occurrence of cracks in the solder W can be suitably prevented. Thus, the electrode portion 1c is soldered to the circuit terminal 2a.

In the conductive coil spring 1, the pitch winding portion 1 is located on the side opposite to the electrode portion 1b.
A larger-diameter winding portion 1d, which is larger in diameter than the pitch winding portion 1a, is formed as a radially projecting engagement portion between a and the other electrode portion 1c. The diameter-increased winding portion 1d is slightly larger than the inner diameter of the large-diameter hole 14a of the through-hole 14, and in the assembled state shown in FIG. It is in contact and engaged.

The conductive coil spring 1 thus configured
In order to attach the conductive coil spring 1 to the insulating plate 13, as shown by the arrow A in FIG.
Insert into 4. At this time, the large-diameter winding portion 1d larger in diameter than the large-diameter hole portion 14a abuts against the opening edge of the large-diameter hole portion 14a. Can be elastically deformed so as to shrink in the radial direction, so that the large-diameter winding portion 1d can be inserted into the large-diameter hole portion 14a.

Thus, the electrode portion 1c is connected to the circuit terminal 2
Before soldering to the large diameter hole 14a,
It is prevented from coming off in a state where it is resiliently engaged. Therefore, even if the insulating plate 13 is not turned upside down so that the tapered step 9c is on the lower side, the conductive coil spring 1 does not fall out of the through-hole 1, so that the assembling work can be easily performed. Can be. For example, the following soldering step can be performed with the electrode portion 1c being on the lower side. Further, there is no need to adopt a structure in which a retaining plate provided with an opening that allows only the electrode portion 1c to face outward is laminated on the insulating plate 13, and the number of components and the number of assembling steps can be reduced.

FIG. 16 shows an eighth example according to the present invention, which is another example of the structure for preventing the conductive coil spring 1 from coming off. Also in this illustrated example, the same parts as those in FIG. 14 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the eighth example, as shown in FIG. 17, a protruding portion projecting radially inward is formed at a part of the periphery of the opening on the lower side of the large-diameter hole 14a in the figure. 19 are provided. In the illustrated example, as shown in FIG. 17B, four projections 19 are provided at equal angular pitches around the axis of the large-diameter hole 14a, and the distance between the opposed projections 19 is determined. b is set to be slightly smaller than the outer diameter of the pitch winding portion 1a.

By doing so, when assembling the conductive coil spring 1 to the insulating plate 13, the conductive coil spring 1 is inserted into the through hole 14 from the large-diameter hole portion 14 a side as in the above-described example. At this time, the protrusion 19 can be inserted by using the gap between the windings of the pitch winding portion 1a so as to dodge it. Then, as shown in FIG. 17 (a), by receiving the entire pitch winding portion 1 a in the large-diameter hole portion 14 a, the outermost winding portion of the pitch winding portion 1 a is located between the opposing projections 19. As a result of the bridging, a part of the pitch winding portion 1a (the outermost winding portion) is engaged with the protrusion, and the through-hole is formed in a state where the conductive coil spring 1 is prevented from coming off. 14 is assembled.

Therefore, also in the eighth example, the conductive coil spring 1 can be temporarily attached to the through hole 14 before the soldering step, and the same operation and effect as described above can be obtained.

FIG. 18 shows a ninth example based on the present invention. Also in this illustrated example, the conductive coil spring 1
This is another example of the retaining structure, and the same parts as those in FIG. 14 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the ninth example, as shown in FIG. 19, a projection 20 extending in the axial direction is provided on the inner peripheral surface of the large-diameter hole 14a. The conductive coil spring 1 may be the same as in the seventh example, and is provided with an enlarged diameter portion 1d.

In the illustrated example, as shown in FIG. 19B, three ridges 20 are provided at equal angular pitches around the axis of the large-diameter hole 14a. 20
The diameter d of a circle passing through each of the projecting ends is slightly smaller than the outer diameter D of the enlarged diameter portion 1d.

By doing so, when assembling the conductive coil spring 1 to the insulating plate 13, the conductive coil spring 1 is inserted into the through hole 14 from the large-diameter hole portion 14 a side as in the above-described example. The conductive coil spring 1 can be pushed in while being slidably contacted with each of the ridges 20 with the enlarged diameter portion 1d elastically deformed. When the entire pitch winding portion 1a is received in the large-diameter hole portion 14a, the enlarged diameter portion 1
d resiliently engages with each ridge 20, and the conductive coil spring 1 is prevented from coming off.

Therefore, also in the ninth example, the conductive coil spring 1 can be temporarily attached to the through hole 14 before the soldering step, and the same operation and effect as described above can be obtained.

The engaging force of the conductive coil spring 1 in each of the seventh to ninth examples may be such that it does not fall off due to its own weight or slight vibration. By setting such a small engaging force, the conductive coil spring 1 does not fall down in the temporarily fixed state, and a state in which the electrode portion 1b is brought as close as possible to the axis C of the wire end of the electrode portion 1b can be secured. In particular, the ninth
In the example, the enlarged diameter portion 1d is supported from three directions, and can be supported in a well-balanced manner.

In the wire 4 in each of the above examples,
Although the illustrated example has a circular cross-sectional shape, the shape is not limited to the circular cross-sectional shape, and may have various cross-sectional shapes.
For example, the same effect can be obtained by using a wire having a rectangular cross section.

In the illustrated example, one side (1c) of the conductive contact 1 is soldered. However, the other side (1b) may be soldered, or both sides (1b and 1c) may be soldered. It is possible to eliminate the contact resistance at the soldered portions. Particularly, when both sides are soldered, the contact resistance can be completely eliminated, and the overall resistance value can be further reduced.

In each of the illustrated examples, when the insulating plates are laminated, two insulating plates 7 and 8 are laminated to form a housing for holding the conductive contact 1, but three or more insulating plates are used. They may be stacked. In particular, if one insulating plate is manufactured for each hole of a different diameter, the holes provided in each insulating plate can be straight holes, and only one drilling process is required. In this case, the die structure can be simplified even when the through-holes are formed, and through-holes having various reduced diameter portions can be provided only by overlapping the insulating plates thus formed.

[0061]

As described above, according to the present invention, in the coiled conductive contact, the terminal of the electrode portion (the position of the contact point with the contacted object) can be brought as close as possible to the axis of the coil spring, and It is possible to widen the allowable range of positioning with respect to the body, and also to provide a plating layer to reduce the resistance with respect to an increase in resistance due to a decrease in the cross-sectional area of the wire.

Further, by soldering the axial ends of the coil springs to the circuit terminals, it is possible to reduce the occurrence of contact resistance, thereby reducing the resistance value of the entire conductive contact and the substrate. If the upper pad and one end of the contact are fixed with solder, a positional shift due to expansion and contraction due to an environmental change (temperature and humidity) does not occur, so that a stable connection state can be obtained.

Alternatively, the diameter of the coil end on the side to be soldered to the circuit terminal is reduced so as to enter the inside of the outer winding part as it reaches the coil end, and on the surface perpendicular to the axis of the coil spring. In this state, the portion of the coil end that is in contact with the circuit terminal is flattened, and the coil spring is positioned at right angles to the surface of the circuit terminal in a state of being in contact with the circuit terminal. The soldering operation can be performed in a state where the coil spring is stable. Also,
Solder easily penetrates into the gap between the outer winding portion and the inner winding portion, so that the solder spreads over the entire coil end portion, and cracks can be suitably prevented.

Further, by guiding the pitch winding portion of the conductive coil spring by the through hole of the insulating support, the displacement of the electrode portion with respect to the axis of the coil spring can be reduced, and the position of the electrode portion can be stabilized. I do.

The conductive coil spring may be formed as a radial protrusion by, for example, slightly increasing the diameter of a portion of the conductive coil spring from the inner diameter of the through hole or providing an inward protrusion in the through hole. By elastically deforming, it can be inserted into the through-hole, and after insertion, it can be elastically engaged with the inner peripheral surface of the through-hole or locked by an inward projection to prevent it from falling off. Since the conductive coil spring does not fall out of the through hole during the subsequent soldering work to the circuit terminals, it is possible to handle the insulating support with the insertion side opening facing down, eliminating restrictions on the soldering work. It is possible to improve the assembling workability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a conductive contact to which the present invention is applied.

FIG. 2 is an enlarged sectional view of a main part of the conductive contact of FIG.

FIG. 3 is an explanatory diagram showing alignment of a needle-like body with a contacted body (pad 7a).

FIG. 4 is an enlarged sectional view of a main part showing another embodiment of plating.

FIG. 5 is a partial cross-sectional view when a large amount of solder adheres to a circuit terminal.

FIG. 6 is a diagram corresponding to FIG. 5 when the amount of solder is small.

FIG. 7 is a partial cross-sectional side view showing the second embodiment.

FIG. 8 is a view corresponding to FIG. 7, showing a use state;

FIG. 9 is a view showing a second example corresponding to FIG. 7;

FIG. 10 is a view showing a third example corresponding to FIG. 7;

FIG. 11 is a view showing a fourth example corresponding to FIG. 7;

FIG. 12 is a view showing a fifth example corresponding to FIG. 7;

FIG. 13 is a view showing a sixth example corresponding to FIG. 7;

FIG. 14 is a diagram showing a seventh example based on the present invention.

FIG. 15 is a view showing an assembling procedure of a seventh example.

FIG. 16 is a diagram showing an eighth example based on the present invention.

FIG. 17 (a) is a diagram showing an assembling procedure of an eighth example, and FIG. 17 (b) is a diagram showing a shape of a projection 19 viewed from an arrow XVIIb in FIG. 17 (a).

FIG. 18 shows a ninth example based on the present invention.

FIG. 19A is a view showing an assembling procedure of a ninth example, and FIG. 19B is a view showing a ridge 20 viewed from an arrow IXXb in FIG.
FIG.

[Explanation of symbols]

1 conductive contact, 1a pitch wound part, 1b ・ 1c
Electrode part, 1d enlarged diameter part 2 Substrate, 2a circuit terminal 3 IC chip 4 Wire 5a, 5b, 5c Plating layer 7.8 Insulating plate 9 Through hole, 9a Large diameter hole, 9b Small diameter hole, 9c
Tapered step 10 Through hole, 10a Small diameter hole, 10b Tapered hole 11 Needlelike body 12 Through hole 13 Insulating plate 14 Through hole, 14a Large diameter hole 15 Insulating plate 16 Through hole, 16a Large diameter hole, 16b Small diameter hole,
16c Tapered step 17 Insulating plate 18 Through hole 19 Projection 20 Projection

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01R 13/24 H01R 33/76 // H01R 33/76 9/09 B

Claims (6)

[Claims] 1. An electrode portion for elastically contacting at least one coil end of a conductive coil spring in a conical shape tapering outward in an axial direction and making a resilient contact with a contacted body is formed. In order to reduce the winding diameter at the tapered end of the electrode portion and bring the terminal of the electrode portion of the coil spring closer to the axis of the coil spring, the wire material of the coil spring is reduced in diameter, and the wire material is reduced. A conductive contact, characterized in that a low-resistance plating layer is provided on the wire in order to reduce the resistance of the coil spring, which is increased by reducing the diameter. 2. An electrode part for elastically contacting at least one coil end portion of a conductive coil spring in a conical shape tapering outward in the axial direction to form a resilient contact with a contacted body. A conductive contact, wherein the other end of the conductive coil spring opposite to the electrode portion is soldered to a circuit terminal. 3. The conductive contact according to claim 2, wherein the other coil end is formed in a conical shape that tapers toward a portion to be soldered to the circuit terminal. . 4. The other coil end is reduced in diameter so as to enter the inside of the outer winding part as it reaches the coil end, and is wound on a plane perpendicular to the axis of the coil spring. The conductive contact according to claim 2, wherein the conductive contact is provided. 5. The conductive coil spring has a pitch winding portion that acts as a spring, and the pitch winding portion is coaxially guided by a through hole provided in an insulating support when expanding and contracting. The conductive contact according to claim 1, wherein the conductive contact is received. 6. The conductive coil spring is provided on at least one of a part of a portion of the conductive coil spring opposite to the electrode portion and received in the through hole and the through hole. 6. The conductive contact according to claim 5, further comprising a radial projection that can be inserted when inserting into the through hole and that can be prevented from being removed after the insertion.