JP4384765B2 - Conductive contact - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to contact probes and probe cards for semiconductor device inspection and wafer test, or LGA (land grid array), BGA (ball grid array), CSP (chip side package), bare chip, etc. The present invention relates to a conductive contact suitable for use in a socket or a connector.
[0002]
[Prior art]
Conventionally, for conducting electrical inspection (open / short test, environmental test, burn-in test, etc.) of conductor patterns and electronic parts on printed wiring boards, or for contact probes for wafer tests, etc., and semiconductor elements (LGA / BGA / Conductive contacts of various structures are used for sockets (including products) for CSP / bare chips) and connectors.
[0003]
For example, when used for the above-mentioned socket for semiconductor elements, in recent years, the signal frequency used for the semiconductor elements has been increased, and several hundred MHz is also used. Accordingly, since the socket used for such a semiconductor element that operates at high speed is required to further reduce the inductance and the resistance of the conductive contact that is the conductive portion thereof, for example, the same As described in Japanese Patent Application No. 8-188199 by the applicant, the coil end of the conductive coil spring is tightly wound in a tapered conical shape to form a conductive needle-like body. There is a coil spring-like conductive contact that integrates a cylindrical body and a compression coil spring to reduce inductance and resistance.
[0004]
[Problems to be solved by the invention]
When conducting multipoint simultaneous contact using a unit provided with a plurality of conductive contacts as described above, for example, a plurality of members are provided on a single plate (or block) member. This is possible by providing support holes and arranging each conductive coil spring in each support hole.
[0005]
In the case of such a structure, the conductive coil spring is assembled so as to be dropped into the support hole so that the coil end opposite to the electrode portion side is up, and each conductive coil spring is arranged in each support hole. A substrate having a wiring pattern formed so as to correspond to each support hole is superimposed on the plate-like member in a state, and the coil end of the conductive coil spring and the wiring pattern are soldered by, for example, a reflow process.
[0006]
However, if the conductive coil spring is simply placed in the support hole as described above, the conductive coil spring will fluctuate in the support hole when moving from the process of assembling the conductive coil spring to the support hole to the reflow process. There is a possibility that the conductive coil spring may fall out of the support hole due to vibration during conveyance.
[0007]
[Means for Solving the Problems]
Solving such a problem, it is possible to prevent the conductive coil spring from falling out of the coil spring support hole of the conductive contact in which the conductive needle and the coil spring are formed of a conductive coil spring. Therefore, in the present invention, a conductive contact having a conductive coil spring having a coil end as an electrode portion and a holder provided with a coil spring support hole for coaxially receiving the conductive coil spring. And at least one of the part of the conductive coil spring opposite to the electrode part and received by the coil spring support hole and the coil spring support hole, An engagement portion that can press-fit the coil spring into the coil spring support hole is provided, and the engagement portion extends in the axial direction on the inner peripheral surface of the coil spring support hole. Of the columnar protrusions formed Serial a recess open to and the opening side is provided on the opening side of the coil spring support hole was assumed that the contact portion definitive to said said conductive coil spring recess is welded.
[0008]
According to this, even if vibration such as impact occurs when moving from the process of inserting and assembling the conductive coil spring into the coil spring support hole of the holder to the soldering process of the conductive coil spring and the substrate, Since a part of the conductive coil spring is fixed to the coil spring support hole, it can be prevented from falling off due to the vibration.
[0009]
In addition , the welding target portion of the conductive coil spring can be engaged with the recess, and the axial insertion depth of the coil spring support hole can be regulated, and positioning of the conductive coil spring with respect to the axial direction of the coil spring support hole can be controlled. High accuracy can be achieved.
[0010]
Further, the welding is performed by laser heating a portion corresponding to the engaging portion on the coil spring support hole side, or by performing high frequency heating on the conductive coil spring. Work can be done easily and reliably.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail based on specific examples shown in the accompanying drawings.
[0012]
FIG. 1 is a fragmentary longitudinal sectional view showing a state before a conductive contact to which the present invention is applied is brought into contact with a contacted body. In the illustrated example, only one conductive contact is shown, but a conductive contact unit in which a plurality of conductive contacts are arranged in parallel according to the number of objects to be contacted. Can be used.
[0013]
As shown in FIG. 1, the conductive contact includes a bullet-type conductive coil spring 1 and a holder 3 provided with a support hole 2 that coaxially receives the conductive coil spring 1. The conductive coil spring 1 may be formed by winding a metal wire having good conductivity. However, when high conductivity or durability is required, the surface of the wire is plated with gold or the like. Good to do. The holder 3 may be an insulating substrate, and a support hole 2 is formed by processing a hole penetrating in the thickness direction in the insulating substrate.
[0014]
The conductive coil spring 1 includes a pitch winding portion 1a at an intermediate portion in the axial direction, one electrode portion 1b tightly wound in a substantially conical shape at one coil end with respect to the pitch winding portion 1a, and the other The other electrode part 1c which consists of a coil edge part is formed.
[0015]
The support hole 2 has a large-diameter hole 2a that receives the pitch winding part 1a and a small diameter that is smaller than the large-diameter hole 2a so that only one electrode part 1b can protrude outward of the support hole 2. A taper formed between the large-diameter hole 2a and the small-diameter hole 2b so as to prevent the conductive coil spring 1 from coming off by striking the hole 2b and the pitch winding 1a side portion of one electrode 1b. It consists of a hole 2c.
[0016]
A circuit board 4 is laminated on a corresponding surface (lower surface in the drawing) of the holder 3 so as to face the other electrode portion 1 c of the conductive coil spring 1 received in the support hole 2. The circuit board 4 is provided with a conductor for forming a wiring pattern, and a circuit terminal 4a comprising a part thereof faces the large-diameter hole 2a. The other electrode portion 1c of the conductive coil spring 1 is soldered (W) to the circuit terminal 4a. Note that the holder 3 and the circuit board 4 are integrated with each other by, for example, screws inserted through them.
[0017]
In the natural state of the conductive coil spring 1 configured as described above, the tapered end portion (upper end portion in the drawing) of one electrode portion 1b is located above the upper surface of the holder 7 as shown in the drawing. The amount is prominent. The axial length of the large-diameter hole 2a and the taper angle of the tapered hole 2c may be set so that an initial load is applied to the pitch winding 1a in this natural state. A reliable contact state can be ensured by stabilizing the position and sufficient contact pressure to the contacted object (for example, a pad of a semiconductor device) 5.
[0018]
Further, the electrode portion 1c on the side to be soldered to the circuit terminal 4a is reduced in diameter so as to enter the inside of the outer winding portion as it reaches the coil end, and on the surface orthogonal to the axis of the coil spring. It is formed by winding. By doing so, the portion of the electrode portion 1c that is in contact with the circuit terminal 4a is flattened, and the conductive coil spring 1 is brought into contact with the surface of the circuit terminal 4a in a state of being in contact with the circuit terminal 4a. The soldering operation can be performed in a state where the conductive coil spring 1 is stable.
[0019]
Furthermore, a certain amount of clearance is provided between the inner and outer winding portions of the electrode portion 1c so that solder can easily enter. For this reason, the solder W spreads over the entire electrode portion 1c and the entire circumference of the element wire, and the occurrence of cracks in the solder W is preferably prevented. In this way, the electrode portion 1c is soldered to the circuit terminal 2a.
[0020]
And in this electroconductive coil spring 1, it is a side opposite to the electrode part 1b, and is diameter-expanded larger than the pitch winding part 1a between the pitch winding part 1a and the other electrode part 1c. The winding part 1d is formed as an engaging part. Further, as shown in FIG. 2 showing the state before the circuit board 4 is assembled, the large-diameter hole portion 2a is provided with a wall-like protrusion 6 extending in the axial direction as an engaging portion. Yes. In addition, if it sees from the wall-shaped projection part 6 side of the large diameter hole 2a, the enlarged diameter winding part 1d becomes an engaging part.
[0021]
As shown in FIG. 2 (b), the wall-shaped protrusion 6 of the illustrated example is formed in a wall shape having flat surfaces at four locations at an equiangular pitch around the axis of the large-diameter hole 2a. The diameter b of the circle passing through the projecting surface of each wall-like projection 6 is made slightly smaller than the outer diameter of the pitch winding portion 1a.
[0022]
In order to assemble the conductive coil spring 1 configured in this way to the holder 3, as shown by the arrow A in FIG. 2, the conductive coil spring 1 is placed on the large-diameter hole 2a side with the electrode portion 1b first. It inserts into the through-hole 2 from (downward in the figure). At this time, a part of the diameter-enlarged winding portion 1d having a diameter larger than that of the large-diameter hole portion 2a and the wall-shaped protrusions 6 exposed at the opening edge of the large-diameter hole portion 2a are buffered. However, when the conductive coil spring 1 is further pushed in, the spring expanded diameter winding portion 1d can be elastically deformed so as to be contracted in the radial direction. Therefore, the expanded diameter winding portion 1d can be inserted into the large diameter hole portion 2a. it can.
[0023]
In this way, before the electrode portion 1c is soldered to the circuit terminal 4a, the diameter-enlarged winding portion 1d is in a press-fit state in which it is elastically engaged with the large-diameter hole portion 2a (each wall-like protrusion 6). The conductive coil spring 1 is temporarily fixed.
[0024]
According to the present invention, before the soldering step between the electrode portion 1c and the circuit terminal 4a is started, the wall-shaped protrusion 6 is locally heated by, for example, laser light L irradiation as shown in FIG. As a result, the wall-shaped protrusion 6 is melted, and the wall-shaped protrusion 6 is welded or seized to a portion where the diameter-enlarged winding portion 1d is in contact, and the two are fixed to each other. Therefore, even when there is a possibility that the conductive coil spring 1 may fall off due to some impact during conveyance in the state where only the press-fitting is performed, such dropping can be reliably prevented.
[0025]
The local heating method is not limited to laser beam irradiation. For example, a part or the whole of the conductive coil spring 1 is energized to cause the conductive coil spring 1 to generate heat, or high-frequency heating is applied to a metal (conductive). It is also possible to generate heat by reacting only the coil spring 1).
[0026]
Next, an example in which a shape different from the above-described wall-shaped protrusion 6 is applied to FIG. In addition, the same code | symbol is attached | subjected about the part similar to the said example of illustration, and the detailed description is abbreviate | omitted.
[0027]
In the illustrated example, as shown in FIG. 4A, the tapered hole portion extends from the lower opening and extends in the axial direction of the large-diameter hole portion 2a in the same manner as the wall-shaped protrusion 6 in the illustrated example. Similarly, four columnar protrusions 7 having a mountain-shaped cross-section extending to 2c are provided. Concave portions 7 a are respectively provided on the large-diameter hole portions 2 a side of the columnar protrusions 7. The recess 7a is open to the opening side.
[0028]
Further, as shown in FIG. 4B, the distance b between the columnar protrusions 7 facing each other is larger than the outer diameter of the pitch winding portion 1a and smaller than the enlarged diameter winding portion 1d. Thereby, the pitch winding part 1a of the conductive coil spring 1 can be guided by the respective columnar protrusions 7 that can be brought into point contact at four points on the outer periphery thereof, and the electrode part 1b with respect to the axis C of the conductive coil spring 1 can be guided. The shift can be reduced, and the position of the electrode portion 1b is stabilized.
[0029]
Further, the diameter e of a circle passing through the inward bottom surface of the recess 7a is set to a size that can press-fit the expanded winding portion 1d. In the illustrated example, the enlarged diameter winding portion 1d can be engaged with the concave portion 7a in a press-fit state, and the concave portion 7a and the enlarged diameter winding portion 1d are fixed by heat treatment as described above. The function and effect are the same as in the illustrated example.
[0030]
Further, in the illustrated example, when the conductive coil spring 1 is inserted into the support hole 1, the diameter-enlarged winding portion 1d comes into contact with the end surface in the axial direction of the recess 7a. All insertion depths can be made constant. In order to achieve uniform soldering with respect to all the conductive coil springs 1, it is necessary to increase the position of the electrode portion 1d in the axial direction, but according to the illustrated example, the electrode portion 1d is inserted by the recess 7a. Since the depth can be regulated, it is possible to achieve high accuracy of the position accuracy with a simple operation of only an insertion operation.
[0031]
In the illustrated example, the diameter e of the circle passing through the inward bottom surface of the recess 7a is smaller than the diameter of the large-diameter hole 2a, but may be larger. In this case, the outer diameter of the enlarged diameter winding portion 1d is larger than the diameter of the large diameter hole portion 2a, but the enlarged diameter winding portion 1d is fixed to the support hole 2, and there is no problem.
[0032]
In addition, although the wall-like protrusions 6 and the columnar protrusions 7 in each of the above illustrated examples are provided at four places, the number is not limited, as long as it is three or more.
[0033]
【The invention's effect】
As described above, according to the present invention, vibration such as impact is generated when the process moves from the process of inserting and assembling the conductive coil spring into the coil spring support hole of the holder to the process of soldering the conductive coil spring and the substrate. Even if it happens, since a part of the conductive coil spring is fixed to the coil spring support hole, it can be prevented from falling off due to the vibration, so the holder can be handled with the insertion side opening facing downward. It is possible to eliminate restrictions on the soldering work, such as being able to be performed, and to improve the assembly workability.
[0034]
In addition, according to the present invention, the conductive coil spring is a recess that is open to the opening of the coil spring support hole of the columnar protrusion formed so as to extend in the axial direction on the inner peripheral surface of the coil spring support hole. It is possible to engage the welding target portion with the recess and restrict the insertion depth of the coil spring support hole in the axial direction, and the positioning of the conductive coil spring in the axial direction of the coil spring support hole can be made highly accurate.
[0035]
In addition, the part corresponding to the engaging part on the coil spring support hole side is heated by laser, or the conductive coil spring is heated by high frequency to weld a part of the coil spring, thereby facilitating the welding work. And it can be done reliably.
[Brief description of the drawings]
FIG. 1 is a fragmentary longitudinal sectional view of a conductive contact to which the present invention is applied.
2A is a view showing a procedure for assembling the conductive contact shown in FIG. 1, and FIG. 2B is a view showing a shape of a wall-like protrusion 6 as viewed from an arrow IIb in FIG.
FIG. 3 is an explanatory view showing a welding procedure with a wall-shaped protrusion 6 of a conductive coil spring.
4A is a diagram corresponding to FIG. 2A illustrating another example, and FIG. 4B is a diagram corresponding to FIG. 2B illustrating another example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductive coil spring 1a Pitch winding part, 1b * 1c Electrode part, 1d Large diameter winding part 2 Coil spring support hole, 2a Large diameter hole part, 2b Small diameter hole part, 2c Taper hole part 3 Holder 4 Circuit board, 4a Circuit Terminal 5 Contacted object 6 Wall-shaped protrusion 7 Columnar protrusion, 7a Recess

Claims (3)

A conductive contact having a conductive coil spring having an electrode end as a coil portion and a holder provided with a coil spring support hole for coaxially receiving the conductive coil spring;
The conductive coil spring is disposed on at least one of the part of the part that is opposite to the electrode portion of the conductive coil spring and received in the coil spring support hole and the coil spring support hole. An engagement portion that can be pressed into the coil spring support hole is provided,
The engaging portion is provided on the opening side of the coil spring support hole of the columnar protrusion formed so as to extend in the axial direction on the inner peripheral surface of the coil spring support hole, and is opened to the opening side. A recess,
Conductive contact to the contact portion definitive in said recess and said conductive coil spring is characterized in that it is welded. The conductive contact according to claim 1, wherein the welding is performed by laser heating a portion corresponding to the engagement portion on the coil spring support hole side . The conductive contact according to claim 1, wherein the welding is performed by high-frequency heating the conductive coil spring .

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