JPH0617082Y2 - Contact pin rotation prevention structure in the contact probe unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a contact pin rotation preventing structure in a contact probe unit, and more specifically, a four-terminal measurement contact as a means for measuring electrical resistance of a mounted printed circuit board or the like. The present invention relates to a radial stop structure for a contact pin in a probe.

[Conventional technology]

As is well known, a semiconductor integrated circuit (hereinafter referred to as an IC) is initially provided as a so-called dual in-line package having a 2.54 mm (hereinafter referred to as mm) pitch as a connection terminal, and a higher-order electronic device equipped with these is provided. In order to obtain a circuit function body, normally, a printed circuit board is mounted and connected with a circuit component such as an IC to form a printed circuit board,
It constituted a control circuit in a highly functional electronic device or the like.

Therefore, the contact probe for making various tests and inspections by making electrical contact with the contact terminal members such as these wiring boards is also mainly compatible with the 2.54 mm pitch grid.

On the other hand, it is well known that the four-terminal measurement method is used for electrical resistance measurement, particularly for more accurately measuring a small resistance value such as contact resistance.

This four-terminal measuring method is, as schematically shown in FIG. 10, two contact probes 2a, 3a, 2b each electrically insulated and held in parallel via insulators 1a, 1b such as plastic or ceramic. Contact members 7a at both ends of the resistance to be measured 5 by a constant current of a constant current source 6 flowing through the resistance to be measured 5 through the contact probes 2a and 3b of a pair of contact probe units 4a and 4b having 3b.
The voltage drop generated between 7b and contact probe 3a,
This is a method of obtaining the resistance value of the resistance to be measured 5 by the high impedance voltmeter 8 via 2b.

As the contact probes 2a, 2b, 3a, 3b in the contact probe units 4a, 4b, the one shown in FIG. 9 is generally used.

That is, in FIG. 9, the contact pin 11 having the sharpened contact portion 12 is slidable in the sleeve axial direction in the sleeve 10, and the inner peripheral constricted portion 13 of the sleeve 10 is slidable.
The compression spring 1 is inserted between the stopper 15 and the rear end surface of the contact pin 11 which are inserted so as not to come off and are fitted and formed in the sleeve 10 by forming the solder pot 14.
6 is mounted elastically, and the action of the compression spring 16 allows the contact pin 11 to move with the contact pressure.

It should be noted that the sleeve 10 is made of bronze or brass and is gold-plated, the contact pin 11 is made of beryllium-copper alloy, and the exterior is rhodium or /
And gold plated.

The stopper 15 is made of brass, the compression spring 16 is made of piano wire, and is plated with gold.

The difference between the inner diameter of the sleeve 10 and the outer diameter of the contact pin 11 is set to, for example, 0.1 mm or less, and the pressure of the compression spring 16 is 0.1 k at the contact pin contact portion 12.
It is set to generate gf.

Such a contact probe can cope with a case where the pitch interval between the contact terminals is relatively wide, but with the development of various technologies in the semiconductor and its application field as in recent years, I
C becomes progressively faster and more highly integrated, and its connection terminals are also made smaller, resulting in high-density mounting on a printed circuit board.
The demand for higher reliability is increasing more and more, and as an example of increasing the density of mounted parts, the pitch spacing of connection terminals by surface mount parts is increased.
2.54 mm → 1.27 mm → 0.635 mm, which is becoming smaller and smaller, and the size of the chip is progressing, and the conductor pattern width and pattern interval on the printed circuit board are also becoming extremely small. Currently, it is difficult to measure with the contact probe with the above configuration. Is.

Therefore, the contact probe shown in FIG. 4 has been used as a contact probe that conventionally constitutes a contact probe unit for measuring four terminals.

That is, the two electrodes that are insulated and held in parallel via the insulator 20
The individual contact probes 21a, 21b are inserted into the sleeves 22a, 22b, and the tip portions of the contact pins 23a, 23b slidable along the axial direction thereof are formed with beveled angles so that the contact portions 24a, 24b are formed. The contact pin 23 is moved inward by a radius and serves as a contact probe.
It has a structure capable of accommodating a contact member having a diameter smaller than that of a (23b), and also has two contact portions 24a, 24b.
Are capable of contacting a common object to be measured with their respective independent contact functions, and external contact lines taken out from the sleeves 22a and 22b can be independently drawn out.

However, the contact probe 21 shown in FIG.
Since the contact portions 24a and 24b of the contact pins 23a and 23b of the a and 21b are beveled, the contact pins 23a and 23b are slid in the sleeve 22a as the contact pins 23a and 23b slide in the axial direction. Since it rotates in the circumferential direction within 22b, it is necessary to provide a rotation stopping means for this, as shown in FIGS. 5 and 6, the contact portion 24 of the contact pin 23a is provided.
A groove 25a is provided on the side surface opposite to a, and an inward projection 26a is provided on the sleeve 22a. The engagement of the groove 25a and the inward projection 26a causes the contact pin 23a to slide in the axial direction. Sleeve 22a
It is designed so that it is prevented from turning in the circumferential direction inside, and as shown in FIGS. 7 and 8, a groove 27a is provided on the side surface of the contact pin 23a opposite to the contact portion 24a. At the same time, the guide pin 28a is planted at the outer end of the sleeve 22a.
The tip protruding inward is engaged with the groove 27a so that the contact pin 23a can be slid in the axial direction but prevented from turning in the radial direction.

Note that the detent structure of the above two examples shows only one contact probe 21a, and the other contact probe 21b is completely the same, and is therefore omitted.

[Problems to be solved by the invention]

However, the contact probe whirl-stop structure described in the related art has a problem that it cannot cope with the minimization of the pitch interval of the connection terminals, and the cost also increases.

That is, the pitch pitch of the connection terminals is minimized (2.
54mm → 1.27mm → 0.635mm), it is required to minimize the contact probe for 4-terminal measurement as much as possible. From this viewpoint, the outer diameter of the sleeve 22a is 2.54mm → 1.27mm.
For example, 0.8 mm → 0.4 mm → 0.2 mm is inevitably expected corresponding to mm → 0.635 mm, and if the outer diameter of the sleeve 22a is 0.4 mm corresponding to a pitch interval of 1.27 mm, the contact pin 2
The diameter of 3a is about 0.3 mm, the widths of the grooves 25a and 27a are 0.1 mm, and the depth is about 0.05 mm, which exceeds the level of manufacturing technology that can be easily realized from the viewpoint of reliability and increases the cost. There is a dot, and as the pitch interval of the connection terminals
If it is made to correspond to 1.0 mm or less, the outer diameter of the sleeve 22a is expected to be about 0.3 mm or less, and there is a problem that the manufacturing becomes extremely difficult.

The present invention has been made in view of the above problems of the conventional technique, and an object of the present invention is to make it possible to minimize the pitch interval of the connection terminals and to reduce the cost.
It is to provide a contact probe for terminal measurement.

[Means for solving problems]

In order to achieve this object, the present invention provides two contact probes having a sleeve and a contact pin elastically supported in the sleeve so as to be slidable in the axial direction of the sleeve. In the contact probe unit configured as described above, a pair of insertion holes for the one contact pin and a loose insertion hole for the other contact pin, which form a pair, are provided at appropriate positions of the protruding portions of the two contact pins from the sleeve. Of the insulating detents are fixed at a predetermined interval and fixed through the mutual insertion holes, and the pair of detents prevent the contact pins from turning in the radial direction. It is characterized by the configuration.

〔Example〕

Hereinafter, an embodiment of the present invention will be described together with its operation based on the drawings.

FIG. 1 is a side view showing a partial cross-section of an example of a detent structure according to the present invention, and FIG. 2 is a perspective view of the same. In these figures, a contact probe unit 30 includes two contact probes 31a. , 31b are insulated and held in parallel via an insulator 32. Further, although the axial direction is independent of the common plane of the measured object, the insulator 32 is supported and pressed. In the state, they are mutually adjusted so that they contact the object to be measured almost at the same time.

The contact probes 31a and 31b are sleeves 33a,
33b, contact pins 34a, 34b having beveled contact portions 35a, 35b, and the like, and the specific structure and the material of each member are the same as those of the conventional example shown in FIG. Are not shown and described.

The pair of anti-rotation members 36a, 36b that prevent the contact pins 34a, 34b from rotating in the radial direction are discs made of an insulating material such as plastic or ceramic, and are their diameters equal to the outer diameter of the insulating member 32? , The insertion hole 37a (37b) of one of the pair of contact pins 34a (34b), which has a dimension smaller than that and is substantially the same as the outer diameter of the contact pin 34a (34b). Diameter hole] and the loose insertion hole 38a (3) of the other contact pin 34b (34a)
8b) [holes having a diameter slightly larger than the outer diameter of the contact pin 34b (34a)], and these turning stoppers 36a, 36b
Is the sleeve 33 on the contact pins 34a, 34b
a and 33b are provided at a substantially intermediate portion of the projecting portion with a predetermined interval and are adhesively fixed through the insertion holes 37a and 37b of each other, and are fixed by adhesion through the insertion holes 37a and 37b. The contact pins 34a and 34b are prevented from rotating in the radial direction, and the loose insertion holes 38a and 38b do not prevent the mating contact pins 34a and 34b from sliding in the axial direction.

The rotation stoppers 36a and 36b can be replaced with a metal material whose surface is treated with insulation coating.

Further, although the rotation stoppers 36a and 36b are circular in plan view, this can be easily and accurately manufactured by lathe turning or plastic molding, and the assembling work only needs to be adhered to a predetermined position. This is because, if a material having a good slip property is selected, the purpose of the rotation stop can be surely achieved without disturbing the axial movement with use.

FIG. 3 is a partial cross-sectional side view showing another example of the present invention. In this example, two contact probes 31a and 31b are insulated and held in parallel via at least two insulators 39 and 40. By doing so, it is possible to assemble the pieces by adhering the plastic pieces by turning the plastic pieces, omitting the number of steps for inserting a long hole or a construction method such as insert molding.

Further, the rotation stoppers 36a and 36b are attached to the contact pin 34.
When fixed to a predetermined portion of a, 34b, a short brim 41 is externally attached to the contact pin 34a and a long brim 42 is externally attached to the contact pin 34b, whereby the rotation stoppers 36a, 36b are fixed. The respective positions are easily brought out during wearing, and a predetermined interval is maintained.

In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numbers.

[Effect of device]

Therefore, according to the present invention, it is not necessary to form a groove in the contact pin or an inward projection on the sleeve as in the conventional case, and the contact pin and the sleeve can be processed without any processing. Since it suffices to attach a stopper, it is possible to provide a four-terminal measurement contact probe that sufficiently corresponds to the minimization of the pitch interval of the connection terminals.

In addition, the turning stopper is a turning process that is easy to process and assemble,
Since it is obtained by injection molding of thermoplastics or use of an adhesive, it is possible to provide an inexpensive contact probe for measuring minute four terminals.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing an embodiment of the present invention, and FIG.
FIG. 3 is a perspective view of the same as above, FIG. 3 is a partial cross-sectional side view showing another embodiment of the present invention, FIG. 4 is a schematic explanatory view of a conventional contact probe unit for measuring four terminals, and FIG. 5 is a conventional contact pin. Fig. 6 is a sectional view showing the rotation preventing structure of Fig. 6, Fig. 6 is an end view seen from 6 directions of the same as above, Fig. 7 is a sectional view showing another example of the conventional rotation preventing structure, and Fig. 8 is an end view seen from 8 directions of the same as above. Figure, No. 9
The figure is a cross-sectional view showing a general contact probe.
The figure is a schematic diagram of four-terminal measurement performed with a contact probe. 30-contact probe unit 31a, 31b-contact probe 32, 39, 40-insulator 33a, 33b-sleeve 34a, 34b-contact pin 36a, 36b-rotation stopper 37a, 37b-insertion Holes 38a, 38b ... loose insertion holes

Claims (1)

[Scope of utility model registration request] 1. A two contact probe having a sleeve and a contact pin that is elastically supported in the sleeve so as to be slidable in the axial direction thereof and has a beveled contact portion at the tip thereof is made of an insulator. In the contact probe unit, which is insulated and held in parallel with each other, the insertion holes of the one contact pin and the other contact pin that form a pair are provided at appropriate positions of the protruding portions of the two contact pins from the sleeve. A pair of insulative detents having loose insertion holes are provided at a predetermined interval and are fixedly mounted through the mutual insertion holes, and the pair of detents are provided in the sleeve of each contact pin. A structure for preventing the contact pin from rotating in the circumferential direction of the contact probe unit in a contact probe unit.