JP3838225B2 - Probe pin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a probe pin suitable for use in printed circuit board inspection.
[0002]
[Prior art]
For a printed circuit board on which an electronic component such as an IC is mounted, a function test for inspecting whether or not the electronic circuit has a predetermined characteristic after the mounting is performed. In the functional test, a fixture provided with a plurality of probe pins is used. The probe pin is used to contact a terminal or the like of an electronic component mounted on a mounting board, and a plurality of pins are used as needed. As examples of these, in FIG. 1, a hollow type (a), a saddle type (b), a round type (c), a flat type (d), a chisel type (e), a needle type (f), a crown type The shape of each probe pin of (g) is shown. Each of the saddle-type, chisel-type, needle-type, and crown-type probe pins has a sharp tip, and the tip of the pin removes foreign matters such as solder oxide and flux applied to the terminals. Meanwhile, the tip of the pin is brought into contact with the terminal. In addition, probe pins that do not have a certain shape in the θ direction, such as a chisel shape and a crown shape, may rotate and contact in the θ direction. Moreover, since a contact area is obtained when a terminal is convex shape, a hollow type may be suitable. In Patent Document 1, a first plunger having a hollow center portion in the axial direction, a second plunger inserted through the center portion of the first plunger and having a tip projecting from the first plunger, A contact probe comprising a spring that applies an upward force along the axial direction to these plungers is disclosed. This contact probe has a self-cleaning mechanism in which, when the second plunger comes in contact with and separates from the inspection point, the probe moves in the axial direction, whereby the flux and the like peeled off from the mounting substrate are completely removed. Further, Patent Document 2 discloses a technique that has an acute angle portion and a curved portion and has knife characteristics by configuring the edge of the tip portion of the contact probe into a curved shape. Thereby, the contact resistance is reduced and the contact property is increased as compared with the point contact probe.
[0003]
[Patent Document 1]
JP-A-7-12846
[Patent Document 2]
JP-A-8-35986
[0004]
[Problems to be solved by the invention]
However, each probe pin shown in FIG. 1 has a problem that foreign matters such as solder oxide film and flux adhere to the tip of the probe pin. In particular, in round and flat probe pins, the tip of the probe pin has an obtuse angle, so that foreign matters such as solder oxide and flux on the mounting board are not sufficiently removed, and the contact resistance increases. is there. On the other hand, the saddle-type, chisel-type, needle-type, and crown-type probe pins have sharp tips, so the contact area is small and the force per unit area is large, making it more than necessary for the inspection terminals. There is a problem of scratching. In addition, the crown type has a problem that frequent cleaning is required to remove foreign matter accumulated on the tip of the probe pin. The technique described in Patent Document 1 also has a problem that the internal structure is complicated. Moreover, although the technique described in Patent Document 2 has a structure in which foreign matter is difficult to adhere, it does not have a self-cleaning mechanism.
The present invention has been made in view of the above-described circumstances, and provides a probe pin that can be pressed while removing foreign matter attached to a terminal and released while removing foreign matter attached to a tip. Is.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration. The parentheses are examples.
The probe pin according to claim 1, wherein a shaft, a first contact (wedge portion) formed at a tip portion of the shaft and having a first side surface, and a second contacting the first side surface. and a second contact having a side (wedge portions), each contact in the axial direction of the shaft is compressed, or by the fact that each contact is deformed when released, the first One side surface and the second side surface are narrowed inward with respect to the shaft or rub against each other in a direction extending outward .
Furthermore, in the configuration according to claim 2, in each of the probe pins according to claim 1, each contactor is a columnar body using an elastic body (spring material) having a fan-shaped end surface. Has an inclination angle with respect to a plane perpendicular to the central axis of the shaft, so that the apex angle portion of the end face protrudes.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
1. Configuration of Embodiment The structure of a probe pin according to an embodiment of the present invention will be described with reference to the external view of FIG.
In FIG. 2, reference numeral 10 denotes a probe shaft, which is a cylindrical rigid body having conductivity. Reference numerals 20 and 25 denote wedge portions, which are fan-shaped columnar sections having square side surfaces 31, 32, 33, and 34, and are formed of a spring material having conductivity. Further, the wedge portions 20 and 25 are fixed to the tip of the probe shaft 10, and among the side surfaces 31 and 33 of the wedge portions 20 and 25, the vicinity of the apex portion of the sector shape is partially in contact. Thereby, the apex portion of the fan-shaped shape is directed substantially in the center direction, the arc portion is directed to the outer side of the circumference of the probe shaft 10, and the side surfaces 31 and 33 of the wedge portions 20 and 25 are center axes of the probe shaft 10. Are in contact with each other. Further, the fan-shaped end surfaces 36 and 37 of the wedge portions 20 and 25 have an inclination angle of about “10 °” with respect to a plane perpendicular to the central axis of the probe shaft 10, and the vertical angles of the fan-shaped portions are included. Portions or edge portions 27 and 28 protrude from the tip of the probe pin 100. Note that the end surfaces 36 and 37 have an inclination angle, and the length of the upper side of the quadrangle forming the side surfaces 31, 32, 33 and 34 of the wedge portions 20 and 25 is longer than the lower side and outside the circumference of the probe shaft 10. Therefore, the wedge portions 20 and 25 have an appearance that is open to the outside of the probe shaft 10.
[0007]
2. Operation of the Embodiment Hereinafter, the operation of the probe pin 100 of the present embodiment will be described with reference to each drawing of FIG.
In each figure, reference numeral 300 denotes a printed circuit board on which an electrode pattern is formed and an electronic component is mounted. Reference numeral 350 denotes foreign matters such as flux and solder oxide applied to the electrode pattern. 3A is a side view and a top view of the probe pin 100 in a state where it is released from the printed circuit board 300. FIG. FIG. 3B is a side view and a top view of the state when the probe pin 100 moves in the axial direction and contacts the printed board 300. FIG. 3C is a side view and a top view showing a state in which the probe pin 100 is pushing the printed circuit board 300. FIG. 3D is a side view and a top view of the state where the press contact is completed. FIG. 3E is a side view and a top view of the probe pin 100 in a state in which it is released from the printed circuit board 300 and released again.
[0008]
At the time of release shown in FIG. 3A, a part of each of the side surfaces 31 and 333 of the wedge portions 20 and 25 is in contact. Further, since the front ends of the wedge portions 20 and 25 are open outward, the arc portions 42 of the wedge portions 20 and 25 protrude outward from the circumference of the probe shaft 10. As shown in FIG. 3B, the probe pin 100 has a similar shape even when it is in contact with the printed circuit board 300. However, the foreign object 350 is deformed into the shape of the edge portion 27 of the wedge portions 20 and 25 while making contact. To do. Further, in the state where the probe pin 100 is pressing the printed circuit board 300 as shown in FIG. 3 (c), the wedge portion opened to the outside by pressing the edge portion 27 of the wedge portions 20 and 25. The wedge portions 20, 25 are deformed so that the tips of the 20, 25 are narrowed inward. Thereby, the one side surfaces of the two wedge portions 20 and 25 rub against each other, and the side surface portion 40 in contact with the wedge portions 20 and 25 in parallel is widened. As the wedge portions 20 and 25 are deformed, the foreign material 350 is removed.
[0009]
Further, as shown in FIG. 3 (d), at the time of press contact, the entire fan-shaped cross section of the wedge portions 20 and 25 is accommodated inside the circumference of the probe shaft 10, and the entire wedge portions 20 and 25 are axially arranged. Compressed. Then, the wedge portions 20 and 25 are pressed against the printed circuit board 300, and a function test of the printed circuit board is performed in the pressed state. Further, in the released state as shown in FIG. 3E, the compressed wedge portions 20 and 25 spread outward again and the side surfaces rub against each other. Is removed.
[0010]
As described above, according to the present embodiment, the edge portions 27 of the wedge portions 20 and 25 are in contact with each other while removing foreign matters (solder oxide film, flux) added to the surface of the printed circuit board terminal. Is avoided. As the probe pin 100 moves in the axial direction, the side surfaces of the wedge portions 20 and 25 rub against each other, so that foreign matter attached to the tip of the probe pin is removed. Further, since the end face shape of the wedge portion is a fan shape, the scratches on the printed circuit board terminals during press contact are small.
[0011]
3. Modifications The present invention is not limited to the above-described embodiments. For example, the following various modifications are possible and all fall within the scope of the present invention.
(1) In the above-described embodiment, it is used for functional inspection of a printed circuit board, but it can also be applied to semiconductor chip inspection (die sort inspection). In this case, fine processing of the tip portion is required, but the probe mark can be made smaller than the sensing lever type pin.
[0012]
【The invention's effect】
As described above, according to the configuration of the present invention, the first contact having the first side surface and the second contact having the second side surface in contact with the first side surface is formed at the tip portion of the shaft. The first side surface and the second side surface rub against each other by deformation of each contact when the contact is compressed or released in the axial direction.
[Brief description of the drawings]
1 is an example of a conventional probe pin. FIG. 2 is an external view of a probe pin according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an operation of the probe pin according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Probe shaft, 20, 25 ... Wedge part, 27, 28 ... Edge part, 31, 32, 33, 34 ... Side surface, 36, 37 ... End surface, 40 ... Side surface part, 42 ... Arc part, 100 ... Probe pin, 300 ... printed circuit board, 350 ... foreign matter

Claims (2)

The axis,
A first contact formed at the tip of the shaft and having a first side;
A second contactor having a second side surface in contact with the first side surface,
Wherein each contact in the axial direction of the shaft is compressed, or by the fact that each contact is deformed when released, inwardly relative to the first side and the second side is the shaft A probe pin that rubs against each other in the direction of narrowing or spreading outward . Each of the contacts is a columnar body using an elastic body having a fan-shaped end surface. The end surface has an inclination angle with respect to a plane perpendicular to the central axis of the axis, so that the apex portion of the end surface is The probe pin according to claim 1, wherein the probe pin is provided so as to protrude.

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