JP3806874B2 - Contact probe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a contact probe, and more particularly to a contact probe used for inspecting a semiconductor, a liquid crystal, a circuit pattern formed at an ultra fine pitch of an electric / electronic device, and the like.
[0002]
[Prior art]
The circuit pattern of an electronic circuit board is miniaturized as electronic elements such as semiconductors, resistors, capacitors, and coils mounted on the board are miniaturized. On the other hand, as a contact probe used for inspecting a circuit pattern of an electronic circuit board, a structure in which a probe is elastically urged by a coil spring (coil spring type contact probe) has been conventionally known. However, this has not been able to cope with the inspection of a miniaturized circuit pattern because it is difficult to reduce the size.
[0003]
By the way, the probe tip (probe tip) of a contact probe that can be adapted to the inspection of a miniaturized circuit pattern is required to have a fine spherical or square shape with a radius of about 0.1 mm, and is adjacent to it. It has been found that the inter-probe pitch is required to have a precision of about 0.2 mm or less. In this respect as well, the above-described coil spring type contact probe cannot satisfy the requirement.
[0004]
Therefore, a cantilever type or a buckling type has been used as a contact probe having means for urging and energizing the probe. Of these, the buckled contact probe has the disadvantage that the elastic modulus of the spring part cannot be increased, or that it becomes longer in the lengthwise direction of buckling and is difficult to reduce in size. However, there is a drawback that the service life is shortened and cannot be put to practical use if the value is increased to some extent. On the other hand, the cantilever-type contact probe has been used more than ever since it is a type having a fine contact, but the problem of the service life has not been solved as in the case of the buckled contact probe.
[0005]
On the other hand, there has been a contact probe configured by laminating a large number of thin plates with protruding beam portions having a probe (see, for example, Patent Document 1). In this contact probe, the beam portion is raised from a thin plate into a crane neck shape by forming a thin notch on the thin plate, and a probe called a pointed leadle is provided at the tip of the beam portion.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-83179
[Problems to be solved by the invention]
As mentioned above, conventional buckled contact probes and cantilever contact probes known as contact probes that can be used for inspection of miniaturized circuit patterns do not satisfy both miniaturization and service life. There wasn't.
[0008]
The present invention has been made in view of the above circumstances, and can provide the advantages of a cantilever-type contact probe, that is, can have fine contacts, and can be downsized more easily than a buckled contact probe. It is an object of the present invention to provide a contact probe that can satisfy both the miniaturization and the service life by forming the spring portion for elastically energizing the probe with the beam portion while taking advantage of the advantages. To do.
[0009]
It is another object of the present invention to provide a contact probe that can be easily and inexpensively manufactured while being applicable to inspection of a miniaturized circuit pattern.
[0010]
[Means for Solving the Problems]
The contact probe according to the present invention is a laminate of a large number of conductive thin plates from which beam portions having probes are projected, and the individual conductive thin plates are electrically insulated from each other. And while the beam portion having the same width as the thickness of the conductive thin plate is formed in a meandering shape having elastic elasticity, the probe formed by sharpening the tip of the beam portion, At the tip of the beam portion, it protrudes from a part in the thickness direction of the conductive thin plate.
[0011]
When this configuration is adopted, since the beam portion is formed in a meandering shape, the linear protrusion width of the beam portion becomes shorter than the creepage length of the beam portion. In addition, since the beam portion having the same width as the thickness of the conductive thin plate is formed in a meandering shape having expansion and contraction elasticity, the beam portion itself has a spring property for elastically biasing the probe. The part itself acts as a spring part with a long service life. For these reasons, it is easy to promote downsizing of the contact probe, and the service life is also increased.
[0012]
Further, the beam portion having the same width as the plate thickness of the conductive thin plate is formed in a meandering shape having elastic elasticity, and the probe formed by sharpening the tip of the beam portion, Since the tip of the beam part protrudes from a part in the thickness direction of the conductive thin plate, it is easier to manufacture the probe than when the probe is formed by a separate member and fixed to the tip of the beam part. In addition, by employing means such as polishing, the tip of the probe can be easily finished into a spherical shape with a desired radius or a desired square shape.
[0013]
In the present invention, terminals to which lead wires are connected are provided at the end portions of the individual conductive thin plates, and it is desirable that these terminals are displaced so as not to overlap each other in the stacking direction of the conductive thin plates. By adopting this configuration, it is possible to easily connect lead wires to the respective terminals, and there is no room for short-circuiting between the terminals.
[0014]
In the present invention, it is desirable that adjacent conductive thin plates are electrically insulated by an electrically insulating film or an electrically insulating coating film. According to this, the stacking pitch of the electrically conductive thin plates is shortened to provide a probe. Therefore, it becomes easy to adapt the pitch between the probes to the miniaturization of the circuit pattern.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1A is a schematic side view of a conductive thin plate 1 that is a component of a contact probe according to the present invention, FIG. 1B is a plan view of the conductive thin plate 1, and FIG. FIG. 2A is a partially broken side view of the main part of the contact probe, FIG. 2B is a sectional view taken along the line IIB in FIG. 3A, and FIGS. It is explanatory drawing about a crystallization promotion effect | action and a spring property.
[0016]
The conductive thin plate 1 shown in FIG. 1 has a beam portion 2 extending from an appropriate point on one side as a starting point a, and a probe 3 is provided at the tip of the beam portion 2. The beam portion 2 is formed in a meandering shape, and can be expanded and contracted in the direction of the arrow s in which the pitch of the mountain-shaped portion or the valley-shaped portion expands and contracts, and when the beam portion 2 expands and contracts, Has elasticity to return to shape. The conductive thin plate 1 constitutes a contact probe by a laminated body formed by superposing a large number of sheets as shown in FIG. 2, and in such a contact probe, the individual conductive thin plates 1 are electrically connected to each other. In addition, each conductive thin plate 1 is provided with a terminal 4 for connecting a lead wire.
[0017]
Thus, the conductive thin plate 1 is provided with the meandering beam portion 2 having the probe 3 at the tip, so that the width of the conductive thin plate 1 can be kept short and the contact probe can be miniaturized. Not only does the service life increase. This point will be described with reference to FIG.
[0018]
FIG. 3A shows a cantilever-type flat leaf spring material 10 formed as an action point where one end 11 is fixed and the other end 12 receives a load P. FIG. In this leaf spring material 10, the magnitude of the load P that can bend the leaf spring material 10 is inversely proportional to the linear length L from one end 11 to the other end 12 of the leaf spring material 10. It is proportional to the plate width W.
[0019]
This can be expressed as an expression:
P∝ (t ²・ W) / L ………… (1)
It becomes. Since the leaf spring material 10 is flat, the linear length L from the one end 11 to the other end 12 of the leaf spring material 10 is the creepage length (the leaf spring) from the one end 11 to the other end 12 of the leaf spring material 10. The length along the surface of the material 10). Therefore, when the plate thickness t and the plate width W are increased to increase the load P and the leaf spring material 10 is bent, the useful life as a spring is shortened and plastic deformation occurs. On the other hand, since the service life is proportional to the straight line length L, increasing the straight line length L extends the service life, but the leaf spring material 10 becomes longer and larger.
[0020]
On the other hand, a leaf spring material 10 ′ having a creeping length from one end to the other end that is the same as that of the leaf spring material 10 in FIG. 3A is bent into a meandering shape as shown in FIG. Then, the linear length L ′ of the leaf spring material 10 ′ is shorter than the linear length L of the leaf spring material 10 of FIG. Further, the meandering leaf spring material 10 ′ can be expanded and contracted in the direction in which the pitch of the mountain-shaped portion or the valley-shaped portion expands and contracts, and when it expands and contracts in that direction, it tries to return to the original natural shape. Exhibits elasticity.
[0021]
Therefore, as described with reference to FIG. 1, when the beam portion 2 is formed in a meandering shape having elastic elasticity, the width of the conductive thin plate 1 is kept short, and the contact probe is miniaturized. The creeping length of the beam portion 2 becomes longer with respect to the linear length, and the meandering beam portion 2 itself exhibits elasticity, so that the service life is also increased. Accordingly, when a contact probe is formed by laminating a large number of such conductive thin plates 1, a contact probe having a small width and a long service life of the conductive thin plate 1 can be manufactured. become.
[0022]
Next, as shown in FIGS. 1B and 1C, the probe 3 protrudes from a part of the thickness direction m of the conductive thin plate 1 at the tip of the beam portion 2. The probe 3 is formed in a pointed shape by etching the beam portion 2, laser processing or wire cut processing, and polishing the processed portion. Protruding the probe 3 from a part of the thickness direction m of the conductive thin plate 1 at the tip of the beam portion 2 means that the width of the beam portion 2 (thickness of the conductive thin plate 1) and the beam portion 2 This is useful for increasing the wall thickness and extending its service life, and for providing the probe 3 integrally with the beam portion 2 at the tip thereof. Practically, the conductive thin plate 1 having a thickness of about 0.1 mm or less is used. Therefore, as described above, the probe 3 is placed at the tip of the beam portion 2 in the thickness direction of the conductive thin plate 1. When protruding from a part of m, the pitch between adjacent probes 3 at the contact probe is also the same as the thickness of the conductive thin plate 1.
[0023]
As shown in FIGS. 2A and 2B, the terminals 4 of the individual conductive thin plates 1 forming the laminated body are displaced so as not to overlap each other in the stacking direction of the conductive thin plates 1. Specifically, the positions of the terminals 4 of the individual thin conductive plates 1 are shifted little by little so that they are arranged obliquely. If this is done, not only will it not be possible for the terminals 4 to short-circuit between adjacent conductive thin plates 1, but lead wires (not shown) may be connected to the individual terminals 4 by soldering or the like. In this case, there is an advantage that the connection work can be easily performed without being disturbed by other terminals.
[0024]
In the contact probe, the laminated individual thin conductive plates 1 need to be electrically insulated from each other. Such electrical insulation can be achieved by forming an oxide film that exhibits electrical insulation on the surface of the conductive thin plate 1 including the beam portion 2 or by electrically insulating the surface of the conductive thin plate 1 including the beam portion 2. It can be ensured by forming an electrically insulating coating film by applying paint, and by doing so, the stacking pitch of the conductive thin plates 1 can be shortened to reduce the pitch between the probes 3. Since it becomes easy to shorten, there exists an advantage that it becomes easy to adapt the mutual pitch of the probe 3 to refinement | miniaturization of a circuit pattern.
[0025]
In the contact probe according to the present invention, the meandering shape of the beam portion 2 is limited to a shape in which a mountain-shaped portion or a valley-shaped portion is formed in an upside down V-shape as shown in FIG. Instead, for example, the valley-shaped portion may be U-shaped, and the mountain-shaped portion may have a shape in which the rising portions of the valley-shaped portion are overlapped.
[0026]
【The invention's effect】
As described above, the contact probe according to the present invention has the advantages of the cantilever-type contact probe, that is, it can have a fine probe, and can be downsized more easily than the buckled contact probe. The spring part for elastically energizing the probe is formed by the beam part itself having a meandering expansion / contraction elasticity to satisfy both miniaturization and service life. It can be done. Therefore, it has the performance required for the inspection of the miniaturized circuit pattern and can be sufficiently adapted to the inspection of the miniaturized circuit pattern. Nonetheless, the beam part bears a spring part for elastically biasing the probe without using elastic urethane resin or silicon resin, or a spring material that is separate from the beam part. Therefore, the number of parts is small, and it can be easily and inexpensively manufactured.
[Brief description of the drawings]
1A is a schematic side view of a conductive thin plate that is a component of a contact probe according to the present invention, FIG. 1B is a plan view of the conductive thin plate, and FIG. 1C is an enlarged view of a main part of a beam portion. FIG.
2A is a partially broken side view of the main part of the contact probe, and FIG. 2B is a view taken along the line IIB in FIG.
FIGS. 3A and 3B are explanatory views of a miniaturization promoting action and a spring property. FIGS.
[Explanation of symbols]
1 Conductive thin plate 2 Beam 3 Probe 4 Terminal

Claims (3)

In a contact probe in which a beam portion having a probe is a laminated body of a plurality of conductive thin plates protruding, and the individual conductive thin plates are electrically insulated from each other,
The beam portion having the same width as the thickness of the conductive thin plate is formed in a meandering shape having elastic elasticity, and the probe formed by sharpening the tip of the beam portion includes the beam portion. A contact probe characterized in that it protrudes from a part in the thickness direction of the conductive thin plate at the tip of the part . 2. The contact according to claim 1 , wherein a terminal to which a lead wire is connected is provided at an end of each of the conductive thin plates, and the terminals are displaced so as not to overlap each other in the stacking direction of the conductive thin plates. probe. The contact probe according to claim 1 or 2 , wherein the adjacent conductive thin plates are electrically insulated by an electrically insulating film or an electrically insulating coating film.

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