JP5344740B2 - Contact probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact prove drastically shortened compared with a conventional contact probe. <P>SOLUTION: The contact probe A1 used while standing in a land 4b of a testing circuit board is configured of a core 1 having rubber elasticity, and an annular terminal 2 which is disposed around the outer circumference of the core 1 formed by winding at least once with a conductive wire material having elasticity, and having a loop 2b in the middle, and at both ends thereof, a terminal 2c of the start of winding of the wire material and a terminal 2d of the end of winding 2d of start of the winding material, wherein any of the terminal 2c of the start of the winding and a terminal of the end of the winding are fixed to the land 4b of the testing circuit board. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a contact probe, and more particularly, to a contact probe having a novel structure that is significantly reduced in height as compared with a conventional contact probe.

For example, inspection of electrical characteristics of an electronic circuit of an electronic component manufactured on a manufacturing line is generally performed using an inspection apparatus provided with a contact probe.
As contact probes, the following types are widely known. In the first type, a coil spring is disposed in the center of the interior of the metal tube, contact pins are disposed at the upper and lower portions of the coil spring, and both end openings of the metal tube are partially closed to each element part. The structure is held inside a metal tube.

  This type of contact probe is assembled in a predetermined arrangement on a probe support substrate on which a wiring pattern for transmitting and receiving electrical signals for inspection is formed, and for example, upper contact pins are connected to electrodes of electronic components to be inspected (for example, solder) It is used in such a manner that the lower contact pin is brought into contact with the land portion of the inspection circuit board of the inspection apparatus and a predetermined electrical signal is transmitted from the inspection apparatus.

At this time, since both the contact pins are biased by the coil springs, the contact pins are strongly pressed against the electrodes of the electronic component and the land portion of the circuit board for inspection, and the contact state between them is maintained well.
In the second type, a coil spring is also arranged inside the metal tube, and a contact pin is arranged on the upper part of the coil spring to partially close the upper opening of the metal tube, and the lower opening of the metal tube is the entire surface. In a sealed structure.

  This type of contact probe is usually used by being directly assembled to an inspection circuit board of an inspection apparatus. That is, a through hole is formed in the input / output land portion of the wiring circuit wired in a predetermined pattern on the circuit board for inspection, and the above-described contact probe is inserted therethrough, and usually fixed to the land portion using solder. Be placed. For example, a contact pin protruding upward by applying pressure from the back side of the circuit board for inspection is used in contact with the electrode of the electronic component.

Although there are various other variations, a conventional contact probe basically has a structure including a coil spring, a contact pin, and a metal tube that houses and holds them as essential components. Therefore, when manufacturing a contact probe, precise machining and assembly of these elements are required.
By the way, recent electrical and electronic devices are rapidly becoming smaller, thinner, lighter, and more densely packaged. With that, electronic components built into these devices have terminals ( The electrode) is becoming finer and the pitch between terminals is becoming narrower.

  This causes a problem that the distance between the inspection surface of the electronic component and the arrangement surface of the probe becomes narrow when inspecting the electronic component with an inspection device equipped with a contact probe. Therefore, there is a strong demand for the problem of lowering the height and the problem of diameter reduction (miniaturization). In particular, there is a strong demand for reducing the height of contact probes.

In order to cope with such a demand, a part of the sliding shaft portion of the two probes (contact pins) whose upper portion is fixed to the second probe is included in the coil spring, and the lower portion of the sliding shaft portion is included. Has been proposed which is slidably inserted into a cylindrical first probe to reduce the overall height and reduce the pitch during arrangement.
Although this contact probe belongs to the first type described above, it uses a coil spring and uses two contact pins of a predetermined length as in the conventional case. It is considered difficult to achieve a significant reduction in profile.

On the other hand, the above-described second type contact probe is advantageous in comparison with the first type in terms of reducing the height in that it has one contact pin. For this reason, various types of contact probes of the second type have been developed and are already on the market (refer to Non-Patent Document 1).
However, since these are structures using a spring coil for urging the contact pin, it cannot be said that such a low profile is realized. For example, in the case of this type of contact probe, the total height from the bottom surface of the probe to the tip of the contact pin is about 3.5 to 4 mm even if it is low.
JP 2008-128784 A

  The present invention is completely different from a conventional contact probe in which a coil spring and a contact pin that require precise machining are incorporated in a metal tube, and thus does not use a coil spring or a contact pin. It is an object of the present invention to provide a contact probe having a novel structure that can be reduced in height to about 1 mm in overall height and that has an appropriate contact pressure with a land portion of an electronic component.

In order to achieve the above object, in the present invention,
A contact probe that is used standing on a land portion of a circuit board for inspection,
An electrically insulating core having rubber elasticity;
Disposed around the outer periphery of the core, the ends of the winding start side of the wire loop part formed of a conductive wire rod having spring elasticity Rotate once winding and respectively positioned at both ends of the loop portion and A ring terminal having an end on the winding end side,
Both the end portion on the winding start side and the end portion on the winding end side are fixed to the land portion of the circuit board for inspection ,
The ring terminal has an electrical connection point with an electronic component to be inspected on a side opposite to a position where the end portion on the winding start side and the end portion on the winding end side are arranged via the loop portion. And has a top
A plurality of the core members wound with the wire rods arranged side by side so that the wire rods are substantially parallel ;
Is provided.

  Since the contact probe of the present invention is used in a state of being erected on the land portion of the circuit board for inspection, the overall height is defined by the outer diameter of the annular terminal disposed on the outer periphery of the core body. Yes. And, it has a structure in which the top (highest point) of the ring terminal is brought into pressure contact with the land part of the electronic component to be inspected by the combined action of the spring force of the ring terminal and the rubber elasticity of the core body. By appropriately selecting the wire diameter and cross-sectional dimensions of the wire used to manufacture the ring terminal, the overall height can be compared to that of a conventional contact probe with a spring coil and contact pin built in a metal tube. The height can be significantly reduced.

  In addition, since the spring coil, contact pin, metal tube, and the like manufactured by precision machining are not necessary, the production cost can be greatly reduced. Then, by fixing the annular terminal to the land portion of the circuit board for inspection using solder, the repair work of the contact probe after repeated use can be simplified.

The contact probe of the present invention is used in a state where it is erected on the input / output land portion of the circuit board for inspection. One example of this state is shown in FIG. 2 which is a cross-sectional view taken along the line II-II in FIG. 1 and FIG.
In the figure, a contact probe A1 includes an electrically insulating core body 1 having rubber elasticity, and a loop portion 2b formed by winding a conductive wire 2a having spring elasticity once around the outer periphery of the core body 1. The ring terminal 2 is formed by an end 2c on the winding start side of the wire extending from the loop portion 2b and an end 2d on the winding end side of the wire.

The end portion 2c on the winding start side and the end portion 2b on the winding end side of the wire are both joined and fixed to the land portion 4b of the wiring circuit 4a in the circuit board 4 for inspection by the solder 3, and the contact The probe A1 is erected on the land portion 4b with the top portion 2e of the ring terminal 2 facing up.
Here, as the material of the core body, an electrically insulating material having rubber elasticity is used. Specifically, various natural rubbers, synthetic rubbers, silicone rubbers, and elastomer resins such as NBR are suitable.

  The core body is arranged on the land portion 4b in a state where a columnar body (in the case of FIGS. 1 and 2) having a length L and a diameter D is turned sideways. In this case, the length L is related to the size of the diameter D, but is set to a length that does not cause the columnar body to fall down even when an external force is applied from obliquely above in the axial direction. As the columnar body, a cylindrical body as shown in the figure, a prismatic body such as a triangular prism with a triangular cross section, a rectangular parallelepiped with a quadrangular cross section or the like can be used.

  The ring terminal 2 is formed by winding a wire 2a having a certain length once, and has a loop portion 2b at the center, a winding start side end 2c and a winding end side end 2d at both ends. Have. The wire used may be anything as long as it has spring elasticity and has electrical conductivity. For example, the wire of piano wire, tungsten wire, and phosphor bronze wire shows great spring elasticity even if it is thin. In particular, there are piano wires with various wire diameters ranging from thin wires with a diameter of about 0.01 mm to those with a diameter of about 1 mm in relation to the musical scale, and they all exhibit excellent spring elasticity over a long period of time. Therefore, it is preferable.

  In order to arrange the core body on the outer periphery of the annular terminal 2, first, a wire 2a having a predetermined wire diameter (d) is wound once to form a loop portion 2b having a desired inner diameter. However, since the wire rod returns to its original state due to spring elasticity in this state, annealing is once performed at a predetermined temperature to fix the loop shape. Next, after inserting, for example, a rubber cylinder having an outer diameter that is substantially the same as or slightly smaller than the inner diameter of the loop portion 2b, the cylinder is cut into a predetermined length (L).

Then, this structure is placed on the land portion 4b of the circuit board for inspection 4, and the end portion 2c on the winding start side and the end portion 2d on the winding end side of the wire are soldered to the land portion 4b. As shown in FIG. 2, the contact probe A1 is erected on the land portion 4b.
At this time, by appropriately selecting the wire diameter (d) of the wire to be used and the inner diameter (D) of the loop portion to be formed, when the height of the erected contact probe A1 or the loop portion 2b is crushed in the vertical direction The magnitude of the generated spring force (repulsive force) can be set to an arbitrary value.

Further, depending on the line width of the wiring circuit 4a (width of the land portion 4b), the pitch between the wiring circuits (pitch between the land portions), the wire width (d) of the wire, the inner diameter (D) of the loop portion, By appropriately selecting the length (L) of the core body, it is possible to cope with a narrow pitch of the wiring circuit.
For example, when the wiring circuit 4a on the circuit board for inspection has a line width of 5000 μm and a line spacing of 1000 μm, a core with a diameter (D) of 2.0 mm and a length (L) of 1.0 mm, and a wire diameter (d) of 0. A contact probe A1 having an overall height of 2.1 mm can be manufactured by combining a ring terminal formed with an inner diameter (D) of 1.9 mm using a 1 mm piano wire.

This contact probe A1 is used in the mode shown in FIG.
The inspection circuit board 4 on which the contact probe A1 is mounted is placed on a test table 5 that can move up and down. Then, the top 2e of the ring terminal 2 in the contact probe A1 is aligned with the center of the land 6a of the electronic component 6 to be inspected.
While maintaining this state, the electronic component 6 is lowered as indicated by the arrow in FIG. 3 or the test table 5 is raised, and the loop portion 2b of the annular terminal 2 and the land portion 6a of the electronic component 6 are pressed. To do. As a result, a conductive relationship is formed between the electronic component 6 and the inspection circuit board 4 in a state where the top portion 2e of the loop portion 2b is an electrical connection point, thereby enabling inspection work.

  At this time, the loop portion 2b of the ring terminal 2 is compressed and deformed in the height direction, and the core body is also compressed downward. Since the end 2c and 2d of the loop portion 2b are fixed to the land portion 4b of the wiring circuit by soldering, an upward spring force is generated in the loop portion 2b, and the loop portion 2b is made of an electronic component. The lands 6a are kept in pressure contact with each other, and the conduction relationship between the land 6a of the electronic component and the land 2b of the circuit board for inspection is ensured in a stable state.

The core body 1 compressed in the radial direction and deformed downward also exerts its rubber elasticity and pushes the loop portion 2b upward to contribute to securing a conduction relationship. In this case, since the length (L) of the core body 1 is set to an appropriate length, the core body 1 falls down in this process, and the annular terminal 2 moves away from the land portion 6a of the electronic component. There will be no occurrence of a disconnection.
Since the contact probe A1 acting in this way can be reduced in height to about 2 mm, even if the gap between the inspection location of the electronic component and the test table is a narrow gap, the gap An inspection test can be carried out by inserting the contact probe A1. Specifically, inspection can be performed up to a gap of about 1 mm.

FIG. 4 shows another contact probe example A2 of the present invention. In the contact probe A2, a loop portion 2b is formed by aligning an end portion 2c on the winding start side and an end portion 2d on the winding end side of the ring terminal 2 in the same direction.
The contact probes A1 and A2 described above are used by mounting one contact probe on one wiring circuit (one land portion) as shown in FIG. However, as shown in FIG. 5, for example, a single long columnar body is used as the core body 1, and a plurality of annular terminals 2 are arranged on the outer periphery of the core body. An integrated structure may be manufactured, and the contact probes A2 may be mounted on each land portion by placing the structure over a land portion arranged on the circuit board for inspection. In this case, when the land part of the electronic component and the top part of the annular terminal are pressed against each other, the fear of causing the core body 1 to fall down is surely removed.

FIG. 6 shows an example of another contact probe A3 of the present invention.
In the contact probe A3, the core body 1 is a long columnar body, and the annular terminal 2 includes a plurality of loop portions 2b formed by winding a wire rod in a spiral shape. It is of the type arranged on the outer periphery. Then, the whole end portion 2c and the end portion 2d on the winding end side of the loop portion 2b are soldered to the land portion 4b of the wiring circuit so that the whole is erected on the land portion.

Also in this case, since the core body 1 is long, the fear that the core body 1 falls down when the land portion of the electronic component and the top portion of the annular terminal are pressed is eliminated.
In the case of this contact probe A3, the annular terminal is formed by winding a wire in a spiral shape. Therefore, if the spiral pitch is appropriately adjusted and the overall length is made relatively long. Even if the core body is not inserted into the annular terminal, it can be used as an annular terminal that does not cause a lateral collapse as it is.

  Since the contact probe of the present invention is significantly reduced in height as compared with the conventional contact probe, the distance from the object to be inspected has recently been narrowed to about 2 to 4 mm, for example, inspection of light emitting elements under a microscope. It can be used as a probe.

It is a partial notch perspective view which shows the state which mounted the contact probe A1 of this invention in the circuit board for a test | inspection. It is sectional drawing which follows the II-II line | wire of FIG. It is sectional drawing which shows the state which test | inspects an electronic component with the contact probe A1. It is sectional drawing which shows another contact probe A2 of this invention. It is a partial notch perspective view which shows the state which mounted the elongate contact probe A2 in the circuit board for a test | inspection. It is a partial notch perspective view which shows the state which mounted further another contact probe A3 of this invention on the circuit board for a test | inspection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core body 2 Ring terminal 2a Wire material 2b Loop part 2c End part of winding start side of wire 2d End part of winding end side of wire 3 Solder 4 Circuit board for inspection 4a Wiring circuit 4b Land part 5 Test stand 6 Electronic component 6a Electronic parts land

Claims (4)

A contact probe that is used standing on a land portion of a circuit board for inspection,
An electrically insulating core having rubber elasticity;
Disposed around the outer periphery of the core, the ends of the winding start side of the wire loop part formed of a conductive wire rod having spring elasticity Rotate once winding and respectively positioned at both ends of the loop portion and A ring terminal having an end on the winding end side,
Both the end portion on the winding start side and the end portion on the winding end side are fixed to the land portion of the circuit board for inspection ,
The ring terminal has an electrical connection point with an electronic component to be inspected on a side opposite to a position where the end portion on the winding start side and the end portion on the winding end side are arranged via the loop portion. And has a top
A contact probe characterized in that a plurality of the core bodies around which the wire is wound are arranged side by side so that the wires are substantially parallel .   The contact probe according to claim 1, wherein the core body is made of rubber or elastomer resin, and the shape thereof is a cylindrical body or a prismatic body.   The contact probe according to claim 1 or 2, wherein the wire is a piano wire.   The contact probe according to claim 1, wherein an end portion on the winding start side and an end portion on the winding end side of the wire are fixed to the land portion of the circuit board for inspection using solder.

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