JP4444799B2 - Four-probe measuring probe for contact equipment - Google Patents

Description

  The present invention relates to a four-probe measuring probe used for a contact device used for relaying to connect each electrode of an electronic component such as a semiconductor element and an electronic circuit such as a tester circuit.

  Electronic circuits using ICs, LSIs, transistors, and other electronic components are used in a large number of devices and devices, and their applications are steadily expanding. It is usually configured using a printed circuit board with wiring films printed on both sides. An electronic circuit is mounted by mounting various electronic components such as IC, LSI, transistor, etc. on the printed circuit board and performing necessary soldering. Is configured.

Many of devices and devices using electronic circuits are required to be downsized, highly functional, and high in performance, and accordingly, the circuit configuration of electronic circuits is complicated and high integration is required. Therefore, the wiring of the printed circuit board also tends to be miniaturized and highly integrated, and as a result, measurement for the inspection becomes difficult. This is because it is necessary to increase the arrangement density of the probes for measurement and the accuracy of the arrangement position by miniaturization and high integration of the wiring. Nevertheless, the importance of inspection is increasing.
This is because the incidence of short-circuit defects increases as the wiring becomes finer and more integrated.

  A tester equipped with a measurement circuit is used for the inspection, and a contact device is used for electrical derivation of each wiring film, electrode, etc. of the printed circuit board to the measurement circuit. This contact device has a number of probes on a plate, one end of each probe is brought into contact with a portion to be electrically connected to a measurement circuit such as each wiring film on a printed circuit board, and the other end of a cord connected to the measurement circuit. Many are designed to come into contact with the tip. In this regard, the applicant company has made various proposals according to Japanese Patent Application No. 7-61728, Japanese Patent Application No. 8-183449, Japanese Patent Application No. 10-66333, and the like.

  By the way, it is difficult to measure four probes with any of the conventional contact devices. This is because four probe measurement requires separate electrical contact at two probe terminals [I (current) terminal, V (voltage) terminal] for one probe point. This is because it was considered impossible. And it has become a big problem that a contact apparatus cannot respond to four-probe measurement. This problem will be specifically described as follows.

  For example, in resistance measurement by four-probe measurement, taking the case of measuring the parasitic resistance between two points A and B to be measured as an example, a predetermined current is passed between the two points A and B. Thus, the voltage drop generated between A and B is obtained, and the parasitic resistance is obtained by dividing this voltage drop by the current, and the measurement accuracy is extremely high. However, as described above, it is necessary to simultaneously contact a contact pin for passing a current to each of the two points A and B and a contact pin for measuring a voltage drop, which is impossible in the past. It was.

  In addition, printed circuit boards continue to be integrated, wiring films tend to be thin and thin, and the number of cases in which wiring films are electrically connected by lamination due to multi-layering and contact resistance intervenes there increases. Therefore, parasitic resistance tends to increase. Therefore, there is a need to accurately and reliably and quickly (effectively) measure and inspect whether it exceeds the allowable limit.

Therefore, in order to solve such problems, the inventor of the present application has developed to provide four-probe measurement contact pins capable of four-probe measurement, contact devices using the contact pins, and the like. . And the result was announced by Unexamined-Japanese-Patent No. 2002-207049.
The outline of this announcement includes at least a middle terminal and a cylindrical peripheral terminal fitted externally in a state of being electrically insulated from the middle terminal as a four-probe measurement contact pin, Using an electric path from one end of the middle terminal to the other end and an electric path from one end to the other end of the peripheral terminal, for example, the middle terminal is used for four-probe measurement. The peripheral terminal is used as the V terminal as the I terminal.

According to such a contact pin, when the middle terminal and the circumferential terminal are brought into contact with one probe point, the one probe point is formed by two electrically insulated terminals of the middle terminal and the circumferential terminal. Two electrical contacts can be made, and the probe points can be electrically derived from each other in the different electric paths. Therefore, four-point probe measurement becomes possible.
Japanese Patent Application No. 7-61728 Japanese Patent Application No. 8-183449 Japanese Patent Application No. 10-66333 JP2002-207049

However, according to the prior art published by the above-mentioned JP-A-2002-207049, four-probe measurement is possible, but the electrical connection between the middle side terminal and the peripheral side terminal and the circuit on the tester side is made. There is a problem that it is difficult to respond to the request for lowering the price of contact devices.
This is because, according to the prior art published by Japanese Patent Laid-Open No. 2002-207049, it is necessary to connect the tips of each of the middle terminal and the peripheral terminal and the wiring (lead wire) by soldering. Because the connection is quite troublesome. In particular, it is extremely difficult to connect the tip of the inner middle terminal to the wiring (lead wire). In addition, the difficulty of connection is increasing as the probe is miniaturized as the IC is highly integrated.

  The present invention has been made to solve the above-described problems, and is a contact device that facilitates electrical connection between the four-probe measurement probe and the tester circuit side, and can reduce the manufacturing cost. An object of the present invention is to provide a four-probe measuring probe used in the above.

The four-probe measuring probe according to claim 1 is electrically insulated from the outer peripheral side of the inner relay element composed of a pair of rod-shaped conductors and elastic means interposed so as to be biased in a direction to be separated from each other. An electrical path from one end of the inner relay element to the other end by loosely fitting a peripheral relay element composed of a pair of cylindrical conductors and elastic means interposed so as to be biased in a direction away from each other And a first insulating tube is fixed to the outer end of the outer peripheral surface of each bar-like conductor of the inner relay element, and the peripheral relay element An inward engagement step portion is formed by enlarging the inner diameter on the inner side from the outer side at an appropriate distance from the inner ends of the inner peripheral surfaces of the respective cylindrical conductors. On the outer peripheral side of each of the rod-shaped conductors on the inner peripheral side, and on the engaging stepped portion on the outer end. A second insulating tube having an inner diameter smaller than the outer diameter of the first insulating tube and capable of engaging with the first insulating tube is disposed, and the space between the second insulating tubes is widened. The elastic means for urging in the direction is arranged.

According to the four-probe measuring probe of claim 1 , the pair of first insulating tubes fixed to the outer peripheral surface of the pair of rod-shaped conductors constituting the inner relay element are arranged on the outer peripheral side of the rod-shaped conductor. Since the second insulating tube is engaged, the positional relationship of the pair of rod-shaped conductors constituting the inner relay element with respect to the pair of cylindrical conductors constituting the circumferential relay element is determined by the elastic force of the elastic means. It can be stabilized.

The four-probe measuring probe according to the present invention is electrically insulated from a pair of rod-shaped conductors and an inner relay element formed of elastic means interposed so as to be biased in a direction to be separated from each other. A circumferential relay element comprising a pair of cylindrical conductors and elastic means interposed so as to be urged away from each other, and an electric path extending from one end of the inner relay element to the other end; and Although it is preferable to use one having an electrical path extending from one end to the other end of the peripheral side relay element, the first and second insulating tubes have sufficient insulation and mechanical strength. Strong and heat resistant materials are preferred. For this, polyimide is suitable.

  The elastic means interposed between the pair of second insulating tubes does not need conductivity, but may be conductive as long as there is no possibility of coming into contact with other elastic means. However, it can be said that the use of an insulating material is preferable because a short-circuit accident does not occur even when it comes into contact with other elastic means.

Hereinafter, the present invention will be described in detail according to illustrated embodiments. FIGS. 1A, 1B and 2 show one embodiment of the present invention, and FIG. 1A is a cross-sectional view showing a four-probe measuring probe constituting the main part of a contact device. B) is a sectional view showing a state in which the probe storage board and the cable holding board are combined, and FIG. 2 is a sectional view showing a state when the contact device is in use.
First, the four-probe measurement probe in a state before the probe storage board is assembled to the cable holding board will be described with reference to FIG. 1 is a contact device, and 2 is a probe storage board, which is formed by laminating a plurality of plates 2a, 2b, 2c, and 2d. In FIG. 1, the probe storage board 2 is shown only in a portion where one probe storage hole 4 is formed. However, the probe storage board 2 has a plurality of probe storage holes 4, 4,. In this embodiment, the structure and dimensions of each probe storage hole 4 are exactly the same.

Each of the probe storage holes 4 is an inward retaining step 4a formed by increasing the inner diameter of the outer side toward the inner side of the main body of the probe storage board 2 from the inner side. 4a. Four probe measuring probes 6 are stored in the respective probe storage holes 4.
The four-probe measurement probe 6 includes an inner relay element 8 and a circumferential relay element 10 that is located outside and can move independently of the inner relay element. The inner relay element 8 is composed of a pair of rod-shaped conductors 12 and 12 and a conductive spring 14 that is interposed between the pair of rod-shaped conductors 12 and 12 and biases them in a direction to separate them.

Each of the rod-shaped conductors 12 and 12 is formed such that a substantially inner half portion is made smaller in diameter than a substantially outer half portion, and an inwardly inclined step portions 16 and 16 are formed therebetween. By engaging the stepped portions 16 and 16 between the rod-shaped conductors 12 and 12, they are biased in the direction of separating them. The conductive spring 14 is basically in the form of a coil, but the intermediate portion is configured so that the adjacent wire ring portions are in contact with each other. The portions are elastic without contact between adjacent wire ring portions. Thus, the part which adjacent wire ring parts contact is provided in order to make the parasitic resistance between the both ends of the electroconductive spring 14 smaller.
Reference numerals 18 and 18 denote insulating tubes (first insulating tubes) fixed to the outer half portions of the outer peripheral surfaces of the rod-shaped conductors 12 and 12 in an outer fitting manner.

  The peripheral relay element 10 includes a pair of cylindrical conductors 20 and 20 and a conductive spring 22 that is interposed between the pair of cylindrical conductors 20 and 20 and biases them in a direction to separate them. Each of the cylindrical conductors 20, 20 has stepped portions 24, 24 facing inward at the inner end of the outer peripheral surface, and the spring 22 has stepped portions 24, 24 between the cylindrical conductors 20, 20. By being engaged with each other, it is urged in the direction of separating them. The conductive spring 22 is basically coiled like the conductive spring 14, but the intermediate wire portion is in contact with the adjacent wire ring portion, and the intermediate portion is elastic. However, the outer portion of the outer ring portion is not in contact with each other and has elasticity.

26 and 26 are stepped portions facing the inside formed on the inner peripheral surfaces of the cylindrical conductors 20 and 20, and an insulating tube made of, for example, polyimide (second insulating tube) is formed inside each of the stepped portions 26 and 26. ) 28 and 28 are arranged. The inner diameters of the insulating tubes 26 and 26 are appropriately smaller than the outer diameters of the insulating tubes (first insulating tubes) 18 and 18.
A spring 30 is disposed between the insulating tubes 28 and 28 and urges the springs in a direction to separate them. The spring 30 may be a conductive material or an insulating material.

Each of the four-probe measuring probes 6 has a cylindrical conductor of the peripheral relay element 10 on a stepped portion 4a, 4a for retaining it formed on the inner peripheral surface of each probe storage hole 4 of the probe storage board 2. The step portions 32 and 32 formed on the outer peripheral surfaces 20 and 20 are prevented from coming off by engaging with each other.
In each of the four-probe measuring probes 6, the cylindrical conductors 20 and 20 constituting the circumferential relay element 10 are elastically formed by the elasticity of the conductive spring 22 and the spring 30. Is stably positioned where it engages with the steps 4a, 4a for retaining.

In addition, electrical conduction is established between both ends of the peripheral relay element 10 of each four-probe measurement probe 6 by a conductive spring 22.
On the other hand, the inner relay element 8 is electrically connected between both ends by a conductive spring 14 between the rod-shaped conductors 12 and 12.

Next, the cable holding board (50) will be described with reference to FIG. 1 (B) showing a state where the cable holding board is assembled to the probe storage board 2.
A cable holding board 50 is formed with cable holding holes 52, 52,... Corresponding to the probe holding holes 4 of the probe storage board 2, and only one of them 52 appears in FIG. . One end of a coaxial cable 54 is inserted and fixed in each cable holding hole 52. The other end of the coaxial cable 54 is connected to a tester circuit not shown in FIG.
56 is a core wire of the coaxial cable 54, 58 is an insulation coating that similarly covers the core wire 56, 60 is a shield wire formed outside the insulation coating 58, and each coaxial cable 54 has a core wire 56, an insulation coating 58 and a shield wire. 60 is inserted and fixed in each probe storage hole 52 so that the end face of 60 is located on substantially the same plane as the one main surface of the cable holding board 50.

One end of the inner relay element 8 of each coaxial cable 54 is connected to the outer end of the other end side bar-shaped conductor (cable holding board 50 side bar-shaped conductor) 12 of the four-probe measurement probe 6 and the peripheral side relay element 10. The cable holding board 50 is positioned with respect to the probe storage board 2 so that one end is in contact with the outer end of the other end side cylindrical conductor (cable holding board 50 side cylindrical conductor) 20 of the four-probe measurement probe 6. And are firmly fixed.
By bringing the main surface of the probe storage board 2 and the main surface of the cable holding board 50 into close contact with each other, the tips of the other end side cylindrical conductor 20 and the other end side bar conductor 12 are brought to the main surface of the cable holding board 50. The springs 22, 14 and 30 are pushed into the probe housing hole 4 against the elastic force of the springs 22, 14 and 30, and the springs 22, 14 and 30 sufficiently store the elastic force. The conductor 12 and the core wire 56 are elastically contacted with the other end side cylindrical conductor 20 and the shield wire 60, and a good electrical connection state can be formed therebetween.

  The insulating tube (first insulating tube) 18 engages with the insulating tube (second insulating tube) 28 that engages with the inner end of the step portion 16, whereby the spring 30 that contacts the insulating tube 28. Due to the elastic force, the positional relationship in the axial direction between the rod-shaped conductor 12 and the cylindrical conductor 20 is regulated, and the positional relationship in the axial direction therebetween is stabilized.

According to such a contact device, each coaxial cable 54 can be electrically connected to the corresponding four-probe measurement probe 6 simply by contact without connection by soldering or the like.
Accordingly, the manufacturing cost of the contact device can be reduced.
Further, since the four-probe measuring probe 6 engages the insulating tube 18 fixed on the outer peripheral surface of the rod-shaped conductor 12 with the insulating tube 28 disposed on the outer peripheral side of the rod-shaped conductor, the spring 30 Due to this elastic force, the positional relationship of the rod-shaped conductor 20 constituting the inner relay element 8 with respect to the cylindrical conductor 20 constituting the circumferential relay element 10 can be stabilized.

Next, the usage mode will be described with reference to FIG. 2 which is a sectional view showing one usage mode of the contact device shown in FIG.
70 is a BGA (ball grid array) type semiconductor device, and 72, 72,... Are solder ball electrodes.
At the time of measurement, the semiconductor device 70 is connected to the contact device 1 shown in FIG. 1 with respect to each solder ball electrode 72 and the corresponding peripheral relay element 10 and rod-shaped conductor 12 of each of the four probe measuring probes 6. The four probe measuring probes 6 and the corresponding solder ball electrodes 72 can be in an electrically connected state by aligning them so that one end of each of them is in contact and appropriately bringing the distance therebetween. As a result, each solder ball electrode 72 and the corresponding coaxial cable 54 can be connected by the contact device 1.
Reference numeral 74 denotes a tester measurement circuit to which the other end of the coaxial cable 54 is connected.
Therefore, the contact device 1 can form a state in which the solder ball electrodes 72, 72,... Of the semiconductor device 70 are electrically connected to the tester circuit 74 via the contact device 1, and measurement is possible. It becomes a state.

  INDUSTRIAL APPLICABILITY The present invention is generally applicable to a four-probe measurement probe used for a contact device used for relaying to connect each electrode of an electronic component such as a semiconductor element and an electronic circuit such as a tester circuit. .

(A), (B) shows one Example of this invention, (A) is sectional drawing which shows the probe for four-probe measurement which comprises the principal part of a contact apparatus, (B) is a probe storage board, It is sectional drawing which shows the state combined with the cable holding board. FIG. 2 is a cross-sectional view showing a state when the contact device shown in FIG. 1 is used.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Contact apparatus, 2 ... Probe storage board, 4 ... Probe storage hole,
4a... Steps for retaining, 6... Four probe measuring probe, 8... Inner relay element, 10... Circumference relay element, 12. Conductive elastic means (spring),
16 ... Stepped portion, 18 ... First insulating tube, 20 ... Cylindrical conductor,
22 ... conductive elastic means (spring), 24 ... stepped portion, 26 ... stepped portion,
28 ... second insulating tube, 30 ... elastic means (spring), 32 ... stepped portion,
50. Cable holding board, 52 ... Cable holding hole, 54 ... Coaxial cable,
56 ... core wire, 58 ... insulator, 60 ... shield wire,
70: Electronic device to be measured (semiconductor device), 72 ... Electrode,
74: Tester circuit (measurement circuit).

Claims (1)

A pair of cylindrical conductors and a pair of cylindrical conductors in a state of being electrically insulated from each other on the outer peripheral side of the inner relay element composed of a pair of rod-shaped conductors and elastic means interposed so as to be urged away from each other. An electrical path from one end of the inner relay element to the other end and the other end from the other end of the peripheral relay element are loosely fitted with elastic means interposed so as to be biased in a direction away from each other. Has an electrical path to the end,
A first insulating tube is fixed to the outer end side of the outer peripheral surface of each bar-shaped conductor of the inner relay element,
An inward engagement step portion is formed by increasing the inner diameter of the inner side from the outer side at a position that is appropriately deviated from the inner side from both outer ends of the inner peripheral surface of each cylindrical conductor of the peripheral side relay element,
Engage with the engaging step at the outer end on the inner peripheral side of each cylindrical conductor on the outer peripheral side of each rod-shaped conductor, and have an inner diameter smaller than the outer diameter of the first insulating tube A second insulating tube that can be engaged with the first insulating tube,
A four-probe measuring probe characterized in that elastic means for urging the second insulating tube in a direction to expand the space is disposed between the second insulating tubes.

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