JP2008224586A - Inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device dispensing with teaching by an operator, capable of keeping always a proper contact state between a probe and an electrode pad. <P>SOLUTION: In this inspection device, at least either of an inspection object and the probe is moved vertically, and the probe is brought into contact with the electrode pad of the inspection object, to thereby inspect the inspection object. The device is equipped with a pressure sensor for detecting a contact pressure between the electrode pad and the probe, and a control part for controlling vertical movement of the inspection object or the probe based on a detection result by the pressure sensor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inspection apparatus for inspecting an inspection object by moving at least one of the inspection object or the probe up and down and bringing the probe into contact with an electrode pad to be inspected.

  Patent Document 1 discloses a technical disclosure of an IC tester that performs inspection by moving an IC to be inspected upward and bringing a probe of an inspection device into contact with an electrode pad of the IC.

  FIG. 3 is a functional block diagram showing a configuration example of a conventional inspection apparatus. The object to be inspected is the flat panel 1, and the probes 31 to 3n installed on the contactor 4 descending from above are in contact with the plurality of electrode pads 21 to 2n formed on the upper surface of the panel.

  The probes 31 to 3n are electrically connected to the inspection device 5, and various inspections are performed by the inspection device. The probes 31 to 3n have a certain degree of spring characteristics so as not to damage the flat panel 1 when contacting the electrode pads 21 to 2n.

  The inspection device 5 includes diagnostic means 51 for self-diagnosis that the contact between all the probes and all the electrode pads is normal before the start of the inspection. The diagnosis result is displayed on the display unit 6 and the operator 7 Monitoring is possible. In the self-diagnosis, an open check between the probe and the electrode pad, a short-circuit check with an adjacent electrode pad, an internal resistance check, and the like are executed.

  As a method of bringing the probes 31 to 3 into contact with the electrode pads 21 to 2n, the contact mechanism 81 coupled to the contactor 4 is operated up and down in the Z-axis direction. The contact mechanism includes a contact mechanism 81 coupled to the contactor 4 and a contact mechanism 83 coupled to the contact mechanism 81 via a connecting member 82.

  The contact mechanism 83 is coupled to the rotating shaft of the motor 10 fixed to the support housing 9 with a ball screw, and is operated up and down in the direction of arrow P (Z-axis direction) by rotating the motor. The operation command Ma of the lower operation means 11 of the motor 10 and the operation command Mb of the upper operation means 12 of the motor 10 are selectively supplied to the motor 10 via the changeover switch 13.

  In the Z-axis position operation of the contactor 4, the operator 7 monitors the self-diagnosis result of the diagnostic means 51, and determines the position where the contact with the electrode pad of the flat panel is good in advance. Then, the operator 7 performs teaching to set a setting value T for outputting the operation command Ma of the lower operation means 11.

JP 2000-162282 A

The Z-axis position operation of the contactor 4 by the conventional teaching method has the following problems.
(1) Due to the sag in the height direction due to the deterioration of the probe over time, a contact abnormality with the electrode pad occurs, and an abnormal state in which the inspection is not properly executed gradually becomes. This abnormal state may not be detected by the self-diagnosis means 51 that executes the various checks described above.

(2) If there is a teaching mistake by the operator, the inspection result becomes unstable due to insufficient contact.

(3) When switching the inspection object to a new type, it is necessary to reset the teaching setting, which is complicated and prone to errors.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to realize an inspection apparatus that does not require teaching by an operator and can always maintain an appropriate contact state between a probe and an electrode pad.

In order to achieve such a subject, the present invention has the following configuration.
(1) In an inspection apparatus for inspecting an inspection object by moving at least one of the inspection object or the probe up and down, bringing the probe into contact with the electrode pad of the inspection object,
A pressure sensor for detecting a contact pressure between the electrode pad and the probe;
Based on the detection result of the pressure sensor, a control unit that controls the vertical movement of the inspection target or the probe;
An inspection apparatus characterized by comprising:

(2) The semiconductor inspection apparatus according to (1), wherein the control unit controls the position of the inspection target or the probe so that a detection value of the pressure sensor becomes a predetermined pressure setting value. .

(3) The control unit uses a pressure setting value calculated based on a mass of a probe support mechanism that supports the probe, the number of the probes, and characteristics of the probe, according to (2). Semiconductor inspection equipment.

(4) In an inspection apparatus for inspecting an inspection target by moving at least one of the inspection target or the probe up and down, bringing the probe into contact with the electrode pad of the inspection target,
An inspection apparatus comprising a fluid pressure thrusting means for bringing the object to be inspected into contact with the probe by a thrust generated based on a predetermined command value.

(5) The inspection apparatus according to (4), wherein the fluid pressure thrusting unit uses a command value calculated based on the number of the probes, the characteristics of the probes, and a predetermined offset value.

(6) The inspection apparatus according to (4) or (5), wherein the fluid pressure thrusting means is an air buffer means for generating air pressure based on the command value.

According to the present invention, the following effects can be expected.
(1) Regardless of the deterioration of the probe over time, the probe can always be brought into contact with the electrode pad at an appropriate pressure.

(2) Subtle teaching work by the operator, which has been necessary in the past, is no longer necessary, and stable inspection results can be obtained only by simple pressure setting.

(3) Even when the inspection object is switched to a new type, it is not necessary to perform the teaching setting reworking operation that has been required in the past, and it is possible to reduce inspection abnormalities due to work mistakes.

  The present invention will be described in detail below with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of an inspection apparatus to which the present invention is applied. The same elements as those of the conventional inspection apparatus described with reference to FIG.

  The structural features of the present invention are the pressure sensor 100 and the control unit 200. The contact mechanism 81 that supports the contactor 4 is connected to the contact mechanism 83 via the connecting portion 82 and the LM guide 84. The contactor 4 and the contact mechanism 81 form a probe support mechanism.

  On the support member 85 extended from the bottom of the contact mechanism 83 to the lower part of the contact mechanism 81, a pressure sensor 100 such as a load cell is installed so as to receive the weight of the contact mechanism 81. The detection value Pi of the pressure sensor 100 is input to the control unit 200.

  The control unit 200 includes a target value calculation unit 201, a subtracter 202, a pressure control unit 203, and a motor driver 204. The subtractor 202 calculates a deviation e between the pressure detection value Pi and the pressure target value Ps and passes it to the pressure control means 203.

  The pressure control means 203 executes a control calculation based on the deviation e from the subtracter 202 and outputs a downward operation command Ma to the motor 10 via the motor driver 204 to operate the contact mechanism 83 downward. By this downward operation, the contact mechanism 81 to be connected is lowered.

  When the contact mechanism 81 is lowered to a position where the probe and the electrode pad are in contact, the detection value Pi of the pressure sensor 100 is reduced by receiving the repulsive force of the spring provided in the probe itself from the point where the probe and the electrode pad start to contact.

  If the feedback control by the control unit 200 is performed so that the pressure detection value Pi at this time becomes equal to the appropriate pressure target value Ps, the contact pressure between the probe and the electrode pad can always be maintained at an appropriate value.

The target value calculation means 201 calculates the optimum contact pressure target value Ps, and the contact mechanism 81 and the mass M of the contactor 4 that are set (the mass of the contactor 4 is much higher than the mass of the contact mechanism 81). If it is smaller, the mass of the contactor 4 may be ignored.), The number of probes n and the spring constant k of the probe are input, and the target value Ps is expressed by the following formula: Ps = M−n · k
Calculate and output based on. M, n, and k are all constants, and therefore Ps is a constant value.

  FIG. 2 is a functional block diagram showing another embodiment of the inspection apparatus to which the present invention is applied. The feature of this embodiment in comparison with the embodiment of FIG. 1 is that the contact pressure control by feedback control is realized, and an appropriate contact pressure is realized by an open loop thrust generating means.

  The contactor 4 is supported by the contact mechanism 86. The contact mechanism 81 is coupled to the contact mechanism 86 via an air buffer means 300 that forms a thrust generating means. The contact mechanism 86 is displaced in the Z-axis direction indicated by the arrow Q by the air pressure input to the air buffer means 300, and changes the contact pressure between the probe and the electrode pad.

  The air pressure input to the air buffer means 300 is set by the electropneumatic regulator 400 using the command value Pa. This command value Pa is calculated by the command value calculation means 500. The contact mechanism 81 is operated to an appropriate position according to the setting S of the lower operation means 11 set by the operator 7.

The command value calculation means 500 inputs the number n of probes, the spring constant k of the probe, and the offset value α, and determines the command value Pa by the following formula: Pa = n · k + α
Calculate and output based on. n, k and α are all constants, and therefore Pa is also a constant value.

  As the thrust generating means, various thrust generating means that are commercially available as actuators such as joint mechanisms, such as an actuator means that operates by fluid pressure, as well as an air buffer means that operates by air pressure, can be adopted.

  In the embodiment of FIG. 2 that features contact loop control by open loop, the control accuracy is lower than the contact pressure control by feedback control of FIG. 1, but at a lower cost by using a commercially available product that can ensure practical accuracy. There is an advantage that a highly reliable inspection system can be realized.

  In the embodiment described above, the inspection object is described as a flat panel. However, the present invention is applicable to all inspection apparatuses in which a probe is brought into contact with an electrode pad such as an IC chip on a wafer transferred by a handler or the like.

It is a functional block diagram showing one embodiment of an inspection device to which the present invention is applied. It is a functional block diagram which shows other embodiment of the test | inspection apparatus to which this invention is applied. It is a functional block diagram which shows the structural example of the conventional inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flat panel 21-2n Electrode pad 31-3n Probe 4 Contactor 5 Inspection apparatus 51 Diagnosis means 6 Display part 7 Operator 81, 83 Contact mechanism 82 Connection part 84 LM guide 85 Support member 10 Motor 12 Upper operation means 13 Changeover switch 100 Pressure Sensor 200 Control unit 201 Target value calculation means 202 Subtractor 203 Pressure control means 204 Motor driver

Claims (6)

In the inspection apparatus for inspecting the inspection object by moving at least one of the inspection object or the probe up and down, bringing the probe into contact with the electrode pad of the inspection object,
A pressure sensor for detecting a contact pressure between the electrode pad and the probe;
Based on the detection result of the pressure sensor, a control unit that controls the vertical movement of the inspection target or the probe;
An inspection apparatus characterized by comprising:   The semiconductor inspection apparatus according to claim 1, wherein the control unit controls the position of the inspection target or the probe so that a detection value of the pressure sensor becomes a predetermined pressure setting value.   3. The semiconductor inspection according to claim 2, wherein the control unit uses a pressure setting value calculated based on a mass of a probe support mechanism that supports the probe, the number of the probes, and characteristics of the probe. apparatus. In the inspection apparatus for inspecting the inspection object by moving at least one of the inspection object or the probe up and down, bringing the probe into contact with the electrode pad of the inspection object,
An inspection apparatus comprising a fluid pressure thrusting means for bringing the object to be inspected into contact with the probe by a thrust generated based on a predetermined command value.   The inspection apparatus according to claim 4, wherein the fluid pressure thrusting unit uses a command value calculated based on the number of the probes, the characteristics of the probes, and a predetermined offset value.   6. The inspection apparatus according to claim 4, wherein the fluid pressure thrusting means is an air buffer means for generating air pressure based on the command value.

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