JP2011052986A - Pin board inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of inspecting a pin board for inspecting electric characteristics of a circuit board. <P>SOLUTION: The inspection method of the pin board 20 inspects electric characteristics of the circuit board and includes a positioning pin 24 positioning the circuit board and a probe pin 26 abutting against an electrode pad of the circuit board. The inspection method includes: a measurement step of measuring relative position of the probe pin 26 relative to the positioning pin 24 when viewing the pin board 20 in plan view; and a comparison step of comparing the measured relative position with a design value of a relative position of the electrode pad relative to a positioning pin hole in the circuit board. The inspection method can precisely measure the accuracy of the pin board 20 itself by inspecting the pin board 20 using the relative position of the probe pin 26 with reference to the position of the positioning pin 24 without using a dedicated tool simulating a work. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for inspecting a pin board itself for inspecting electrical characteristics of a circuit board. In particular, the present invention relates to a method for inspecting a pin board having positioning pins for positioning a circuit board and probe pins that abut on electrode pads of the circuit board.

  A pin board is used when inspecting the electrical characteristics of a circuit board. The pin board is a so-called interface that connects the circuit board inspection device body and the circuit board. Probe pins that contact the electrode pads of the circuit board are attached to the pin board. When inspecting a circuit board, by attaching a pin board to the circuit board and bringing the probe pin into contact with the electrode pad, applying an electrical signal to the electrode pad via the probe pin, or acquiring an electrical signal from the electrode pad Measure the electrical characteristics of the circuit board. If the probe pins on the pin board do not contact the electrode pads on the circuit board with certainty, poor contact will occur and hinder inspection of the circuit board. When inspecting the circuit board, it is necessary to inspect the pin board itself to check whether the probe pin is surely in contact with the electrode pad of the circuit board. Patent Document 1 discloses a technique for inspecting a pin board using a dedicated jig. In this technique, a dedicated jig simulating a circuit board is prepared in advance. It is possible to inspect whether or not the electrode pad and the probe pin are in contact with each other by bringing the probe pin into contact with the electrode pad of the dedicated jig and examining the conduction between the probe pins.

JP 2000-147001 A

  However, even a dedicated jig includes certain manufacturing errors. In addition, an installation error occurs when attaching the dedicated jig and the pin board. In the inspection using the dedicated jig, the result including these errors is acquired, so that the inspection accuracy of the pin board itself may be lowered.

  The present invention was created in view of the above problems. An object of this invention is to provide the method of test | inspecting a pin board, without using a dedicated jig.

The novel pinboard inspection method disclosed in this specification is a method of inspecting a pinboard for inspecting the electrical characteristics of a circuit board. More specifically, this is a method for inspecting a pin board including positioning pins for positioning a circuit board and probe pins that abut on electrode pads of the circuit board. This pinboard inspection method includes the following two steps.
(1) A measuring step of measuring the relative position of the probe pin with respect to the position of the positioning pin when the pin board is viewed in plan.
(2) A comparison step of comparing the measured relative position with the design value of the relative position.

  In this pinboard inspection method, the relative position of the probe pin relative to the position of the positioning pin is compared with the design value of the relative position of the probe pin. Thereby, the quality of the pinboard itself can be determined without preparing a dedicated jig.

  In the novel pinboard inspection method disclosed in the present specification, it is preferable to determine that the pinboard is defective when the difference between the measured relative position and the design value of the relative position is outside the allowable range in the comparison step. .

Moreover, it is preferable that the novel pinboard inspection method disclosed in the present specification includes the following three steps in the measurement step.
(1) A step of measuring absolute positions of a plurality of positioning pins and absolute positions of probe pins in an absolute coordinate system.
(2) A step of obtaining the position of the pin board in the absolute coordinate system and the rotation angle around the pin board vertical line from the absolute positions of the plurality of positioning pins.
(3) A step of converting the absolute position of the probe pin into the relative position of the probe pin with respect to the position of the positioning pin based on the obtained position of the pin board and the rotation angle around the pin board vertical line.

  Image processing is suitable for measuring the relative positions of the probe pins. That is, it is preferable to take a plan view of the pin board with a camera and obtain the position of the positioning pin and the position of the probe pin from the taken image. When shooting a pinboard, it is cumbersome to accurately position the pinboard with respect to the optical axis of the camera. In the above method, the position of the pin board and the rotation angle around the board vertical line in the coordinate system (absolute coordinate system) based on the vertical and horizontal directions of the image are obtained, and the relative position of the probe pin is obtained based on them. There is no need to accurately position the pinboard when shooting. Also, the apparatus used in the novel pinboard inspection method disclosed in this specification is only required to be able to determine the relative positions of the probe pins by image processing or the like, and is formed exclusively for the inspection of the pinboard. There is no need.

  The novel pinboard inspection method disclosed in this specification provides a method for inspecting a pinboard without using a dedicated jig.

FIG. 1 is a schematic side view of the pin board 20. FIG. 2 is a schematic diagram of the inspection device 40 for the pin board 20. FIG. 3 shows a flowchart for inspecting the pin board 20. FIG. 4 is a diagram for explaining processing in the processing device 46. FIG. 5 is a diagram illustrating processing in the processing device 46. FIG. 6 is a diagram for explaining processing in the processing device 46.

  Before describing the inspection method of the pin board 20 of the present embodiment, first, the pin board 20 will be described. The pin board 20 is a so-called interface that connects the apparatus main body for inspecting the electrical characteristics of the circuit board and the circuit board. In this specification, description of the apparatus main body is omitted. FIG. 1 schematically shows a side view of the pin board 20. The pin board 20 includes a base 22 that is an insulating plate material. The base 22 is drilled at positions corresponding to reference holes, electrode pads, and the like on the circuit board 30, and positioning pins 24, probe pins 26, and work receivers 28 are attached to the processed holes. The positioning pin 24, the probe pin 26, and the work receiver 28 extend vertically from the base 22.

  Two positioning pins 24 are provided, one for each of the diagonal positions of the base 22. When the circuit board 30 is inspected using the pin board 20, the circuit board 30 is moved relative to the pin board 20 as indicated by an arrow 32, and the positioning pins 24 are passed through the reference holes of the circuit board 30. The substrate 30 is fixed to the pin board 20. The relative positional relationship between the circuit board 30 and the pin board 20 is fixed by the positioning pins 24.

  The probe pin 26 has electrical conductivity, and is attached to a position corresponding to the electrode pad of the circuit board 30 when the circuit board 30 is fixed to the pin board 20. When the circuit board 30 is inspected using the pin board 20, the tip portion of the pin board 20 contacts the electrode pad of the circuit board 30. The probe pin 26 is connected to the apparatus main body (not shown) on the back surface of the base 22. The apparatus main body inspects the electrical characteristics of the circuit board 30 by applying signals to the electrode pads via the probe pins 26 or acquiring signals from the electrode pads.

  A plurality of workpiece receivers 28 are provided on the base 22. When the circuit board 30 is inspected using the pin board 20, the front end surface of the work receiver 28 comes into contact with the surface of the circuit board 30. As a result, the distance between the pin board 20 and the circuit board 30 is kept at a predetermined distance, and the circuit board 30 is prevented from being excessively pressed against the pin board 20. This prevents the probe pin 26 from being bent or misaligned.

  It is not limited to the above case that the probe pin 26 is bent, misaligned, or the like. The probe pin 26 may be misaligned due to a manufacturing error of the pin board 20 itself. If the probe pin 26 is bent and misaligned, the probe pin 26 may not contact the electrode pad of the circuit board 30 reliably, resulting in poor contact between the electrode pad and the probe pin 26. There is a fear. Therefore, it is necessary to inspect the pin board 20.

  In FIG. 2, the schematic diagram of the test | inspection apparatus 40 used for the test | inspection method of the pin board 20 of a present Example is shown. The inspection device 40 includes a table 42, a camera 44, and a processing device 46. The pin board 20 is placed on the surface 42 a of the table 42. The camera 44 is disposed to face the surface 42 a of the table 42. The camera 44 can move parallel to the surface 42a and can change the focal position in a direction perpendicular to the surface 42a. Therefore, when shooting a three-dimensional shooting object using the camera 44, an image at a specific height of the three-dimensional object can be acquired. For example, when the object to be imaged is the probe pin 26, an image at the tip portion of the probe pin 26 can be acquired. The processing device 46 is connected to the camera 44 via the communication line 48 and controls the shooting position and shooting timing of the camera 44. The processing device 46 acquires image data captured by the camera 44. The processing device 46 processes the acquired image data to check whether the pinboard 20 is normal.

  FIG. 3 is a flowchart showing the inspection steps of the pin board 20 by the processing device 46. Hereinafter, the flow of inspection of the pin board 20 by the processing device 46 will be described along the flowchart shown in FIG.

  First, the pin board 20 is placed on the surface 42a of the table 42 (S2), and the camera 44 is used to photograph the pin board 20 (S4). In step S4, photographing is repeated while the camera 44 is translated by a predetermined amount determined by the visual field area of the camera 44 with respect to the pin board 20, and photographing of the entire area of the pin board 20 is performed. The captured image data is input to the processing device 46 via the communication line 48. In the processing device 46, the captured image data is stored in association with the shooting position information of the camera 44. Thereby, in the processing device 46, the image data is stored in association with the coordinate data in the absolute coordinate system of the inspection device 40. When photographing the pin board 20, it is not necessary to accurately position the pin board 20 with respect to the optical axis of the camera 44. As will be described later, the relative position of the probe pin 26 with respect to the positioning pin 24 is calculated in consideration of the position and inclination of the pinboard 20 in the acquired image data (rotation angle around the vertical line of the pinboard 20). Because it does.

  Next, the processing device 46 identifies the positioning pin 24 and the probe pin 26 included in the image data (S6). The processing device 46 stores image data of the positioning pins 24 and the probe pins 26 or image data features (hereinafter referred to as feature data) in advance. The processing device 46 identifies a part that matches the feature data from the captured image data. Further, the processing device 46 measures the coordinate data of the positioning pin 24 and the probe pin 26 from the specified part (S8). For example, when the specified part is image data having a circular shape, the coordinate data of the center point of the circular shape is measured. As a result, the processing device 46 acquires coordinate data D of the positioning pin 24 and coordinate data group D (see FIG. 4) which is the coordinate data of the probe pin 26 in the absolute coordinate system of the inspection device 40.

  Next, the processing device 46 specifies the position P of the pin board 20 and the rotation angle θ around the vertical line of the pin board 20 from the acquired coordinate data of the positioning pin 24 (S10). As shown in FIG. 4, the processing device 46 identifies the coordinate data of the first positioning pin 24 a among the coordinate data of the positioning pin 24 as the position P of the pin board 20. Further, the processing device 46 specifies the angle formed by the straight line K connecting the first positioning pin 24 a and the second positioning pin 24 b and the X axis in the absolute coordinate system as the rotation angle θ around the vertical line of the pin board 20.

Next, the processing device 46 calculates the relative position M of the probe pin 26 with reference to the position of the positioning pin 24 using the acquired coordinate data group D (S12). The processing device 46 performs conversion for subtracting the coordinate data of the position P of the pinboard 20 from each of the acquired coordinate data group D. Thereby, as shown in FIG. 5, the first positioning pin 24a is converted into the origin O, and the coordinate data group D is converted into the conversion data group D1. Further, the processing device 46 stores in advance a rotation angle θo that is a design value of the rotation angle θ. The processing device 46 calculates a difference rotation angle (θ−θo) between the identified rotation angle θ and the design value of the rotation angle θo. Then, the processing device 46 performs conversion by rotating each of the conversion data group D1 around the origin O by a difference rotation angle (θ−θo). Thereby, as shown in FIG. 6, the conversion data group D1 is converted into the conversion data group D2. By the above conversion, the first positioning pin 24a and the second positioning pin 24b are converted into designed positions.
The processing device 46 acquires the position of the probe pin 26 in the conversion data group D2 as the relative position M of the probe pin 26 with the position of the positioning pin 24 as a reference. The above steps S2 to S12 can be referred to as a measurement process for measuring the relative position M of the probe pin.

  In the processing device 46, as indicated by a dotted line in FIG. 6, a design value J of the relative position of the probe pin 26 is stored in advance. The processing device 46 compares the acquired relative position M of the probe pin 26 with the design value J of the relative position (S14). In the processing device 46, an allowable range determined in advance based on the width of the electrode pad of the circuit board 30 is set in advance. The processing device 46 detects, for each probe pin 26, whether or not the acquired relative position M of the probe pin 26 is included in an allowable range centered on the design value J of the relative position. The processing device 46 determines that the probe pin 26 is normal when the acquired relative position M of the probe pin 26 is within the allowable range. Further, the processing device 46 determines that the probe pin 26 is defective when the acquired relative position M of the probe pin 26 is not within the allowable range.

  The processing device 46 determines pass / fail of the pin board 20 based on the determination result of the probe pin 26 in step S14 (S16). The processing device 46 determines that the pin board 20 is normal when it is determined that all the probe pins 26 included in the pin board 20 are normal. If the probe board 26 determined to be defective exists in the pin board 20, it is determined that the pin board 20 is defective. If the pin board 20 is determined to be defective, the probe pin 26 determined to be defective in step S14 is inspected in more detail, and necessary measures such as replacement or correction of the probe pin 26 are performed.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. In the above embodiment, the relative position M of the probe pin 26 with respect to the position of the positioning pin 24 is obtained by converting the absolute position data of the positioning pin 24 and the probe pin 26 corresponding to the design value. However, the reverse is also possible. That is, the reference value indicating the normal position of the probe pin 26 corresponding to the measured absolute position data may be measured by converting the design value corresponding to the measured absolute position data. The pin board 20 can be inspected by comparing the reference value with the measured absolute position data.

  In addition, the scale of the design value may be different from the scale of the measured absolute position data. In such a case, it is preferable to further execute a process for enlarging or reducing the design value in accordance with the measured absolute position data. Thereby, the scale of the design value becomes equal to the scale of the measured absolute position data, and the pin board 20 can be inspected more accurately.

  It is also preferable to compare the measured relative position of the probe pin 26 with the design value of the relative position of the electrode pad with respect to the reference hole (positioning pin hole on the circuit board) of the circuit board, not the design value of the probe pin 26. It is. In this case, in the comparison step, if the difference between the measured relative position and the design value of the relative position of the electrode pad is outside the allowable range, the pinboard may be determined to be defective. The following advantages can be obtained by determining the quality of the pin board based on the design position of the electrode pad (more precisely, the design value of the relative position between the positioning pin hole and the electrode pad). For example, the position of the electrode pad on the actual circuit board may deviate from the designed position. Such a circuit board is preferably judged to be defective in the inspection of the board. If a circuit board in which the actual electrode pad position deviates from the designed position is attached to the pin board inspected based on the design position of the electrode pad, the probe and the electrode pad do not come into contact with each other correctly. A contact failure is detected in the substrate inspection. That is, if a pin board inspected based on the design of the electrode pad is used, it is possible to determine a defective circuit board in which the position of the electrode pad is deviated from the design value.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

20: Pin board 22: Base 24: Positioning pin 26: Probe pin 28: Workpiece receiver 30: Circuit board 40: Inspection device 42: Base 44: Camera 46: Processing device M: Relative position of probe pin 26 J: Relative position Design value P: Pinboard position θ: Angle of rotation around pinboard vertical line

Claims (3)

A pin board for inspecting electrical characteristics of a circuit board, and a method for inspecting a pin board comprising positioning pins for positioning the circuit board and probe pins abutting on the electrode pads of the circuit board,
A measurement process for measuring the relative position of the probe pin with respect to the position of the positioning pin when the pin board is viewed in plan view;
A comparison process for comparing the measured relative position with the design value of the relative position;
A pinboard inspection method comprising:   The pinboard inspection method according to claim 1, wherein, in the comparison step, the pinboard is determined to be defective when a difference between the measured relative position and a design value of the relative position is outside an allowable range. The measurement step includes
Measuring the absolute position of a plurality of positioning pins and the absolute position of probe pins in an absolute coordinate system;
Obtaining the pinboard position in the absolute coordinate system and the rotation angle around the pinboard vertical line from the absolute position of the plurality of positioning pins;
Converting the absolute position of the probe pin into the relative position of the probe pin with respect to the position of the positioning pin based on the obtained position of the pin board and the rotation angle around the pin board vertical line;
The pin board inspection method of Claim 1 or 2 containing these.

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