JP3088146B2 - Substrate inspection method and substrate used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the disconnection or short circuit of a pattern on a substrate such as a printed circuit board, and corrects the positional deviation even if the pattern is slightly deviated from a predetermined position. It relates to a method of inspecting.

[0002]

2. Description of the Related Art In general, a board inspection apparatus for electrically inspecting a printed board includes a head section having a large number of contact probes for making contact with a board to be inspected, and a control section for sequentially applying an inspection voltage to the contact probes. And a mechanism for moving the head and the substrate.

In recent substrates, the pattern density has been increasing,
The pattern interval is 0.5mm pitch, and 0.3
Standards with a pitch of less than mm have also emerged. In such a high-density substrate, the wiring pattern may be deviated from a predetermined position in design or the like in a manufacturing process. Such a positional deviation is a positional deviation from a predetermined position with respect to a guide hole serving as a reference of the position of the substrate, and may be a double-sided substrate. The direction of the positional deviation may be a displacement in a parallel movement direction (X-axis direction, Y-axis direction), a rotation movement direction (θ-axis direction), or all directions (X-axis direction, Y-axis direction) in a plane including the substrate. , Θ axis direction).

[0004] In this way, when the pattern of the substrate is displaced, the contact probe is displaced from the high-density pattern even if the positional deviation is within the allowable range in the specification of the product. It is easy to get upset.

[0005] If a contact failure occurs between the pattern and the contact probe, even if it is a normal substrate, it appears as if there is an inconsistency in the pattern. . To do so, the manual alignment must be accurate,
There has been a problem that work efficiency is poor due to recent labor shortage.

Recently, it has been proposed to use a camera to perform automatic position adjustment as a method for automating such a fine position adjustment operation. However, such an apparatus requires a high-resolution camera provided on a two-axis moving table and an image processing apparatus for processing an image by the camera and detecting a positional shift. The camera and the image processing apparatus have new problems in that they require a large space occupied by the apparatus and that the cost of the apparatus increases.

Therefore, in the present invention, the position shift can be performed in a short time and automatically by using the function of the moving table already provided without using a camera or an image processing apparatus requiring a lot of space and cost. It is intended to provide a method that can be corrected.

[0008]

In order to achieve the above object, there is provided a substrate inspection apparatus for inspecting a substrate having a pattern formed on a surface thereof, wherein the substrate has a relative position between the shape of the substrate and the pattern. The board inspection apparatus includes a moving unit capable of relatively moving the substrate and the head unit, and inspects continuity and non-conductivity at each position of the pattern on the substrate to pass / fail. In a substrate inspection apparatus having a determination unit for determining, if the determination result of the substrate is rejected, by relatively slightly moving the substrate or the head unit by the moving unit,
Perform a re-inspection after slightly displacing the relative position between the board shape and the pattern, and if the re-inspection gives a rejection result, make a final decision of rejection on the board and pass it by re-inspection When the judgment result is obtained, a final judgment of passing is made for the substrate.

In the determination means, reject data appearing through each inspection probe when actually inspecting a substrate to be inspected is made to correspond to correction data obtained in advance using a reference substrate. Inspected. Also,
In the determination means, reject data appearing via each inspection probe when actually inspecting the substrate to be inspected,
The inspection is performed in correspondence with the correction data obtained in advance by the simulation of the CAD for preparing the board inspection jig.

A substrate inspection apparatus for inspecting a substrate having a pattern formed on a surface thereof, wherein the substrate includes a relative displacement between the shape of the substrate and the pattern. Moving means capable of relatively moving the substrate to be inspected and the head unit having the inspection probe, and determining means for inspecting continuity and non-conductivity at each position of the pattern on the substrate to determine pass / fail. A predetermined check pattern is provided on the substrate, and four check probes spaced apart from each other are provided at positions corresponding to the vicinity of the periphery of the check pattern. Then, one confirmation probe is provided at a position corresponding to the center of the confirmation pattern, and the confirmation pattern of the substrate is inspected by the five confirmation probes. ,Previous And configured to determine the direction of relative displacement shape and pattern of the substrate in the substrate.
Further, the configuration is such that a pattern for confirming a predetermined arrangement is provided at a predetermined position.

[0011]

According to the present invention, when the board is set on the head of the inspection apparatus, the judgment result of the board is incorrect because the pattern of the board is slightly shifted within the allowable range in the product standard. When the pass data is detected, when the re-inspection is performed by moving the substrate side or the head portion relatively by the moving means in the direction and the amount corresponding to the positional deviation, the reject data due to the cause is ,
No longer detected.

[0012] Even if the direction and amount of the positional deviation of the pattern on the substrate are unknown, the inspection is repeated while moving in a small amount in various directions, thereby eliminating the rejected data and setting a correct set state. Is also possible. Because, if there is a disadvantage of conduction / non-conduction in the substrate itself,
This is because no matter how much the positional deviation is corrected, the reject data does not disappear, but if the reject data is caused by a positional deviation within the standard range of the pattern of the substrate, it should disappear if the positional deviation is corrected.

However, if the position of the pattern is out of the standard range, it is rejected.

Even if such re-inspection is repeated a predetermined number of times, if reject data is detected, a final judgment of rejection is made for the board. Alternatively, if the inspection in the portion of the pattern for confirmation passes, but there is a rejection in the other portion, the board may make a final determination of rejection.

Although the direction and amount of the positional deviation of the pattern of the substrate are unknown, the appearance of the reject data is corrected in advance by moving the probe in various directions with respect to the reference substrate. The moving direction and the amount may be determined in advance as data, and the appearance of the rejected data appearing in the actual inspection is made to correspond to the correction data.

Alternatively, it can be determined by simulation of a CAD for manufacturing a board inspection jig. Alternatively, when providing the pattern for confirmation,
It is also possible to determine the arrangement of the probes to be brought into contact with the pattern, and obtain the relationship between the appearance of rejected data in the probes and the direction of the positional deviation. For example, 5
The four probes are arranged in a cross shape, and in a state where there is no displacement, a pattern is provided on the substrate so that all of the five probes are in contact with each other and are mutually conductive. By monitoring which probe deviates from the pattern and becomes non-conductive, the direction of the positional deviation and the degree of the positional deviation can be known.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a substrate inspection method according to the present invention. In FIG. 1, reference numeral 1 denotes a substrate to be inspected, and a surface having a high pattern density is set on the upper side. Reference numeral 2 denotes a fixed head unit on which a contact probe on the lower surface is set, and 3 denotes a moving head unit 3 on which a contact probe on the upper surface is set. A moving table 4 provided with the moving head unit 3 moves in the positive and negative directions of the X axis. An X-axis direction moving unit 41 for moving, a Y-axis direction moving unit 42 for moving the moving table in the positive and negative directions of the Y axis, and a θ-axis direction moving unit 43 for rotating the moving table in the positive and negative directions around the θ axis. Allows three-axis movement. These X
The axial moving section 41, the Y-axis moving section 42, and the θ-axis moving section 43 have built-in pulse motors.

Reference numeral 5 denotes a pulse motor driver for driving the X-axis direction moving unit 41, Y-axis direction moving unit 42, and θ-axis direction moving unit 43; 6, a controller for controlling the pulse motor driver 5; Controller 6, pulse motor driver 5
The moving head 4 is controlled by controlling the moving table 4
Is a measurement control unit that moves a desired amount in a desired direction. The control program includes a reference data program P1 for obtaining standard data from a reference board, and inspection data obtained from the jig to determine whether the board is acceptable or not. An inspection program P2 for correcting the position by moving the head unit 3 and re-inspection is provided. The measurement control unit 7 can be configured by a fuzzy control unit incorporating a fuzzy control program.

In the substrate inspection method having the above structure, first,
Activate the reference data program P1. Then, the reference substrate used for the jig manufacturing operation is set in the inspection apparatus, and the standard data is read and stored in the memory 71. Alternatively, standard data serving as a reference such as CAD data read from an external device is stored in the memory 71. The standard data is, for example, data for specifying the numbers of the four probes near the four corners of the substrate and the numbers of the probes near the center.

Next, the X-axis moving section 41 of the moving table 4 is controlled via the controller 6 and the pulse motor driver 5 to move the moving head section 3 in the positive direction of the X-axis.
A little. Here, the board is inspected to obtain board inspection data. If no reject data appears in the inspection data, the moving head unit 3 is further shifted.

When the reject data appears, the number of the probe in which the reject data appears and the X from the reference position at that time.
The amount of movement of the movement table in the positive direction of the axis is stored in the memory 71. The above steps are also performed for the X-axis negative direction, the Y-axis positive / negative direction, and the θ-axis positive / negative direction, and six sets of correction data are stored in the memory 71.

The correction data includes data indicating in which direction and how much the state is shifted from the reference position when reject data appears on which probe. That is, the appearance pattern of the rejected data and the corresponding moving direction and moving amount differ depending on the pattern on the substrate.

This correction data is, for example, the 4
Reject data appears on four probes near the corner,
If no reject data appears for the probe near the center,
Rotate and move by θ (a) about the θ axis. Similarly, three of the four probes near the four corners of the substrate
When the reject data appears only in the book, it is rotated by θ (b) around the θ axis. At this time, θ (a)> θ
(B). As described above, there is a manner in which the reject data appears depending on the pattern of the substrate.

The above correction data is obtained from the CA
It can also be obtained by simulation in D. Alternatively, it is also possible to obtain correction data in advance on a substrate provided with a pattern for confirming a positional deviation.

Next, the inspection program P2 is activated to perform the inspection. The inspection program P2 will be described with reference to FIG. [S1] The substrate to be inspected is set in the inspection apparatus, the data obtained from each probe is inspected, and if the inspection result passes, the next substrate is set. [S2] As a result of the inspection, if rejected data appears, the way of appearance of the rejected data is compared with the way of appearance of rejected data of the correction data stored in the memory 71. The correction data in the state indicating the closest condition is extracted. The correction data includes the direction to be corrected (X axis,
(The positive and negative directions of the Y axis and the θ axis) and the amount of movement to be corrected. In the direction to be corrected, the moving head unit 3 is moved by a moving amount corresponding to the moving amount to be corrected. [S3] Next, after being moved, the substrate is inspected again in the same manner as described above. [S4] If the rejection data does not appear in the re-inspection, it is determined that the cause of the rejection data is a positional deviation in the set state, and the rejection is canceled and the rejection is determined. [S5] As a result of the re-inspection, the board is determined to be unacceptable if the rejection data does not disappear even if the above-mentioned position movement and re-inspection are repeated a prescribed number of times, for example, once or twice.

The position correction in the inspection program P2 can be realized by fuzzy control.

As shown in FIG. 4, a rectangular confirmation conductive pattern 11 is formed on the substrate 1 in addition to the guide holes 12 and 13 for position reference, and the confirmation conductive pattern 11 5 probes 31 and 3 corresponding to 11
2, 33, 34 and 35 may be arranged. At this time, if the entire pattern on the substrate 1 is displaced within the probe interval in the positive direction of the X-axis, the probe 35
Becomes non-conductive with the other probe and is displaced in the negative direction of the X-axis, the probe 33 becomes non-conductive with the other probe, and is displaced in the positive direction of the Y-axis. Becomes non-conductive with other probes and is displaced in the negative direction of the Y-axis, the probe 32 becomes non-conductive with other probes. Because it becomes non-conductive,
The direction and amount of each position shift can be known.

Further, by disposing the above-described conductive patterns for confirmation 11 at both end portions of the substrate, etc., it is also possible to detect a rotational shift of the substrate 1 in the θ-axis direction.

As described above, according to the board inspection method of the present invention, the displacement of the set position of the board can be detected and the position can be corrected without the conventional image processing system having a camera. . Therefore, a device capable of accurately inspecting even a high-density substrate in which rejection data is erroneously detected due to poor contact even if there is a slight displacement of the pattern of the substrate, including hardware such as a camera. The effect is that it can be realized inexpensively and simply.

Further, since it is not necessary to move the camera on the moving table, it takes no time to correct the position. Further, by controlling the position correction by fuzzy control, the position can be corrected at a higher speed than the detection and correction of the position shift by the image processing.

[0031]

As described above, according to the substrate inspection method of the present invention, an apparatus capable of inspecting a high-density substrate at high speed without hardware such as a camera can be manufactured inexpensively and simply. The effect of being able to provide is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a schematic configuration of an inspection apparatus used for a substrate inspection method of the present invention.

FIG. 2 is a configuration diagram when a control device in the board inspection method of the present invention is realized by fuzzy control.

FIG. 3 is a schematic flowchart of an inspection program in the embodiment of the substrate inspection method of the present invention.

FIG. 4 is a plan view showing an arrangement of a substrate and a main part of a probe used in the substrate inspection method of the present invention.

[Description of Signs] 1 Substrate to be inspected 11 Confirmation pattern 2 Fixed head section with probe set 3 Moving head section with probe set 4 Moving table (moving means) 7 Measurement control section (judging means) S1 Inspect S2 Move the board slightly S3 Re-inspect the board S4 Final judgment of pass S5 Final judgment of reject

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 31/02 G01R 1/06-1/073 G01R 31/28 H05K 3/00

Claims (5)

(57) [Claims] 1. A substrate inspection apparatus for inspecting a substrate having a pattern formed on a surface thereof, wherein the substrate includes a relative displacement between a shape of the substrate and a pattern. A board inspecting apparatus comprising: a moving unit capable of relatively moving the substrate and the head unit; and a judging unit for judging pass / fail by inspecting continuity and non-conductivity at each position of the pattern of the substrate. In the case where the determination result of the substrate is rejected, the relative position between the shape of the substrate and the pattern is slightly shifted by relatively moving the substrate or the head portion by the moving means. Perform a re-inspection, make a final decision of rejection for the board if rejection results in rejection, and make a final decision of rejection for the board if re-inspection results in rejection. Substrate inspection method, characterized by being configured to Suyo. 2. The method according to claim 1, wherein the rejection data appearing through each inspection probe when actually inspecting the substrate to be inspected is associated with correction data obtained in advance using a reference substrate. 2. An inspection is performed.
3. The method for inspecting a substrate according to claim 1. 3. The determination means according to claim 1, wherein said reject data appearing through each inspection probe when actually inspecting the substrate to be inspected is corrected data obtained in advance by simulation of a CAD for producing a substrate inspection jig. 2. The method for inspecting a substrate according to claim 1, wherein the inspection is performed in correspondence with the following. 4. A substrate inspection apparatus for inspecting a substrate having a pattern formed on a surface thereof, wherein the substrate includes a relative displacement between a shape of the substrate and a pattern. Moving means capable of relatively moving the substrate to be inspected and the head unit having the inspection probe, and determining means for inspecting continuity and non-conductivity at each position of the pattern on the substrate to determine pass / fail. A predetermined check pattern is provided on the substrate, and four check probes spaced apart from each other are provided at positions corresponding to the vicinity of the periphery of the check pattern. In the position corresponding to the center of the confirmation pattern,
A probe for book confirmation is provided, and the pattern for confirmation of the board is inspected by the five probe for confirmation, whereby the shape of the substrate on the board and the direction of relative displacement of the pattern are examined. A board inspection method characterized by comprising: 5. The substrate used in the inspection method according to claim 4, wherein a pattern for confirming a predetermined arrangement is provided at a predetermined position.