JP2000266799A - Printed circuit board inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable inspection, even if a density of the point of a test object on a printed circuit board to be inspected is high. SOLUTION: Inspection probe pins PB to the number corresponding to the number of inspection points of a wiring pattern on a board 4 are planted on a lower-part inspection jig 2B. The probe pins PB are in electrical contact with base parts PB', and the probe pins PB or the base parts PB' have springs within, and the probe pins PB have a enough length for the heads thereof to be exposed to the surface of a protective board. A distribution density of the head parts of the probe pins PB is smaller than that of the root parts thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board inspection apparatus, and more particularly to an apparatus capable of performing an inspection even when the density of points to be inspected on a printed circuit board to be inspected (hereinafter simply referred to as a substrate) is high. It is.

[0002]

2. Description of the Related Art Conventionally, a guide pin erected on an inspection jig is inserted into a guide hole provided on a substrate, thereby obtaining
The position of the inspection jig and the substrate has been adjusted, but in order to cope with a printed circuit board having an increasingly higher density, it has become necessary to achieve more accurate and quicker alignment. Therefore, Japanese Patent Application Laid-Open No. 1-184473 discloses an apparatus that can detect the relative positional shift between the upper inspection jig and the substrate by using a camera and image processing technology, and finely adjust the position by using an XYθ axis movable table. No. 1
180780.

Further, in Japanese Patent Application No. 9-162950, when correcting the positional deviation between the upper inspection jig and the substrate, the substrate is held so that the substrate does not move slightly from the state where the positional deviation is measured. There has been proposed an inspection apparatus having means for performing the above. The present invention has been made with the object of providing a technique for applying the displacement correction technique proposed by the above-described invention to the inspection of even higher-density substrates.

[0004]

According to claim 1 of the present invention,
The probe pin held by the jig is pressed by a pressing means to the wiring pattern formed on the inspected printed circuit board so as to make electrical contact with the wiring pattern formed on the inspected printed circuit board. In a printed circuit board inspection device configured to perform a continuity inspection, an adjustment mechanism is provided for aligning the inspected printed circuit board with the tip of a probe pin, and the inspected printed circuit board and the jig are connected to each other. A protective plate that is in close contact with the printed circuit board to be inspected in the pressed state is interposed therebetween, and a tip of the probe pin is disposed so as to penetrate the protective plate and electrically contact the printed circuit board to be inspected, The distribution density of the tip of the probe pin on a part of the protection plate surface is larger than the distribution density of the root of the probe pin on the jig surface. It is. In claim 2,
There is provided a first urging means for urging the printed circuit board in a direction to separate the printed circuit board from the jig with an urging force weaker than the pressing force. According to a third aspect of the present invention, there is provided a second urging means for urging the protection plate in a direction to separate the protection plate from the jig with an urging force weaker than the pressing force. In claim 4,
4. The printed circuit board inspection apparatus according to claim 1, further comprising: an imaging unit configured to capture an image of a surface of the inspected printed circuit board; Detecting means for detecting a large positional deviation, and the adjusting mechanism is configured to align the printed circuit board to be inspected with the tip of the probe pin based on the detected positional deviation. According to a fifth aspect of the present invention, the printed circuit board inspection apparatus according to the first, second, or third aspect is provided with an anisotropic conductive rubber interposed between a printed circuit board to be inspected and a tip of a probe pin. It is characterized by. In claim 6, claim 1,
The printed circuit board inspection apparatus according to 2 or 3, further comprising a surface contact unit that electrically contacts a predetermined area of the wiring pattern formed on the printed circuit board to be inspected. According to a seventh aspect of the present invention, the printed circuit board inspection apparatus according to the first, second, or third aspect is configured to supply or detect an inspection signal by electromagnetic coupling with a wiring pattern formed on a printed circuit board to be inspected. It is characterized by comprising the configured electromagnetic coupling means.

When wiring patterns are formed on the upper and lower surfaces of the substrate to be inspected, a pair of upper and lower jigs are provided, and the protective plates are also provided on both surfaces of the printed circuit board. The pressing means includes a state in which the protective plate and the substrate are separated from each other by the first urging means, a state in which the protective plate and the substrate are in close contact by pressing against the first urging means, It is preferable to operate in three states of being pressed against the urging means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A printed circuit board inspection apparatus according to the present invention will be described below in detail with reference to the drawings showing an embodiment thereof. In FIG. 1, 12A and 12B are CCD cameras as imaging means, 2A is an upper inspection jig, 2B is a lower inspection jig, 3A and 3B are protection plates, 4 is a substrate, 8A is an upper adjustment mechanism, and 8B is a lower adjustment jig. Mechanism. Reference numeral 7 denotes a control device, which is a detecting means for detecting a positional deviation based on an image from the CCD camera, a position controlling means for controlling the upper adjusting mechanism and the lower adjusting mechanism based on the positional deviation, and connected to each probe pin. And built-in electrical inspection means.

Reference numeral 6 denotes a main press for driving the lower inspection jig 2B. The upper adjustment mechanism 8A is attached to the base 62A so as to drive the upper base 61A. The lower adjustment mechanism 8B is attached to the base 62B so as to drive the lower base 61B.

Cameras 12A, 12B mounted on jig bottom plates 6A, 6B fixed to bases 61A, 61B
Is composed of a CCD image pickup device having a right-angle prism having a bent surface at an angle of 45 degrees on the optical axis. Light for illumination is transmitted from the ends of a plurality of optical fibers arranged around the optical axis. Irradiated along.

A wiring pattern is formed on both sides of the substrate 4 and a positioning guide hole is formed in the substrate 4. In the upper inspection jig 2A and the lower inspection jig 2B, a number of inspection probe pins PA and PB corresponding to the number of inspection points of the wiring pattern of the substrate 4 are implanted. The probe pins PA, PB are in electrical contact with the bases PA ′, PB ′, and the probe pins PA, PB or the base P
A 'and PB' have built-in springs and probe pins PA and P
The length of B is long enough to be exposed on the surface of the protection plate.

In the following, for convenience, 16 probe pins are arranged in 4 (rows) × 4 (rows) within the range of a (mm) × a (mm) as shown in FIG. An example will be described. That is, in this example, the interval between the probe pins is a
/ 3 (mm). The protection plates 3A and 3B are formed of an insulating and non-flexible plate, for example, a glass epoxy plate, and are arranged so that the tips of the probe pins are inserted and the tips are exposed on the surface on the substrate side. As shown in FIG. 2B, the tips of the 16 probe pins are arranged in the narrower b (mm) × b (mm) range. That is, in this example,
The minimum distance between the tips of the probe pins is c (mm). Here, c <a / 3, and the distribution density at the tip of the probe pin is smaller than the distribution density at the root.
Therefore, a high-density wiring pattern can be inspected using the conventional probe pins.

Reference numeral 5A denotes an upper reference plate, which is attached to an upper base 62A by a column 38A. 5B
Is a lower reference plate, which is attached to the lower base 62B by a support post 38B. Reference numeral 31 denotes a guide pin, which stands on the reference plate 5B, and inserts a tip into a guide hole provided in the printed circuit board 4 so that the relative position between the printed circuit board 4 and the reference plates 5A and 5B is adjusted. decide. The positions of the reference plates 5A and 5B relative to the bases 62A and 62B are determined by the columns 38A and 38B.

Reference numeral 35B denotes a support pin as a first urging means. The base is fixed to the reference plate 5B, and the printed circuit board 4 at the tip thereof is separated from the protection plate 3B by a built-in spring. It is energizing. Reference numeral 36B denotes a protection plate guide pin as a second urging means. The base is fixed to the upper support plate 22B and the lower support plate 21B, and the printed protection plate 3B, the tip of which is fixed by a built-in spring, is used as a reference plate. It is urged in a direction away from 5B. Reference numeral 34B denotes a protection plate support pin, which stands on the jig 2B, and whose tip is fixed to the protection plate 3B, thereby determining the relative position between the protection plate 3B and the jig 2B. 40
B is a spring that biases the protective plate 3B to separate it from the reference plate 5B.

Reference numeral 37B denotes a reference pin, the base of which is fixed to a jig bottom plate 6B, and a jig 2B and a lower support plate 21B.
And the upper end is fixed to the upper support plate 22B. The reference pin 37B fixes the horizontal relative positional relationship between the jig bottom plate 6B, the jig 2B, and 21B22B, and the protection plate support pin 34B further allows the horizontal relative position between 22B and the protection plate 3B. The positional relationship is also fixed. The horizontal relative positions of the jig bottom plate 6B fixed to the base 61B and the base 62B are finely adjusted by the lower adjustment mechanism 8B. Therefore, by controlling the lower adjustment mechanism 8B, the positional relationship between the printed circuit board 4 and the tip of the probe pin PB is finely adjusted.

In the above description, “B” added to the numeral code is a code attached to the lower component of the printed circuit board 4, and the same component is also provided above the printed circuit board 4. It is arranged. Corresponding upper components are designated by the same numeral with an "A" appended, where necessary. Those which do not need to be described are not described or shown.

A case where an actual printed circuit board is inspected by the printed circuit board inspection apparatus having the above configuration will be described below. First, the lower inspection jig 2B is lowered by the main press 6, the substrate 4 is transported by a transport mechanism (not shown), and the guide pins set up on the lower inspection jig 2B as shown in FIG. 31 is inserted into the guide hole of the substrate 4 and set.

Next, the lower inspection jig 2 is operated by the main press 6.
When B is raised, the printed circuit board 4 becomes the upper and lower protective plates 3
A, 3B begins to be pressed.
The spring of 5B is contracted, and the substrate 4 is sandwiched and held between the protection plates 3A and 3B from above and below. Explaining below, the spring built into the protection plate guide pin 36B and the spring 40B
Is shrunk, and the printed circuit board 4, the protection plate 3B, and the reference plate 5B come into close contact with each other. At this time, the tips of the inspection probe pins PA and PB of the upper inspection jig 2A and the lower inspection jig 2B are pressed against the inspection points such as the wiring patterns on the front and back of the printed circuit board 4 to make electrical contact. In this state,
Upper CCD camera 12A and lower CCD camera 12B
The controller 7 images the reference holes provided in the upper and lower inspection jigs 2A and 2B and the reference marks formed on the front and back of the substrate 4, and the controller 7 controls the relative displacement between the upper inspection jig 2A and the substrate 4. Is calculated, and an electrical continuity / non-continuity inspection between the inspection probe pins PA and PB in contact with a predetermined position of each wiring pattern is performed. It should be noted that holes are provided in each plate on the optical axis of the CCD camera.

If the electrical inspection fails, it is possible that the inspection probe pins PA and PB do not accurately contact the predetermined positions. To correct the displacement, operate the main press 6 and
The lower inspection jig 2B is lowered to separate the upper and lower protective plates 3A, 3B from the upper and lower reference plates 5A, 5B, and further separates the printed circuit board 4 from the upper and lower protective plates 3A, 3B. 3B and the reference plates 5A, 5B are relatively movable. In this case, the spring of the protection plate guide pin 36B and the spring 40B are extended to separate the protection plate 3B from the reference plate 5B, and the printed board 4 is separated from the protection plate 3B by the support pins 35B. Hold. That is, the printed circuit board 4 includes upper and lower support pins 35.
A and 35B support the upper and lower protective plates 3A and 3B apart from each other. Therefore, even in this state, the printed circuit board 4 holds the upper and lower support pins 35A, 35A.
B, the printed circuit board 4
Is prevented from being displaced or bent, and accurate positioning becomes possible.

That is, even when the jig is moved up and down, the printed circuit board is held at the initial position with respect to the base 62B by the support pins 35A and 35B. Since the support pins 35A and 35B are fixed to the base 62B together with the jig, the horizontal direction relative to the board 4 and the main body of the inspection apparatus, that is, the base 62B can be adjusted even by fine adjustment for raising and lowering the jig and correcting misalignment. Thus, a configuration in which the position does not change is realized.

The detection means built in the control device 7 uses the image processing technique to detect the displacement data of the substrate 4 around the reference hole obtained by the camera 12A and the data of the displacement around the reference hole obtained by the left camera (not shown). From the data of the displacement of the substrate 4, the displacement component (X
a, Ya, θa) are calculated. The upper inspection jig 2A is controlled by controlling the upper adjustment mechanism 8A based on the shift component.
Is slightly moved to accurately align the upper inspection jig 2 and the substrate 4.

Similarly, the CCD camera 12B and the left CCD camera (not shown) image the reference holes provided in the lower inspection jig 2B and the reference marks on the substrate, and calculate the relative displacement by the image processing device. , Lower adjustment mechanism 8
B and finely move the lower inspection jig 2B,
The relative displacement between the lower inspection jig 2B and the substrate 4 is also corrected. In this manner, the upper inspection jig 2A (the protection plate 3
A), the lower inspection jig 2B (protective plate 3B) and the substrate 4 are accurately aligned with each other. The positioning method used here is disclosed in Japanese Patent Application No. Hei 3-23119.
The technology proposed in 7 can also be used.

After correcting the displacement as described above, an electrical inspection is performed again. After the inspection is completed, the protection plate and the jig are separated from the substrate 4 by lowering the main press again, and are conveyed to the stock portion of the non-defective substrate and the stock portion of the defective substrate using the conveyance mechanism. I do.

According to this printed circuit board inspection apparatus, the probe pins PA and PB of the jig are separated from the substrate while the substrate is held between the support pins 35A and 35B, and the relative position between the jig and the substrate is increased. Since it corrects the misalignment,
This prevents the position of the substrate from deviating from the state in which the displacement has been calculated. Therefore, each time a positional displacement is calculated and fine-tuned based on the result, the relative position between the substrate and the jig is corrected so as to accurately match. Also, the probe pin can be accurately brought into contact with a predetermined position. In addition, even if it is difficult to arrange high density on the jig due to the restriction of the structure of the probe pin, it is possible to inspect the high density wiring pattern by bringing the tip of the probe pin closer. is there.

It is also possible to remove the jig having the above configuration and replace it with a conventional jig (for example, the jig in the embodiment of Japanese Patent Application No. 9-162950). When the substrate has a wiring pattern formed only on one side, only one of the upper and lower jigs on which the probe pins are implanted may be used. However, it is necessary to provide two upper and lower support pins 35A and 35B to sandwich the substrate. Also,
The correction of the displacement may be performed automatically or manually. The transport mechanism includes Japanese Patent Application No. 3-346.
654, Japanese Patent Application No. 4-214333, and the like. Further, as the jig, the technology proposed in Japanese Patent Application Nos. 2-196566, 3-245676, 3-346654 can be used.

FIG. 3 is a view showing the structure of a printed circuit board inspection apparatus according to a fifth embodiment of the present invention.
2A, 72B and the pitch conversion boards 71A, 71B are interposed between the protection plate and the printed board. FIG. 4 is a configuration diagram showing the configuration of the printed circuit board inspection apparatus according to claim 6 of the present invention. A short rubber 91 as a surface contact means is provided at the tip of the cylinder 9. The short rubber 91 may be brought into contact with a portion where a large number of inspection points are dense, such as a mounting surface of an LSI such as a CPU, to short-circuit a plurality of inspection points. FIG. 5 is a block diagram showing the configuration of a printed circuit board inspection apparatus according to claim 7 of the present invention, which includes a non-contact sensor 92 as an electromagnetic coupling means, and an electromagnetic field due to a weak AC signal supplied to the pattern of the printed circuit board. Alternatively, an electromagnetic wave or the like may be detected in a non-contact manner by electromagnetic coupling. Alternatively, electromagnetic coupling may be performed by a contact sensor instead of the non-contact sensor. Further, a configuration may be employed in which a position shift is detected and corrected based on electrical characteristics obtained by electrical contact between each probe pin and a specific pattern on a printed circuit board without using a camera. In any case, any technique for electrically inspecting a printed circuit board with the configuration described in the claims of the present invention belongs to the technical scope of the present invention.

[0025]

As described above, according to the printed board inspection apparatus of the present invention, a jig capable of accurately inspecting a high-density wiring pattern can be realized by using the conventional probe pins.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a printed circuit board inspection device of the present invention.

FIG. 2 is an explanatory diagram illustrating a main part of the printed board inspection device of the present invention.

FIG. 3 is a configuration diagram showing a configuration of a printed circuit board inspection apparatus according to a fifth embodiment of the present invention.

FIG. 4 is a configuration diagram showing a configuration of a printed circuit board inspection apparatus according to claim 6 of the present invention.

FIG. 5 is a configuration diagram showing a configuration of a printed circuit board inspection apparatus according to a seventh aspect of the present invention.

[Explanation of symbols]

 12A CCD camera 12B CCD camera 2A Upper inspection jig 2B Lower inspection jig 31 Guide pin 34B Protective plate support pin 35B Support pin 36B Protective plate guide pin 3A Protective plate 3B Protective plate 4 Printed circuit board to be inspected 5A Reference plate 5B Reference plate 6 Main press 6A (upper) jig bottom plate 6B (lower) jig bottom plate 8A upper adjustment mechanism 8B lower adjustment mechanism PA probe pin PB probe pin PA 'base of probe pin PB' base of probe pin

Claims (7)

[Claims] A probe formed by pressing a probe pin held by a jig with a wiring pattern formed on a printed circuit board to be electrically contacted with a wiring pattern formed on the printed circuit board, thereby forming a wiring formed on the printed circuit board. In a printed circuit board inspection device configured to inspect the conduction / non-conduction of a pattern, an adjustment mechanism is provided for aligning the inspection target printed board with the tip of a probe pin, and the inspection target printed board is A protective plate that is in close contact with the printed circuit board to be inspected in the pressed state is interposed between the jig and the tip of the probe pin is electrically connected to the printed circuit board to be inspected through the protective plate. The distribution density of the tip of the probe pin on a part of the surface of the protection plate is larger than the distribution density of the root of the probe pin on the jig surface. PCB inspecting apparatus according to claim Rukoto. 2. The apparatus according to claim 1, further comprising first urging means for urging the printed circuit board in a direction for separating the printed circuit board from the jig with an urging force weaker than the pressing force of the pressing means. The printed circuit board inspection device according to the above. 3. The apparatus according to claim 1, further comprising a second urging means for urging the protective plate in a direction to separate the protective plate from the jig with an urging force weaker than the pressing force of the pressing means.
A printed circuit board inspection device according to claim 1. 4. An imaging device for capturing an image of a surface of a printed circuit board to be inspected, and a detecting means for detecting a relative displacement between the printed circuit board to be inspected and a tip of a probe pin from the captured image data. 4. The printed circuit board inspection according to claim 1, wherein the adjustment mechanism is configured to align the printed circuit board to be inspected with a tip of a probe pin based on the detected positional deviation. apparatus. 5. The printed circuit board inspection according to claim 1, further comprising an anisotropic conductive rubber interposed between the printed circuit board to be inspected and the tip of the probe pin. apparatus. 6. The printed circuit board inspection according to claim 1, further comprising a surface contact means for electrically contacting a predetermined area of the wiring pattern formed on the printed circuit board to be inspected. apparatus. 7. An apparatus according to claim 1, further comprising electromagnetic coupling means configured to supply or detect an inspection signal by electromagnetic coupling with a wiring pattern formed on a printed circuit board to be inspected. 4. The printed circuit board inspection device according to 2, 3 or 4.