JP3592279B2 - Substrate inspection probe and substrate inspection device using the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a board inspection probe for performing continuity inspection, insulation inspection, and the like of a circuit pattern on a circuit board, and a board inspection apparatus using the same.
[0002]
[Prior art]
As a conventional board inspection probe, Japanese Unexamined Patent Application Publication No. 2001-41979 discloses a technique in which the tip of a needle pin at the tip of the probe is restrained by a restraining member during non-inspection to improve the vibration characteristics of the needle pin. A technique has been disclosed for reducing the vibration of the needle pin when repeatedly performing the above, thereby speeding up the inspection.
[0003]
Specifically, as shown in FIG. 8, the probe 90 has a needle pin 93 soldered to a socket 95 supported detachably on an electrode bar 97, and has a substantially L-shaped cross section for holding the electrode bar 97. When the holding member 99 is driven by a drive mechanism (not shown), the probe 90 is positioned at a predetermined position. A restraining member 100 for restraining the tip of the needle pin 93 is fixed to the holding member 99 with a screw 110. The restraining member 100 is made of a conductive material. As shown in FIG. 9, a substantially drop-shaped hole 102 is formed in the lower horizontal portion 101, and has a structure in which the needle pin 30 is inserted therethrough. The electrode rod 97 and the restraining member 100 are electrically connected by an electric wire 103, and the conduction between the needle pin 30 and the restraining member 100 is detected by an ammeter 104 provided in the middle of the path, whereby the substrate P of the needle pin 30 is detected. A contact detection circuit configured to detect contact with the device is configured.
[0004]
That is, in the probe 90, when the needle pin 93 shown by a solid line in FIG. 8 is not in contact with the substrate P, the needle pin 93 abuts on the left end wall of the hole 102 of the restraining member 100 and is restrained. The pin 93 and the restraining member 100 are brought into conduction, and the contact detection circuit including the restraining member 100, the needle pin 93, the socket 95, the electrode rod 97, and the electric wire 103 is closed, while the needle pin indicated by a two-dot chain line in FIG. When the pin 30 is pushed into contact with the substrate P, the needle pin 93 bends in the + X direction and separates from the inner wall of the hole 102 of the restraining member 100, so that the needle pin 93 and the restraining member 100 become non-conductive. The circuit opens.
[0005]
In the board inspection apparatus using the probe 90, the height of the needle pin 93 in the vertical direction (Z-axis direction) can be detected by an open / close signal from the ammeter 104, and the inspection is not performed when the inspection is repeated. The speed of the inspection is increased by restraining the tip of the needle pin 93 with the restraining member 100 to attenuate the vibration of the needle pin 93 in the above.
[0006]
[Problems to be solved by the invention]
However, the substrate inspection apparatus using the probe 90 has a configuration in which the vibration of the needle pin 93 during non-inspection is attenuated by restraining the tip end of the needle pin 93 with one restraining member 100. If the value exceeds a predetermined value, the vibration of the needle pin 93 cannot be sufficiently attenuated, and there is a possibility that a problem that the inspection accuracy is reduced may occur.
[0007]
An object of the present invention is to solve such a problem of the related art, and an object of the present invention is to provide a board inspection probe which has good attenuation characteristics and can speed up the inspection, and a board inspection apparatus using the same. .
[0008]
[Means for Solving the Problems]
The board inspection probe according to the present invention is for performing a circuit pattern inspection by relatively moving the distal end of the needle pin held in the holding member on the base end side in the pushing direction and making contact with the circuit board, The needle pin is made of a conductive elastic member, and its tip is restrained in a bending direction by a first restraining member, while an intermediate portion is restrained in a direction opposite to the bending direction by a second restraining member and is curved. It is held in a state, and is configured such that when a force in the pushing direction acts on the distal end, the tip is deformed in a predetermined bending direction orthogonal to the pushing direction and the restraint by the two restraining members is released.
[0009]
According to this configuration, when a force in the pushing direction acts on the tip of the needle pin, the needle pin is deformed in a predetermined bending direction orthogonal to the pushing direction, and the restraining of the needle pin by both restraining members is released, Since the needle pin comes into contact with the circuit pattern of the circuit board due to its own toughness characteristics, the tip of the needle pin does not deviate from the measurement position in the circuit pattern, and the circuit pattern inspection can be performed with high precision without damaging the board It is possible to do.
[0010]
On the other hand, when the force in the pushing direction is no longer applied, the bent needle pin returns to its original shape, and the needle pin is restrained by the two restraining members in directions opposite to each other at the distal end portion and the intermediate portion. Decays quickly and quickly. Therefore, it is possible to immediately move to the next inspection location in the circuit pattern, and to speed up the inspection and shorten the inspection time of the substrate.
[0011]
The board inspection probe has a contact detection circuit that detects contact of the needle pin with the circuit board by detecting conduction between the first constraint member and the needle pin, and a force in a pushing direction is applied to the tip of the needle pin. The contact detection circuit opens when the needle pin is restrained by the two restraining members and the contact detection circuit opens while the force in the pushing direction does not act and the needle pin is restrained by the two restraining members so that the contact detection circuit closes. To be configured.
[0012]
According to this configuration, when a force in the pushing direction acts on the tip of the needle pin, the needle pin is deformed in a predetermined bending direction orthogonal to the pushing direction, and the restraining of the needle pin by the two restraining members is released, and the first restraining member is released. And the needle pin becomes non-conductive, the contact detection circuit is opened, and it is detected that the tip of the needle pin has contacted the circuit board.
[0013]
On the other hand, when the force in the pushing direction is no longer applied, the bent needle pin returns to its original shape and the needle pin is restrained at the distal end portion and the intermediate portion by both restraining members, so that the first restraining member and the needle pin are electrically connected. In this state, the contact detection circuit is closed, and it is detected that the tip of the needle pin has separated from the circuit board.
[0014]
A substrate inspection apparatus according to the present invention includes any one of the above-described substrate inspection probes, an inspection unit that moves the probe, and a transport table that transports a circuit board to be inspected. The circuit pattern is inspected by being moved and brought into contact with the circuit board.
[0015]
According to this configuration, since the board inspection probe exhibits good attenuation characteristics, the circuit board to be inspected is transported by the transport table, and the probe is moved to the inspection location of the circuit pattern by the inspection unit at a high speed. Inspection of the pattern can be performed with high accuracy in a short time.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
[0017]
FIG. 1 shows a configuration example of a board inspection apparatus 1 using a board inspection probe 3 according to the present invention.
[0018]
In the board inspection apparatus 1, an opening / closing door 21 is attached to the front side (−X direction) of the apparatus main body 1 a so as to be openable and closable. It is configured to be mounted and the inspection unit T inspects the substrate P. Here, the substrate P is a bare substrate on which a circuit pattern is printed, and on which electronic components such as an IC chip, a capacitor, and a resistor are not mounted.
[0019]
In the board inspection apparatus 1, after the board P is inspected by the inspection unit T and the quality of the board P is determined, the inspected board P is opened by the opening / closing door 21 and carried out from the carry-in / out unit C by the operator.
[0020]
In this embodiment, the loading and unloading of the substrate P is performed manually by the operator. However, the substrate P is received from an external device on one side in the ± X direction of the loading / unloading portion C, and the substrate before inspection is transferred to the loading / unloading portion C. It is possible to automatically transfer the substrate P by providing a board loading mechanism for transferring the P, and additionally installing a board loading mechanism for receiving the inspected board P from the loading / unloading section C on the other side and unloading the board to an external device. Become.
[0021]
In the substrate inspection apparatus 1, the transport table 2 is provided so as to be reciprocally movable in the ± X direction in order to transport the substrate P between the carry-in / out section C and the inspection section T by the transport table driving mechanism 6. Specifically, the transport table driving mechanism 6 includes a feed screw 62 such as a ball screw, a drive shaft 64, and a motor 63, and the transport table 2 adjusts the rotation amount of the motor 63 via a bracket 65 screwed to the ball screw 62. It is designed to move accordingly.
[0022]
The inspection unit T is provided with an inspection unit 4 including a plurality of substrate inspection probes 3, and is disposed above the transport table drive mechanism 6. Each probe 3 is driven by a probe driving mechanism 43 controlled by a control device. The probe driving mechanism 43 includes a driving unit that drives the probe 3 with respect to the substrate inspection apparatus 1 in the XYZθ axis directions. The substrate P is placed on the transport table 2 and transported to a predetermined inspection position. Then, after positioning the probe 3 on the substrate P at the inspection position, the probe 3 is moved downward in the −Z direction, and the tip of the needle pin 30 is brought into contact with the circuit pattern of the substrate P for inspection. Is separated from the substrate P.
[0023]
The needle pin 30 of the probe 3 is made of a conductive elastic member. As shown by a solid line in FIG. 2, the distal end portion 30a is restrained in the bending direction H1 by the first restraining member 33, while the intermediate portion 30b is The second restraining member 34 restrains in a direction H2 opposite to the bending direction H1 and is held in a curved state. When a force in the pushing direction V1 acts on the tip of the needle pin 30, the needle pin 30 is deformed in a bending direction H1 orthogonal to the pushing direction V1 as shown by a two-dot chain line in FIG. It is configured such that the restraint by 33 and 34 is released.
[0024]
The type of the needle pin 30 is not particularly limited as long as it is a conductive material having extremely small toughness even when pressed into the substrate P. For example, SK steel, phosphor bronze, or brass is used. be able to. Here, SK steel having a diameter of 125 μm and a length of 25 mm is used. FIG. 7 shows the toughness characteristics of the needle pin 30. As a result of measuring the toughness characteristics by pushing the needle pin 30 in the V direction, the stress of the needle pin 30 was almost 0 g when the pushing amount in the V direction was 0 mm, and was approximately 8 g when the pushing amount was 0.03 mm or more. On the other hand, the contact resistance value of the needle pin is 10 KΩ or more when the pushing amount is 0 mm, but is constant at about 3Ω when the pushing amount is 0.5 mm or more. As is apparent from this stress characteristic, since the stress becomes constant when the pushing amount becomes 0.03 mm or more, it is preferable to lower the probe 3 so as to push the needle pin 30 by 0.03 mm or more. However, if the pushing amount is too large, the moving time of the probe 3 takes a long time, resulting in a longer measuring time. Therefore, in order to shorten the measuring time, the pushing amount of the needle pin 30 must be increased more than necessary. Not to be too large.
[0025]
The base end side of the needle pin 30 is soldered to a holder 32 made of a glass epoxy material having a gold plated surface, and the holder 32 is fixed to an upper portion of a holder base 31 made of an aluminum material by screws. I have. The holder base 31 is fixed to the lower part of the probe holding member 41 of the inspection unit 4 with a screw from below. On the lower surface of the holder base 31, a band-shaped second restraining member 34, a substantially rectangular spacer 35, and a first restraining member 33 having a substantially rectangular cross section are stacked on the holder base 31 in this order. They are fastened together with screws. Here, the second constraint member 34 is made of SUS304, the spacer 35 is made of aluminum, and the first constraint member 33 is made of brass. An electric wire is connected to the electrode member 36 and the first restraining member 33 that are electrically connected to the holder 32 to form a closed-loop contact detection circuit 21 that connects the needle pin 30 and the first restraining member 33. At 22, conduction between the first restraining member 33 and the needle pin 30 is detected, whereby contact of the needle pin 30 with the substrate P can be detected.
[0026]
In the state where the force in the pushing direction V1 does not act on the tip of the needle pin 30 indicated by the solid line in FIG. 2, the tip 30a of the needle pin 30 is formed at the tip of the inclined portion 33a of the first restraining member 33 by the V groove 33b ( The intermediate portion 30b of the needle pin 30 is restrained in the bending direction H1 by the narrow portion 34b (see FIG. 5) of the substantially drop-shaped hole 34a formed in the second restraining member 34. In the opposite direction H2.
[0027]
More specifically, in a state in which a force in the pushing direction V1 is applied to the distal end portion 30a of the needle pin 30 indicated by a two-dot chain line in FIG. It is released. That is, as shown by a two-dot chain line in FIG. 6, the distal end portion 30a of the needle pin 30 moves in the H1 direction and separates from the V groove 33b formed at the distal end of the inclined portion 33a of the first restraining member 33. At the same time, as shown in FIG. 5, the intermediate portion 30b separates from the narrow portion 34b of the substantially drop-shaped hole 34a formed in the second restraining member 34 in the direction H1 and comes to the position G. As a result, the needle pin 30 is released from the two restraining members 33 and 34, and the needle pin 30 comes into contact with the circuit pattern of the substrate P with its own toughness characteristics. Further, the first restraining member 33 and the needle pin 30 are brought out of conduction, and the contact detection circuit 21 is opened.
[0028]
On the other hand, the needle pin 30 returns to the original shape in a state where the force in the pushing direction V1 indicated by the solid line in FIG. 2 does not act, and the needle pin 30 is restrained by the restraining members 33 and 34. That is, as shown by the solid line in FIG. 6, the tip end portion 30a of the needle pin 30 moves in the H2 direction and contacts and is restricted by the V groove 33b formed at the tip end of the inclined portion 33a of the first constraint member 33. At the same time, as shown in FIG. 5, the intermediate portion 30b moves in the H2 direction from the narrow portion 34b of the substantially drop-shaped hole 34a formed in the second restraining member 34, and comes to the point F where it comes into contact with the side wall. As described above, the needle pin 30 is restrained in the opposite directions by the two restraining members 33 and 34, and the two restraining members 33 and 34 have a push-pull relationship with respect to the needle pin 30. Decays quickly and quickly. Further, the first restraining member 33 and the needle pin 30 are brought into conduction, and the contact detection circuit 21 is closed.
[0029]
As described above, in the board inspection apparatus 1 using the above-described probe 3, when a force in the pushing direction V1 is applied to the distal end portion 30a of the needle pin 30, the needle pin 30 is moved in the predetermined bending direction orthogonal to the pushing direction V1. Then, the needle pin 30 is released from the restraint by the restraining members 33 and 34, and the needle pin 30 is brought into contact with the circuit pattern of the substrate P by its own toughness characteristic. The circuit pattern can be inspected with high accuracy without damaging the substrate P so as not to deviate from the measurement position in the circuit pattern. In addition, the contact detection circuit 21 is opened with the first restraining member 33 and the needle pin 30 in a non-conductive state, so that it is detected that the tip of the needle pin 30 has contacted the surface of the substrate P. .
[0030]
On the other hand, when the force in the pushing direction V1 does not act, the bent needle pin 30 is returned to the original shape, and the needle pin 30 is restrained by the restraining members 33 and 34 in the opposite directions at the distal end portion 30a and the intermediate portion 30b. Thus, the vibration of the needle pin 30 is rapidly attenuated in a short time. In addition, by bringing the first restraining member 33 and the needle pin 30 into a conductive state and closing the contact detection circuit 21, it is detected that the tip of the needle pin 30 has separated from the substrate P. In this way, it is possible to immediately move to the next inspection location in the circuit pattern, to speed up the inspection, and to shorten the inspection time of the substrate P.
[0031]
In the board inspection apparatus 1, the board P to be inspected is transported on the transport table 2 using the board inspection probe 3 exhibiting good attenuation characteristics, and the probe 3 is connected to the circuit pattern of the board P by the inspection unit T. The inspection pattern can be moved to the inspection location at a high speed, and the inspection of the circuit pattern can be performed in a short time with high accuracy.
[0032]
Further, by configuring the contact detection circuit 21, when the old needle pin 30 is replaced with a new needle pin 30 due to wear, breakage, or the like, the contact of the needle pin 30 with the substrate P is detected by the ammeter 22. Thus, the height adjustment in the Z-axis direction at the tip of the needle pin 30 is facilitated.
[0033]
The substrate inspection probe according to the present invention and the substrate inspection apparatus using the same are not limited to the specific configuration of the above-described embodiment, and the configuration is appropriately modified, added, replaced, or deleted as necessary. Needless to say, the configuration may be adopted.
[0034]
For example, in the above description, the probe 3 is moved in the XY directions with respect to the stationary substrate P and positioned, and then the probe 3 is moved down in the Z-axis direction and the needle pins 30 are pushed into the substrate P for inspection. Although shown, the present invention is not limited to this, and the probe P may be moved in the XY directions and positioned, and then the substrate P may be raised in the Z direction and contacted with the needle pins 30 of the probe 3. Good. Further, it is also possible to adopt a configuration in which the needle pins 30 are brought into contact with the substrate P by being pushed in the X-axis direction or the Y-axis direction instead of being pushed in the Z-axis direction.
[0035]
【The invention's effect】
As described above, according to the board inspection probe of the present invention, the tip of the needle pin is restrained in the bending direction by the first restraint member in a state where the force in the pushing direction does not act on the tip of the needle pin. Since the intermediate portion is held in a curved state by being restrained by the second restraining member in a direction opposite to the bending direction, the vibration of the needle pin can be rapidly attenuated in a short time.
[0036]
On the other hand, when a force in the pushing direction acts on the tip of the needle pin, the needle pin is deformed in a predetermined bending direction orthogonal to the pushing direction and the restraint by the two restraining members is released, so that the needle pin has its own pin. Since the toughness comes into contact with the circuit pattern of the substrate, the tip of the needle pin does not deviate from the measurement position in the circuit pattern of the substrate, and the circuit pattern can be inspected with high accuracy without damaging the substrate.
[0037]
In addition, by using a probe exhibiting such good attenuation characteristics in the substrate inspection apparatus, the inspection can be speeded up, and the inspection of the circuit pattern can be performed in a short time and with high accuracy.
[0038]
In addition, if the probe has a contact detection circuit configured to detect conduction between the first restraining member and the needle pin, it is possible to detect contact of the needle pin with the circuit board.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration example of a board inspection apparatus using a board inspection probe according to the present invention.
FIG. 2 is a side view showing a configuration example of a substrate inspection probe according to the present invention.
FIG. 3 is a front view showing a configuration example of a board inspection probe according to the present invention.
4A and 4B are lower views showing a configuration example of a board inspection probe according to the present invention, wherein FIG. 4A is an overall view, and FIG. 4B is an enlarged view of a main part showing a restrained state by a first restraining member. Respectively.
FIG. 5 is a bottom view showing an example of a shape of a hole formed in a second restraining member of the probe for board inspection according to the present invention.
FIG. 6 is an enlarged main part side view showing a state in which the needle pin of the board inspection probe according to the present invention is pushed in the pushing direction to release the restraint at the distal end of the needle pin restrained by the first restraining member. .
FIG. 7 is a diagram showing toughness characteristics of a needle pin used in a probe for substrate inspection according to the present invention.
FIG. 8 is a side view showing a configuration example of a conventional board inspection probe.
FIG. 9 is a bottom view showing a configuration example of a conventional board inspection probe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate inspection apparatus 2 Carrying table 3 Substrate inspection probe 4 Inspection unit 21 Contact detection circuit 30 Needle pin 30a Needle pin tip part 30b Needle pin intermediate part 31 Holder base (holding member)
32 Holder (holding member)
33 1st restraint member 34 2nd restraint member V1 Pushing direction H1 Bending direction P orthogonal to pushing direction P board (circuit board)

Claims (3)

A probe for inspecting a circuit pattern in which a proximal end of a needle pin held by a holding member is relatively moved in a pushing direction to abut on a circuit board to inspect a circuit pattern. It is made of an elastic member, and its tip is restrained in a bending direction by a first restraining member, while an intermediate portion is restrained by a second restraining member in a direction opposite to the bending direction and held in a curved state, A substrate inspection probe characterized in that, when a force in the pushing direction acts on the tip, the tip is deformed in a predetermined bending direction orthogonal to the pushing direction and the restraint by the two restraining members is released. A contact detection circuit for detecting contact of the needle pin with the circuit board by detecting conduction between the first restraining member and the needle pin; The contact detection circuit is configured to be opened when the restriction of the needle pin is released, while the contact detection circuit is closed by the restriction of the needle pin by both restriction members without the force in the pushing direction being applied. The probe for substrate inspection according to 1. 3. A circuit board, comprising: a board inspection probe according to claim 1; an inspection unit configured to move the probe; and a transport table configured to transport a circuit board to be inspected, wherein a tip of the probe is relatively moved in a pushing direction. A board inspection apparatus for inspecting a circuit pattern in contact with a substrate.

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