JP4233904B2 - Board inspection equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate inspection device provided with an inspection short sheet to electrically short together the respective conductive patterns in contact with the plurality of conductive patterns formed on one surface of the circuit board.
[0002]
[Prior art]
For example, a circuit board P having a multilayer structure shown in FIG. 6 is conventionally known as a circuit board on which a bare chip can be mounted. As shown in the figure, the circuit board P has conductor patterns 51, 51,... Connected to the connection terminals of the bare chip by wire bonding or bump connection, for example, 0. The conductive patterns 52, 52,... Are formed on the back surface Pb side (upper surface side in the figure) at a pitch of about 1.27 mm, for example. In this case, the conductor patterns 51 and 52 are electrically connected to each other via internal connection patterns 53, 53,. Also, insulating resists 54, 54,... Are formed around the conductor patterns 51, 52.
[0003]
On the other hand, as a board inspection apparatus for inspecting this type of circuit board, the applicant discloses a circuit board inspection apparatus (1) in Japanese Patent Application Laid-Open No. 2000-193705. This circuit board inspection apparatus includes a rear surface side unit (2), a front surface side unit (3), a control unit (4), and the like, and includes conductor patterns 51, 51,... And conductor patterns 52, 52,. The continuity test between them (the continuity test of the internal connection patterns 53, 53,...) Can be executed. In this case, the back-side unit includes a probe holding plate (11) on which the probe (12) is disposed, a holding plate (13) that holds the circuit board P by forming a holding hole (13a), and the like. Has been. On the other hand, the front side unit moves the continuity inspection jig (27) provided with the conductive rubber plate-like electrode (27a) with respect to the circuit board P in the XY direction and the vertical direction. -Y movement mechanism (25) is provided. The control unit controls the movement of the continuity inspection jig by the XY movement mechanism, and executes a quality determination process for the circuit board P.
[0004]
When performing the continuity test of the internal connection patterns 53, 53,... On the circuit board P using this circuit board inspection device, first, the circuit board P to be inspected is inserted into the holding hole of the holding plate in the back side unit. To do. At this time, the conductor patterns 52, 52... On the back surface Pb of the circuit board P are in contact with the probe. Next, the control unit 6 moves the continuity inspection jig downward with respect to the XY movement mechanism. At this time, the electrodes of the continuity inspection jig come into contact with the conductor patterns 51, 51... On the surface Pa of the circuit board P. As a result, the conductor patterns 51, 51,... Are electrically connected to each other via the electrodes. Next, an inspection voltage is applied between the conductor patterns 51 and 52 via the electrodes and the probe. In this case, when the internal connection pattern 53 is disconnected, the inspection current does not flow between the conductor patterns 51 and 52, so that the disconnection is detected.
[0005]
[Patent Document 1]
JP 2000-193705 (page 6-7)
[0006]
[Problems to be solved by the invention]
However, this circuit board inspection apparatus has the following problems to be solved. That is, in this circuit board inspection apparatus, the conductor patterns 51, 51,... Are electrically connected to each other by bringing a plate-like electrode (27a) made of conductive rubber into contact therewith. In this case, as shown in FIG. 7, when the surface of the conductor pattern 51 is deep with respect to the surface of the resist 54 formed in the periphery, there is a possibility that the electrode is in poor contact with the conductor pattern 51. is there. Therefore, in this circuit board inspection apparatus, the internal connection pattern 53 is normal because no current flows between the conductor patterns 51 and 52 due to the contact failure between the electrode (27a) and the conductor pattern 51. Nevertheless, it may be erroneously determined that the wire is disconnected, and it is preferable to improve this point.
[0007]
The present invention has been made in view of such a problem, and includes a short circuit sheet for inspection that can reliably short-circuit each conductor pattern formed on a circuit board to be measured, and can perform a highly reliable inspection. The main purpose is to provide an inspection device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the substrate inspection apparatus according to claim 1 has a large number of small needle-like members having conductivity and elasticity so as to protrude substantially vertically from one surface of the sheet-like base portion having conductivity. The base portion is formed in a cloth shape having air permeability by a conductive fiber and is in contact with a plurality of conductor patterns formed on one surface of the circuit board so that each conductor pattern is formed. substrate mounting table for holding electrically shorted to allow-formed test short sheets to each other, by the circuit substrate placed on one side for that inspection short sheet sucking through a short sheet for the inspection When, and a probe capable of contacting with the conductor pattern formed on the other surface of the circuit board that is mounted on the one surface of the test short sheets, short sheets Contact for the test Wherein are formed on the circuit board by applying a test voltage between the fine said probe being executable to configure the electrical inspection of each conductive pattern.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, with reference to the accompanying drawings, a description will be given of a preferred embodiment of the engagement Ru board inspection apparatus according to the present invention. In addition, about the circuit board P which is an example of a test object, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
[0010]
First, the configuration of the substrate inspection apparatus 1 will be described with reference to the drawings.
[0011]
As shown in FIG. 1, the substrate inspection apparatus 1 includes a substrate mounting table 2, an intake pump 3, a short-circuit sheet 4, a moving mechanism 5, a control unit 6, a RAM 7, and a ROM 8. As shown in FIG. 2, the substrate mounting table 2 is formed in a box shape as a whole, and a concave portion 2 a into which the short-circuit sheet 4 and the circuit board P can be fitted is formed on the upper surface thereof. Further, the substrate mounting table 2 is configured by forming a plurality of air inlets 2b, 2b... On the bottom surface of the recess 2a. Furthermore, the substrate mounting table 2 is configured with an air inlet 2c formed on a side surface thereof. The intake pump 3 communicates with an intake port 2 c of the substrate platform 2 via an intake pipe (not shown) and sucks air in the internal space S of the substrate platform 2.
[0012]
As shown in FIG. 3, the short-circuit sheet (inspection short-circuit sheet) 4 is arranged so that a large number of contact needles 4b, 4b,... Protrude in a substantially vertical direction (preferably a vertical direction) from one surface side of the base portion 4a. It is installed and configured. In this case, the base portion 4a is formed (woven) into a cloth shape having air permeability and flexibility with conductive fibers (as an example, stainless fibers) having a diameter of about 20 μm. Moreover, the base part 4a is formed in the substantially same magnitude | size as the circuit board P, for example. The contact needle 4b corresponds to a needle-like member in the present invention, and is formed, for example, with a length of about 2 mm using a fiber having the same kind of conductivity and elasticity as the base portion 4a (in this example, a stainless fiber having a diameter of about 20 μm). Has been. The contact needles 4b, 4b,... Are arranged at a pitch (for example, a pitch of about 50 μm) narrower than the pitch of the conductor patterns 51, 51,. In this case, since the base portion 4a and the contact needles 4b, 4b,... Are formed of conductive fibers, the contact needles 4b, 4b,... Are electrically connected to each other via the base portion 4a. ing.
[0013]
Under the control of the control unit 6, the moving mechanism 5 moves the probe holding unit 5 a and the probe 5 b shown in FIG. 2 in the XY direction and the vertical direction (Z direction) with respect to the circuit board P fixed to the substrate mounting table 2. And the back surface Pb of the circuit board P in a state of being placed on the short circuit sheet 4 so that the conductor pattern 51 and the tip of the contact needle 4b on the surface Pa (one surface) of the circuit board P are in contact with each other. The tip of the probe 5b is brought into contact with the conductor pattern 52 formed on the other surface.
[0014]
The control unit 6 controls the movement of the probe 5 b (probe holding unit 5 a) by the moving mechanism 5 and the driving of the intake pump 3. Further, the control unit 6 applies a predetermined inspection voltage (DC voltage or AC voltage) between the conductor patterns 51 and 52 via the short-circuit sheet 4 and the probe 5 b, so The measurement of the current flowing through each internal connection pattern 53 and the quality determination process (electrical inspection of the conductor patterns 51 and 52) of the circuit board P based on the measurement value are executed. The RAM 7 temporarily stores measurement values measured by the control unit 6. The ROM 8 stores an operation program for the control unit 6.
[0015]
Next, a method for inspecting the circuit board P using the substrate inspection apparatus 1 will be described with reference to the drawings.
[0016]
First, as shown in FIG. 2, the short circuit sheet 4 is set (placed) on the bottom of the recess 2 a in the substrate platform 2 with the base portion 4 a facing downward. Next, the circuit board P is placed on the short circuit sheet 4 with the surface Pa facing downward. At this time, as shown in FIG. 4, the contact needles 4b, 4b,... Located below the resist 54 in the circuit board P abut against the resist 54, and at that time, elastic deformation is caused by the own weight of the circuit board P. To do. On the other hand, the tips of the contact needles 4b, 4b,... Positioned below the conductor pattern 51 on the circuit board P are in contact with the conductor pattern 51. In this case, since the contact needles 4b, 4b,... Are electrically connected to each other via the base portion 4a, the conductor patterns 51, 51,... Are connected to the contact needles 4b, 4b,. Are electrically connected (short-circuited) to each other.
[0017]
Next, the control unit 6 operates the intake pump 3. At this time, since the air in the internal space S in the substrate mounting table 2 is sucked out by the intake pump 3 and the internal space S becomes negative pressure, the air outside the substrate mounting table 2 is sucked from the intake port 2b. In this case, since the base portion 4a is formed in a cloth shape having air permeability, air between the circuit board P and the base portion 4a is sucked. For this reason, the circuit board P is attracted to the bottom of the recess 2 a and is held by the substrate mounting table 2. Therefore, as shown in FIG. 5, the contact needles 4 b, 4 b... Of the short circuit sheet 4 are further elastically deformed by the suction of the circuit board P. As a result, the contact needles 4b, 4b,... Located below the conductor pattern 51 have their tip portions pressed by the conductor pattern 51 and reliably contact the conductor pattern 51.
[0018]
Subsequently, the control unit 6 moves the probe holding unit 5 a with respect to the moving mechanism 5 to bring the tip of the probe 5 b into contact with one conductor pattern 52 on the circuit board P. Next, the control unit 6 applies a test voltage between the conductor patterns 51 and 52 via the short-circuit sheet 4 and the probe 5b, measures the current flowing through the internal connection pattern 53, and stores the measured value in the RAM 7. Let Next, the control unit 6 brings the tip of the probe 5 b into contact with another conductor pattern 52 adjacent to one conductor pattern 52 with respect to the moving mechanism 5, and an internal connection pattern 53 corresponding to this conductor pattern 52. Is measured, and the measured value is stored in the RAM 7. Hereinafter, similarly, the control unit 6 executes current measurement for each of the internal connection patterns 53, 53... And storage of measurement values in the RAM 7. Next, when the current measurement for all the internal connection patterns 53 is completed, the control unit 6 determines the quality of the circuit board P based on each measurement value stored in the RAM 7. In this case, when any of the current values is a reference value (for example, 10 mA) or less (0 A or almost 0 A), the internal connection pattern 53 corresponding to the current value is disconnected. The circuit board P is determined to be defective. On the other hand, when all the measured values exceed the reference value, the control unit 6 determines that the circuit board P is good.
[0019]
Subsequently, when the inspection is completed, the circuit board P is taken out from the recess 2 a of the substrate platform 2. At this time, since the weighting by the circuit board P is released, the contact needle 4b of the short-circuit sheet 4 returns from the elastically deformed state to the upright state before the weighting. Therefore, even if the short-circuit sheet 4 is repeatedly used for the inspection of the circuit board P, the contact needle 4b is reliably deformed at the tip end thereof without being deformed.
[0020]
As described above, according to the short-circuit sheet 4 and the substrate inspection apparatus 1, the small diameter contact needle 4 b having conductivity and elasticity is projected substantially vertically from one surface of the sheet-like base portion 4 a having conductivity. When the circuit board P is placed on the short circuit sheet 4, the contact needle 4b is elastically deformed by the weight of the circuit board P, and the conductor pattern 51 and the tip of the contact needle 4b are displaced. Therefore, even if the surface of the conductor pattern 51 is recessed with respect to the surface of the resist 54, the conductor patterns 51 can be reliably short-circuited. Therefore, it is possible to reliably avoid a situation in which it is erroneously determined that the internal connection pattern 53 is disconnected although the internal connection pattern 53 is normal due to poor contact between the conductor pattern 51 and the short-circuit sheet 4. As a result, highly reliable substrate inspection can be performed.
[0021]
Further, since the base portion 4a of the short-circuit sheet 4 is formed in a cloth shape having air permeability with conductive fibers, air is sucked from the bottom surface of the recess portion 2a in the substrate mounting table 2 so that the concave portion 2a is inserted through the base portion 4a. Since the circuit board P can be sucked and adsorbed to the bottom side of the circuit board P, the conductor patterns 51, 51,... Of the circuit board P and the tips of the contact needles 4b, 4b,. As a result, the conductor patterns 51, 51,... Can be short-circuited more reliably.
[0022]
The present invention is not limited to the above-described embodiments. For example, the material of the base portion 4a and the contact needle 4b is not limited to stainless steel, and various metals such as copper and brass can be employed. A non-metallic conductive material such as carbon can also be used. Further, the base portion 4a and the contact needle 4b can be formed of resin fibers or the like subjected to metal plating. Further, after the entire short-circuit sheet 4 is formed of a non-conductive material, the entire surface can be plated with metal. Furthermore, the length and thickness of the contact needle 4b are not limited to the above-mentioned size, and can be defined to an arbitrary size according to the weight of the circuit board P. Further, the arrangement pitch of the contact needles 4b can also be defined as an arbitrary pitch according to the pitch of the conductor patterns 51 on the circuit board P.
[0023]
Furthermore, the base portion 4a of the short-circuit sheet 4 is not limited to a cloth shape, and may be configured by forming a vent hole in a sheet-like member having airtightness, for example. In this case, the air permeability is not necessarily required, and a configuration in which no air hole is formed may be employed. In the above-described embodiment, the substrate inspection apparatus 1 including only one probe 5b has been described as an example. However, a configuration including two or more probes can be employed, and the conductor patterns 52, 52,. It is also possible to employ a fixture type probe in which the same number of probes 5b, 5b,... According to these configurations, the probes 5b, 5b,... Can be brought into contact with the conductor patterns 52, 52,. The inspection time for the substrate P can be sufficiently shortened.
[0024]
【The invention's effect】
As described above, according to the board inspecting apparatus according to claim 1, wherein, so as to protrude substantially perpendicularly from one surface of the sheet-like base portion having a conductivity thin needle-like member and have electrical conductivity and elasticity When the circuit board to be inspected is placed on the inspection short circuit sheet with one surface facing downward, the needle-like member is elasticized by its own weight. The tip and the conductor pattern on one surface of the circuit board come into contact with each other, so even if the surface of the conductor pattern is recessed with respect to the surface of the surrounding resist, for example, Can be short-circuited. Therefore, the connection between the conductor patterns formed on both sides of the circuit board due to poor contact between the conductor pattern formed on one side of the circuit board and the short circuit sheet for inspection is disconnected despite the normal connection. As a result, it is possible to surely avoid a situation where it is erroneously determined that the inspection is performed, so that a highly reliable substrate inspection can be performed.
[0025]
Further, according to the board inspection device, by forming a cloth having air permeability of a conductive fiber base portion of the shorting sheet inspection, for example, be inhaled the surface side of the air loading of the substrate mounting table As a result, the circuit board can be sucked to the board mounting table via the base portion, so that the conductor pattern formed on one surface of the circuit board can be reliably brought into contact with the tip of the needle-like member. The pattern can be short-circuited more reliably. Therefore, the connection between the conductor patterns formed on both sides of the circuit board due to poor contact between the conductor pattern formed on one side of the circuit board and the short circuit sheet for inspection is disconnected despite the normal connection. As a result, it is possible to surely avoid the situation of erroneously determining that it is being performed, so that a more reliable substrate inspection can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a substrate inspection apparatus 1 according to an embodiment of the present invention.
2 is a cross-sectional view showing a configuration of a substrate mounting table 2 in the substrate inspection apparatus 1. FIG.
FIG. 3 is a perspective view showing a configuration of a short-circuit sheet 4. FIG.
4 is a cross-sectional view of the short circuit sheet 4 and the circuit board P in a state where the circuit board P is placed on the short circuit sheet 4. FIG.
FIG. 5 is a cross-sectional view of the short circuit sheet 4 and the circuit board P in a state where the circuit board P is adsorbed to the substrate mounting table 2 side.
6 is a cross-sectional view showing a configuration of a circuit board P. FIG.
7 is a cross-sectional view showing a configuration of a conductor pattern 51 and a resist 54 formed on the surface Pa of the circuit board P. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Board | substrate inspection apparatus 2 Board | substrate mounting base 4 Short circuit sheet 4
4a base part 4b contact needle 5 moving mechanism 5b probe 51, 52 conductor pattern 53 internal connection pattern P circuit board Pa surface Pb back surface

Claims (1)

A large number of thin needle-like members having conductivity and elasticity are arranged so as to protrude substantially vertically from one surface of the conductive sheet-like base portion, and the base portion has conductivity. A short circuit sheet for inspection formed in a cloth shape having air permeability by fibers, and formed so as to be able to electrically short each conductor pattern by contacting a plurality of conductor patterns formed on one surface of the circuit board ,
A substrate mounting table for holding by the circuit substrate placed on one side of the short sheet the inspection sucking through a short sheet for the inspection,
And a probe capable of contacting with the conductor pattern formed on the other surface of the circuit board that is mounted on the one surface of the test short sheet,
A board inspection apparatus configured to apply an inspection voltage between the inspection short-circuit sheet and the probe to perform an electrical inspection on each of the conductor patterns formed on the circuit board.

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