JP2017026407A - Circuit board inspection device, and contact check method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a contact check in a short time in a compound circuit board inspection device for inspecting one circuit board surface by a flying probe and inspecting the other circuit board surface by a press-jig type probe.SOLUTION: A pattern having pads 2b, 3c, 3d conducted through a via hole conductor and the like on both surfaces is set as a representative pattern, and the pad 2b of one circuit board surface 1a side of the representative pattern is brought into contact with a flying probe 21 upon performing a contact check. After probes 31a to 31e of a press-jig side are brought into contact with pads 3a to 3e of the other circuit board surface 1b side, electrostatic capacitance is measured between the flying probe 21 and the probes 31a, 31b, 31e of the press-jig side. When the electrostatic capacitance is less than the prescribed threshold value, the site is determined to have a contact failure so as to finish the contact check, and when not having a contact failure; conduction inspection is subsequently performed between the flying probe 21 and the probes 31c, 31d.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit board inspection apparatus, and more particularly to a contact check function for inspecting conduction / non-conduction between a probe and a pad.

  Referring to FIG. 2, as one of circuit board inspection apparatuses for inspecting a substrate 1 to be inspected (in this example, a double-sided board of a bare board), a flying probe 20 is used on one substrate surface side, and the other substrate surface side There is a composite circuit board inspection apparatus using a press jig type test head 30 (see, for example, Patent Document 1).

  In the example of FIG. 2, the flying probe 20 includes two flying probes 20 a and 20 b, both of which are movable in three directions of XYZ. In addition, there is a test head that includes a flying probe for a guard and has three flying probes.

  The other press jig type test head 30 includes a pin board 30A on which a plurality of probes, for convenience of drawing, five probes 31 (31a to 31e) are implanted in this example. Each probe 31 is arranged so as to correspond to a pad (or land) at a predetermined position formed on the inspected substrate 1.

  The pin board 30A can move in the Z-axis direction (vertical direction in FIG. 2), and each probe 31 comes into contact with the pad by bringing the pin board 30A close to (increase) the substrate 1 to be inspected.

  In addition, the circuit board inspection apparatus includes a measurement signal supply source 40 that supplies a predetermined measurement signal to the substrate 1 to be inspected, a detection unit 50 that detects an electrical signal from the substrate 1 to be inspected, and signal supply to the substrate 1 to be inspected. And a scanner (switching means) 60 for switching the path and the signal detection path.

  In the example of FIG. 2, the measurement signal supply source 40 includes a DC power supply 41 and an AC power supply 42, and the detection unit 50 uses an ammeter 51. The flying probe 20, the press jig type test head 30, the measurement signal source 40, and the scanner 60 are controlled by a control unit (not shown), and the control unit performs an inspection such as short / open based on a detection signal from the detection unit 50. Do.

  By the way, no matter what item is inspected, it is premised that the flying probe 20 (20a, 20b) and the press jig side probe 31 (31a-31e) are in contact with the corresponding pads. For example, in a non-conducting test for inspecting that there is no conduction between patterns, if the probe is not in contact with the pad, there is a risk that it will be missed even though the pattern is short-circuited.

  In the case of the composite type, the flying probe 20 moves toward and contacts a predetermined pad according to the control program, so that there is little possibility of causing contact failure. However, the probe 31 on the press jig side is not provided with a hole in the pin board 30A. Compared to the flying probe 20, there is a high possibility of causing contact failure due to positional accuracy, warpage of the substrate to be inspected, and the like.

  For this reason, prior to the original measurement, a contact check for inspecting whether or not the probe is in contact with the pad is performed. Conventionally, a contact check is basically performed by a continuity inspection.

  For example, in the case of the inspected substrate 1 shown in FIG. 2, the continuity test between the press jig side probe 31c and the press jig side probe 31d, the continuity test between the flying probe 20a and the press jig side probe 31b, the flying probe 20b, If continuity inspection between the probes 31e on the press jig side is performed and these are all PASS (conductivity) determination, it is guaranteed that the probes 31b to 31e on the press jig side are in contact with the pad.

  However, in the case of a pad that is electrically independent from other patterns (circuit wiring) and only on one side (the pad on the other side of the probe 31a on the press jig side in FIG. 2), the continuity test cannot be performed. The contact check cannot be performed on the side probe 31a.

  In addition, there are many places where pads on one substrate surface side and pads on the other substrate surface side are conducted via via-hole conductors (pads corresponding to the probes 31b and 31e on the press jig side in FIG. 2). In this case, the continuity test using the flying probe 20 is repeatedly performed at each location, but it takes time to move the flying probe 20, so that there is a problem that it takes time to check the contact.

JP 2005-315775 A

  Therefore, an object of the present invention is to perform contact check for a short time in a composite circuit board inspection apparatus in which a flying probe is applied to one substrate surface side of a double-sided substrate and a press jig test head is applied to the other substrate surface side. It is to be able to do in.

In order to solve the above-mentioned problems, the present invention provides a first probe that can be moved in the X, Y, and Z directions disposed on one substrate surface side of a substrate to be inspected, and a press jig type pin board. A second probe disposed on the other substrate surface side, a measurement signal supply source for supplying a predetermined measurement signal to the substrate to be inspected via the first and second probes, and the target by the measurement signal. While controlling the detection part which detects the electric signal which arises on a test substrate, the switching means which switches the signal supply path | route and signal detection path | route with respect to the said to-be-inspected board, the drive means of the said 1st, 2nd probe, and the said switching means In the circuit board inspection apparatus comprising a control unit that performs contact check of each probe based on the signal detected by the detection unit,
In the control unit, one specified pattern having pads that are conductive through via-hole conductors and / or inner layer patterns on both surfaces is set as a representative pattern among the patterns existing on the substrate to be inspected. And
In performing the contact check of each of the probes, the control unit contacts the first probe with a pad on one substrate surface side of the representative pattern, and each of the second probes is disposed on the other substrate surface side. The capacitance between the first step to contact each positionally corresponding pad, the first probe, and the second probe in contact with the non-conductive pad not conducting to the representative pattern is measured. Conductivity inspection is performed between the second step, the first probe, and the second probe that is in contact with the conductive pad that is conductive with the representative pattern among the pads on the other substrate surface side. A third step, and when the capacitance measured in the second step is less than or equal to a predetermined threshold value, the location is determined to be poor contact.

  As the representative pattern, a power supply pattern or a ground pattern in which the inner layer pattern has a large area is preferably selected.

  Moreover, when it is determined that the contact is poor by the capacitance measurement in the second step, it is preferable not to proceed to the third step.

  The present invention also includes a contact check method for a circuit board inspection apparatus. In this contact check method, conduction is performed on both surfaces via via-hole conductors and / or inner layer patterns from among the patterns existing on the substrate to be inspected. One specified pattern having a certain pad is set as a representative pattern, the first probe is brought into contact with a pad on one substrate surface side of the representative pattern, and each of the second probes is connected to the other pattern. After contacting each positionally corresponding pad on the substrate surface side, the capacitance between the first probe and the second probe that is in contact with the non-conductive pad that is not conductive with the representative pattern is If the measured capacitance is less than or equal to a predetermined threshold value, the contact is determined to be a poor contact, and the contact check is completed. If the measured capacitance exceeds a predetermined threshold value, then, the first probe and the conductive pad connected to the representative pattern among the pads existing on the other substrate surface side are contacted. A continuity test is performed with the second probe.

  According to the present invention, the first probe (flying probe) needs to be moved only once toward the pad of the representative pattern, and the time required for the contact check can be shortened accordingly.

The schematic diagram which shows the principal part of one Embodiment of the circuit board inspection apparatus by this invention. The schematic diagram which shows the principal part of the circuit board inspection apparatus as a prior art example.

  Next, an embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited to this. In the following description, the same reference numerals are used for components that do not require any change from the conventional example described above with reference to FIG.

  The board 1 to be inspected will be described in more detail with reference to FIG. 1. The board 1 to be inspected is a double-sided board of a bare board before component mounting, and one board surface (upper surface in FIG. Two pads (or lands) 2a to 2c are provided, and five pads 3a to 3e are provided on the other substrate surface (lower surface in FIG. 1) 1b.

  Among these, the pads 2a and 3b and the pads 2c and 3e are electrically connected by the via-hole conductor, and the pad 2b is electrically connected to the two pads 3c and 3d through the via-hole conductor and the inner layer pattern. Since the pad 3a on the lower surface 1b side is electrically independent as an island-like pattern and is not conductive with other pads, the continuity test cannot be performed.

  The circuit board inspection apparatus in this embodiment is also a composite using a flying probe 20 on one substrate surface 1a side and a press jig type test head 30 on the other substrate surface 1b side, as in the conventional example described in FIG. Type circuit board inspection device.

  The flying probe 20 has 2 to 3 flying probes (corresponding to the first probe in claim 1), and FIG. 1 shows one flying probe 20a. The flying probe 20a is moved in three directions XYZ by the moving mechanism 201. The X direction and the Y direction are directions orthogonal to each other in a plane parallel to the substrate surface of the substrate 1 to be inspected, and the Z direction is a direction orthogonal to the substrate surface of the substrate 1 to be inspected (in FIG. Direction).

  The press jig type test head 30 includes a pin board 30A in which a plurality of probes (corresponding to the second probe in claim 1), in this example, five probes 31 (31a to 31e) are implanted. The probes 31a to 31e on the press jig side are arranged so as to correspond to the pads 3a to 3e, respectively.

  The pin board 30A can be moved in the Z direction (vertical direction in FIG. 1) by the moving mechanism 301. By bringing the pin board 30A closer to the substrate 1 to be inspected (raised), the probes 31a to 31e on the press jig side Each contacts the pads 3a-3e.

  In addition, the circuit board inspection apparatus includes a measurement signal supply source 40 that supplies a predetermined measurement signal to the substrate 1 to be inspected, a detection unit 50 that detects an electrical signal from the substrate 1 to be inspected, and signal supply to the substrate 1 to be inspected. A scanner (switching means) 60 that switches between a path and a signal detection path, and a control unit 70 are provided.

  Also in this embodiment, the measurement signal supply source 40 includes a DC power supply 41 and an AC power supply 42, and the detection unit 50 uses an ammeter 51.

  The control unit 70 includes a CPU (Central Processing Unit), a microcomputer, and the like. The control unit 70 includes the flying probe 20, the moving mechanisms 201 and 301 of the press jig type test head 30, the measurement signal source 40, and the scanner 60. Control.

  Further, the control unit 70 performs, for example, a short / open inspection or a predetermined calculation based on a detection signal from the detection unit 50 or the like. Connected to the control unit 70 are an operation unit 71 including a keyboard for inputting inspection items and the like to the control unit 70 and a display unit 72 including an LCD for displaying inspection results and the like. A connection port for communicating with an external device such as a personal computer may be provided.

  In performing a contact check of the probe, as a preparation stage, a representative pattern is set for the control unit 70 from patterns (circuit wirings) existing on the substrate 1 to be inspected by the operation unit 71.

  The representative pattern is a specified pattern having pads that are conductive through via-hole conductors and / or inner layer patterns on each of the upper surface 1a and the lower surface 1b. In the example of FIG. A circuit unit having 2a and 3b, a circuit unit having three pads 2b, 3c and 3d, and a circuit unit having two pads 2c and 3e are applicable. In this embodiment, three pads 2b, 3c and 3d are provided. The circuit portion that has it is set as a representative pattern.

  When a contact check command is issued from the operation unit 71 with the representative pattern set in this way, the control unit 70 moves the flying probe 20a to the representative pattern via the moving mechanisms 201 and 301 as the first step. While moving toward the pads 2b on the one substrate surface 1a side, the probes 31a to 31e on the press jig side are moved toward the corresponding pads 3a to 3e on the other substrate surface 1b side. Then, the second step is executed.

  In the second step, the electrostatic capacitance between the flying probe 20a that is in contact with the pad 2b and the press jig side probes 31a, 31b, and 31e corresponding to the pads 3a, 3b, and 3e that are non-conductive with the pad 2b is set. Measure and perform contact check.

  At this time, the scanner 60 connects the flying probe 20 a to the AC power source 42 and sequentially connects the press jig-side probes 31 a, 31 b, and 31 e to the ammeter 51. On the contrary, the flying probe 20a may be connected to the ammeter 51, and the probes 31a, 31b, 31e on the press jig side may be sequentially connected to the AC power source 42.

  Thereby, the capacitance between the flying probe 20a and the probe 31a on the press jig side, between the flying probe 20a and the probe 31b on the press jig side, and between the flying probe 20a and the probe 31e on the press jig side is measured. If the capacitance value is not more than a preset threshold value, it is determined that the contact is defective.

  The electrostatic capacitance between the flying probe 20a and the probe 31 (31a, 31b, 31e) on the press jig side is determined by the calculation function of the control unit 70, the AC voltage of the AC power source 42, and the AC current detected by the ammeter 51. Is calculated from The threshold value for the capacitance value is set by the operation unit 71.

  In this embodiment, if the determination in the second step is NG (there is a contact failure location), the contact check is terminated without proceeding to the next step, but the determination is PASS (no contact failure location). Performs the following third step.

  In the third step, the DC power source 41 is selected in a state where the flying probe 20a is kept in contact with the pad 2b without being moved, and the flying probe 20a and the pads 3c and 3d that are electrically connected to the pad 2b are selected. A direct current is passed between the probes 31c and 31d on the press jig side, and continuity inspection is performed between the flying probe 20a and the probe 31c on the press jig side and between the flying probe 20a and the probe 31d on the press jig side.

  At this time, the scanner 60 connects the flying probe 20 a to the DC power supply 41 and sequentially connects the press jig side probes 31 c and 31 d to the ammeter 50. Conversely, the flying probe 20a may be connected to the ammeter 51, and the probes 31c and 31d on the press jig side may be sequentially connected to the DC power source 41.

  If predetermined currents are detected by the ammeter 51 between the flying probe 20a and the probe 31c on the press jig side and between the flying probe 20a and the probe 31d on the press jig side, respectively, the flying probe 20a and the probe 31c on the press jig side, 31d is determined to be PASS as being in contact with the pad.

  On the other hand, when a predetermined current is not detected between the flying probe 20a and the press jig side probe 31c, one or both of the flying probe 20a and the press jig side probe 31c are in poor contact. -When a predetermined current is not detected between the probes 31d on the press jig side, one or both of the flying probe 20a and the probe 31d on the press jig side are judged to be in contact failure.

  The determination results in the second step and the third step are displayed on the display unit 72 in either case of PASS or NG. In addition, in place of the display unit 72 or separately from the display unit 72, a notification unit such as a buzzer may be provided.

  Further, when the substrate 1 to be inspected has a power supply pattern, a ground pattern, or the like formed with a large area in the substrate, these inner layer patterns (power supply pattern, ground pattern or a corresponding wide pattern) It is preferable to set the area inner layer pattern) as a representative pattern.

  As described above, according to the present invention, at the time of contact check, it is only necessary to move the flying probe toward the pad of the representative pattern once, and then it is not necessary to move the flying probe. Contact check can be completed in a short time.

1 Substrate 2a-2c, 3a-3e Pad 20 (20a, 20b) Flying probe (first probe)
201 moving mechanism 30 press jig type test head 30A pin board 31 (31a to 31e) probe on the press jig side (second probe)
DESCRIPTION OF SYMBOLS 301 Movement mechanism 40 Measurement signal supply source 41 DC power supply 42 AC power supply 50 Detection part 51 Ammeter 60 Scanner 70 Control part 71 Operation part 72 Display part

Claims (4)

A first probe which is arranged on one substrate surface side of a substrate to be inspected consisting of a double-sided substrate and which can be moved in the XYZ direction, and is placed on a press jig type pin board and arranged on the other substrate surface side A second probe, a measurement signal supply source for supplying a predetermined measurement signal to the substrate to be inspected via the first and second probes, and a detection unit for detecting an electric signal generated on the substrate to be inspected by the measurement signal And a switching means for switching a signal supply path and a signal detection path for the substrate to be inspected, a driving means and the switching means for the first and second probes, and a signal detected by the detection unit. In a circuit board inspection apparatus comprising a control unit that performs contact check of each probe based on the above,
In the control unit, one specified pattern having pads that are conductive through via-hole conductors and / or inner layer patterns on both surfaces is set as a representative pattern among the patterns existing on the substrate to be inspected. And
In performing the contact check of each probe, the control unit,
A first step of bringing the first probe into contact with a pad on one substrate surface side of the representative pattern, and bringing each of the second probes into contact with a corresponding pad on the other substrate surface side;
A second step of measuring a capacitance between the first probe and a second probe in contact with a non-conductive pad that is not conductive with the representative pattern;
A third step of conducting a continuity test between the first probe and a second probe in contact with the conductive pad that is conductive with the representative pattern among the pads on the other substrate surface side; Prepared,
The circuit board inspection apparatus according to claim 1, wherein, when the capacitance measured in the second step is equal to or less than a predetermined threshold value, the location is determined to be poor contact.   2. The circuit board inspection apparatus according to claim 1, wherein a power supply pattern or a ground pattern in which the inner layer pattern has a large area is selected as the representative pattern.   3. The circuit board inspection apparatus according to claim 1, wherein if the contact is determined to be poor by the capacitance measurement in the second step, the process does not proceed to the third step. 4. A first probe which is arranged on one substrate surface side of a substrate to be inspected consisting of a double-sided substrate and which can be moved in the XYZ direction, and is placed on a press jig type pin board and arranged on the other substrate surface side A second probe, a measurement signal supply source for supplying a predetermined measurement signal to the substrate to be inspected via the first and second probes, and a detection unit for detecting an electric signal generated on the substrate to be inspected by the measurement signal And a contact check method for a circuit board inspection apparatus comprising a switching means for switching a signal supply path and a signal detection path for the substrate to be inspected.
One specified pattern having pads that are conductive on both surfaces via via hole conductors and / or inner layer patterns is set as a representative pattern from among the patterns present on the substrate to be inspected, and then the first probe is used. Are brought into contact with pads on one substrate surface side of the representative pattern, and each of the second probes is brought into contact with each positionally corresponding pad on the other substrate surface side,
When the capacitance between the first probe and the second probe that is in contact with the non-conductive pad that is not conductive with the representative pattern is measured, and the measured capacitance is equal to or less than a predetermined threshold value Determines that the contact is poor and ends the contact check.
If the measured capacitance exceeds a predetermined threshold value, then, among the pads present on the first probe and the other substrate surface side, a conductive pad that is electrically connected to the representative pattern is subsequently applied. A contact check method for a circuit board inspection apparatus, wherein a continuity inspection is performed with a second probe in contact with the second probe.