JP4657758B2 - Substrate inspection apparatus and substrate inspection method - Google Patents

Description

  The present invention relates to a substrate inspection apparatus and a substrate inspection method for performing a continuity inspection between two measurement points that are set in advance on the wiring pattern with respect to a substrate to be inspected on which a plurality of wiring patterns are formed. In particular, the present invention relates to a substrate inspection apparatus and a substrate inspection method for performing a continuity inspection between the two measurement points on a buildup substrate having a via.

  The wiring pattern on a circuit board needs to accurately transmit electrical signals to electrical components such as ICs and resistors mounted on the circuit board. Between printed wiring boards, circuit wiring boards on which wiring patterns are formed on liquid crystal panels and plasma display panels, or wiring patterns formed on boards such as semiconductor wafers, between measurement points provided on wiring patterns to be inspected The resistance value is measured and the quality is inspected.

Thus, in order to determine the quality of the substrate based on the resistance value between the measurement points, it is necessary to accurately measure the resistance value between the measurement points, and a higher accuracy can be achieved by using a known four-terminal measurement method. A measurement method capable of measurement has been proposed (see Patent Document 1).
Japanese Patent Laid-Open No. 10-123189

  On the other hand, in recent years, with the progress of miniaturization of circuit boards, the width of the wiring pattern is narrowed, and the influence of the variation in the width (or thickness) of the wiring pattern on the resistance value between the measurement points is increasing. Therefore, the variation in the resistance value between the measurement points is large, and even when the resistance value between the measurement points is measured with high accuracy as described above, it is difficult to set a threshold value that is a criterion for the pass / fail judgment. It may be difficult to accurately perform a continuity test of the substrate.

  In particular, when the substrate is a build-up substrate having vias, for example, the increase in resistance value between measurement points due to a bonding failure occurring in a via such as a laser via is small, and the measurement is accompanied by variations in the width of the wiring pattern, etc. It becomes almost the same as (or less than) the variation in the resistance value between the points, and it becomes extremely difficult to set a threshold value as a criterion for pass / fail judgment.

  The present invention has been made in view of the above problems, and an object thereof is to provide a substrate inspection apparatus and a substrate inspection method for accurately performing a continuity inspection of a substrate to be inspected.

The substrate inspection apparatus according to claim 1 is a substrate inspection apparatus that performs a continuity inspection between two measurement points set in advance on each wiring pattern for a substrate to be inspected on which a plurality of wiring patterns are formed. A test signal generating means for sequentially generating a signal in which the absolute value of the test signal changes to at least two levels, and applying the generated test signal between the two measurement points; Measuring means for measuring an output signal between the two corresponding measurement points; and a determination means for determining the quality of the inspected substrate based on the output signal , wherein the inspection signal generating means has a positive polarity A positive test signal that is a test signal and a negative test signal that is a test signal having a negative polarity are alternately generated for a predetermined period, and the absolute value of each signal changes every period. The absolute value of the inspection signal is A signal that increases every period and sequentially generates signals having substantially the same absolute value, and the measurement means is a positive output that is an output signal between the two measurement points corresponding to the positive test signal and the negative test signal, respectively. A signal and a negative output signal are measured, and the determination means determines the quality of the substrate to be inspected based on the positive output signal and the negative output signal, and the resistance according to an increase in an absolute value of the inspection signal When the difference between the minimum value and the maximum value is greater than or equal to a predetermined threshold value, it is determined that the substrate to be inspected is defective .

  According to the above configuration, the inspection signal generation means sequentially generates a signal in which the absolute value of the inspection signal changes to at least two levels, and the generated inspection signal has two measurements set in advance on each wiring pattern. It is given between points. Then, an output signal between two measurement points corresponding to each level of the inspection signal is measured by the measuring means, and the quality of the substrate to be inspected is determined based on these output signals by the determining means.

  Therefore, since the quality of the substrate to be inspected can be determined based on the output signals corresponding to the inspection signals whose absolute values change to at least two levels, the continuity inspection of the substrate to be inspected can be accurately performed.

  According to the above configuration, the test signal generation means alternately generates a positive test signal that is a positive test signal and a negative test signal that is a negative test signal for a predetermined period, and A signal whose absolute value changes every cycle is generated. Then, a positive output signal and a negative output signal, which are output signals between two measurement points respectively corresponding to the positive inspection signal and the negative inspection signal, are measured by the measurement means, and the positive output signal and the negative output signal are determined by the determination means. Based on this, the quality of the substrate to be inspected is determined.

  Therefore, since a positive output signal and a negative output signal, which are output signals between two measurement points corresponding to the positive test signal and the negative test signal, are measured, measurement errors due to polarity (measurement errors due to Seebeck effect etc.) ) Is measured, and an accurate measurement is possible.

  In addition, a positive test signal and a negative test signal are generated for a predetermined period, and a signal in which the absolute value of each signal changes every cycle is generated, which accompanies a change in the absolute value of the positive test signal and the negative test signal. Since the quality of the board to be inspected can be determined based on the change in the positive output signal and the negative output signal, the continuity inspection of the board to be inspected can be accurately performed.

  According to said structure, the signal which the absolute value of a positive test signal and a negative test signal increases for every period is produced | generated by a test signal production | generation means.

  Accordingly, a signal for increasing the absolute value of the positive inspection signal and the negative inspection signal every period is given between two measurement points set in advance on each wiring pattern, so that irreversibility in a defective portion in the wiring pattern is provided. Even when the output signal changes due to a general change, the possibility that a defect is detected increases, and the continuity inspection of the substrate to be inspected can be performed accurately.

  For example, when a positive inspection signal or a negative inspection signal having an absolute value greater than or equal to a predetermined value is applied, an irreversible change in the wiring pattern (for example, when there is a contact failure in a via, a joint failure portion is melted by heat generation) When the change occurs, the output signal changes before and after the predetermined value, so that a defect is detected and the continuity inspection of the substrate to be inspected can be performed accurately.

  According to the above configuration, the inspection signal generation unit sequentially generates signals having substantially the same absolute value as the positive inspection signal and the negative inspection signal.

  Accordingly, since a positive output signal and a negative output signal, which are output signals between two measurement points respectively corresponding to a positive test signal and a negative test signal having substantially the same absolute value, are measured, measurement errors associated with polarity are further increased. An output signal that can be canceled out precisely is measured, and a more accurate measurement is possible.

The substrate inspection apparatus according to claim 2 , wherein the inspection signal generation unit generates a rectangular wave having a predetermined width as the positive inspection signal and the negative inspection signal, and the measurement unit includes the positive output signal and the negative output. Each of the signals is measured a predetermined number of times equal to or greater than 2, and the determination means determines the absolute values of the positive test signal and the negative test signal and the average of the number of the positive output signals and the negative output signals corresponding to the predetermined number of times. It is characterized by determining based on the value.

  According to the above configuration, the inspection signal generation unit generates a rectangular wave having a predetermined width as the positive inspection signal and the negative inspection signal, and the measurement unit outputs the positive output signal and the negative output signal two or more times each. Only measured. Then, the determination means determines the quality of the substrate to be inspected based on the absolute values of the positive inspection signal and the negative inspection signal and the average values of the number of positive output signals and negative output signals corresponding to a predetermined number of times. .

  Therefore, the quality of the inspected substrate is determined based on the average value of each of the positive output signals and the negative output signals corresponding to a predetermined number of times of 2 or more, so that a more accurate output signal is measured, and further Accurate determination is possible.

The substrate inspection apparatus according to claim 3 , wherein the inspection signal generation unit sequentially generates a positive inspection current and a negative inspection current from a constant current source whose output level can be changed as the positive inspection signal and the negative inspection signal. The measuring means measures a positive output voltage value and a negative output voltage value, which are voltage values respectively corresponding to the positive inspection current and the negative inspection current, and the determination means is an absolute value of the positive inspection current and the negative inspection current. And a positive output voltage value and a negative output voltage value, and a resistance value is obtained, and a determination is made based on the obtained resistance value.

  According to the above configuration, the positive inspection current and the negative inspection current are sequentially generated from the constant current source whose output level can be changed as the positive inspection signal and the negative inspection signal by the inspection signal generation means, and the positive inspection current is generated by the measurement means. A positive output voltage value and a negative output voltage value, which are voltage values respectively corresponding to the current and the negative inspection current, are measured. Then, the determination means obtains the resistance value using the absolute values of the positive inspection current and the negative inspection current, and the positive output voltage value and the negative output voltage value, and the quality of the inspected substrate is determined based on the obtained resistance value. Is determined.

  Therefore, since the inspection signal is generated by the constant current source whose output level can be changed, the inspection signal is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value, an appropriate continuity test is performed.

The substrate inspection apparatus according to claim 4 , wherein the inspection signal generation unit sequentially generates a positive inspection voltage and a negative inspection voltage from a constant voltage source whose output level can be changed as the positive inspection signal and the negative inspection signal. The measuring means measures a positive output current value and a negative output current value, which are current values respectively corresponding to the positive inspection voltage and the negative inspection voltage, and the determination means is an absolute value of the positive inspection voltage and the negative inspection voltage. And the positive output current value and the negative output current value are used to determine a resistance value, and a determination is made based on the obtained resistance value.

  According to the above configuration, the positive inspection voltage and the negative inspection voltage are sequentially generated from the constant voltage source whose output level can be changed as the positive inspection signal and the negative inspection signal by the inspection signal generation means, and the positive inspection voltage is generated by the measurement means. A positive output current value and a negative output current value, which are current values corresponding to the voltage and the negative test voltage, are measured. Then, the determination means obtains the resistance value using the absolute value of the positive inspection voltage and the negative inspection voltage, and the positive output current value and the negative output current value, and the pass / fail of the inspected board is determined based on the obtained resistance value. Is determined.

  Accordingly, since the inspection signal is generated by the constant voltage source whose output level can be changed, the inspection signal is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value, an appropriate continuity test is performed.

According to the configuration of the first aspect, the substrate to be inspected is determined to be defective by the determination means when the change in resistance value accompanying the increase in the absolute value of the inspection signal is equal to or greater than a predetermined threshold.

  Accordingly, whether or not the substrate to be inspected is defective is determined depending on whether or not the change in the resistance value accompanying the increase in the absolute value of the inspection signal is greater than or equal to a predetermined threshold value. The quality of the substrate is determined.

  Here, “change in resistance value” is a concept that includes not only the amount of change in resistance value but also the rate of change in resistance value, etc. “predetermined threshold” corresponds to the form of “change in resistance value”. To do. For example, in the case of a change amount of the resistance value, it is a threshold value of the change amount.

The substrate inspection apparatus according to claim 5 is characterized in that the substrate to be inspected is a build-up substrate having vias.

  According to the above configuration, since the substrate to be inspected is a build-up substrate having vias, whether or not the substrate to be inspected is accurately determined even when a bonding failure or the like occurs in the vias.

  For example, when there is a bonding failure in the via, the inspection current applied to the via increases, and the resistance value decreases when the bonding failure portion melts due to heat generation and the conduction area increases. By detecting a change in the resistance value, a via junction failure is detected.

The substrate inspection method according to claim 6 is a substrate inspection method for performing a continuity inspection between two measurement points set in advance on each wiring pattern for a substrate to be inspected on which a plurality of wiring patterns are formed. A test signal generating step of sequentially generating a signal in which the absolute value of the test signal changes to at least two levels, and applying the generated test signal between the two measurement points; A measurement step of measuring an output signal between the two corresponding measurement points; and a determination step of determining pass / fail of the inspected substrate based on the output signal , wherein the inspection signal generation step has a positive polarity A positive test signal that is a test signal and a negative test signal that is a test signal having a negative polarity are alternately generated for a predetermined period, and the absolute value of each signal changes every period. Inspection The absolute value of the signal increases every period, and signals having substantially the same absolute value are sequentially generated, and the measurement step is performed between the two measurement points corresponding to the positive test signal and the negative test signal, respectively. A positive output signal and a negative output signal, which are output signals, are measured, and the determination step is to determine pass / fail of the substrate to be inspected based on the positive output signal and the negative output signal, and an absolute value of the inspection signal When the difference between the minimum value and the maximum value of the resistance value accompanying the increase in the value is equal to or greater than a predetermined threshold value, it is determined that the substrate to be inspected is defective .

  According to the above method, signals in which the absolute value of the inspection signal changes to at least two levels are sequentially generated. Then, an output signal between two measurement points corresponding to each level of the inspection signal is measured. Furthermore, the quality of the substrate to be inspected is determined based on these output signals.

  Therefore, since the quality of the substrate to be inspected can be determined based on the output signals corresponding to the inspection signals whose absolute values change to at least two levels, the continuity inspection of the substrate to be inspected can be accurately performed.

According to the first and sixth aspects of the present invention, the quality of the substrate to be inspected can be determined based on the output signals respectively corresponding to the inspection signals whose absolute values change to at least two levels. Inspection can be performed accurately.

According to the invention of claim 1, 6, the positive output signal and negative output signal which is the output the signal between the two measurement points corresponding to the positive test signal and a negative test signal is measured, due to the polarity An output signal that can cancel a measurement error (measurement error due to the Seebeck effect or the like) is measured, and an accurate measurement can be performed.

According to the first and sixth aspects of the present invention, a signal for increasing the absolute values of the positive inspection signal and the negative inspection signal every period is provided between two measurement points set in advance on each wiring pattern. Therefore, even when the output signal changes due to an irreversible change in the defective portion in the wiring pattern, the possibility that a defect is detected increases, and the continuity inspection of the substrate to be inspected can be performed accurately.

According to the invention of claim 1,6, measured positive output signal and negative output signal which is the output signal between two corresponding measurement points each absolute value is substantially the same positive test signal and a negative test signal to each other Therefore, an output signal that can more accurately cancel the measurement error due to the polarity is measured and can be measured more accurately.

According to the invention described in claim 2, since the quality of the substrate to be inspected is determined on the basis of the respective average value of the positive output signal and negative output signal of the number corresponding to two or more predetermined number of times, more accurate As a result, a more accurate determination can be made.

According to the third aspect of the invention, since the inspection signal is generated by the constant current source whose output level can be changed, the inspection signal is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value, an appropriate continuity test can be performed.

According to the fourth aspect of the invention, since the inspection signal is generated by the constant voltage source whose output level can be changed, the inspection signal is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value, an appropriate continuity test can be performed.

According to the first aspect of the present invention, it is determined whether or not the substrate to be inspected is defective depending on whether or not the change in the resistance value accompanying the increase in the absolute value of the inspection signal is equal to or greater than a predetermined threshold value. Therefore, it is possible to determine the quality of the substrate to be inspected more accurately.

According to the fifth aspect of the present invention, since the substrate to be inspected is a build-up substrate having vias, it is possible to accurately determine the quality of the substrate to be inspected even when a bonding failure occurs in the vias.

  FIG. 1 is a side sectional view showing an embodiment of a substrate inspection apparatus according to the present invention, and FIG. 2 is a plan view of the substrate inspection apparatus of FIG. In order to clarify the directional relationship with each drawing described later, XYZ rectangular coordinate axes are described.

  As shown in these drawings, in this substrate inspection apparatus, an opening / closing door 11 is disposed on the front side (−Y side) of the apparatus so as to be openable and closable with respect to the apparatus main body 1, and the opening / closing door 11 is opened. Then, a substrate 2 (corresponding to a substrate to be inspected: see FIG. 6), which is a build-up substrate having wiring patterns formed in a plurality of layers, is transferred from the loading / unloading portion 3 provided in the central portion on the front side of the device. It is possible to carry in. In addition, on the rear side (+ Y side) of the loading / unloading unit 3, a plurality of (for example, 500) contacts 44 for transmitting an inspection signal are provided, and a land (corresponding to a measurement point) of the wiring pattern of the substrate 2. An inspection unit 4 is provided for moving an inspection jig 41 (to be described later) so as to bring the contact 44 into contact therewith.

  Further, an instruction signal for moving the contactor 44 to contact the measurement point and an inspection signal output to the measurement point via the contactor 44 are output to the inspection unit 4, and A measurement execution unit 74 that receives an output signal or the like and transmits the output signal to a control unit 8 (not shown), which will be described later, is disposed at an appropriate place (here, in the upper part of the apparatus main body 1). Then, the substrate 2 that has been inspected by the inspection unit 4 and the measurement execution unit 74 (that is, pass / fail determination) is returned to the carry-in / out unit 3, and the opening / closing door 11 is opened, so that the operator can carry it out.

  In this substrate inspection apparatus, in order to transfer the substrate 2 between the loading / unloading unit 3 and the inspection unit 4, the transfer table 5 is provided movably in the Y direction, and the transfer table 5 is It is configured to be moved and positioned in the direction. That is, in the transport table drive mechanism 6, the two guide rails 61 extending in the Y direction are arranged apart from each other in the X direction by a predetermined interval, and the transport table 5 is slidable along these guide rails 61. .

  A ball screw 62 is disposed in parallel with the guide rails 61. One end (−Y side) of the ball screw 62 is pivotally supported by the apparatus main body 1, and the other end (+ Y side) is used for driving the transport table. It is connected with the rotating shaft 64 of the motor 63. Further, a bracket 65 to which the transport table 5 is fixed is screwed onto the ball screw 62, and when the motor 63 is rotationally driven in response to a command from the control unit 8 (see FIGS. 3 and 5) described later, The transfer table 5 moves in the Y direction according to the amount of rotation, and is reciprocated between the loading / unloading unit 3 and the inspection unit 4.

  With reference to FIG. 2, the transfer table 5 includes a substrate mounting portion 51 for mounting the substrate 2. The substrate platform 51 includes an urging means (not shown) that urges the substrate 2 from a direction opposite to the engagement pins 53 while the substrate 2 placed is engaged with the three engagement pins 53. ), The substrate 2 is urged toward the engagement pin 53 and the substrate 2 can be held on the substrate mounting portion 51. Further, in order to bring a contact 44 of the lower inspection unit 4D, which will be described later, into contact with the wiring pattern formed on the lower surface of the substrate 2 held in this manner, the substrate mounting portion 51 has a through opening (not shown). Is formed.

  The inspection unit 4 includes an upper inspection unit 4U for inspecting a wiring pattern formed on the upper surface side of the substrate 2 on the upper side (+ Z side) across the movement path of the transport table 5, and a lower side (−Z side). And a lower inspection unit 4D for inspecting a wiring pattern formed on the lower surface side of the substrate 2. The inspection units 4U and 4D have substantially the same configuration, and are arranged substantially symmetrically across the movement path of the transport table 5. The inspection units 4U and 4D include an inspection jig 41 and an inspection jig driving mechanism 43.

  FIG. 3 is a configuration diagram illustrating an example of an electrical configuration of the substrate inspection apparatus. The board inspection apparatus includes a CPU, a ROM, a RAM, a motor driver, etc., and controls the entire apparatus according to a program stored in the ROM in advance (see FIG. 4), a tester controller 75, and a measurement execution section 74. And.

  The tester controller 75 receives an inspection start command from the control unit 8, and in accordance with a program stored in advance, the wiring pattern to be inspected from among the plurality of contacts 44 abutted on the land of the wiring pattern on the substrate 2 The two contacts 44 respectively contacting the two lands (hereinafter referred to as “measurement point set”) located at both ends are sequentially selected. In addition, the tester controller 75 outputs a scan command to the measurement execution unit 74 so as to perform an inspection between the two selected contacts 44. Further, the tester controller 75 receives the resistance value measured from the measurement execution unit 74 (an inspection processing unit 741 described later with reference to FIG. 6) and transmits the resistance value to the control unit 8.

  On the other hand, as shown in FIG. 3, the inspection jig driving mechanism 43 is connected to an X jig driving unit 43 </ b> X that moves the inspection jig 41 in the X direction with respect to the apparatus main body 1 and an X jig driving unit 43 </ b> X. Y jig driving portion 43Y for moving the inspection jig 41 in the Y direction, θ jig driving portion 43θ connected to the Y jig driving portion 43Y for rotating the inspection jig 41 around the Z axis, and θ The Z jig driving section 43Z is connected to the jig driving section 43θ and moves the inspection jig 41 in the Z direction. The control section 8 moves the inspection jig 41 relative to the transport table 5 relative to the conveyance table 5. The contactor 44 can be brought into contact with or separated from the wiring pattern formed on the substrate 2 by positioning or raising / lowering the inspection jig 41 in the vertical direction (Z direction). ing.

  FIG. 4 is a configuration diagram illustrating an example of a hardware configuration of the control unit 8. The control unit 8 includes, for example, a personal computer, and includes a main control unit 81 that controls the overall operation of the control unit 8, an operation unit 82 that includes an unillustrated keyboard and mouse that accept external operations, and an external device The data transmission path includes a speaker 83 for outputting sound, a monitor 84 for outputting an image to the outside, a communication control unit 85 for communicating with the tester controller 75, and a printer 86 for printing various information on recording paper. It is connected via the bus BA8.

  The main control unit 81 controls the overall operation of the control unit 8, and includes an information processing unit (CPU) 811, a RAM 812 that temporarily stores information during processing, an OS (operating system), a predetermined And a ROM 813 in which image information and the like are stored in advance.

  Of various data stored in the RAM 812 or the ROM 813, data that can be stored in a removable recording medium can be read by a driver such as a hard disk drive, an optical disk drive, a flexible disk drive, a silicon disk drive, or a cassette medium reader. In this case, the recording medium is, for example, a hard disk, an optical disk, a flexible disk, a CD, a DVD, a semiconductor memory, or the like.

  The interface units 821 and 861 are used to exchange data between the operation unit 82 and the printer 86 and the main control unit 81, respectively. The audio reproducing unit 831 outputs predetermined audio (for example, alarm, audio for operation guidance, etc.) to the speaker 83 in accordance with an instruction from the main control unit 81. The drawing processing unit 841 displays a required image on the monitor 84 in accordance with an image display instruction from the main control unit 81, and includes a video RAM and the like.

  FIG. 5 is a conceptual diagram showing an example of the configuration of the substrate 2. (A) is the perspective view which transparentized except the wiring pattern, (b) is sectional drawing. The substrate 2 includes a first substrate 21 having a wiring pattern 211a formed on the upper surface 211 of the insulating substrate 212, a wiring pattern 221a formed on the upper surface 221 of the insulating substrate 222, and a wiring pattern 223a formed on the lower surface 223. It is a build-up multilayer (here, three layers) printed wiring board (corresponding to a build-up board) composed of the second board 22.

  The wiring pattern 211a is connected to the wiring pattern 221a through the via TH1 formed in the insulating substrate 212 so as to be energized. Further, the wiring pattern 221a is connected to the wiring pattern 223a through the via TH2 formed in the insulating substrate 222. And connected to be energized. Here, the via TH1 and the via TH2 are laser vias, which are micro vias formed by a laser, and are defective in the bonding surface between the copper plating layer formed on the cylindrical side surface of the via and the wiring patterns 221a and 223a. However, when the defect is minor, the increase in the resistance value between the measurement point sets accompanying the defect (for example, between the measurement point MP1 and the measurement point MP2 on the wiring pattern 211a) is small, and detection is performed. May be difficult.

<First Embodiment>
FIG. 6 is a conceptual diagram for explaining an example of the configuration of the measurement execution unit 74 according to the first embodiment. The measurement execution unit 74 includes a current generation unit 742 (corresponding to a constant current source and a part of the inspection signal generation unit) including a current source that outputs an inspection current having a predetermined value (value set by the control unit 8) If. A voltage measuring unit 743 (corresponding to a part of the measuring means) that measures a voltage drop amount (potential difference) generated in the wiring pattern by the inspection current, and a plurality of contacts 44 provided in the inspection jig 41 To a contactor 44 selected by a tester controller 75 (see FIG. 3), and a scanner 744 including a switch array or the like for connecting a current generation unit 742 and a voltage measurement unit 743 to each other.

  In response to the scan command from the tester controller 75, the inspection processing unit 741 connects the current generation unit 742 between the two contacts 44 that are current supply targets, and the voltage between the two contacts 44 that are potential difference detection targets. A control signal is output to the scanner 744 to connect the measuring units 743 to each other. The inspection processing unit 741 transmits the voltage value (potential difference) measured by the voltage measuring unit 743 to the tester controller 75.

  Next, the board | substrate inspection apparatus which concerns on 1st Embodiment of this invention is demonstrated using FIGS. FIG. 7 is a configuration diagram illustrating an example of a functional configuration of the control unit 8 according to the first embodiment. The CPU 811 of the control unit 8 includes an inspection signal generation unit 811a (corresponding to a part of the inspection signal generation unit) that generates an inspection signal, and a measurement unit 811b (corresponding to a part of the measurement unit) that measures an output signal. And a determination unit 811c (corresponding to determination means) for determining the quality of the substrate 2.

  The inspection signal generation unit 811a causes the current generation unit 742 to alternately generate a positive inspection current having a positive inspection current and a negative inspection current having a negative polarity, and generate the generated positive inspection current. In addition, a negative inspection current is sequentially applied between two predetermined measurement points of the substrate 2 via the contactor 44.

  Further, the test signal generator 811a sequentially generates currents having the same absolute value (I0) as the positive test current Ia and the negative test current Ib as shown in FIG. As shown, a current whose absolute value I0 increases every period is generated for a predetermined period (here, four periods). Specifically, the test signal generation unit 811a has predetermined current values If of + I1, -I1, + I2, -I2, + I3, -I3, + I4, and -I4 as described later with reference to FIGS. A substantially rectangular wave current having a width (for example, a width of 10 msec) is generated (absolute values I0 = I1 to I4). However, values of I1, I2, I3, and I4 increase in this order. For example, I1 = 10 mA, I2 = 15 mA, I2 = 20 mA, and I4 = 25 mA.

  As shown in FIG. 8, the measurement unit 811b measures a positive output voltage Va and a negative output voltage Vb, which are output voltages between two measurement points corresponding to the positive inspection current Ia and the negative inspection current Ib, respectively. . Further, as will be described later with reference to FIGS. 9 and 10, the measurement unit 811 b uses the current values If (= + I 1, −I 1, + I 2, −I 2, + I 3, −I 3, + I 4, -I4) is to measure voltage values Va00 to Va09 and voltage values Vb00 to Vb09 (not shown) a predetermined number of times (here, 10 times).

  The determination unit 811c determines the quality of the substrate 2 based on the positive output voltage Va and the negative output voltage Vb. Specifically, as will be described later with reference to FIGS. 9 and 10, the determination unit 811 c determines the absolute values of the positive inspection currents + I 1, + I 2, + I 3, + I 4 and the negative inspection currents −I 1, −I 2, −I 3, −I 4. (I1, I2, I3, I4), 10 positive test voltages Va00 to Va09 and negative test signal Vb00 corresponding to the positive test currents + I1 to + I4 and the negative test currents −I1 to −I4 at four output levels, respectively. The resistance values Rx1 to Rx4 are obtained using the average values Va1 to Va4 and Vb1 to Vb4 of ˜Vb09 (not shown), and the determination is made based on the obtained resistance values Rx1 to Rx4.

  Specifically, the determination unit 811c determines that the substrate 2 is defective when changes in the resistance values Rx1 to Rx4 are equal to or greater than a predetermined threshold. Specifically, for example, when the difference ΔRx between the minimum value and the maximum value of the resistance values Rx1 to Rx4 is equal to or greater than a predetermined threshold (for example, 10 mΩ), the substrate 2 is determined to be defective (see FIG. 10).

  A board inspection program that causes the control unit 8 to function as the inspection signal generation unit 811a, the measurement unit 811b, and the determination unit 811c is stored in, for example, the ROM 813, and is executed by the CPU 811. It functions as each function part of the production | generation part 811a, the measurement part 811b, and the determination part 811c.

  FIG. 8 is an explanatory diagram for explaining a measurement error due to the Seebeck effect. When there is a temperature difference between the contactor 44 and the measurement point MP1 and the measurement point MP2, an electromotive force proportional to the temperature difference is generated (this phenomenon is called Seebeck effect). Here, as shown in the figure, electromotive forces Veb and Ved are generated between the contact 44 connected to the current generation unit 742 and the measurement points MP1 and MP2, respectively, and are connected to the voltage measurement unit 743. A case where electromotive forces Vea and Vec are generated between the contactor 44 and the measurement points MP1 and MP2, respectively, will be described. However, as shown in the figure, the polarities of the electromotive forces Veb and Ved and the electromotive forces Vea and Vec are positive on the contact 44 side (the potential of the contact 44 is higher than the potential of the measurement points MP1 and MP2). Shall.

When the current generator 742 applies a current having an absolute value I0 from the measurement point MP1 to the measurement point MP2, the voltage Va between the measurement points MP1 and MP2 measured by the voltage measurement unit 743 is the measurement point MP1. , MP2 is expressed by the following equation (1) using the resistance value Rx.
Va = I0 × Rx−Vea + Vec (1)
In addition, when the current generation unit 742 applies a current having an absolute value I0 from the measurement point MP2 to the measurement point MP1, the voltage Vb between the measurement points MP1 and MP2 measured by the voltage measurement unit 743 is: (2).
Vb = −I0 × Rx−Vea + Vec (2)
As described above, the voltage detected due to the electromotive forces Vea and Vec differs depending on the polarity of the current applied between the measurement points MP1 and MP2, so that a measurement error corresponding to the polarity of the current occurs. Here, the measurement error is determined by the electromotive forces Vea and Vec caused by the Seebeck effect.

  FIG. 9 is a waveform diagram for explaining an example of operations of the inspection signal generation unit 811a and the measurement unit 811b. (A) is a waveform diagram for one cycle of the inspection current If generated by the current generation unit 742 based on the instruction of the inspection signal generation unit 811a, and (b) is a voltage based on the instruction of the measurement unit 811b. It is a wave form diagram of voltage Vs measured by measurement part 743, and (c) is a part of (b) expanded.

  As shown in (a), the inspection signal generation unit 811a (current generation unit 742) has the same absolute value (I0) as the positive inspection current Ia and the negative inspection current Ib, and a predetermined width (for example, , (T3−t2), (t5−t4) = 10 msec) is generated and is applied between the measurement points MP1 and MP2.

Then, in correspondence with the inspection current given by the inspection signal generation unit 811a (current generation unit 742), as shown in (b), the measurement unit 811b (voltage measurement unit 743) is connected between the measurement points MP1 and MP2. The output voltage Vs is measured. Here, as described above with reference to FIG. 8, the positive output voltage Va and the negative output voltage Vb respectively corresponding to the positive inspection current Ia and the negative inspection current Ib drift by the voltage ΔV defined by the following equation (3). (Refer to the above formulas (1) and (2)).
ΔV = −Vea + Vec (3)
Moreover, as shown in (c), the voltage Va00-Va09 is measured for every predetermined time (for example, every 1 msec) by the measurement part 811b (voltage measurement part 743). Similarly, the voltages Vb00 to Vb09 are measured every predetermined time (for example, every 1 msec) (not shown) by the measurement unit 811b (voltage measurement unit 743). Then, the positive output voltage Va and the negative output voltage Vb used for obtaining the measurement value of the resistance value Rx between the measurement points MP1 and MP2 by the determination unit 811c are expressed as the following average values of the four measurement values (4 ) And (5).

That is, the measurement error is suppressed by using the average value of 10 measurement values.
Va = (Va00 + Va01 + Va02 + Va03 + Va04 + Va05 + Va06 + Va07 + Va08 + Va09) / 10 (4)
Vb = (Vb00 + Vb01 + Vb02 + Vb03 + Vb04 + Vb05 + Vb06 + Vb07 + Vb08 + Vb09) / 10 (5)
Using the positive output voltage Va and the negative output voltage Vb thus obtained, and the absolute values (here, I0) of the positive inspection current Ia and the negative inspection current Ib, the determination unit 811c uses the following (6): The resistance value Rx is calculated using the equation.
Rx = (Va−Vb) / (2 × I0) (6)
Here, the following equation (7) is established from the above equations (1) and (2).
Va−Vb = 2 × I0 × Rx (7)
That is, by calculating the resistance value Rx using the difference between the positive output voltage Va and the negative output voltage Vb, measurement errors due to the electromotive forces Vea and Vec due to the Seebeck effect are prevented.

  FIG. 10 is a waveform diagram illustrating an example of the operation of the determination unit 811c. (A) is a waveform diagram of the inspection current If generated by the current generation unit 742 based on an instruction from the inspection signal generation unit 811a, and (b) is obtained for each cycle of the inspection current If by the determination unit 811c. It is a graph which shows the change of resistance value Rx obtained.

  As described above, the positive output voltages Va1 to Va4 and the negative outputs respectively corresponding to the positive inspection current Ia and the negative inspection current Ib having the absolute values I0 = I1 to I4 by the measurement unit 811b (voltage measurement unit 743) and the determination unit 811c. The voltages Vb1 to Vb4 are obtained, and the resistance values Rx1 to Rx4 corresponding to the absolute values I1 to I4 of the inspection current are obtained by the determination unit 811c using the above-described equation (6).

  Here, the case where the resistance value Rx between the measurement points decreases as the absolute value of the inspection current increases is shown. Further, when the difference ΔRx between the minimum value Rmin (here, the resistance value Rx1) and the maximum value Rmax (here, the resistance value Rx4) of the resistance values Rx1 to Rx4 is equal to or larger than a predetermined threshold (for example, 10 mΩ). The determination unit 811c determines that the substrate 2 is defective in conduction. Here, the resistance value Rx0 indicates the level of the resistance values Rx1 to Rx4 when the conduction of the substrate 2 is good.

  That is, when there is a bonding failure in the vias TH1 and TH2 shown in FIG. 5, the absolute value I0 of the inspection current applied to the vias TH1 and TH2 increases (I1 <I4), and the bonding failure portion melts due to heat generation. When the conduction area increases, the resistance value Rx decreases (Rx1> Rx4). Therefore, by detecting a change in the resistance value Rx accompanying an increase in the absolute value I0 of the inspection current, a via junction failure is detected. .

  In this way, since the positive output voltage Va and the negative output voltage Vb, which are output signals between the two measurement points MP1 and MP2, respectively corresponding to the positive inspection current Ia and the negative inspection current Ib, are measured, measurement according to polarity An output voltage that can cancel an error (measurement error due to the Seebeck effect or the like) is measured, and an accurate measurement is possible.

  Further, as the positive inspection current Ia and the negative inspection current Ib, signals whose absolute values I0 increase every cycle (I0 = I1 to I4, I1 <I2 <I3 <I4) are generated, and the positive inspection current Ia Since the quality of the substrate 2 can be determined based on changes in the positive output voltage Va and the negative output voltage Vb accompanying the increase in the absolute value I0 of the negative inspection current Ib, it is possible to accurately perform the continuity inspection of the substrate 2. Become.

  Furthermore, since the positive output voltage Va and the negative output voltage Vb, which are output signals between the two measurement points MP1 and MP2, respectively corresponding to the positive test current Ia and the negative test current Ib having the same absolute value I0, are measured. An output signal that can more accurately cancel the measurement error due to the polarity is measured, and more accurate measurement is possible.

  In addition, the quality of the substrate to be inspected is determined based on the average values of the positive output voltages Va0 to Va9 and the negative output voltages Vb0 to Vb9 corresponding to a predetermined number of times of 2 or more (here, 10 times). Therefore, a more accurate output signal is measured and a more accurate determination is possible.

  In addition, since the inspection signal is generated by the current generator 742 whose output level can be changed, the inspection current If is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value Rx, an appropriate continuity test is performed.

  Further, the difference ΔRx between the maximum value Rmax and the minimum value Rmin of the resistance values Rx1 to Rx4 obtained corresponding to the increase in the absolute value I0 of the inspection current (I0 = I1 to I4, I1 <I2 <I3 <I4). Since it is determined whether or not the substrate 2 is defective depending on whether or not it is equal to or greater than a predetermined threshold value, the quality of the substrate 2 is determined more accurately.

  In addition, this embodiment can take the following modifications.

  (A) In the first embodiment, the case where the inspection signal generation unit 811a sequentially generates currents having the same absolute value (I0) as the positive inspection current Ia and the negative inspection current Ib has been described. Different forms may be used for the absolute values of the inspection current Ia and the negative inspection current Ib. For example, a form in which the absolute value of the negative inspection current Ib is ½ of the positive inspection current Ia may be employed.

  (B) In the first embodiment, the case where the inspection signal generation unit 811a generates the positive inspection current Ia and the negative inspection current Ib for four cycles has been described. However, the inspection signal generation unit 811a has at least two cycles or more. The positive test current Ia and the negative test current Ib may be generated. The smaller the number of cycles generated, the shorter the time required for measurement.

  (C) In the first embodiment, the inspection signal generation unit 811a uses the same amount of change as the positive inspection current Ia and the negative inspection current Ib (here, I2-I1, I3-I2, I4-I3). = 5 mA) has been described, but a monotonically increasing form may be used. For example, the form in which the amount of change in the absolute value of the current gradually increases may be used.

  (D) In the first embodiment, the case where the measurement unit 811b measures the voltage only 10 times for each applied current has been described. However, the measurement may be performed twice or more times. The measurement time is shortened as the number of times decreases, and conversely, the measurement accuracy improves as the number of times increases. Therefore, when there is a concern about a decrease in inspection accuracy (for example, when the absolute value of the applied current is small), the number of times may be increased.

  (E) In the first embodiment, the determination unit 811c determines whether the substrate 2 is good or not based on whether the difference ΔRx between the minimum value Rmin and the maximum value Rmax of the resistance values Rx1 to Rx4 is equal to or greater than a predetermined threshold value. Although the case has been described, the substrate 2 may be determined in accordance with whether the change in the resistance values Rx1 to Rx4 is equal to or greater than a predetermined threshold value.

  For example, the substrate 2 may be judged to be good or bad based on whether the ratio (= Rmax / Rmin) between the minimum value Rmin and the maximum value Rmax of the resistance values Rx1 to Rx4 is equal to or higher than a predetermined threshold value, or adjacent 2 Alternatively, the substrate 2 may be judged as good or bad depending on whether the ratio (or difference) between the two resistance values is equal to or greater than a predetermined threshold value.

<Second Embodiment>
Next, a substrate inspection apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The configuration described with reference to FIGS. 1 to 5 is the same as that of the first embodiment, and thus the description thereof is omitted.

  FIG. 11 is a conceptual diagram for explaining an example of the configuration of the measurement execution unit 74a according to the second embodiment. The measurement execution unit 74a includes a voltage generation unit 742a (corresponding to a constant voltage source and a part of the inspection signal generation unit) including a voltage source that outputs a test voltage having a predetermined value (value set by the control unit 8) Vf. , A current measuring unit 743a (corresponding to a part of the measuring means) that measures a current value that flows in the wiring pattern by the inspection voltage, and a tester controller 75 (from among the plurality of contacts 44 provided in the inspection jig 41) A contactor 44 selected in accordance with FIG. 3) is provided with a scanner 744a formed of a switch array or the like for connecting the voltage generation unit 742a and the current measurement unit 743a.

  In response to the scan command from the tester controller 75, the inspection processing unit 741a connects the voltage generation unit 742a between the two contacts 44 to be supplied with voltage, and the voltage between the two contacts 44 to be detected as a potential difference. A control signal is output to the scanner 744a in order to connect the measuring units 743 to each other. Further, the inspection processing unit 741a transmits the current value measured by the current measuring unit 743a to the tester controller 75.

  FIG. 12 is a configuration diagram illustrating an example of a functional configuration of the control unit 8 according to the second embodiment. The CPU 811 of the control unit 8 includes an inspection signal generation unit 811d (corresponding to a part of the inspection signal generation unit) that generates an inspection signal, and a measurement unit 811e (corresponding to a part of the measurement unit) that measures an output signal. And a determination unit 811f (corresponding to determination means) for determining whether the substrate 2 is good or bad.

  The inspection signal generation unit 811d causes the voltage generation unit 742a to alternately generate a positive inspection voltage that is a positive inspection voltage and a negative inspection voltage that is a negative inspection voltage, and generate the generated positive inspection voltage. The negative inspection voltage is sequentially applied between two preset measurement points of the substrate 2 via the contactor 44.

  Further, as shown in FIG. 13, the inspection signal generation unit 811d sequentially generates voltages having the same absolute value (V0) as the positive inspection voltage and the negative inspection voltage, and the absolute value (V0). ) Is generated for a predetermined period (here, four periods) that increases every period. Specifically, as will be described later with reference to FIG. 13, the inspection signal generation unit 811 d has a predetermined width (+ V1, −V1, + V2, −V2, + V3, −V3, + V4, −V4) as the voltage value Vf. For example, a substantially rectangular wave voltage having a width of 10 msec) is generated. However, values of V1, V2, V3, and V4 increase in this order. For example, V1 = 10 mV, V2 = 15 mV, V2 = 20 mV, and V4 = 25 mV.

  The measuring unit 811e measures a positive output current Ia and a negative output current Ib that are output voltages between two measurement points corresponding to the positive inspection voltage and the negative inspection voltage, respectively. In addition, the measurement unit 811e performs a predetermined number of times (here, each of the voltage values Vf (= + V1, −V1, + V2, −V2, + V3, −V3, + V4, −V4)) applied by the inspection signal generation unit 811d. 10 times) current values Ia00 to Ia09 (or current values Ib00 to Ib09) are measured (see FIG. 9).

  The determination unit 811f determines the quality of the substrate 2 based on the positive output current Ia and the negative output current Ib. Specifically, as will be described later with reference to FIG. 13, the determination unit 811f determines the absolute values (V1) of the positive inspection voltages + V1, + V2, + V3, + V4 and the negative inspection voltages -V1, -V2, -V3, -V4. , V2, V3, V4) and 10 positive test currents Ia00 to Ia09 and negative test currents Ib00 to Ib09 corresponding to the positive test voltages + V1 to + V4 and the negative test voltages −V1 to −V4 of the four output levels, respectively. The resistance values Ry1 to Ry4 are obtained using average values Ia1 to Ia4 and Ib1 to Ib4 (not shown), and the determination is made based on the obtained resistance values Ry1 to Ry4.

  The determination unit 811f determines that the substrate 2 is defective when changes in the resistance values Ry1 to Ry4 are equal to or greater than a predetermined threshold. Specifically, for example, when the difference ΔRy between the minimum value Rmin and the maximum value Rmax of the resistance values Ry1 to Ry4 is equal to or larger than a predetermined threshold (for example, 10 mΩ), the substrate 2 is determined to be defective. (See FIG. 13).

  Note that a board inspection program that causes the control unit 8 to function as the inspection signal generation unit 811d, the measurement unit 811e, and the determination unit 811f is stored in the ROM 813, for example, and is executed by the CPU 811 so that the control unit 8 It functions as each function part of the production | generation part 811d, the measurement part 811e, and the determination part 811f.

  FIG. 13 is a waveform diagram illustrating an example of the operation of the determination unit 811f. (A) is a waveform diagram of the inspection voltage Vf generated by the voltage generation unit 742a based on an instruction from the inspection signal generation unit 811d, and (b) is obtained for each cycle of the inspection voltage Vf by the determination unit 811f. It is a graph which shows the change of the resistance value Ry obtained.

As described above, the positive output currents Ia1 to Ia4 and the negative output current Ib1 corresponding to the positive inspection voltage and the negative inspection voltage of the absolute values V0 = V1 to V4 by the measurement unit 811e (current measurement unit 743a) and the determination unit 811f, respectively. ˜Ib4 is obtained, and the resistance values Ry1 to Ry4 corresponding to the absolute values V1 to V4 of the inspection voltage are obtained by the determination unit 811f using the equation (8) shown below.
Ry = 2 × V0 / (Ia−Ib) (8)
Here, the case where the resistance value Ry between the measurement points decreases as the absolute value of the inspection voltage increases is shown. When the difference ΔRy between the maximum value Rmax (here, the resistance value Ry1) and the minimum value Rmin (here, the resistance value Ry4) of the resistance values Ry1 to Ry4 is equal to or greater than a predetermined threshold (for example, 10 mΩ). The determination unit 811f determines that the substrate 2 is defective in conduction. Here, the resistance value Ry0 indicates the level of the resistance values Ry1 to Ry4 when the conduction of the substrate 2 is good.

  That is, when there is a bonding failure in the vias TH1 and TH2 shown in FIG. 5, the absolute value V0 of the inspection voltage applied to the vias TH1 and TH2 increases (V1 <V4), and voltage breakdown occurs at the bonding failure portion. Then, since the resistance value Ry decreases (Ry1> Ry4), a via junction failure is detected by detecting a change in the resistance value Ry accompanying an increase in the absolute value V0 of the inspection voltage.

  In this way, since the positive output current Ia and the negative output current Ib, which are output signals between the two measurement points MP1 and MP2, respectively corresponding to the positive inspection voltage and the negative inspection voltage, are measured, the measurement error ( An output current that can cancel out a measurement error due to the Seebeck effect or the like is measured, and accurate measurement is possible.

  In addition, as the positive inspection voltage Va and the negative inspection voltage Vb, signals whose absolute values V0 increase every cycle (V0 = V1 to V4, V1 <V2 <V3 <V4) are generated, respectively. Since the quality of the substrate 2 can be determined based on changes in the positive output current Ia and the negative output current Ib that accompany the increase in the absolute value V0 of the negative inspection voltage, the continuity inspection of the substrate 2 can be accurately performed.

  Furthermore, since the positive output current Ia and the negative output current Ib, which are output signals between the two measurement points MP1 and MP2, respectively corresponding to the positive test voltage and the negative test voltage having the same absolute value V0, are measured. An output signal that can more accurately cancel the associated measurement error is measured, and a more accurate measurement is possible.

  In addition, the quality of the substrate to be inspected is determined based on the average values of the positive output currents Ia00 to Ia09 and the negative output currents Ib00 to Ib09 corresponding to a predetermined number of times of 2 or more (here, 10 times). Therefore, a more accurate output signal is measured and a more accurate determination is possible.

  In addition, since the inspection signal is generated by the voltage generator 742a whose output level can be changed, the inspection voltage Vf is generated with a simple configuration. Furthermore, since pass / fail is determined based on the accurately measured resistance value Ry, an appropriate continuity test is performed.

  Furthermore, the difference ΔRy between the maximum value Rmax and the minimum value Rmin of the resistance values Ry1 to Ry4 obtained corresponding to the increase in the absolute value V0 of the inspection voltage (V0 = V1 to V4, V1 <V2 <V3 <V4). Since it is determined whether or not the substrate 2 is defective depending on whether or not it is equal to or greater than a predetermined threshold value, the quality of the substrate 2 is determined more accurately.

  In addition, this embodiment can take the following modifications.

  (F) In the second embodiment, the case where the inspection signal generation unit 811d sequentially generates voltages having the same absolute value (V0) as the positive inspection voltage and the negative inspection voltage has been described. The negative inspection voltage may have different absolute values. For example, a form in which the absolute value of the negative inspection voltage is ½ of the positive inspection voltage may be employed.

  (G) In the second embodiment, the case where the inspection signal generation unit 811d generates the positive inspection voltage and the negative inspection voltage for four cycles has been described. However, the inspection signal generation unit 811d has a positive signal of at least two cycles or more. It is also possible to generate a test voltage and a negative test voltage. The smaller the number of cycles generated, the shorter the time required for measurement.

  (H) In the second embodiment, the inspection signal generation unit 811d uses the same amount of change as the positive inspection voltage and the negative inspection voltage (here, V2-V1, V3-V2, V4-V3 = 5 mV). ) Has been described, but it may be a monotonically increasing form. For example, a form in which the amount of change in the absolute value of the voltage gradually increases may be used.

  (I) In the second embodiment, the case where the measurement unit 811e measures the current only 10 times for each applied voltage has been described. However, the measurement may be performed twice or more times. The measurement time is shortened as the number of times decreases, and conversely, the measurement accuracy improves as the number of times increases. Therefore, when there is a concern about a decrease in inspection accuracy (for example, when the absolute value of the applied voltage is small), the number of times may be increased.

  (J) In the second embodiment, the determination unit 811f determines whether the substrate 2 is good or not based on whether or not the difference ΔRy between the minimum value Rmin and the maximum value Rmax of the resistance values Ry1 to Ry4 is equal to or greater than a predetermined threshold value. Although the case has been described, the substrate 2 may be determined in accordance with whether or not the change in the resistance values Ry1 to Ry4 is equal to or greater than a predetermined threshold value.

  For example, the substrate 2 may be judged to be good or bad depending on whether the ratio (= Rmax / Rmin) between the minimum value Rmin and the maximum value Rmin of the resistance values Ry1 to Ry4 is a predetermined threshold value or more. Alternatively, the substrate 2 may be judged as good or bad depending on whether the ratio (or difference) between the two resistance values is equal to or greater than a predetermined threshold value.

  Furthermore, the present invention can take the following forms.

  (K) In the first and second embodiments, the substrate inspection apparatus is described as including the upper inspection unit 4U and the lower inspection unit 4D. However, the substrate inspection apparatus is at least one of the upper inspection unit 4U and the lower inspection unit 4D. The form provided with.

  (L) In the first and second embodiments, an inspection jig that supports a large number of contacts 44 and presses the tips of the contacts 44 to the respective measurement points of the substrate 2 by being moved in the Z-axis direction. Although the case where the present invention is applied to a substrate inspection apparatus provided with a so-called multi-needle inspection jig has been described, a pair of contactors 44 (or probes) are each independently X, Y, Z In a substrate inspection apparatus provided with an inspection jig (so-called moving probe type inspection jig) that is supported so as to be movable in the axial direction, and that sequentially presses the tip of the contactor 44 to a measurement point of the substrate 2 according to a preset program. The form to which this invention is applied may be sufficient.

  (M) In the first and second embodiments, the case where the substrate 2 to be inspected is a build-up substrate having vias has been described. However, other types of substrates (for example, one side on one insulating substrate) Or a printed wiring board having a wiring pattern formed thereon.

  (N) In the first and second embodiments, the inspection signal generation unit 811a (or the inspection signal generation unit 811d) includes a positive inspection signal having a positive polarity and a negative inspection signal having a negative polarity. Although the case where the inspection signals are alternately generated has been described, a signal of at least one polarity (for example, a positive inspection signal) may be generated. In this case, the configuration of the control unit 8 is simplified and the processing time is shortened.

  (O) In the first and second embodiments, the case where the inspection signal generation unit 811a (or the inspection signal generation unit 811d) generates an inspection signal whose absolute value increases has been described. However, the inspection signal generation unit 811a The inspection signal generation unit 811d may generate an inspection signal whose absolute value decreases.

It is side surface sectional drawing which shows one Embodiment of the board | substrate inspection apparatus which concerns on this invention. It is a top view of the board | substrate inspection apparatus shown in FIG. It is a block diagram which shows an example of the electrical structure of a board | substrate inspection apparatus. It is a block diagram which shows an example of the hardware constitutions of a control part. It is a conceptual diagram which shows an example of a structure of a board | substrate. It is a conceptual diagram for demonstrating an example of a structure of the measurement execution part which concerns on 1st Embodiment. It is a block diagram which shows an example of a function structure of the control part which concerns on 1st Embodiment. It is explanatory drawing explaining the measurement error by a Seebeck effect. It is a wave form diagram explaining an example of operation | movement of the test | inspection signal production | generation part and measurement part which concern on 1st Embodiment. It is a wave form diagram explaining an example of operation | movement of the determination part which concerns on 1st Embodiment. It is a conceptual diagram for demonstrating an example of a structure of the measurement execution part which concerns on 2nd Embodiment. It is a block diagram which shows an example of a function structure of the control part which concerns on 2nd Embodiment. It is a wave form diagram explaining an example of operation | movement of the determination part which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Board | substrate 3 Carry-in / out part 4 Inspection part 44 Contactor 74 Measurement execution part 744,744a Scanner 741,741a Inspection process part 742 Current generation part (a part of inspection signal generation means)
743 Voltage measurement unit (part of measurement means)
742a Voltage generator (part of inspection signal generator)
743a Current measuring unit (part of measuring means)
75 Tester Controller 8 Control Unit 81 Main Control Unit 811 CPU
811a, 811d Inspection signal generation unit (part of inspection signal generation means)
811b, 811e Measuring unit (part of measuring means)
811c, 811f determination unit (determination means)

Claims (6)

A substrate inspection apparatus that performs a continuity inspection between two measurement points set in advance on each wiring pattern for a substrate to be inspected on which a plurality of wiring patterns are formed,
Inspection signal generating means for sequentially generating a signal whose absolute value of the inspection signal changes to at least two levels, and applying the generated inspection signal between the two measurement points;
Measuring means for measuring an output signal between the two measurement points respectively corresponding to the inspection signal of each level;
Determination means for determining the quality of the substrate to be inspected based on the output signal ,
The inspection signal generation means alternately generates a positive inspection signal that is a positive inspection signal and a negative inspection signal that is a negative inspection signal for a predetermined period, and the absolute value of each signal is one period. Each time, the absolute values of the positive test signal and the negative test signal are increased every cycle, and signals having substantially the same absolute value are sequentially generated,
The measuring means measures a positive output signal and a negative output signal that are output signals between the two measurement points corresponding to the positive inspection signal and the negative inspection signal, respectively;
The determination means determines the quality of the substrate to be inspected based on the positive output signal and the negative output signal, and the minimum value and the maximum value of the resistance value according to an increase in the absolute value of the inspection signal. A substrate inspection apparatus , wherein when the difference is equal to or greater than a predetermined threshold, the substrate to be inspected is determined to be defective . The inspection signal generation means generates a rectangular wave having a predetermined width as the positive inspection signal and the negative inspection signal,
The measuring means measures the positive output signal and the negative output signal for a predetermined number of times of 2 or more,
The determination means determines based on absolute values of the positive inspection signal and the negative inspection signal and an average value of each of the positive output signals and the negative output signals corresponding to the predetermined number of times. The substrate inspection apparatus according to claim 1 . The inspection signal generation means sequentially generates a positive inspection current and a negative inspection current from a constant current source whose output level can be changed as the positive inspection signal and the negative inspection signal,
The measuring means measures a positive output voltage value and a negative output voltage value, which are voltage values corresponding to the positive inspection current and the negative inspection current, respectively.
The determination means obtains a resistance value using the absolute values of the positive inspection current and the negative inspection current and the positive output voltage value and the negative output voltage value, and makes a determination based on the obtained resistance value. The board inspection apparatus according to claim 2 , wherein: The inspection signal generation means sequentially generates a positive inspection voltage and a negative inspection voltage from a constant voltage source whose output level can be changed as the positive inspection signal and the negative inspection signal,
The measuring means measures a positive output current value and a negative output current value, which are current values corresponding to the positive inspection voltage and the negative inspection voltage, respectively.
The determination means obtains a resistance value using the absolute values of the positive inspection voltage and the negative inspection voltage and the positive output current value and the negative output current value, and makes a determination based on the obtained resistance value. The board inspection apparatus according to claim 2 . The inspection substrate, a substrate inspection apparatus according to any one of claims 1 to 4, characterized in that a build-up substrate having via. A substrate inspection method for performing a continuity inspection between two measurement points set in advance on each wiring pattern for a substrate to be inspected on which a plurality of wiring patterns are formed,
A test signal generating step of sequentially generating a signal in which the absolute value of the test signal changes to at least two levels, and applying the generated test signal between the two measurement points ;
A measurement step of measuring an output signal between the two measurement points respectively corresponding to the inspection signal of each level;
A determination step of determining pass / fail of the substrate to be inspected based on the output signal ,
The inspection signal generation step alternately generates a positive inspection signal that is a positive inspection signal and a negative inspection signal that is a negative inspection signal for a predetermined period, and the absolute value of each signal is one period. Each time, the absolute values of the positive test signal and the negative test signal are increased every cycle, and signals having substantially the same absolute value are sequentially generated,
The measuring step measures a positive output signal and a negative output signal that are output signals between the two measurement points corresponding to the positive test signal and the negative test signal, respectively.
The determination step is to determine the quality of the substrate to be inspected based on the positive output signal and the negative output signal, and between the minimum value and the maximum value of the resistance value accompanying an increase in the absolute value of the inspection signal. A substrate inspection method comprising: determining that the substrate to be inspected is defective when the difference is equal to or greater than a predetermined threshold value.

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