JP2005055369A - Substrate inspection device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an area where defective short circuiting generated between the first and second wiring pattern groups is generated, in a substrate provided with the first and second wiring pattern groups formed to be brought into a condition insulated each other. <P>SOLUTION: This device/method is provided with a current generation part 5 for making a prescribed measuring current flow between an inspection point on a wiring pattern included in the first wiring pattern group, and an inspection point on a wiring pattern included in the second wiring pattern group, a voltage measuring part 6 for measuring a voltage generated therebetween, and a control part 12 for measuring a resistance value between the inspection points by a four terminal measuring method, based on measured voltage and a measuring current value, and for detecting a package substrate WC where the short circuiting is generated between the first and second wiring pattern groups, out of the package substrates WC constituting the substrate 101, based on the measured resistance value between the inspection points, in the every package substrate WC constituting the substrate 101. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate inspection apparatus, and more particularly to a substrate inspection apparatus capable of detecting a location where a wiring pattern is short-circuited by resistance measurement. And it is related with the board | substrate inspection method utilized for such a board | substrate inspection apparatus. The present invention is not limited to a printed wiring board, but includes, for example, electrical wiring on various substrates such as flexible substrates, multilayer wiring substrates, electrode plates for liquid crystal displays and plasma displays, and package substrates and film carriers for semiconductor packages. In this specification, these various wiring boards are collectively referred to as “substrates”.

  In the substrate 101 shown in FIG. 7, for example, a total of 64 package substrates WC used in an IC package such as a BGA (Ball Grid Array), for example, four rows in a row and 16 columns in a row are continuously formed integrally. . FIG. 8 is an enlarged view of a portion surrounded by a broken line of the substrate 101 shown in FIG. Since the surface of the substrate 101 is subjected to surface treatment such as gold plating using a method such as electrolytic plating on the surface of the wiring pattern 103 or the like, a short-circuit wiring pattern 102 for electrolytic plating to which one end of all the wiring patterns is connected. Is formed.

  FIG. 9 is an enlarged view of the package substrate WC. In FIG. 9, all ball grid pads 104 provided on the package substrate WC are connected to the short-circuit wiring pattern 102 via the wiring pattern 103. As a result, in the electrolytic plating process, by applying a voltage to the wiring pattern 103, the wiring pattern 103, the pads 104, or the package substrate WC for wire bonding of semiconductor chips to all the wiring patterns 103 formed on the substrate 101 are omitted. Electroplating can be performed on patterns such as connection pads.

  FIG. 10 is a view further enlarging a part of the package substrate WC shown in FIG. 9 and showing it together with its inspection means. In the package substrate WC shown in FIG. 10, the wiring pattern 103 a having one end connected to the short-circuit wiring pattern 102 a formed on the front surface of the substrate 101 is connected to the substrate 101 via the via hole 105 penetrating the substrate 101. It is connected to a pad 104a formed on the surface on the back side. Further, the wiring pattern 103 b having one end connected to the short-circuit wiring pattern 102 b formed on the back surface of the substrate 101 is connected to the pad 104 b formed on the back surface of the substrate 101. A first wiring pattern group including a wiring pattern 103a, a via hole 105, and a pad 104a connected to the shorting wiring pattern 102a, and a wiring pattern 103b and a pad 104b connected to the shorting wiring pattern 102b. The second wiring pattern group is formed to be insulated from each other.

  As a method for inspecting a wiring pattern as shown in FIG. 10, the following method is known. That is, first, the contact for inspection is brought into contact with the pad connected to the wiring pattern to be inspected. For example, when the wiring pattern 103b is inspected, the contacts 109 and 110 are brought into contact with the two pads 104b respectively connected to the two wiring patterns 103b. An ammeter (not shown) is connected between the contact 109 and the contact 110, and the current flowing between the contact 109 and the contact 110 can be measured.

Then, the magnetic field applying unit 108 in which the coil 107 is wound around the magnetic core 106 is disposed to face the substrate 101, and a magnetic flux that changes with time is generated from the magnetic field applying unit 108 so as to be linked to the wiring pattern 103b. Then, the contact 109, the wiring pattern 103b connected to the pad 104b in contact with the contact 109, the shorting wiring pattern 102b, the wiring pattern 103b connected to the pad 104b in contact with the contact 110, the contact 110, and the above-mentioned An induced current corresponding to a change in magnetic flux from the magnetic field application unit 108 flows through a current loop including an ammeter. Then, based on the current value obtained by measuring the induced current with the ammeter, a method and apparatus for performing a disconnection / short circuit inspection of the wiring pattern 103b and the like constituting the current loop (hereinafter referred to as a magnetic field inspection). Is known (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 2001-41994

  By the way, when the substrate inspection method using the magnetic field inspection as described above is used, the first wiring pattern group and the second wiring pattern group can be inspected. It is impossible to detect a short circuit failure that has occurred between the first wiring pattern group and the second wiring pattern group. Therefore, it is conceivable to detect the continuity between the short-circuit wiring pattern 102a and the short-circuit wiring pattern 102b and determine that the substrate 101 is defective when it is conductive.

  However, when such a determination method is used, a short circuit failure occurs between the first wiring pattern group and the second wiring pattern group even in one of the 64 package substrates WC included in the substrate 101. When the short circuit wiring pattern 102a and the short circuit wiring pattern 102b are conducted, the entire substrate 101 is determined to be defective, and 63 non-defective products other than the package substrate WC in which the short circuit defect has occurred. There is a problem that even the package substrate WC must be handled as a defective product.

  The present invention has been made in view of such a problem, and the first and second wiring patterns are provided on the substrate including the first and second wiring pattern groups formed so as to be insulated from each other. An object of the present invention is to provide a substrate inspection apparatus capable of detecting a region where a short-circuit failure occurs between groups. And it aims at providing the board | substrate inspection method utilized for such a board | substrate inspection apparatus.

  In order to achieve the above object, a substrate inspection apparatus according to a first means of the present invention comprises a plurality of wiring patterns connected to a first short-circuit wiring pattern formed on one surface of a substrate. A plurality of wiring patterns connected to one wiring pattern group and a second short-circuit wiring pattern formed on the other surface of the substrate and formed to be insulated from the first wiring pattern group A substrate inspection apparatus for inspecting a substrate having a second wiring pattern group consisting of: a plurality of inspection regions are set on the substrate, and each inspection region is included in the first wiring pattern group. A resistance measuring unit that measures a resistance value between an inspection point on the wiring pattern and an inspection point on the wiring pattern included in the second wiring pattern group; and a resistance value measured by the resistance measuring unit. The plurality It is characterized in that a determination unit for detecting an examination region of a short circuit has occurred between said second wiring pattern group and the first wiring pattern group of the examination region.

  In the above-described substrate inspection apparatus, the determination unit detects the inspection region in which the smallest resistance value is measured among the resistance values measured by the resistance measurement unit as the inspection region in which the short circuit occurs. It is characterized by doing.

  Moreover, in the above-described substrate inspection apparatus, the determination unit arranges the resistance values of the inspection regions measured by the resistance measurement unit in the order of arrangement of the inspection regions on the substrate and becomes a resistance that becomes a peak on the low resistance side. The inspection area where the value is measured is detected as an inspection area where the short circuit occurs.

  Moreover, in the above-described substrate inspection apparatus, the determination unit includes the inspection region in which a resistance value smaller than a predetermined reference value is measured among the resistance values for each of the inspection regions measured by the resistance measurement unit, It is detected as an inspection area where the short circuit occurs.

  In the above-described substrate inspection apparatus, the resistance measurement unit includes first and second current supply contacts and first and second voltage measurement contacts for contacting the inspection points on the wiring pattern. A current generation unit that causes a predetermined level of measurement current to flow between the first and second current supply contacts, and a voltage measurement unit that measures a voltage between the first and second voltage measurement contacts In the plurality of inspection regions on the substrate, for each inspection region, the first current supply contact that contacts the inspection point on the wiring pattern included in the first wiring pattern group, and The measurement current is caused to flow by the current generator between the second current supply contact that contacts the inspection point on the wiring pattern included in the second wiring pattern group, and the first wiring pattern For inspection points on the wiring pattern included in the group The voltage generated between the touched first voltage measuring contact and the second voltage measuring contact in contact with the inspection point on the wiring pattern included in the second wiring pattern group, The measurement is performed by a voltage measurement unit, and the resistance value for each inspection region is measured from the voltage measurement value and the measurement current.

  Further, in the above-described substrate inspection apparatus, when the resistance value is measured by the resistance measurement unit, the inspection point in contact with the first current supply contact and the first voltage measurement contact The inspection point is different from the inspection point in contact with the child, and the inspection point in contact with the second current supply contact is in contact with the second voltage measuring contact. It is characterized by an inspection point different from the point.

  Furthermore, in the above-described substrate inspection apparatus, the substrate includes a plurality of workpiece pieces that are continuously formed integrally in a plane, and the inspection region is set corresponding to the workpiece pieces. It is a feature.

  Further, the substrate inspection method according to the second means of the present invention includes a first wiring pattern group consisting of a plurality of wiring patterns connected to a first short-circuit wiring pattern formed on one surface of the substrate, A second wiring pattern group composed of a plurality of wiring patterns connected to a second short-circuit wiring pattern formed on the other surface of the substrate and insulated from the first wiring pattern group A plurality of inspection areas are set on the substrate, and the inspection points on the wiring patterns included in the first wiring pattern group and the inspection points are set for each of the inspection areas. When a resistance value between the inspection points on the wiring patterns included in the second wiring pattern group is measured and a short circuit occurs between the first wiring pattern group and the second wiring pattern group In addition, the resistance measurement unit Based on the measured resistance value I, it is characterized by detecting the examination region where the short circuit has occurred among the plurality of inspection areas.

  The substrate inspection apparatus and the substrate inspection method having such a configuration include an inspection point on the wiring pattern included in the first wiring pattern group for each inspection region, and an inspection point on the wiring pattern included in the second wiring pattern group. Based on the resistance value between them, it is possible to detect an inspection region in which a short circuit has occurred between the first wiring pattern group and the second wiring pattern group among the plurality of inspection regions.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a diagram for explaining an example of the configuration of the substrate inspection apparatus 1 according to the first embodiment of the present invention. A substrate inspection apparatus 1 shown in FIG. 1 includes a multi-needle inspection contact 2, a multiplexer 3, a current detection unit 4, a current generation unit 5, a voltage measurement unit 6, a continuity detection unit 7, an AC signal generation circuit 8, and a magnetic field application. A unit 9, an XY positioning mechanism 10, a marker 11, and a control unit 12. A substrate 101 shown in FIG. 1 is a substrate to be inspected, and has a configuration similar to that of the substrate 101 shown in FIGS. 7, 8, 9, and 10.

  The multi-needle inspection contact 2 is for making contact with a pad 104 serving as an inspection point on a wiring pattern formed on the substrate 101, and is placed on a substrate 101 placed and fixed on a substrate holder (not shown). In contrast, the individual contacts constituting the multi-needle inspection contact 2 come into contact with the pads 104 on the lower surface of the substrate 101, respectively. Each contact is connected to one of the current detection unit 4, the current generation unit 5, the voltage measurement unit 6, and the continuity detection unit 7 by the multiplexer 3. The contact connected to the current detection unit 4 functions as a current measurement contact for measuring an induced current corresponding to a change in magnetic flux from the magnetic field application unit 9, and is connected to the current generation unit 5. The contactor functions as a current supply contactor for resistance measurement, and the contactor connected to the voltage measurement unit 6 functions as a voltage measurement contactor for resistance measurement.

  The multiplexer 3 is composed of a switch array or the like that is turned on / off in response to a control signal from the control unit 12, and includes individual contacts of the multi-needle contact 2, a current detection unit 4, a current generation unit 5, and a voltage The connection with the measurement unit 6 is switched. The current detection unit 4 measures a current between two contacts connected to the current detection unit 4 by the multiplexer 3 and measures an induced current induced in accordance with a change in magnetic flux from the magnetic field application unit 9. .

  The current generator 5 is composed of a constant current source that outputs a predetermined level of measurement current, and outputs a predetermined level of measurement current between the two contacts connected to the current generator 5 by the multiplexer 3. The voltage measurement unit 6 measures the voltage between the two contacts connected to the voltage measurement unit 6 by the multiplexer 3 and outputs the voltage measurement value to the control unit 12. The voltage measurement unit 6 may output the resistance value obtained from the current value of the measurement current output from the current generation unit 5 and the voltage measurement value to the control unit 12.

  The continuity detection unit 7 is a so-called simple tester for detecting the presence or absence of a short circuit between the wiring patterns. The continuity detection unit 7 first applies a predetermined voltage between the two contacts connected to the continuity detection unit 7 by the multiplexer 3 in accordance with a control signal from the control unit 12. When the current does not flow, the continuity detecting unit 7 outputs a signal indicating that there is no short circuit between the two contacts to the control unit 12, while when the current flows, the two contacts are short-circuited. A signal indicating that this is being performed is output to the control unit 12.

  The AC signal generation circuit 8 outputs an AC current according to a control signal from the control unit 12. The magnetic field applying unit 9 is made of, for example, a magnetic core around which a coil is wound, and is positioned facing the substrate 101. Then, the magnetic field application unit 9 generates a magnetic flux so as to interlink with the wiring pattern on the substrate 101 according to the alternating current output from the alternating current signal generation circuit 8.

  The XY positioning mechanism 10 includes, for example, an XY table, and moves the relative positions of the multi-needle inspection contact 2, the magnetic field application unit 9, the marker 11, and the substrate 101 in accordance with a control signal from the control unit 12. And positioned at the inspection position.

  The marker 11 includes, for example, an ink ejection mechanism that performs marking by ejecting ink, and ejects ink to mark the package substrate WC that is determined to be defective in accordance with a control signal from the control unit 12.

  The control unit 12 controls the overall operation of the substrate inspection apparatus 1. For example, a control program for controlling the operation of the substrate inspection apparatus 1 and a magnetic field for executing a magnetic field inspection for inspecting a wiring pattern on the substrate 101. ROM that stores an inspection program, a resistance measurement program for measuring a resistance value between the first wiring pattern group and the second wiring pattern group, and an area detection program for detecting a package substrate WC in which a short circuit defect has occurred Read only memory), RAM (Random Access Memory) that temporarily stores data, and a microprocessor that reads a control program from the ROM and executes it.

  The control unit 12 functions as a resistance measurement unit by executing a resistance measurement program, and functions as a determination unit by executing a region detection program.

  Next, the operation of the substrate inspection apparatus 1 configured as described above will be described. FIG. 2 is an enlarged view of two adjacent ones of the package substrates WC included in the substrate 101 to be inspected, the package substrate WC1 and the package substrate WC2. The package substrate WC1 shown in FIG. 2 includes wiring patterns 121, 122, 123 formed on the front surface of the substrate 101, wiring patterns 124, 125, 126, 127, 128 formed on the back surface of the substrate 101, and wiring Ball grid pads 133, 134, 135, 136, and 137 connected to the patterns 124, 125, 126, 127, and 128, wiring patterns 121, 122, and 123, ball grid pads 132, the wiring pattern 124, And via holes 129, 130, and 131, which respectively connect through the substrate 101.

  The wiring patterns 121, 122, 123 are connected at one end to the short-circuit wiring pattern 102 a formed on the front surface of the substrate 101, and the wiring patterns 126, 127, 128 are formed on the back surface of the substrate 101. One end is connected to the short-circuit wiring pattern 102b.

  The package substrate WC2 includes wiring patterns 141, 142, and 143 formed on the front surface of the substrate 101, wiring patterns 144, 145, 146, 147, and 148 formed on the back surface of the substrate 101, and wiring patterns 144 and 145. , 146, 147, and 148 respectively connected to the ball grid pads 153, 154, 155, 156, and 157, the wiring patterns 141, 142, and 143, the ball grid pads 152, and the wiring patterns 144 and 145, respectively. Via holes 149, 150, and 151 are provided to connect through the substrate 101.

  The wiring patterns 141, 142, and 143 are connected at one end to the short-circuit wiring pattern 102 a formed on the front surface of the substrate 101, and the wiring patterns 146, 147, and 148 are formed on the back surface of the substrate 101. One end is connected to the short-circuit wiring pattern 102b.

  The wiring patterns 121, 122, 123, 124, 125, 141, 142, 143, 144, and 145 connected to the shorting wiring pattern 102a, the via holes 129, 130, 131, 149, 150, and 151, The pads 132, 133, 134, 152, 153, and 154 are included in the first wiring pattern group. Also, the wiring patterns 126, 127, 128, 146, 147, 148 and the pads 135, 136, 137, 155, 156, 157 connected to the short-circuit wiring pattern 102b are made into the second wiring pattern group. Yes.

  The first wiring pattern group and the second wiring pattern group are formed so as to be insulated from each other, but belong to the pad 132 belonging to the first wiring pattern group and the second wiring pattern group. Since there is a short circuit defect X between the pad 137 and the first wiring pattern group, the first wiring pattern group and the second wiring pattern group are in a conductive state.

  FIG. 3 is a flowchart for explaining an example of the operation of the substrate inspection apparatus 1. First, after the substrate 101 is placed on the contact needle 2 for multi-needle inspection, the substrate 101 is set so that the package substrate WC1 is in the inspection position by the XY positioning mechanism 10 in accordance with a control signal from the control unit 12. Is positioned. Then, referring to FIG. 2, pads 133, 134, 135, 136 that are inspection points of package substrate WC1, and contacts 21, 22, 23, 24 that are contacts of contact needle 2 for multi-needle inspection, Are each contacted. In FIG. 2, only the contacts 21, 22, 23, and 24 that are in contact with the pads 133, 134, 135, and 136 are shown, and the other contacts are not shown.

  Next, in step S <b> 1, the contact 21 in contact with the pad 133 belonging to the first wiring pattern group and the contact 23 in contact with the pad 135 belonging to the second wiring pattern group include the control unit 12. Is connected to the continuity detection unit 7 by the multiplexer 3 in response to the control signal from Then, the continuity detection unit 7 detects the presence or absence of a short circuit between the contact 21 and the contact 23, that is, between the first wiring pattern group and the second wiring pattern group. When the continuity detection unit 7 detects a short circuit between the first wiring pattern group and the second wiring pattern group, the process proceeds to step S2 to detect a package substrate WC having a short circuit defect. On the other hand, if a short circuit is not detected, the process proceeds to step S4 to inspect a conduction short circuit of the wiring pattern of the substrate 101 by a magnetic field inspection. Since the first wiring pattern group and the second wiring pattern group are short-circuited due to the short circuit defect X, the package substrate WC1 shown in FIG. 2 proceeds to Step S2.

  Next, in step S <b> 2, the contacts 22 and 23 are connected to the current generation unit 5 and the contacts 21 and 24 are connected to the voltage measurement unit 6 by the multiplexer 3 in accordance with a control signal from the control unit 12. Then, the measurement current I output from the current generation unit 5 in response to the control signal from the control unit 12 is converted into the contact 22, the pad 134, the wiring pattern 125, the via hole 131, the wiring pattern 123, and the short-circuiting wiring pattern 102 a. The wiring pattern 121, the via hole 129, the pad 132, the short circuit defect X, the pad 137, the wiring pattern 128, the shorting wiring pattern 102 b, the wiring pattern 126, the pad 135, and the path passing through the contact 23.

  Further, the voltage measurement unit 6 allows the voltage between the contacts 21 and 24, that is, the pad 133, the wiring pattern 124, the via hole 130, the wiring pattern 122, the shorting wiring pattern 102a, the wiring pattern 121, the via hole 129, the pad 132, The voltage V generated in the path through the short-circuit defect X, the pad 137, the wiring pattern 128, the short-circuiting wiring pattern 102b, the wiring pattern 127, and the pad 136 is measured.

  Then, the resistance of the measurement target path including the short-circuit defect X is determined by the control unit 12 from the voltage V measured by the voltage measurement unit 6 and the measurement current I flowed by the current generation unit 5 as a resistance value Rx = Calculated as V / I. In this case, since the resistance value Rx is measured by a known four-terminal measurement method (Kelvin method), the low resistance can be measured with high accuracy.

  Further, the contacts 21 and 22 brought into contact with the first wiring pattern group are brought into contact with pads 133 and 134 as different inspection points, and the contacts 23 and 24 brought into contact with the second wiring pattern group are brought into different inspection points. As a result of contact with the pads 135 and 136, the resistance value between the point P1 and the point P2, which is an intersection of the path through which the measurement current I flows and the measurement target path of the voltage V, is obtained due to the effect of the four-terminal measurement method. It is measured as a resistance value Rx.

For example, the resistance measurement by the four-terminal measurement method may be performed in a state where both the contactors 21 and 22 are in contact with the pad 134 and both the contactors 23 and 24 are in contact with the pad 135. In this case, the measured resistance value R is a resistance value R of a path (hereinafter referred to as R0 path) from the pad 134 to the point P1 via the wiring pattern 125, the via hole 131, the wiring pattern 123, and the short-circuiting wiring pattern 102a. ₀ and a resistance value R ₁ of a path (hereinafter referred to as R1 path) from the pad 135 to the point P2 via the wiring pattern 126 and the short-circuit wiring pattern 102b, and R = Rx + R ₀ + R ₁ .

On the other hand, in the present embodiment, the contacts 21 and 22 are brought into contact with the pads 133 and 134, respectively, and the contacts 23 and 24 are brought into contact with the pads 135 and 136, respectively. As a result of functioning as an extension of the measurement probe (part of the probe), the resistance value R ₀ and the resistance value R ₁ that can be regarded as the resistance value of the measurement probe are canceled by the effect of the four-terminal measurement method. Thus, the resistance value of the path between the point P1 and the point P2 including the short circuit defect X can be measured as the resistance value Rx. In this case, since the resistance measurement value Rx does not include the resistance value R ₀ and the resistance value R _1, it is possible to reduce the influence of the wiring pattern resistance other than the short-circuit defect X portion in the resistance measurement value.

  Next, in step S3, the control unit 12 compares a predetermined reference resistance value Rref set in advance with the resistance value Rx measured in step S2, and the resistance value Rx exceeds the reference resistance value Rref. In this case, it is determined that there is no short circuit failure between the first and second wiring pattern groups in the package substrate WC1, and the process proceeds to step S4 to perform a continuity short circuit test by a magnetic field test, while the resistance value Rx is the reference resistance value. If it is equal to or less than Rref, the package substrate WC1 is determined to be defective, and the process proceeds to step S5 to perform marking indicating that the package substrate WC1 is defective. In the case of the package substrate WC1, since there is a short circuit defect X, the resistance value Rx becomes equal to or less than the reference resistance value Rref, and the process proceeds to step S5.

  Next, in step S5, ink is ejected onto the surface of the package substrate WC1 by the marker 11 in accordance with a control signal from the control unit 12, and marking indicating that the package substrate WC1 is a defective product is performed. Thereby, out of the 64 package substrates WC included in the substrate 101, the defective package substrate WC can be detected and the defective package substrate WC can be marked so as to be distinguishable from the non-defective package substrate WC.

  Next, in step S7, if the inspection has been completed for all the package substrates WC of the substrate 101, the inspection for the substrate 101 is completed, and if not, the inspection of the package substrate WC that is the next inspection object is performed. It moves to step S8 to do.

  Next, in step S8, the XY positioning mechanism 10 moves the substrate 101 in accordance with a control signal from the control unit 12, and positions the package substrate WC2 at the inspection position. Thereby, the pads 153, 154, 155, and 156, which are inspection points of the package substrate WC2, and the contacts 21, 22, 23, and 24 are brought into contact with each other. Then, the process proceeds to step S1 again to execute the inspection of the package substrate WC2.

  Next, in step S1, conditional branching is performed according to the presence or absence of a short circuit between the first wiring pattern group and the second wiring pattern group. Since the presence or absence of a short circuit with the group is detected when step S1 is executed for the first time, when step S1 is executed after the second time, the detection result when step S1 is executed for the first time Based on the above, conditional branching may be performed. Therefore, the process proceeds to step S2 to perform resistance measurement on the package substrate WC2.

  Next, in step S <b> 2, the contacts 22 and 23 are connected to the current generation unit 5 and the contacts 21 and 24 are connected to the voltage measurement unit 6 by the multiplexer 3 in accordance with a control signal from the control unit 12. Then, the measurement current I output from the current generation unit 5 in response to the control signal from the control unit 12 is converted into the contact 22, the pad 154, the wiring pattern 145, the via hole 151, the wiring pattern 143, and the short-circuiting wiring pattern 102a. The wiring pattern 121, the via hole 129, the pad 132, the short circuit defect X, the pad 137, the wiring pattern 128, the shorting wiring pattern 102 b, the wiring pattern 146, the pad 155, and the path through the contact 23.

  Further, the voltage measuring unit 6 determines the voltage between the contacts 21 and 24, that is, the pad 153, the wiring pattern 144, the via hole 150, the wiring pattern 142, the shorting wiring pattern 102a, the wiring pattern 121, the via hole 129, the pad 132, The voltage V generated in the path through the short-circuit defect X, the pad 137, the wiring pattern 128, the short-circuiting wiring pattern 102b, the wiring pattern 147, and the pad 156 is measured.

Then, the resistance of the measurement target path including the short-circuit defect X viewed from the package substrate WC2 from the voltage V measured by the voltage measurement unit 6 and the measurement current I flowed by the current generation unit 5 by the control unit 12. Calculated as the value Rx1 = V / I. In this case, the resistance value Rx1 is between the point P3 and the point P4 that are the intersections of the path through which the measurement current I flows and the measurement target path of the voltage V, as in the case of the resistance value Rx measurement on the package substrate WC1. The resistance value is measured as the resistance value Rx1. In this case, the resistance value Rx1, the resistance value Rx in the package base board WC1, and the resistance value R ₂ from point P3 to point P1, substantially equal resistance value R ₃ and is added to the resistance from the point P2 to a point P4 to _{be, Rx1 ≒ Rx + R 2 +} R 3 , and the resistance Rx1, the resistance value is larger than the resistance value Rx.

  Next, in step S3, the control unit 12 compares the reference resistance value Rref with the resistance value Rx1 measured in step S2. If the resistance value Rx1 exceeds the reference resistance value Rref, the package substrate WC2 Is judged that there is no short-circuit failure between the first and second wiring pattern groups, and the process proceeds to step S4 to perform a continuity short-circuit inspection by a magnetic field inspection. On the other hand, if the resistance value Rx1 is less than or equal to the reference resistance value Rref, the package The substrate WC2 is determined to be defective, and the process proceeds to step S5 to perform marking indicating that the package substrate WC2 is defective. Now, the package substrate WC2 does not have the short circuit defect X, and the resistance value Rx1 has a resistance value larger than the resistance value Rx. Therefore, the resistance value can be set by setting the reference resistance value Rref to an appropriate value. When Rx1 exceeds the reference resistance value Rref, it is determined that there is no short circuit failure between the first and second wiring pattern groups in the package substrate WC2, and the process proceeds to step S4.

  Next, in step S4, the control unit 12 performs a continuity short circuit inspection by a magnetic field inspection. Specifically, for example, when magnetic field inspection is performed on the wiring pattern 146 and the wiring pattern 147, first, the contacts 23 and 24 are connected to the current detection unit 4 by the multiplexer 3 in accordance with a control signal from the control unit 12. The Further, the alternating current signal generation circuit 8 outputs an alternating current to the magnetic field application unit 9 according to the control signal from the control unit 12, and the magnetic field application unit 9 according to the alternating current output from the alternating current signal generation circuit 8. Magnetic flux is generated so as to interlink with the wiring patterns 146 and 147.

  Then, according to the current Im flowing between the contacts 23 and 24 by the current detection unit 4, that is, the magnetic flux generated from the magnetic field applying unit 9, the contact 23, the pad 155, the wiring pattern 146, the shorting wiring pattern 102b, the wiring The induced current Im induced in the current loop including the pattern 147, the pad 156, the contact 24, and the current detection unit 4 connected between the contacts 23 and 24 is measured. Similarly, the induced current Im is measured for other wiring patterns of the package substrate WC2.

  In this case, in the magnetic field inspection in step S4, the contact current is measured by bringing the contacts into contact with the pads that are the inspection points of each wiring pattern to be inspected. Therefore, in the resistance measurement in step S2, current supply is performed. If the contact for voltage measurement and the contact for voltage measurement are brought into contact with different pads and resistance measurement is performed by the four-terminal measurement method, the contact for magnetic field inspection can be used for resistance measurement by the four-terminal measurement method. There is no need to provide a separate contact for the four-terminal measurement method, and the cost of the inspection apparatus can be reduced.

  Next, in step S6, the control unit 12 compares the induced current Im measured in step S4 with a predetermined reference current value range Iref. If the induced current Im measured for all the wiring patterns on the package substrate WC2 is within the reference current value range Iref, the control unit 12 determines that the package substrate WC2 is a non-defective product and the other packages to be inspected. If the induced current Im is not within the reference current value range Iref, the package substrate WC2 is determined to be defective and the package is shifted to step S7 again to confirm the presence or absence of the substrate WC (YES in step S6). The process proceeds to step S5 to perform marking indicating that the substrate WC2 is defective (NO in step S6).

  As described above, it is possible to determine pass / fail for all the package substrates WC of the substrate 101 by repeating the processes of steps S1 to S8. Even if the substrate 101 has a short circuit failure between the first and second wiring pattern groups, the package substrate WC in which the short circuit failure has occurred between the first and second wiring pattern groups is selected. It is possible to detect and mark the package substrate WC.

(Second Embodiment)
Next, a substrate inspection apparatus according to a second embodiment of the present invention will be described. The substrate inspection apparatus according to the second embodiment of the present invention has the same configuration as that of the substrate inspection apparatus 1 shown in FIG. 1, and the substrate inspection apparatus according to the first embodiment includes first and second substrates. The operation for detecting the package substrate WC having a short-circuit defect between the wiring pattern groups is different. Since the rest is the same as that of the substrate inspection apparatus according to the first embodiment, the characteristic points of this embodiment will be described below.

  FIG. 4 is a flowchart for explaining a region detection operation for detecting the package substrate WC in which a short circuit failure occurs between the first and second wiring pattern groups. First, resistance measurement is performed on the substrate 101 in which a short circuit failure between the first and second wiring pattern groups is detected in the same manner as in step S1 in FIG. 3 (step S11).

  If the resistance measurement has not been completed for all the package substrates WC of the substrate 101 (NO in step S12), the process proceeds to step S13, and the substrate 101 is detected by the XY positioning mechanism 10 according to the control signal from the control unit 12. Then, the next package substrate WC is positioned at the inspection position, and the process of step S11 is repeated again. On the other hand, if the resistance measurement has been completed for all the package substrates WC (YES in step S12), each package substrate WC. The process proceeds to step S14 in order to detect the package substrate WC in which a short circuit failure has occurred based on the resistance value measured for.

  FIG. 5 is a graph showing an example of a resistance measurement value of each package substrate WC measured in steps S11, S12, and S13. 5, graphs A, B, C, and D correspond to the rows of the substrate 101 shown in FIG. 7, respectively, the horizontal axis indicates the column numbers 1 to 16 of the substrate 101 shown in FIG. The resistance measurement values of the package substrate WC indicated by the rows and columns of FIG. FIG. 6 shows the graph shown in FIG. 5 on three-dimensional coordinates.

  Next, in step S14, the control unit 12 determines that a short circuit failure has occurred between the first and second wiring pattern groups on the package substrate WC having the smallest resistance value among the resistance measurement values of the respective package substrates WC. Is done. For example, in FIG. 5, since the resistance measurement value of the package substrate WC in C row and 10 column is the smallest, the short circuit failure between the first and second wiring pattern groups occurs in the package substrate WC in C row and 10 column. Determined to be a substrate. In this case, it is not necessary to set the reference resistance value Rref in advance. This inspection method is effective when it is assumed in advance that the number of defective substrates is small.

  In step S14, when the measured resistance value of each package substrate WC is represented on the three-dimensional coordinates shown in FIG. 6, the package substrate WC that becomes the peak on the low resistance side is between the first and second wiring pattern groups. It is good also as a structure detected as a board | substrate which has produced the short circuit defect. In FIG. 6, the package substrate WC having the peak on the low resistance side is the package substrate WC of C row and 10 columns, so that the package substrate WC of C row and 10 columns is short-circuit failure between the first and second wiring pattern groups. It is determined that this is a substrate on which is generated. Thereby, for example, when the substrate 101 has a plurality of short-circuit defects between the first and second wiring pattern groups, a plurality of peaks on the low resistance side appear, and therefore, between the first and second wiring pattern groups. It is possible to detect a plurality of package substrates WC in which a short-circuit failure occurs.

  In addition, when the position where the short-circuit failure occurs between the first and second wiring pattern groups is near the boundary line with the adjacent package substrate WC, the resistance measurement values obtained from both the package substrates WC are May be approximately equal. In such a case, both the package substrates WC may be defective.

  In addition, although the substrate 101 includes a plurality of package substrates WC, and an example in which the presence or absence of a short circuit between the first and second wiring pattern groups is detected in units of package substrates WC has been shown, the substrate 101 includes a plurality of packages. Without being limited to the example constituted by the substrate WC, the substrate 101 is divided into predetermined regions to set a plurality of inspection regions, and a short circuit failure between the first and second wiring pattern groups for each inspection region It is good also as a structure which detects the presence or absence of.

  Next, in step S15, ink is ejected by the marker 11 in accordance with a control signal from the control unit 12 onto the surface of the package substrate WC in which the short circuit failure is detected in step S14, and the package substrate WC in which the short circuit failure is detected. The marking indicating that the product is defective is performed. Thereby, out of the 64 package substrates WC included in the substrate 101, the defective package substrate WC can be detected and the defective package substrate WC can be marked so as to be distinguishable from the non-defective package substrate WC.

It is a figure for demonstrating an example of a structure of the board | substrate inspection apparatus which concerns on one Embodiment of this invention. It is the figure which expanded a part of package substrate WC1 and package substrate WC2. It is a flowchart for demonstrating an example of operation | movement of the board | substrate inspection apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating an example of operation | movement of the board | substrate inspection apparatus which concerns on the 2nd Embodiment of this invention. It is a graph which shows an example of the resistance measurement value of the package substrate WC. The graph shown in FIG. 5 is shown on the three-dimensional coordinate. It is a figure for demonstrating the structure of the board | substrate used as a test object. FIG. 8 is an enlarged view of a part of the substrate shown in FIG. 7. It is an enlarged view of the package substrate WC. It is a figure for explaining magnetic field inspection concerning background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate test | inspection apparatus 2 Contact for multi-needle inspection 3 Multiplexer 4 Current detection part 5 Current generation part 6 Voltage measurement part 7 Continuity detection part 8 AC signal generation circuit 9 Magnetic field application part 10 XY positioning mechanism 11 Marker 12 Control part (determination Part)
21, 22, 23, 24 Contactor 101 Substrate 102 Short circuit pattern 102a Short circuit pattern (first short circuit pattern)
102b Short-circuit wiring pattern (second short-circuit wiring pattern)
103, 103a, 103b Wiring patterns 104, 104a, 104b Pad 106 Magnetic core 107 Coil 108 Magnetic field application unit 109, 110 Contacts 121-128, 141-148 Wiring patterns 132-137, 152-157 Pads (inspection points)
WC package substrate (work piece)

Claims (8)

A first wiring pattern group composed of a plurality of wiring patterns connected to a first short-circuit wiring pattern formed on one surface of the substrate, and a second short-circuit wiring formed on the other surface of the substrate A substrate inspection apparatus for inspecting a substrate connected to a pattern and having a second wiring pattern group composed of a plurality of wiring patterns formed to be insulated from the first wiring pattern group,
A plurality of inspection areas are set on the substrate, and inspection points on the wiring pattern included in the first wiring pattern group and inspection on the wiring pattern included in the second wiring pattern group are set for each inspection area. A resistance measurement unit for measuring a resistance value between the points;
Based on the resistance value measured by the resistance measurement unit, an inspection region in which a short circuit occurs between the first wiring pattern group and the second wiring pattern group among the plurality of inspection regions is detected. A board inspection apparatus comprising a determination unit. The said determination part detects the said test | inspection area | region where the smallest resistance value was measured among the resistance values measured by the said resistance measurement part as an test | inspection area | region where the said short circuit has arisen. The board | substrate inspection apparatus of description. The determination unit arranges the resistance values for each of the inspection regions measured by the resistance measurement unit in the order of arrangement of the inspection regions on the substrate, and the inspection region where the resistance value that becomes a peak on the low resistance side is measured. The substrate inspection apparatus according to claim 1, wherein the inspection is performed as an inspection region where the short circuit occurs. The determination unit sets the inspection region in which a resistance value smaller than a predetermined reference value is measured among the resistance values for each of the inspection regions measured by the resistance measurement unit as the inspection region in which the short circuit occurs. The substrate inspection apparatus according to claim 1, wherein detection is performed. The resistance measuring unit is
First and second current supply contacts and first and second voltage measurement contacts for contacting the inspection points on the wiring pattern;
A current generator for flowing a predetermined level of measurement current between the first and second current supply contacts;
A voltage measuring unit for measuring a voltage between the first and second voltage measuring contacts,
In the plurality of inspection areas on the substrate, for each inspection area, the first current supply contact and the second wiring in contact with inspection points on the wiring pattern included in the first wiring pattern group The measurement current is caused to flow by the current generator between the second current supply contact that contacts an inspection point on the wiring pattern included in the pattern group, and is included in the first wiring pattern group. Between the first voltage measurement contact that contacts the inspection point on the wiring pattern and the second voltage measurement contact that contacts the inspection point on the wiring pattern included in the second wiring pattern group. The voltage generated in the step is measured by the voltage measuring unit, and the resistance value for each inspection region is measured from the voltage measurement value and the current for measurement. The board according to any one査 apparatus. When the resistance value is measured by the resistance measurement unit,
The inspection point in contact with the first current supply contact and the inspection point in contact with the first voltage measuring contact are different inspection points,
6. The inspection point different from the inspection point in contact with the second current supply contact and the inspection point in contact with the second voltage measuring contact. Board inspection equipment. The substrate is configured as a work in which a plurality of work pieces are continuously formed integrally in a plane,
The substrate inspection apparatus according to claim 1, wherein the inspection area is set corresponding to the work piece. A first wiring pattern group composed of a plurality of wiring patterns connected to a first short-circuit wiring pattern formed on one surface of the substrate, and a second short-circuit wiring formed on the other surface of the substrate A substrate inspection method for inspecting a substrate connected to a pattern and having a second wiring pattern group composed of a plurality of wiring patterns formed to be insulated from the first wiring pattern group,
A plurality of inspection areas are set on the substrate, and inspection points on the wiring pattern included in the first wiring pattern group and inspection on the wiring pattern included in the second wiring pattern group are set for each inspection area. Measure the resistance between the points,
When a short circuit occurs between the first wiring pattern group and the second wiring pattern group, based on the resistance value measured by the resistance measurement unit, the short circuit among the plurality of inspection regions. A method for inspecting a substrate, comprising: detecting an inspection region in which the phenomenon occurs.

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