JP6520127B2 - Substrate inspection apparatus, substrate inspection method, and substrate inspection jig - Google Patents

Description

  The present invention relates to a substrate inspection apparatus, a substrate inspection method, and a substrate inspection jig for determining the quality of a wiring formed on a substrate, and more specifically, the quality of the wiring formed on the substrate is TDR (Time Domain Reflectometry) The present invention relates to a substrate inspection apparatus, a substrate inspection method, and a substrate inspection jig for efficiently determining the quality of wiring of a substrate using a time domain reflectance measurement method.

  Conventionally, a wire formed on a substrate is used to transmit and receive electrical signals to and from an IC, a semiconductor component or other electronic component mounted on the substrate. Such interconnections are formed finer and more complicated and formed with lower resistance with the recent miniaturization of electronic parts.

  As described above, the wiring provided on the substrate may be provided with a signal wiring for inputting / outputting a clock signal. When judging the quality of such a signal wiring, the TDR measurement method is used to determine the line. May be

  The TDR measurement method will be briefly described. In the inspection method using the TDR measurement method, the pulse wave of the inspection signal is input from one end of the wiring to be inspected, and the output signal is detected from one end of the wiring. Then, based on the detected detection signal, the quality of the wiring is judged. Generally, a substrate to be formed in a good condition is prepared, and an output value and an output waveform of an output signal at the time of performing a TDR measurement method in the wiring of the substrate are measured. The quality of the wiring to be inspected is judged by comparing the measured output value and output waveform with the measured value and measurement waveform of the wiring to be inspected.

  Here, for example, in the printed circuit board inspection device disclosed in Patent Document 1, the purpose is to easily and accurately determine the quality of the inspection portion in the printed circuit board using TDR, and the reference waveform and deviation width of the printed circuit board Solves the problem by setting the output impedance so that the divergence between the measured waveform and the reference waveform increases according to the state of the test site, such as short circuit or open, etc. There is.

  Further, in the circuit module disclosed in Patent Document 2, there is disclosed a technique capable of accurately identifying an open or short failure site even in a close failure site in nondestructive inspection by TDR. In this circuit module technology, it is possible to select a normal signal transmission line and a signal transmission for failure analysis which has a longer signal transmission line than the signal transmission line.

  Although a substrate is exemplified as an inspection object to be inspected using this TDR measurement method, it is not particularly limited, and a printed wiring board, a flexible board, a ceramic multilayer wiring board, an electrode for liquid crystal display or plasma display The present invention can be applied to various substrates such as a plate, a package substrate for a semiconductor package, a film carrier, and a semiconductor device such as a semiconductor wafer, a semiconductor chip, or a CSP (Chip size package).

JP, 2009-294101, A JP, 2013-197999, A

  However, although the techniques disclosed in these patent documents can improve the inspection accuracy, they can not shorten the inspection time. In particular, in the case of inspecting a mass-produced substrate, it is extremely important how to inspect a large number of substrates by shortening the inspection time, and an improvement in inspection efficiency is required. At present, TDR inspection, which requires a long inspection time, has been conducted only for sampling inspection and is unsuitable for inspection of mass-produced substrates. Moreover, many members and devices used for TDR measurement are required to have extremely high-precision specifications, and in particular, when manufacturing an inspection apparatus (or measurement apparatus) for performing measurement of fine wiring, input and output It is necessary to use high-precision electronic components (for example, a multiplexer etc.) for signal switching in order to transmit and receive signals, and in the case of testing a large number of wires, the electronic components must be separately connected to the wires to be measured. It is necessary and has a problem that it becomes an extremely expensive device when a large number of wires are to be inspected.

  The present invention has been made in view of such circumstances, and provides a substrate inspection method and a substrate inspection apparatus with high inspection efficiency when performing inspection by TDR measurement on wiring of a substrate that is mass-produced. Do.

The invention according to claim 1 is a substrate inspection apparatus for inspecting the quality of wiring formed on a substrate, and power source means for supplying an inspection signal for TDR measurement to carry out the inspection; and the inspection signal The inspection object to be inspected when the inspection is carried out, the judgment means for judging the quality of the inspection object part on the basis of the measurement means for measuring the reflection signal reflected by the object, and the reflection signal measured by the measurement means; According to the present invention, there is provided a substrate inspection apparatus comprising: a plurality of wirings which are connected in series; and a connecting unit which connects one end of the serially connected wirings and the power supply unit and the measurement unit.
The invention according to claim 2 includes storage means for storing the reflection signal measured by the measurement means together with time information, and the determination means detects the abnormality in the reflection signal when the abnormality is detected. The substrate inspection apparatus according to claim 1, wherein the stored time information is specified, and one wiring is specified from a plurality of wirings to be inspected from the time information.
The invention according to claim 3 is a method of inspecting the quality of a wiring formed on a substrate, in which a plurality of wirings to be inspected are connected in series, and TDR measurement is performed from one end of the serially connected wirings. A substrate inspection method is provided, which receives an inspection signal to be input, detects a reflection signal of the inspection signal from one end of the wiring, and determines the quality of the serially connected wirings based on the reflection signal.
The invention according to claim 4 is a jig for electrically connecting a substrate inspection apparatus for inspecting the quality of the wiring formed on the substrate and the substrate, wherein an inspection signal for TDR measurement for performing the inspection is used. There is provided a jig for inspecting a substrate, comprising: a first connection portion supplied to one end of the wiring of the substrate; and a second connection portion electrically connecting one end of the wiring and one end of the other wiring.

  According to the invention described in claims 1 and 3, a plurality of wires to be inspected are connected in series, an inspection signal for performing a TDR measurement inspection is input from one end, and a reflection signal reflected from the one end Receive The quality of the plurality of wires connected in series can be inspected based on the reflected signal. Therefore, by connecting a plurality of wires to be inspected in the TDR measurement inspection in series, the inspection can be performed at one time, and the inspection time can be shortened. In addition, even in the case of inspecting a plurality of wires, one terminal can be used to supply an inspection signal to the wires, which eliminates the need for many expensive electronic components.

  Furthermore, by connecting the wirings provided on the substrate in series, even when a large number of substrates are inspected, the inspection time as described above can be shortened and a plurality of wirings for each substrate can be made at one time. Since TDR measurement inspection can be performed, TDR measurement inspection can be performed on all substrates, not sampling inspection.

  According to the second aspect of the invention, since the reflected signal can be stored together with the time information in the storage means, and the judging means can carry out the judgment of the quality based on them, the time information when abnormality is detected is specified It is possible to identify defective portions of the serially connected wires based on the time information.

  According to the fourth aspect of the present invention, the substrate inspection apparatus for performing TDR measurement can be electrically connected to the substrate to be inspected, and the TDR measurement inspection can be performed efficiently.

1 is an embodiment showing an outline of a substrate inspection apparatus according to the present invention. It is a schematic diagram showing one embodiment in case a substrate inspection device concerning the present invention inspects a substrate. It is the graph which showed the resistance value obtained from the reflected signal which the measurement means of the board | substrate test | inspection apparatus of this invention receives with a time-axis. (A) shows the standard of the wiring of the substrate (in the good case), and (b) and (c) show the case where the wiring is abnormal.

The best mode for carrying out the present invention will be described.
FIG. 1 is a schematic view showing an embodiment of a substrate inspection apparatus according to the present invention. The substrate inspection apparatus 1 according to the present invention at least includes a power supply unit 2, a measurement unit 3, a determination unit 4, a storage unit 5, a connection unit 6, and a control unit 7. Although the substrate inspection apparatus 1 of the present invention is used to determine the quality of the wiring provided on the substrate as described above, it is not limited to the wiring of the substrate, and the quality of the conduction state is determined using the TDR measurement method. Can be applied to the inspection object.

  The power supply means 2 supplies a test signal for TDR measurement in order to carry out the test. The inspection performed by the substrate inspection apparatus 1 is an inspection for detecting conduction or short circuit abnormality of the wiring. For example, a pulse generator can be used as the power supply means 2, and a pulse wave generated by the pulse generator can be used as a test signal. The inspection signal for TDR measurement of the power supply means 2 may use, for example, a pulse wave of 50 GHz, but is not particularly limited, and is adjusted according to the wiring of the substrate to be inspected.

  The measuring means 3 measures the reflected reflection signal of the inspection signal supplied from the power source means 2. The measuring means 3 supplies the inspection signal of the power supply means 2 to the wiring to be inspected, and measures the reflected wave reflected at the end of the wiring to be inspected as a reflection signal. An apparatus capable of receiving a reflection signal is adopted as the measurement means 3. However, resistance value information is calculated based on the reflection signal, and this resistance value information is combined with time information to be described later. An oscilloscope that can be displayed can be employed.

  The measuring means 3 measures this reflection signal together with time information. By measuring the reflected signal and the time information together, the measuring means 3 can measure the temporal change of the reflected signal. The present invention utilizes this temporal change to shorten the inspection time for inspection. In addition, the measurement result which the measurement means 3 performs is transmitted to the determination means 4 and the memory means 5 which are mentioned later.

  The judging means 4 judges the quality of the inspection object based on the measured reflection signal. The determination means 4 receives time information together with the reflection signal measured by the measurement means 3, detects a temporal change of the reflection signal, and determines the quality of the wiring to be inspected. A specific determination method performed by the determination means 4 can be implemented by comparing a preset reference value with the measured reflection signal. The determination performed by the determination unit 4 can be performed while receiving the reflection signal from the measurement unit 3 or information such as the reflection signal from the measurement unit 3 is stored in the storage unit 5 described later, The information stored in the storage means 5 can be read again and implemented.

  The determination means 4 compares the measured reference signal with the measured reflected signal, and if it is confirmed that the reflected signal is within the predetermined width with respect to the reference value or the same reference value, the inspection object is good It is determined that the condition is good). On the other hand, when the determination means 4 compares the reference value with the reflection signal and detects a place where the reflection signal is greatly different from the reference value or a position located outside from the predetermined width of the reference value, the wiring to be inspected is abnormal ( It is determined that there is a defect state). As described above, the determination unit 4 determines the good / abnormal state (good or bad) of the wiring.

  Although the method of setting the reference value for the determination of the determination means 4 is not particularly limited, for example, a substrate on which a well-formed wiring is prepared is prepared, and the wiring of this substrate is actually measured. There is also a method of setting the measured value obtained by the measurement as a reference value. Also, based on the design data for creating the wiring of the substrate, it is possible to set the reference value based on the theoretical value obtained from the wiring in a good state.

  The storage unit 5 stores information on the inspection signal supplied by the power supply unit 2 and information on the reflection signal measured by the measurement unit 3 and time information. The storage unit 5 stores reflection signal information and time information in association with each other, and when the determination unit 4 detects an abnormality in the reflection signal, the abnormality and the time information stored in the storage unit are stored. From this time information, it is possible to identify an abnormal part from the wiring (a plurality of wirings) to be inspected.

  The connecting means 6 connects a plurality of wires to be inspected in series, and connects one end of the wires connected in series to the power supply means 2 and the measuring means 3. The connection means 6 has a first connection portion 61 connecting one end of the inspection object (a plurality of wires connected in series) and the power supply means 2 and the measurement means 3. The first connection portion 61 includes a probe connected to one end of the wiring to be inspected, and a cable for connecting the probe, the power supply unit 2 and the measurement unit 3. These probes and cables are formed, for example, so that the impedance is constant, and those which can perform TDR measurement are employed.

  The connection means 6 has a second connection portion 62 which connects a plurality of wires to be inspected in series. The second connection portion 62 connects a plurality of wires to be inspected so as to be connected in series. The second connection portion 62 electrically connects one end of one wiring to one end of the other wiring, and also connects the other end of the other wiring to the one end of the other wiring. Connecting. By connecting the ends of the respective wires in this manner, serial connection is performed. In the wiring in which the first connection portion 61 is connected to one end, the second connection portion 62 is connected to the other end of the wiring.

  The second connection portion 62 connects two ends of predetermined two lines in series by connecting two lines in series, thereby setting a plurality of lines to be inspected as one test target connected in series. For the second connection portion 62, for example, a coaxial cable having a constant impedance can be used.

  The impedance of each of the first connection portion 61 and the second connection portion 62 needs to be constant, but it is preferable that the first connection portion 61 and the second connection portion 62 be set to the same impedance. When TDR measurement is performed on a plurality of wires to be inspected, the effects of the first connection portion 61 and the second connection portion 62 become the same result, and the processing in the case where the determination unit 4 makes the determination based on the reflection signal is simplified. can do. The first connection portion 61 and the second connection portion 62 can be used, for example, using a 50 Ω coaxial cable.

  In FIG. 1, a tester unit 8 having a substrate to be inspected, a power supply unit 2, a measurement unit 3, a determination unit 4, a storage unit 5 and the like as the connection unit 6 including the first connection unit 61 and the second connection unit 62. A jig 8 to connect is provided. By providing the connection means 6 with the jig 8, even if the substrate to be inspected is changed, the jig 8 is designed according to the changed substrate (according to the position of the wiring of the substrate By designing the positions of the first connection portion 61 and the second connection portion 62, it is possible to easily cope with the problem.

  It has been described that the first connecting portion 61 and the second connecting portion 62 are provided in the jig 8 described above, but in order to conduct another electrical inspection (conduction / insulation inspection), It is also possible to provide a contact for conducting contact with the set inspection point.

  The control means 7 prompts and controls the operations of the power source means 2, the measuring means 3, the determination means 4 and the storage means 5. The control means 7 urges and controls the operation of each means to carry out TDR measurement inspection of the wiring to be inspected. The specific operation performed by the control unit 7 is to command the power supply unit 2 to supply a test signal for TDR measurement, or to receive and measure the reflection signal to be measured to the measurement unit 3 Issue an instruction to

Further, the control means 7 instructs the determination means 4 to determine the quality of the wiring to be inspected based on the reflection signal. In this case, when the determination means 4 compares the reference value with the reflection signal to determine the quality, the control means 7 compares the reflection signal with the reference value with respect to the determination means 4 to detect a largely different part. Make an order. The determination means 4 transmits the determination result to the storage means 5, and the storage means 5 receives and stores the determination result and the reflection signal. The control means 7 urges each means to operate so as to carry out an examination based on the examination information stored in the storage means 5 or to store the determination result and the examination result in the storage means 5.
The above is the description of the schematic configuration of the substrate inspection apparatus according to the present invention.

  Next, a method of TDR measurement inspection performed by the substrate inspection apparatus 1 will be described. FIG. 2 is a schematic view showing a state in which the substrate CB to be inspected is prepared in the substrate inspection apparatus 1. In the substrate CB shown in FIG. 2, three wires W1, W2 and W3 to be subjected to TDR measurement inspection are shown. Although only three wires are drawn on the substrate CB in FIG. 2, a plurality of other wires are formed on the actual substrate CB.

  In the embodiment shown in FIG. 2, one end W 11 of the wiring W 1 is conductively connected to the power supply means 2 and the measuring means 3 by the first connection portion 61. Further, the other end W12 of the wiring W1 and the one end W21 of the wiring W2 are electrically connected by the second connection portion 62. Further, the other end W22 of the wiring W2 and one end W31 of the wiring W3 are electrically connected by the second connection portion 62. That is, in the wiring to be inspected in this embodiment, the wiring W1, the wiring W2, and the wiring W3 are connected in series by the second connection portion 62, respectively. In this embodiment, the connection means 6 having the first connection portion 61 and the second connection portion 62 (the second connection portion 62a and the second connection portion 62b) is a jig so as to be able to connect to the substrate CB as described above. Eight are designed.

  When an actual inspection is performed, the substrate CB is mounted on a substrate mounting table (not shown) on which the inspection of the substrate CB is performed. Next, the jig 8 corresponding to the inspection of the substrate CB is connected to the mounted substrate CB. When the jig 8 is connected to the substrate CB, the inspection is performed. In addition, before the actual inspection is performed, the reference value in the good state of the three wirings provided on the substrate CB is stored in the storage unit 5 in advance.

  Next, when the jig 8 is connected to the substrate CB, the control means 7 instructs the power supply means 2 to carry out the inspection of the substrate CB. When the power supply unit 2 receives this command from the control unit 7, it supplies a test signal for TDR measurement to the first connection portion 61 of the connection unit 6. When the inspection signal is supplied to the first connection portion 61, the inspection signal is supplied from the one end W11 of the wiring W1 of the substrate CB to the wiring W1, passes through the other end W12 of the wiring W1, and passes through the second connection portion 62a. , Supplied from the one end W21 of the wiring W2 to the wiring W2, and further supplied to the wiring W3 from the one end W31 of the wiring W3 via the second connection portion 62b through the other end W22 of the wiring W2 The inspection signal is reflected at the other end W32. The reflected inspection signal is returned to the first connection portion 61 in the reverse order to the above as a reflected signal, and reaches the measuring means 3 described later.

  The control means 7 commands the measuring means 3 to receive a reflection of the test signal supplied by the power supply means 2. When the measuring means 3 receives the command from the control means 7, it receives the reflected signal. The measuring means 3 receives the reflected signal and acquires time information associated with the reflected signal. The measuring means 3 sends the reflected signal and the time information to the storage means 5. The storage unit 5 stores the information transmitted from the measurement unit 3.

  The control unit 7 instructs the determination unit 4 to determine whether the wiring to be inspected (the wiring W1, the wiring W2, and the wiring W3) is good or bad based on the reflection signal and the time information stored in the storage unit 5. The judging means 4 compares the reflection signal stored in the memory means 5 with the reference value to carry out the pass / fail judgment of the inspection object.

  The determination performed by the determination means 4 will be specifically described. FIG. 3 is a graph showing a reflected signal based on time information. In FIG. 3, (a) shows a reference value (good state) to be compared by the determination means 4. FIG. 3B shows the case where a defect exists in the wiring W3. FIG. 3C shows the case where a defect exists in the wiring W2. In the graph shown in FIG. 3, the ordinate represents the resistance value, and the abscissa represents the time.

  In the good case shown in FIG. 3A, the resistance value Z1 of the first connection portion 61 is displayed after the start of the test, and then the resistance value Z2 of the wiring W1 is displayed, and then the second connection portion 62a is displayed. The resistance Z3 of the wiring W2 is displayed, and then the resistance Z4 of the wiring W2 is displayed. Furthermore, the resistance value Z5 of the second connection portion 62b connecting the wiring W2 and the wiring W3 is displayed, and then the resistance value Z6 of the wiring W3 is displayed. In this case, by setting the first connection unit 61 and the second connection unit 62 to have the same impedance value, the inspection object can be inspected when the reflected signals are arranged (displayed) in time series based on time information. It is possible to easily detect an object (the wiring W1, the wiring W2 and the wiring W3) and determine the quality. In this case, resistance value Z2 is set as the reference value of wiring W1, resistance value Z4 as the reference value of wiring W2, resistance value Z6 as the reference value of wiring W3, or ± of these resistance values Z2, Z4, and Z6. 15% can be set as an allowable range.

  When the inspection of the substrate CB is actually carried out, the same or substantially the same locus as the graph shown in FIG. 3A or the tolerance (for example, ± 15%) of the graph shown in FIG. When the reflection signal received by the measuring means 3 is present in the set range, the judging means 4 judges that the inspection object (the wiring W1, the wiring W2 and the wiring W3) is in the good state. Become.

  In the case shown in FIG. 3B, the behavior different from the resistance value Z6 of the wiring W3 shown in FIG. 3A is shown at the place where the resistance value Z6 of the wiring W3 is displayed. This indicates that an abnormality such as a conduction failure or a short circuit failure exists in a part of the wiring W3. Therefore, the determination means 4 detects that the resistance value Z6 of the wiring W3 is largely different from the reference value. Note that the determination performed by the determination means 4 may adopt a method of performing quality determination for each wiring, or adopt a method of specifying the location of an abnormality when an abnormality of the inspection object is detected. You can also.

  In the case shown in FIG. 3C, the behavior different from the resistance value Z4 of the wiring W2 shown in FIG. 3A is shown at the place where the resistance value Z4 of the wiring W2 is displayed. In the case shown in FIG. 3C, since the resistance values of the second connection portion 62b after the wire W2 and the wire W3 are not calculated, the wire W2 has a disconnection (conduction abnormality). There is a high possibility. Thus, even if the resistance value of the wiring W3 is not measured, it is possible to determine that the substrate CB is a defective substrate because the wiring W2 has an abnormality. Also in this case, as described above, the determination means 4 can adopt a method of specifying a place (place) after detecting the presence or absence of an abnormality of the inspection object, or determines the quality of each wiring to judge the inspection object. It is also possible to determine the quality of the object.

DESCRIPTION OF SYMBOLS 1 ..... Board inspection apparatus 2 ... power source means 3 ..... measurement means 4 ... determination means 5 ... storage means 6 ... connection means 61 ... first connection portion 62 ... second connection portion 7 ... control means 8 ... jig CB ... substrate

Claims (4)

A substrate inspection apparatus for inspecting the quality of wiring formed on a substrate, comprising:
Power supply means for supplying a test signal for TDR measurement to perform said test;
Measuring means for measuring the reflected signal reflected from the inspection signal;
Based on the reflected signal measured in said measuring means, determination means for determining quality of wiring inspection object,
A connecting means for connecting a plurality of wires to be tested in series and connecting one end of the wires connected in series to the power supply means and the measuring means when the test is performed ;
Storage means for storing the reflection signal measured by the measurement means together with time information;
When the judging means detects an abnormality of the reflection signal, the abnormality and the time information stored in the storage means are specified, and one wiring is specified from a plurality of wires to be inspected from the time information. A substrate inspection apparatus characterized by A method of inspecting the quality of wiring formed on a substrate, comprising
Connect multiple wires to be tested in series,
A test signal for performing TDR measurement is input from one end of the series connected wiring,
Detecting a reflection signal of the inspection signal from one end of the wiring;
Judging the quality of the series connected wiring based on the reflected signal ;
Storing the reflected signal together with time information in storage means;
When an abnormality of the reflection signal is detected in the determination, the abnormality and time information stored in the storage means are specified, and a substrate inspection method of specifying one wiring from a plurality of wirings to be inspected from the time information . A substrate inspection apparatus for inspecting the quality of wiring formed on a substrate, comprising:
Power supply means for supplying a test signal for TDR measurement to perform said test;
Measuring means for measuring the reflected signal reflected from the inspection signal;
Based on the reflected signal measured in said measuring means, determination means for determining quality of wiring inspection object,
When the test is performed, it possesses one end of the series-connected wiring causes serially connected a plurality of wires to be inspected, and a connecting means for connecting the power supply means and the measuring means,
The connection means is
A first connection portion for connecting one end of the serially connected wires to the power supply means and the measurement means;
And a second connection portion connecting in series the plurality of wires to be inspected.
The substrate inspection apparatus according to claim 1, wherein the impedances of the first connection portion and the second connection portion are constant . A jig for electrically connecting a substrate inspection apparatus for inspecting the quality of wiring formed on the substrate and the substrate,
A first connection portion for supplying an inspection signal for TDR measurement to conduct the inspection to one end of the wiring of the substrate;
It possesses a second connecting portion to be connected in series a plurality of wiring by conductive connecting another end to one end of another wire of the wiring,
A jig for inspecting a substrate , wherein an impedance of each of the first connection portion and the second connection portion is constant .

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