JP2007273566A - Detection device, circuit board, and ic chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection device which improves precision in detecting positional shift of an IC chip, and also detects the amount of a positional shift, and to provide a circuit board and an IC chip that are the subject of detection. <P>SOLUTION: According to the detection device 1, when the IC chip 30 is mounted on the circuit board 20, a positional shift between a plurality of mounting pads 21a to 21j and a plurality of terminals 31a to 31j is detected using positional shift detecting pads 22a to 22d and 23a to 23d disposed around mounting pads. The detection device 1 has a detection unit 2 and a calculating unit 5. The detection unit 2 supplies an AC current flowing between the positional shift detecting pads 22a to 22d and 23a to 23d and terminals to be connected to the mounting pads to detect a capacitance between the detecting pads 22a to 22d and 23a to 23d and the mounting pads. Based on the capacitance detected by the detection unit 2, the calculating unit 5 detects a positional shift between the mounting pads and the terminals to be connected to the mounting pads, and also calculates an amount of the positional shift. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a detection device that detects a positional shift that occurs when an IC chip is mounted on a circuit board, a circuit board to be detected, and an IC chip.

  In recent years, in mounting an IC chip on a circuit board, the use of a flip chip method without using a wire is increasing from the viewpoint of miniaturization of the IC chip and improvement of the mounting density. In the flip chip method, the terminals of the IC chip are connected to mounting pads provided on the circuit board.

  In addition, when this flip-chip method is employed, there is a problem of misalignment of the IC chip that cannot be detected by electrical inspection or appearance inspection. Such misalignment does not cause a problem at the time of product shipment, but has a possibility of causing an electrical failure due to subsequent aging.

  For this reason, detection of positional deviation of the IC chip has been conventionally performed (for example, see Patent Document 1). 11A and 11B are diagrams showing a part of a circuit board provided with a conventional positional deviation detection function. FIG. 11A is a plan view and FIG. 11B is a cross-sectional view. In FIG. 11A, only the outer shape and terminals of the IC chip 83 are shown. The terminals of the IC chip 83 are hatched.

  As shown in FIG. 11A, mounting pads 81 a to 81 h of the IC chip 83 are provided on the circuit board 80 so as to correspond to the terminals 84 a to 84 h of the IC chip 83. Further, as shown in FIG. 11B, the terminals 84 a to 84 h of the IC chip 83 are solder bumps provided on the wiring 85. Furthermore, the IC chip 83 is mounted on the circuit board 80 by disposing an anisotropic conductive film 86 having adhesiveness between them and heating and pressing them in that state. By this heating and pressurization, the terminals 84 a to 84 h and the mounting pads 81 a to 81 h are electrically connected by conductive particles (not shown) in the anisotropic conductive film 86. Further, the IC chip 83 is bonded to the circuit board 80 by an anisotropic conductive film 86.

  In addition, as shown in FIG. 11A, position shift detection pads 82a to 82d are provided beside the pads (81a, 81d, 81e, 81h) at the four corners of the circuit board 80. . Further, the mounting pads 81a to 81h and the positional deviation detection pads 82a to 82d are connected to a detection device (not shown). The detection device determines that a positional shift has occurred in the IC chip 83 when continuity is obtained between the pad and the positional shift detection pad.

  For example, as shown in FIG. 11, each of the terminals 84a to 84h of the IC chip 83 is electrically connected to the corresponding mounting pads 81a to 81h, but the IC chip 83 is misaligned. And At this time, due to the displacement of the IC chip 83, the mounting pad 81e and the displacement detection pad 82c are electrically connected to each other by the terminal 84e. The detection device determines that a positional shift has occurred in the IC chip 83 by detecting this conduction.

In recent years, the number of terminals of an IC chip has been increasing year by year, and the pitch between terminals has been narrowing year by year. Therefore, in the detection of positional deviation, improvement in detection accuracy is required. In order to improve the detection accuracy in the conventional positional deviation detection shown in FIGS. 11A and 11B, it is necessary to narrow the gap between the mounting pad and the positional deviation detection pad in the circuit board. .
JP-A 61-17547

  Since the solder bumps (terminals of the IC chip 83) shown in FIG. 11B are usually formed by plating or screen printing, there is a limit to improving the formation accuracy of the solder bumps. Further, the solder bump is deformed by heating and pressurization when mounting the IC chip, but the deformation amount greatly varies depending on the temperature and pressure. Therefore, it is difficult to control the position, size, and dimension after deformation of the solder bump. For this reason, even if the gap between the mounting pad and the positional deviation detection pad is narrowed, it is considered that the detection accuracy of the positional deviation is not so much improved in practice.

  In addition, since the gap between the mounting pad and the positional deviation detection pad is narrowed, the solder bump may come into contact with the positional deviation detection pad even though there is no positional deviation in the IC chip. In this case, since the detection device determines that the product is defective, a non-defective product with no positional deviation is excluded as a defective product. As a result, the yield decreases and the manufacturing cost increases.

  Further, in the conventional positional deviation detection shown in FIGS. 11A and 11B, it can be determined only whether the terminal of the IC chip and the positional deviation detection pad are conductive or not. It is impossible to measure how much the IC chip is displaced. For this reason, even if a positional deviation is detected, it is difficult to reflect this on the mounter for mounting the IC chip, and the positional deviation cannot be eliminated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a detection device capable of solving the above-described problems, improving the detection accuracy of positional deviation of an IC chip, and detecting the amount of deviation, a circuit board to be detected, and an IC chip. is there.

  In order to achieve the above object, when mounting an IC chip on a circuit board, the first detection device according to the present invention includes a plurality of mounting pads provided on the circuit board and the IC chip connected to them. A detection device for detecting a positional deviation between a plurality of terminals using a positional deviation detection pad provided around any mounting pad of the circuit board, comprising: a detection unit; a calculation unit; And the detection unit passes an alternating current between the displacement detection pad and the terminal to which the mounting pad adjacent to the detection pad is connected, and a capacitance between them. Based on the capacitance detected by the detection unit, the calculation unit detects whether the position shift detection pad is adjacent to a mounting pad and a terminal to which the pad is connected. Detected the positional deviation between And calculating the amount of serial misalignment.

  In order to achieve the above object, the second detection apparatus according to the present invention, when mounting an IC chip on a circuit board, and a plurality of mounting pads provided on the circuit board and the above-described mounting pads are connected to them. A detection device that detects a positional deviation between a plurality of terminals of an IC chip using a positional deviation detection terminal provided around any one of the terminals of the IC chip, the detection unit, and a calculation unit The detection unit detects a capacitance between the position shift detection terminal and a mounting pad that is a connection target of a terminal adjacent to the position shift detection terminal, and the calculation unit includes: Based on the capacitance detected by the detection unit, a positional deviation between a terminal adjacent to the positional deviation detection terminal and a mounting pad that is a connection target thereof is detected and detected. Calculating the amount of positional deviation And features.

  Furthermore, in order to achieve the above object, a circuit board in the present invention is a circuit board on which an IC chip is mounted, and a plurality of mounting pads connected to each of a plurality of terminals provided on the IC chip, A misalignment detection pad disposed around any of the mounting pads, and the mounting pad and the misalignment detection pad are insulated from each other by an insulating film covering the misalignment detection pad. It is characterized by being.

  In order to achieve the above object, an IC chip in the present invention is an IC chip mounted on a circuit board, and a plurality of terminals connected to a plurality of mounting pads provided on the circuit board, And a misalignment detection terminal arranged around one of the terminals.

  In the detection apparatus according to the present invention, the capacitance between the circuit board positional deviation detection pad and the IC chip terminal, or the static capacitance between the IC chip positional deviation detection terminal and the circuit board mounting pad. Capacitance is detected. Moreover, these electrostatic capacitances change according to the magnitude of the positional deviation, and there is a certain relationship between the capacitance and the positional deviation amount (see FIG. 4).

  For this reason, the detection apparatus in the present invention detects the occurrence of positional deviation from the magnitude of the capacitance. According to the detection device of the present invention, it is possible to detect the displacement of the IC chip with higher accuracy than in the past. Further, according to the detection apparatus of the present invention, the amount of positional deviation can be calculated from the size of the capacitance, and it is also understood how much positional deviation has occurred.

  When mounting an IC chip on a circuit board, the first detection device according to the present invention is provided between a plurality of mounting pads provided on the circuit board and a plurality of terminals of the IC chip connected thereto. A detection device that detects a positional shift using a positional shift detection pad provided around any of the mounting pads on the circuit board, and includes a detection unit and a calculation unit, and the detection unit includes: A current flowing between the position displacement detection pad and the terminal to be connected to the mounting pad adjacent to the pad, and detecting an electrostatic capacitance between the terminals, and the arithmetic unit Detects a positional deviation between a mounting pad adjacent to the positional deviation detection pad and a terminal to which it is connected based on the capacitance detected by the detection unit. Calculate the amount of detected positional deviation I am characterized in.

  In the first detection apparatus, the calculation unit may calculate the positional deviation from the capacitance detected by the detection unit based on a relationship between a capacitance value obtained in advance and an amount of positional deviation. It is better to calculate the amount of. In this case, the calculation accuracy of the amount of positional deviation can be increased.

  In the first detection device, in the circuit board, the mounting pad and the displacement detection pad may be insulated by an insulating film covering the displacement detection pad. In this case, since the electrostatic capacitance between the position shift detection pad and the IC chip terminal can be increased, stable position shift detection can be performed and detection accuracy can be further improved. In addition, since the frequency of the alternating current flowing through the detection unit can be lowered, the cost of the detection unit can be reduced.

  In the first detection device, in the circuit board, two or more positional deviation detection pads are arranged so as to surround one mounting pad, and the detection unit is for detecting the two or more positional deviations. Capacitance between each of the pads and the terminal that is the connection target of the mounting pad adjacent to each other is detected, and the calculation unit is configured to detect the two or more displacement detection pads. Every time, the distance between each positional deviation detection pad and the terminal to be connected to the one mounting pad is calculated from the capacitance detected by the detection unit, and the two or more positional deviation detection purposes are calculated. Using the distance calculated for each pad, a positional shift and its direction between the one mounting pad and a terminal to be connected to it are detected, and the detected amount of the positional shift is determined. Set the calculation mode It is preferred. In this aspect, since the direction of positional deviation can be detected, the mounting error in the mounting machine can be suppressed by feeding back the detection result to the mounting machine.

  In the above aspect, in the circuit board, two or more mounting pads are surrounded by the two or more positional deviation detection pads, and the arithmetic unit is surrounded by the two or more positional deviation detection pads. For each of the mounting pads, the positional deviation and its direction are detected, the amount of the detected positional deviation is calculated, and using the detection result and the calculation result, the IC chip is arranged in the thickness direction. It is preferable to determine whether or not there is a rotational deviation with the axis along the axis as the rotational axis. If the rotational deviation has occurred, it is preferable to calculate the amount of the rotational deviation. In this aspect, it is possible to feed back the rotational displacement of the IC chip to the mounting machine.

  In addition, when mounting the IC chip on the circuit board, the second detection device according to the present invention includes a plurality of mounting pads provided on the circuit board and a plurality of terminals of the IC chip connected thereto. Is a detection device that detects a position shift between the terminals of any one of the IC chips using a position shift detection terminal, and includes a detection unit and a calculation unit, and the detection unit Detects a capacitance between the position deviation detection terminal and a mounting pad that is a connection target of a terminal adjacent to the terminal, and the arithmetic unit detects the detection by the detection unit. Based on the capacitance, the positional deviation between the terminal adjacent to the positional deviation detection terminal and the mounting pad to which the terminal is connected is detected, and the detected amount of the positional deviation is determined. It is characterized by calculating.

  Also in the second detection device, the calculation unit may calculate the positional deviation from the capacitance detected by the detection unit based on a relationship between a capacitance value obtained in advance and an amount of positional deviation. It is better to calculate the amount of. Also in this case, the calculation accuracy of the amount of positional deviation can be improved.

  In the second detection device, in the IC chip, two or more positional deviation detection terminals are arranged so as to surround one terminal, and the detection unit is provided for each of the two or more positional deviation detection terminals. In addition, the capacitance between the mounting pads that are the connection targets of the terminals that are adjacent to each other is detected, and the calculation unit is provided for each of the two or more positional deviation detection terminals, From the capacitance detected by the detection unit, the distance between each position deviation detection terminal and the mounting pad that is the connection target of the one terminal is calculated, and the distance calculated for each position deviation detection terminal is calculated. Using the distance, the positional deviation and direction between the one terminal and the mounting pad that is the connection target thereof are detected, and the detected amount of the positional deviation is calculated. preferable. In this aspect, since the direction of positional deviation can be detected, the mounting error in the mounting machine can be suppressed by feeding back the detection result to the mounting machine.

  In the above aspect, in the IC chip, two or more terminals are surrounded by two or more positional deviation detection terminals, and the calculation unit is provided for each of the terminals surrounded by two or more positional deviation detection terminals. , Detecting the positional deviation and its direction, calculating the amount of the detected positional deviation, and using the detection result and the calculation result, the axis along the thickness direction of the IC chip is rotated. It is preferable to determine whether or not there is a rotational deviation, and when the rotational deviation occurs, it is preferable to calculate the amount of the rotational deviation. In this aspect, it is possible to feed back the rotational displacement of the IC chip to the mounting machine.

  Furthermore, the circuit board in the present invention is a circuit board on which an IC chip is mounted, and a plurality of mounting pads connected to each of a plurality of terminals provided on the IC chip, and any one of the mounting pads. A misalignment detection pad disposed in the periphery, wherein the mounting pad and the misalignment detection pad are insulated from each other by an insulating film covering the misalignment detection pad. To do.

  In the circuit board according to the present invention, two or more misalignment detection pads may be disposed so as to surround one mounting pad. Further, it is possible to adopt an aspect in which two or more mounting pads are surrounded by two or more displacement detection pads.

  The IC chip in the present invention is an IC chip mounted on a circuit board, and a plurality of terminals connected to each of a plurality of mounting pads provided on the circuit board, and around any one of the terminals. And a positional deviation detection terminal arranged.

  In the IC chip according to the present invention, two or more misalignment detection terminals may be disposed so as to surround one terminal. Further, two or more terminals may be surrounded by two or more positional deviation detection terminals. Further, the IC chip according to the present invention may be provided with the detection device according to the present invention therein.

(Embodiment 1)
Hereinafter, the detection device, the circuit board, and the IC chip according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a schematic configuration of a detection apparatus according to Embodiment 1 of the present invention. 2 is a diagram showing a part of the circuit board shown in FIG. 1, FIG. 2 (a) is a plan view, and FIG. 2 (b) is taken along a cutting line AA 'in FIG. 2 (a). It is sectional drawing obtained by cut | disconnecting. 1 and 2A, only the outer shape and terminals of the IC chip 30 are shown.

  FIG. 3 is a circuit diagram showing an example of a specific configuration of the DC resistance detection unit shown in FIG. FIG. 4 is a diagram illustrating a change in electrostatic capacitance between a pad for detecting a displacement of the circuit board and a terminal of the IC chip. FIG. 5A is a circuit diagram illustrating an example of a specific configuration of the capacitance detection unit illustrated in FIG. 1, and FIG. 5B illustrates an example of the rectifier circuit illustrated in FIG. FIG.

  The detection apparatus 1 shown in FIG. 1 is used in a mounting process for mounting an IC chip 30 on a circuit board 20. As shown in FIG. 1, in the first embodiment, the circuit board 20 includes a plurality of mounting pads 21a to 21j. As shown in FIGS. 2A and 2B, the circuit board 20 includes a base substrate 24 on which an insulating film 25 is provided, and mounting pads 21 a to 21 j are provided on the insulating film 25. . Examples of the base substrate 24 include a glass substrate and a silicon substrate.

  In the first embodiment, the IC chip 30 includes a plurality of terminals 31a to 31j connected to the plurality of mounting pads 21a to 21j, respectively. Furthermore, as shown in FIG. 2B, also in the first embodiment, the terminals 31a to 31j of the IC chip 30 are provided on the wiring 32 in the same manner as the example shown in FIG. 11B in the background art. This is a hemispherical solder bump. The IC chip 30 and the circuit board 20 are bonded to each other by an anisotropic conductive film 33 interposed therebetween.

  Further, as shown in FIG. 1, among the mounting pads 21a to 21j, a misalignment detection pad is provided around the mounting pads 21a and 21j. Specifically, four misalignment detection pads 22a to 22d are arranged around the mounting pad 21a so as to surround the pad 21a (see FIG. 2A). Similarly, four misalignment detection pads 23a to 23d are also arranged around the mounting pad 21j so as to surround the pad 21j.

  The detection device 1 uses these position deviation detection pads to use the position deviation between the mounting pad 21a of the circuit board 20 and the terminal 31a of the IC chip 30, and the mounting pad 21j of the circuit board 20 and the IC chip. The positional deviation between 30 terminals 31j is detected. In the first embodiment, the positional shift means that the terminal of the IC chip 30 is shifted from the reference position on the corresponding mounting pad. In the first embodiment, the reference position is set to a position where the axis passing through the apex of the solder bump coincides with the normal passing through the stop of the contact surface of the mounting pad. The reference position is not particularly limited.

  As described above, the detection device 1 according to the first embodiment also uses the positional displacement detection pad provided around the mounting pad in the same manner as the conventional detection device described with reference to FIG. Detection is in progress. Also in the first embodiment, the position shift detection by the detection device 1 is performed when no problem occurs in the electrical inspection. However, the detection apparatus 1 according to the first embodiment can calculate the amount of positional deviation and detect the positional deviation direction in addition to the detection of the positional deviation. This point will be described below.

  As shown in FIG. 1, the detection device 1 includes a detection unit 2 and a calculation unit 5. In the first embodiment, the detection unit 2 includes a DC resistance detection unit 3 that detects a DC resistance between a terminal of the IC chip 30 and a position shift detection pad, and a terminal of the IC chip 30 and a position shift detection pad. And a capacitance detecting unit 4 for detecting the capacitance between the two. The detection device 1 also includes a first switching circuit 9 and a second switching circuit 11 that perform circuit switching in accordance with an instruction from the calculation unit 5.

  The first changeover circuit 9 includes changeover switches 10a and 10b. The switch 10 a connects any one of the displacement detection pads 22 a to 22 d to the second switching circuit 11 in accordance with an instruction from the calculation unit 5. Similarly, the switch 10b connects any one of the displacement detection pads 23a to 23d to the second switching circuit 11 in accordance with an instruction from the calculation unit 5.

  The second switching circuit 11 includes a combination of the position deviation detection pad selected by the changeover switch 10a and the terminal 31a and the position deviation detection pad selected by the changeover switch 10b and the terminal 31j according to an instruction from the calculation unit 5. Select one of the combinations. Furthermore, the second switching circuit 11 connects the selected one to one of the DC resistance detection unit 3 and the capacitance detection unit 4 in accordance with an instruction from the calculation unit 5. The second switching circuit 11 includes switches 12a to 12f, and the above selection and connection are performed by these switches 12a to 12f.

  In the present embodiment, first, the DC resistance detection unit is used for all the combinations of the position shift detection pads 22a to 22d and the terminal 31a and all the combinations of the position shift detection pads 23a to 23d and the terminal 31j. The DC resistance is detected by 3. Thereafter, the capacitance is detected by the capacitance detection unit 4 for these combinations. However, in the combination in which the direct current resistance is zero, no electrostatic capacitance is generated between the terminal and the positional deviation detection pad, and thus the electrostatic capacitance is not detected. In this case, it is determined that a large positional deviation has occurred.

  The DC resistance detection unit 3 applies a DC voltage between the position deviation detection pad and the terminal, thereby detecting the DC resistance between them. At this time, the application of the DC voltage to the terminal is performed through a mounting pad to which the terminal is electrically connected. For example, as shown in FIG. 2A, when the terminal 31a is not in contact with any of the displacement detection pads 22a to 22d, the DC resistance detection unit 3 is connected to the Detect resistance. The value of the direct current resistance becomes smaller as the terminal 31a approaches the position shift detection pad. Further, when the terminal 31a comes into contact with any position deviation detection pad, the DC resistance is 0 (zero) because the position deviation detection pad and the terminal 31a are electrically connected.

Here, an example of a specific circuit configuration of the DC resistance detection unit 3 will be described. As shown in FIG. 3, when the terminal of the IC chip and the position deviation detection pad are connected to the DC resistance detection unit 3, the resistance R _X generated between the terminal of the IC chip and the position deviation detection pad is: The resistor 13 is connected in series. Further, the series circuit of the resistor R _X and the resistor 13 is connected in parallel to the series circuit of the resistor 14 and the reference resistor 15, and a DC voltage is applied to both ends of both series circuits by a DC power source. Further, as shown in FIG. 3, the branch wiring 16 branched from between the resistor R _X and the resistor 13 and the branch wiring 17 branched from between the resistor 14 and the reference resistor 15 are input terminals of the differential amplifier 18. Connected to. Further, the resistance value of the resistor 13 and the resistance value of the resistor 14 are the same.

When a DC voltage is applied, the differential amplifier 18 outputs an analog signal corresponding to the difference between the reference resistor 15 and the resistor R _X. The analog signal is converted into a digital signal by the A / D conversion circuit 19 and input to the arithmetic unit 5. Note that the resistance value R _S of the reference resistor 15 is set to a resistance value between the terminals of the IC chip 30 and the mounting pad when there is no positional deviation.

When the digital signal is input by the A / D conversion circuit 19, the arithmetic unit 5 determines the position shift state between the position shift detection pad and the terminal based on the output value of the digital signal. For example, when the output value of the digital signal is greater than 0 (zero), the calculation unit 5 determines that a positional deviation has occurred. Further, when the output value of the digital signal is the same value as the resistance value R _S of the reference resistor 15, the calculation unit 5 determines that the two are conducting.

In addition, the electrostatic capacitance detection unit 4 detects the electrostatic capacitance between the non-conductive position deviation detection pad and the terminal. In the first embodiment, the electrostatic capacitance detection unit 4, between the position displacement detection pad 22a~22d and terminal 31a, an AC voltage is applied, formed electrostatic capacitance C ₁ ~ therebetween C ₄ (see FIG. 2A) is detected. The electrostatic capacitance detection unit 4 also applies an alternating voltage between the position deviation detection pads 23a to 23d and the terminal 31j, and also detects the electrostatic capacitance formed therebetween. Furthermore, the capacitance detection unit 4 outputs information regarding the detected capacitance to the calculation unit 5. The application of the AC voltage to the terminal 31a is performed via the mounting pad 21a, and the application of the AC voltage to the terminal 31j is performed via the mounting pad 21j.

  Here, the relationship between the distance between the terminals of the IC chip 30 and the displacement detection pad (the amount of displacement) and the capacitance between them will be described with reference to FIG. As shown in FIG. 4, the capacitance has a certain relationship with the distance between the terminal of the IC chip 30 and the displacement detection pad. That is, the smaller the distance between the terminal of the IC chip 30 and the misalignment detection pad, the larger the capacitance between them, and the smaller the impedance between them. On the other hand, the larger the distance between the terminal of the IC chip 30 and the misalignment detection pad, the smaller the capacitance between them, and the greater the impedance between them.

Therefore, for example, if the capacitances C _{1 to} C ₄ shown in FIG. 2A are known, the distance between each of the displacement detection pads 22a to 22d and the terminal 31a can be known. Furthermore, if these distances are used, it is possible to grasp how much the terminal 31a is displaced in which direction from the reference position. Therefore, in the first embodiment, the calculation unit 5 detects the position shift, calculates the amount of the detected position shift, and further determines the direction of the position shift based on the information output from the capacitance detection unit 4. Is being detected.

In the first embodiment, the specific circuit configuration of the capacitance detection unit 4 includes the circuit configuration shown in FIG. As shown in FIG. 5A, when the terminal of the IC chip and the misalignment detection pad are connected to the capacitance detection unit 4, the capacitance C _X between them is connected in series to the resistor 41. . Further, the series circuit of the capacitance C _X and the resistor 41 is connected in parallel to the series circuit of the resistor 42 and the reference capacitor 43, and an AC voltage is applied to both ends of both series circuits by an AC power supply. .

As shown in FIG. 5A, the branch wiring 44 branched from between the capacitance C _X and the resistor 41 and the branch wiring 45 branched from between the resistor 42 and the reference capacitor 43 are respectively The rectifier circuit 46 is connected to the input terminal of the differential amplifier 47. Furthermore, the resistance value of the resistor 41 and the resistance value of the resistor 42 are the same. As shown in FIG. 5B, the rectifier circuit 46 includes a rectifying diode 46a provided on the branch wiring 44 or 45, and a resistor 46b provided on the branch branched from the branch wiring 44 or 45. , And a capacitor 46c provided in another wiring branched from another position.

Therefore, when an AC voltage is applied, a voltage signal corresponding to the size of the capacitance C _X and a voltage signal corresponding to the size (C _S ) of the reference capacitor 43 are input to the differential amplifier 47. . The differential amplifier 47 outputs an analog signal whose voltage level changes according to the difference between the two. Further, the capacitance value C _S of the reference capacitor 43 is set to the capacitance between the terminals of the IC chip 30 and the mounting pad when no positional deviation occurs. Therefore, the voltage level of the analog signal output from the differential amplifier 47 specifies the amount of deviation from the reference position of the terminal. The analog signal is converted into a digital signal by the A / D conversion circuit 48 and input to the arithmetic unit 5.

At this time, if the output value of the digital signal is larger than 0 (zero), it means that the capacitance C _X is larger than the capacitance value C _S of the reference capacitor 43 and the terminal position is shifted from the reference position. Therefore, the calculation unit 5 determines that a positional deviation has occurred.

  In addition, the memory 6 of the arithmetic unit 5 stores a map and a mathematical expression that specify the relationship between the output value of the digital signal output from the A / D conversion circuit 48 and the distance from the reference position of the terminal of the IC chip 30. ing. For this reason, the calculation unit 5 applies the output value of the digital signal to a map or a mathematical formula, so that the reference of the terminal in the direction from the mounting pad to which the detection target terminal is connected to the detection position misalignment detection pad. Specify the amount of misalignment from the position.

  In addition, this map and mathematical formula are obtained in advance by experiments in the first embodiment. Specifically, an electrode is arranged on the mounting pad, and a digital signal is output while the position of the electrode is shifted stepwise in the direction of each displacement detection pad. Then, if the output value is recorded and an approximate curve is obtained from the recorded value, the above formula can be obtained. If the recorded value is stored in the memory 6 in association with the electrode position, the above map can be obtained. Maps and mathematical formulas obtained by experiments are input to the memory 6 using the input device 7.

  The map and the mathematical expression can also be obtained by calculation from circuit board design data. However, it is preferable to obtain by experiment from the viewpoint that the influence of parasitic capacitance and the like on the circuit board can be taken into consideration and the detection accuracy can be improved.

  Therefore, by using the capacitance detection unit 4 shown in FIG. 5, the calculation unit 5 calculates the amount of positional deviation from the reference position in the four directions centered on the mounting pad for each of the terminals 31a and 31j. Identify. In addition, the calculation unit 5 detects the direction of the positional deviation between the terminals 31a and 31j by vector synthesis of the amount of positional deviation for each direction, and calculates the amount of positional deviation in the detected direction. Further, in the first embodiment, the calculation unit 5 displays the detected position shift direction and the calculated position shift amount on the display device 8.

  Thus, if the detection apparatus 1 (refer FIG. 1) in this Embodiment 1 is used, unlike the past, the amount of position shift can be measured based on an electrostatic capacitance. Further, since it is possible to immediately determine whether or not a positional deviation has occurred between the terminal and the positional deviation detection pad from the detected capacitance, the detection device 1 can detect the positional deviation compared to the conventional case. The accuracy can also be improved. Furthermore, there is no need to narrow the gap between the two in order to improve detection accuracy.

  In the first embodiment, in order to detect the direction of positional deviation, the amount of positional deviation in the four directions is specified for the terminals of the IC chip. However, the present invention is not limited to this. The direction of the positional deviation only needs to be specified in two or more directions. For example, in the example of FIG. 2A, a mode in which only the positional deviation detection pads 22a and 22b, 22b and 22c, 22c and 22d, or 22a and 22d are arranged with respect to the mounting pad 21a may be employed. . Even in these cases, since the amount of positional deviation in two orthogonal directions can be identified, the positional deviation direction can be identified by vector synthesis. However, from the viewpoint of improving the detection accuracy, it is considered that a larger number of positional deviation detection pads is better.

  In the first embodiment, the direction of the positional deviation is detected at two locations of the mounting pads 21a and 21j, and the positional deviation amount is calculated. For this reason, the calculating part 5 can determine whether the rotation shift has arisen in IC chip 30 from the direction and quantity of the position shift of each location.

  Specifically, the arithmetic unit 5 compares the direction and amount of positional deviation at each location, and determines that the rotational deviation has occurred in the IC chip 30 if they do not match. If there is a rotational deviation, the computing unit 5 also calculates the rotational deviation amount (rotation angle) θ by vector synthesis or the like (see FIG. 1). Note that the rotation deviation refers to a deviation caused by rotation with the axis along the thickness direction of the IC chip 30 as a rotation axis.

  In addition, it is preferable to feed back the position deviation direction, amount, and rotation deviation detected by the detection apparatus according to the first embodiment to a mounter (mounting machine) on which the IC chip is mounted. According to this aspect, it is possible to eliminate the positional deviation due to the mounter, and it is possible to increase the mounting accuracy of the IC chip.

  In the first embodiment, the circuit board to be detected is not limited to that shown in FIG. FIG. 6 is a plan view showing another example of a circuit board to be detected by the detection apparatus according to the first embodiment, and FIGS. 6A and 6B show different examples. 6A and 6B, the IC chip is the same as that shown in FIG. 1, and only the outer shape is shown.

  In the circuit board 50 shown in FIG. 6A, among the mounting pads 51a to 51j, the misalignment detection pads 52a to 52d are arranged only around the mounting pad 51e. Further, in the circuit board 53 shown in FIG. 6B, one of the mounting pads 51a to 51j is used for detecting a positional deviation near each of the mounting pads 51a, 51e, 51f, and 51j located at the four corners. Pads 54 to 57 are arranged. In the modes shown in FIGS. 6A and 6B, the rotational deviation cannot be detected, but other positional deviations can be detected. Such an embodiment is effective because it can suppress an increase in cost in a circuit board on which a small square IC chip is mounted, in which rotation deviation does not become a problem.

  In addition, the detection apparatus according to the first embodiment is effective when, for example, the circuit board is an active matrix substrate constituting a display panel, and the IC chip is a driver IC that drives an active element. FIG. 7 is a perspective view showing an example in which the circuit board is an active matrix substrate.

  The display device shown in FIG. 7 is a liquid crystal display device. The liquid crystal display device includes a liquid crystal display panel 63 and a backlight device 69 that illuminates the liquid crystal display panel 63. The backlight device 69 includes a light guide plate 66, a fluorescent tube 67, and a lamp reflector 68. The liquid crystal display panel 63 is configured by sandwiching a liquid crystal layer 61 between an active matrix substrate 60 and a counter substrate 62. In the display area of the active matrix substrate 60, pixels (not shown) composed of active elements (TFTs) and pixel electrodes are arranged in a matrix.

  A gate driver IC 64 and a source driver IC 65 are mounted on the area around the display area of the active matrix substrate 60. Since these driver ICs have an elongated shape as compared with other IC chips, they have a characteristic that a connection failure is likely to occur thereafter when a rotational deviation occurs. For this reason, the position shift detection by the detection apparatus according to the first embodiment is particularly effective.

(Embodiment 2)
Next, a detection device, a circuit board, and an IC chip in the embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a block diagram showing a schematic configuration of the detection apparatus according to Embodiment 2 of the present invention. 9 is a view showing a part of the circuit board shown in FIG. 8, FIG. 9 (a) is a plan view, and FIG. 9 (b) is taken along a cutting line BB ′ in FIG. 9 (a). It is sectional drawing obtained by cut | disconnecting. 8 and 9A, only the outer shape and terminals of the IC chip are shown.

  In the second embodiment, the configuration of the circuit board 27 to be detected is different from the configuration of the circuit board 20 shown in FIG. 2 in the first embodiment. In the second embodiment, as shown in FIG. 9B, the mounting pad 21a and the position shift detection pads 22a to 22d are insulated by the insulating film 26 covering the position shift detection pads 22a to 22d. Has been. Although not shown in FIG. 9B, the mounting pad 21 j and the position deviation detection pads 23 a to 23 d are also insulated by the insulating film 26.

  In the second embodiment, the positional deviation detection pads 22 a to 22 d and 23 a to 23 d are not electrically connected to the terminals of the IC chip 30. Therefore, as shown in FIG. 9B, the positional deviation detection pads 22a to 22d are arranged so that the edge thereof overlaps with the edge of the mounting pad 21a when viewed from above. Further, as shown in FIG. 8, the detection device 28 in the second embodiment is different from the detection device 1 shown in FIG. 1 in the first embodiment, and the detection unit 2 includes only the capacitance detection unit 4. Yes. Except for the points described above, the detection device, the circuit board, and the IC chip in the second embodiment are configured in the same manner as that shown in the first embodiment.

  As described above, according to the second embodiment, it is possible to reduce the distance between the two while ensuring insulation between the misalignment detection pad and the terminal. For example, if the circuit board 27 is the active matrix substrate shown in FIG. 7, the thickness of the insulating film 26 is several hundred μm or less. For this reason, since the electrostatic capacitance between both can be increased compared with Embodiment 1, the stable detection and the improvement of detection accuracy are achieved. Moreover, since the frequency of the alternating current applied by the capacitance detection unit 4 can be lowered by increasing the capacitance, the cost of the capacitance detection unit can be reduced.

  Further, in the second embodiment, since the positional deviation detection pads 22a to 22d and 23a to 23d are hidden from the outside, it is possible to reduce the possibility of a solder failure when the IC chip 30 is mounted.

  In the first and second embodiments, the example in which the positional deviation detection pad is provided on the circuit board is described. However, the present invention is not limited to this. In the present invention, a position shift detection terminal may be provided on the IC chip. FIG. 10 is a plan view showing an IC chip provided with a position shift detection terminal. In FIG. 10, the mounting surface of the IC chip 70 is shown.

  As shown in FIG. 10, the IC chip 70 includes a plurality of terminals 71 a to 71 j on the mounting surface, similarly to the IC chip shown in FIGS. 1 and 8. However, in the example of FIG. 10, the IC chip 70 includes position shift detection terminals 72a to 72d around the terminal 71a, and includes position shift detection terminals 73a to 73d around the terminal 71j. Position shift detection terminals 72a to 72d and 73a to 73d are also formed by solder bumps.

  As described above, in the example of FIG. 10, the role of the circuit board and the role of the IC chip are reversed as compared with the examples shown in the first and second embodiments. Therefore, the detection device (not shown) connected to the IC chip 70 shown in FIG. 10 has a capacitance between the mounting pad to which the terminal of the IC chip 70 is connected and the position shift detection terminal. Detection is performed. Even in this case, it is possible to detect the positional deviation, detect the positional deviation direction, and calculate the positional deviation amount. In this case, the detection device may be incorporated in the IC chip.

  As described above, according to the detection device of the present invention, it is possible to detect a positional deviation and calculate a positional deviation amount when an IC chip is mounted on a circuit board. The detection device according to the present invention can be used for manufacturing and inspection of all devices including a circuit board on which an IC chip is mounted, and has industrial applicability.

FIG. 1 is a block diagram showing a schematic configuration of a detection apparatus according to Embodiment 1 of the present invention. 2 is a diagram showing a part of the circuit board shown in FIG. 1, FIG. 2 (a) is a plan view, and FIG. 2 (b) is taken along a cutting line AA 'in FIG. 2 (a). It is sectional drawing obtained by cut | disconnecting. FIG. 3 is a circuit diagram illustrating an example of a specific configuration of the DC resistance detection unit illustrated in FIG. 1. FIG. 4 is a diagram illustrating a change in electrostatic capacitance between a pad for detecting a displacement of the circuit board and a terminal of the IC chip. FIG. 5A is a circuit diagram illustrating an example of a specific configuration of the capacitance detection unit illustrated in FIG. 1, and FIG. 5B illustrates an example of the rectifier circuit illustrated in FIG. FIG. FIG. 6 is a plan view showing another example of a circuit board to be detected by the detection apparatus according to the first embodiment, and FIGS. 6A and 6B show different examples. FIG. 7 is a perspective view showing an example in which the circuit board is an active matrix substrate. FIG. 8 is a block diagram showing a schematic configuration of the detection apparatus according to Embodiment 2 of the present invention. 9 is a view showing a part of the circuit board shown in FIG. 8, FIG. 9 (a) is a plan view, and FIG. 9 (b) is taken along a cutting line BB ′ in FIG. 9 (a). It is sectional drawing obtained by cut | disconnecting. FIG. 10 is a plan view showing an IC chip provided with a position shift detection terminal. 11A and 11B are diagrams showing a part of a circuit board provided with a conventional positional deviation detection function. FIG. 11A is a plan view and FIG. 11B is a cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 28 Detection apparatus 2 Detection part 3 DC resistance detection part 4 Capacitance detection part 5 Calculation part 6 Memory 7 Input device 8 Display apparatus 9 1st switching circuit 10a, 10b changeover switch 11 2nd changeover circuit 12 Switch 13 , 14, 41, 42, 46b Resistor 15 Reference resistor 16, 17, 44, 45 Branch wiring 18, 47 Differential amplifier 19, 48 A / D converter circuit 20, 27, 50, 53 Circuit boards 21a-21j, 51a-51j Mounting pads 22a-22d, 23a-23d, 52a-52d, 54-57 Position shift detection pads 24 Base substrate 25, 26 Insulating film 30, 70 IC chips 31a-31j, 71a-71j Terminals 32 Wiring 33 Anisotropic conduction Membrane 43 Reference capacitance 46 Rectifier circuit 46a Rectifier diode 46c Capacitance 60 Active matrix substrate 6 The liquid crystal layer 62 opposing the substrate 63 liquid crystal display panel 64 a gate driver IC
65 Source Driver IC
66 Light guide plate 67 Fluorescent tube 68 Lamp reflector 69 Back light 72a to 72d, 73a to 73d Position shift detection terminal

Claims (16)

When mounting an IC chip on a circuit board, a positional shift between a plurality of mounting pads provided on the circuit board and a plurality of terminals of the IC chip connected thereto is set to any one of the circuit boards. A detection device that detects using a displacement detection pad provided around the mounting pad of
A detection unit and a calculation unit;
The detection unit passes an alternating current between the displacement detection pad and the terminal to be connected to the mounting pad adjacent to the detection pad, and detects a capacitance between them. ,
Based on the capacitance detected by the detection unit, the arithmetic unit is configured to detect a positional shift between a mounting pad adjacent to the positional shift detection pad and a terminal to which the pad is connected. And detecting an amount of the detected positional deviation.   The calculation unit calculates the amount of positional deviation from the capacitance detected by the detection unit based on a relationship between a capacitance value obtained in advance and an amount of positional deviation. The detection device described.   2. The detection device according to claim 1, wherein in the circuit board, the mounting pad and the position shift detection pad are insulated by an insulating film that covers the position shift detection pad. In the circuit board, two or more misalignment detection pads are arranged so as to surround one mounting pad,
For each of the two or more displacement detection pads, the detection unit detects a capacitance between the terminals that are the connection targets of the mounting pads that are adjacent to each other,
For each of the two or more positional deviation detection pads, the arithmetic unit is a terminal to be connected to each positional deviation detection pad and the one mounting pad from the capacitance detected by the detection unit. And using the distance calculated for each of the two or more positional deviation detection pads, the positional deviation between the one mounting pad and a terminal to be connected to the one mounting pad. The detection device according to claim 1, wherein a direction of the detected position shift is detected and an amount of the detected position shift is calculated. In the circuit board, two or more mounting pads are surrounded by the two or more displacement detection pads,
The calculation unit detects the positional shift and its direction for each of the mounting pads surrounded by the two or more positional shift detection pads, calculates the amount of the detected positional shift, and the detection result Then, using the calculation result, it is determined whether or not the IC chip has a rotational shift with the axis along the thickness direction as a rotation axis. If the rotational shift has occurred, the rotational shift is determined. The detection device according to claim 4, wherein the amount is calculated. When mounting an IC chip on a circuit board, a positional deviation between a plurality of mounting pads provided on the circuit board and a plurality of terminals of the IC chip connected thereto is determined by any of the IC chips. A detection device for detecting using a position shift detection terminal provided around the terminal,
A detection unit and a calculation unit;
The detection unit detects a capacitance between the position deviation detection terminal and a mounting pad that is a connection target of a terminal adjacent to the terminal.
Based on the capacitance detected by the detection unit, the arithmetic unit is configured to detect a positional shift between a terminal adjacent to the positional shift detection terminal and a mounting pad to which the terminal is connected. And detecting an amount of the detected positional deviation.   The calculation unit calculates an amount of the positional deviation from the capacitance detected by the detection unit based on a relationship between a capacitance value obtained in advance and an amount of the positional deviation. The detection device described. In the IC chip, two or more misalignment detection terminals are arranged so as to surround one terminal,
For each of the two or more position shift detection terminals, the detection unit detects a capacitance between the mounting pads that are the connection targets of the terminals adjacent to each other,
For each of the two or more position shift detection terminals, the calculation unit is connected to each position shift detection terminal and the one terminal from the capacitance detected by the detection unit. And using the distance calculated for each of the positional deviation detection terminals, the positional deviation and the direction between the one terminal and the mounting pad to be connected to the one terminal. The detection device according to claim 6, which detects and calculates an amount of the detected positional deviation. In the IC chip, two or more terminals are surrounded by two or more positional deviation detection terminals,
The calculation unit detects the position shift and its direction for each of the terminals surrounded by two or more position shift detection terminals, calculates the amount of the detected position shift, the detection result and the calculation Using the result of the above, it is determined whether or not the IC chip has a rotational shift with the axis along the thickness direction as a rotation axis. The detection device according to claim 6 to calculate. A circuit board on which an IC chip is mounted,
A plurality of mounting pads connected to each of a plurality of terminals provided on the IC chip, and a displacement detection pad disposed around any of the mounting pads;
The circuit board, wherein the mounting pad and the positional deviation detection pad are insulated from each other by an insulating film covering the positional deviation detection pad.   The circuit board according to claim 10, wherein two or more displacement detection pads are arranged so as to surround one mounting pad.   The circuit board according to claim 11, wherein two or more mounting pads are surrounded by two or more misalignment detection pads. An IC chip mounted on a circuit board,
An IC chip comprising: a plurality of terminals connected to each of a plurality of mounting pads provided on the circuit board; and a position shift detection terminal arranged around any one of the terminals.   The IC chip according to claim 13, wherein two or more misalignment detection terminals are arranged so as to surround one terminal.   The IC chip according to claim 14, wherein two or more terminals are surrounded by two or more positional deviation detection terminals.   The IC chip according to claim 13, wherein the detection device according to claim 6 is provided inside.

Images