JP4676370B2 - Bonding failure detection device and bonding failure detection method - Google Patents

Description

  The present invention relates to a bonding failure detection device used for detecting a bonding failure between a conductive portion provided on a substrate and an electronic component, and a method for detecting a bonding failure between a conductive portion of a substrate and an electronic component.

  In recent years, a large number of electronic components are mounted on a substrate, or so-called lead-free solder that does not contain lead has been used as a solder for mounting electronic components. ing. In general, the above-described lead-free solder has poor wettability with respect to a substrate or the like as compared with lead-containing solder, and there is a possibility that the joint strength is lowered accordingly. Therefore, when an electronic component is mounted on a substrate using lead-free solder, there is a high possibility that a bonding failure between the substrate and the electronic component will occur. Furthermore, in recent years, the area of solder joints tends to be reduced in order to mount electronic components with high density on a substrate, and the possibility of poor bonding due to this tends to increase.

  In recent years, as described above, electronic components are mounted on a substrate at a high density, and semiconductors tend to be highly integrated. Accordingly, the amount of heat generated when the substrate is energized tends to increase. It is in. For this reason, on a board on which electronic components are mounted at a high density or a board on which a highly integrated semiconductor is mounted, a solder joint is cracked due to a difference in linear expansion coefficient between the board and the electronic parts. There is a high possibility that this problem will occur.

Therefore, assuming the occurrence of such a situation, a conductive part and an electronic component provided on the substrate using a bonding failure detection device conventionally called an in-circuit tester disclosed in Patent Documents 1 and 2 below A joint failure is detected. The in-circuit testers disclosed in the following Patent Documents 1 and 2 try to reproduce the heat generation state of the electronic component accompanying energization by heating the electronic component mounted on the substrate, and the bonding failure caused by the heat generation of the electronic component It is configured to detect occurrence.
JP-A-5-297062 Japanese Patent Laid-Open No. 10-19958

  However, in-circuit testers such as those disclosed in Patent Documents 1 and 2 cannot give a large temperature difference to the solder joint even when the electronic component is heated by the heating means. There is a problem in that it is impossible to accurately grasp the possibility of a bonding failure occurring at the solder joint portion or to accurately reproduce the occurrence state of the solder bonding failure.

  Based on this knowledge, the present invention can accurately grasp the possibility of occurrence of bonding failure by giving a large temperature difference to the bonding portion between the electronic component and the substrate, or can accurately reproduce the occurrence state of the bonding failure. An object of the present invention is to provide a bonding failure detection device and a bonding failure detection method.

  Accordingly, the invention according to claim 1, which is provided to solve the above-described problem, is a bonding of an electronic component mounted on a substrate having a conductive part capable of conducting electricity and a joint part between the conductive part. A bonding failure detection device capable of detecting a defect, a component-side contact means capable of electrical contact with an electronic component, a substrate-side contact means capable of electrical contact with a conductive portion of the substrate, and an electronic A component heating means capable of heating the component to a predetermined heating set temperature; and a constant temperature means capable of maintaining the temperature of the substrate within a temperature range lower than the heating set temperature. An electrical continuity between the electronic component and the conductive part of the substrate in a state in which the electrical continuity between the contact means is detected and the temperature of the substrate is adjusted within a predetermined temperature range; The electronic device is heated to a predetermined heating set temperature by heating means. Compare the electrical continuity state between the electronic component and the conductive portion of the substrate in a state where the substrate is maintained within a predetermined temperature range equal to or lower than the heating set temperature while heating, and based on the comparison result, the conductive portion This is a bonding failure detection device comprising a detection means capable of detecting a bonding failure of an electronic component with respect to.

  According to such a configuration, a large temperature difference can be given to a portion where the electronic component and the conductive portion of the substrate are joined, and a bonding failure may occur when the electronic component mounted on the substrate is energized and generates heat. It is possible to provide a bonding failure detection device that can accurately grasp the occurrence of the failure and accurately reproduce the occurrence state of the bonding failure.

  In addition, the bonding failure detection device according to claim 1, wherein the electrical connection between the electronic component and the conductive portion of the substrate in a state where the temperature of the substrate is adjusted within a predetermined temperature range, Is maintained within a predetermined temperature range, and the electric conduction state between the electronic component and the conductive portion of the substrate in a state where the substrate is adjusted within a predetermined temperature range equal to or lower than the heating set temperature by the component heating means It is also possible to have a configuration provided with detection means capable of detecting a bonding failure based on the comparison result.

  According to this configuration, electrical continuity between the electronic component and the conductive portion of the substrate before and after thermal stress acts on the joint between the electronic component and the conductive portion of the substrate as the electronic component is energized. The state can be reproduced. Therefore, according to the present invention, it is possible to provide a bonding failure detection device capable of accurately grasping the possibility of occurrence of a bonding failure between an electronic component and a conductive part and accurately reproducing the occurrence state of the bonding failure.

In the bonding failure detection apparatus according to the first aspect, the substrate can be arranged on a predetermined plane, and the component heating unit and the component side contact unit intersect the first direction and the first direction in the plane. the second direction, and the electronic component in a state where the predetermined plane Ri movable der in a third direction crossing the electronic component while a temperature at and and substrate unheated state within a predetermined temperature range In a state where the substrate is maintained within a predetermined temperature range equal to or lower than the heating set temperature while the electronic component is heated to a predetermined heating set temperature by the component heating means. the may be one which is characterized that you compare the electrical conduction state between the electronic component and the conductive portion of the substrate (claim 2).

  According to such a configuration, it is possible to accurately grasp the possibility of occurrence of poor bonding even on a board having a large number of joints, such as a large number of electronic components mounted on the board, or occurrence of poor bonding. It is possible to provide a bonding failure detection device capable of accurately reproducing the state.

  Here, the bonding failure detection device according to claim 1 or 2 is configured to be able to maintain the substrate within a predetermined temperature range equal to or lower than the heating set temperature by the component heating means. Therefore, when the dew point of the gas present in the test chamber that can accommodate the substrate is equal to or higher than the substrate holding temperature, dew condensation may occur in the constant temperature means or in the vicinity thereof, and it may be impossible to accurately detect a bonding failure.

Therefore, in view of such a problem, the bonding failure detection apparatus according to claim 1 or 2 has a test chamber capable of accommodating a substrate, and the dew point of the gas existing in the test chamber is equal to or higher than the substrate holding temperature. Subject to a dew point it is desirable to adopt a configuration to be introduced into the laboratory test gas below the substrate holding temperature (claim 3).

  According to such a configuration, it is possible to suppress the occurrence of condensation in the constant temperature means or in the vicinity thereof, and it is possible to provide a bonding failure detection device that can accurately detect a bonding failure between the electronic component and the conductive portion of the substrate.

The invention according to claim 4 is a bonding failure detection method for detecting a bonding failure of a bonding portion between an electronic component mounted on a substrate having a conductive portion capable of conducting electricity and the conductive portion, The temperature of the substrate is detected by detecting an electrical conduction state between the component-side contact means that can be electrically contacted with the electronic component and the substrate-side contact means that can be electrically contacted with the conductive portion of the substrate. In an initial state where the electronic component is adjusted within a predetermined temperature range, an electrical conduction state between the electronic component and the conductive portion of the substrate is detected, and the electronic component is heated to a predetermined heating set temperature by the component heating means. While detecting the electrical conduction state between the electronic component and the conductive part of the substrate in the component heating state in which the substrate is maintained within a predetermined temperature range below the heating set temperature, the non-heating state in the initial state is detected . Electronic parts and conductive parts of the substrate The electrical conduction state between the electronic component and the electrical conduction state between the electronic component in the component heating state and the conductive portion of the substrate is compared, and the electronic component is poorly bonded to the conductive portion based on the comparison result. This is a bonding failure detection method characterized by detecting the above.

  According to the bonding failure detection method of the present invention, a large temperature difference can be given to the bonding portion between the electronic component and the conductive portion of the substrate, and the bonding failure occurs when the electronic component mounted on the substrate is energized and generates heat. It is possible to accurately grasp the possibility of occurrence and accurately reproduce the occurrence state of the bonding failure.

  In addition, according to the bonding failure detection method of the present invention, between the electronic component and the conductive portion of the substrate before and after the thermal stress acts on the bonded portion between the electronic component and the conductive portion as the electronic component is energized. It is possible to reproduce and confirm the electrical continuity state. Therefore, according to the bonding failure detection method of the present invention, it is possible to accurately grasp the possibility of occurrence of a bonding failure accompanying energization of an electronic component, or to faithfully reproduce the state of occurrence of a bonding failure.

  The bonding failure detection method according to claim 4 is carried out by accommodating the substrate in a predetermined test chamber, and the dew point is the substrate, provided that the dew point of the gas present in the test chamber is equal to or higher than the substrate holding temperature. A gas having a temperature lower than the holding temperature may be introduced into the test chamber (claim 5).

  According to this method, it is possible to suppress the occurrence of dew condensation in the constant temperature means or in the vicinity thereof when detecting a bonding failure between the electronic component and the conductive portion of the substrate, and the bonding failure can be detected accurately.

  According to the present invention, it is possible to give a large temperature difference to the joint between the electronic component and the conductive portion of the substrate, and it is possible to accurately grasp the possibility of occurrence of a joint failure when energizing the electronic component, It is possible to provide a bonding failure detection device and a bonding failure detection method that can accurately reproduce the state of occurrence of a failure.

  Subsequently, a bonding failure detection apparatus and a bonding failure detection method according to an embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 1 denotes a bonding failure detection apparatus according to this embodiment. In the bonding failure detection apparatus 1 according to the present embodiment, an electronic component P having a pin p1 such as an IC, a capacitor, and a resistor is mounted on a substrate S, and a bonding object using solder is used as an inspection object.

  Here, the board | substrate S has electroconductivity like a copper plate, a copper foil, etc. on the surface of the base material s1 which consists of nonelectroconductive materials which do not conduct electricity like bakelite, an epoxy resin, ceramics like a conventionally well-known thing. The conductive part s2 is provided by bonding the objects. The copper plate or the like constituting the conductive portion s2 is configured such that a circuit is formed by performing an etching process as necessary, or a plating process is performed.

  The electronic component P has a pin p1 and a package part p2 in which a material such as a semiconductor material is packaged. The electronic part P is joined to the substrate S by joining the pin p1 to the conductive part s2 of the substrate S using solder. Yes. When the electronic component P is energized through the pin p1, the package part p2 mainly generates heat.

  As shown in FIG. 1, the bonding failure detection apparatus 1 has a test chamber 2, a constant temperature means 3 is provided at the bottom, and a component heating means 5, a temperature detection means 6, and pin probes 7 a and 7 b are provided in the test chamber 2. It is the structure supported so that it could move freely within. Further, the bonding failure detection apparatus 1 includes a temperature control means 8 for controlling the operation of the constant temperature means 3 and the component heating means 5 outside the test chamber 2, and a determination means electrically connected to the pin probes 7a and 7b. 10.

  The test chamber 2 forms a space that can accommodate the substrate S on which the electronic component P is soldered. The test chamber 2 is provided with a gas inlet 15. The test chamber 2 has a gas inlet 15 and can be maintained in an airtight state by closing the gas inlet 15, and a gas is introduced from the outside via the gas inlet 15. Therefore, the gas such as air existing in the test chamber 2 can be replaced.

  The constant temperature means 3 has a substrate placement surface 20 that is flat and on which the substrate S can be placed. The constant temperature means 3 is arranged so that the substrate arrangement surface 20 is exposed on the bottom side of the test chamber 2. The constant temperature means 3 is configured to be able to appropriately adjust the surface temperature of the substrate arrangement surface 20. In this embodiment, as the constant temperature means 3, the surface temperature of the substrate placement surface 20 can be adjusted within the range of room temperature to −65 ° C., and can be maintained within a range of about ± 3 ° C. with respect to the set temperature Th. The thing is adopted. Therefore, when the substrate S is arranged on the substrate arrangement surface 20 of the constant temperature means 3, the substrate S can be maintained in a substantially constant temperature state.

  The constant temperature means 3 is provided with a temperature sensor 21 capable of detecting the surface temperature of the substrate arrangement surface 20. The constant temperature means 3 and the temperature sensor 21 are electrically connected to a temperature control means 8 provided outside the test chamber 2. The output of the constant temperature means 3 is feedback controlled by the temperature control means 8 based on the temperature detected by the temperature sensor 21 so that the surface temperature of the substrate placement surface 20 is within a range of about ± 3 ° C. with respect to the set temperature Th. .

  The component heating means 5 is configured to be able to move freely within the test chamber 2 as described above. That is, when the component heating unit 5 assumes a plane L parallel to the substrate S when the substrate S is arranged in the test chamber 2 like the substrate arrangement surface 20, the component heating unit 5 has a first direction ( Hereinafter, the X direction is referred to as necessary, a second direction orthogonal to the X direction (hereinafter referred to as the Y direction as necessary), and a third direction perpendicular to the plane L (hereinafter referred to as the Y direction). Hereinafter, it is configured to be freely movable in the Z direction) as required. Therefore, the bonding failure detection apparatus 1 of the present embodiment can move only the component heating means 5 to a position corresponding to the predetermined electronic component P mounted on the substrate S and heat only the electronic component P.

  As the component heating means 5, one capable of heating the electronic component P from a position away from the upper side is adopted. More specifically, the component heating means 5 may employ an appropriate device such as a heating method using a heating wire or a heating method using infrared rays. More specifically, when a heating method using a heating wire is adopted as the component heating means 5, a heating wire (electric heating heater) is provided inside, and the output of the heating heater and the electric heating are based on the temperature detected by the temperature detection means 6. The thing of the structure which can adjust the flow volume and flow velocity of the airflow which pass a heater and are sprayed on the board | substrate S is employable. Further, when an infrared heating method is employed as the component heating means 5, for example, an apparatus having a halogen lamp heater inside is adopted, and the halogen lamp heater is turned on / off based on the temperature detected by the temperature detection means 6. In addition, a configuration that adjusts the output can be adopted.

  The component heating means 5 can locally heat a portion existing below in the range of room temperature to 180 ° C. For this reason, when the component heating means 5 is brought into an operating state with the component heating means 5 being moved above the package portion p2 of the electronic component P, the bonding failure detection device 1 raises the temperature of the package portion p2 and the electronic component P. It is possible to faithfully reproduce the heat generation state and the heat transfer state when the power is applied. The component heating means 5 is electrically connected to the temperature control means 8 described above.

  The temperature detection means 6 is comprised by the conventionally well-known non-contact-type thermometer. The temperature detection unit 6 is provided at a position adjacent to the component heating unit 5 and is configured to be able to detect the temperature of the portion immediately below the component heating unit 5. Further, the temperature detecting means 6 can move in the X, Y and Z directions in the test chamber 2 following the component heating means 5. Therefore, when the component heating means 5 moves above the electronic component P, the temperature detection means 6 follows the electronic component P and moves above the electronic component P to check the heating state of the electronic component P by the component heating means 5. Can do.

  The temperature detection means 6 is electrically connected to the temperature control means 8 described above. The temperature data detected by the temperature detection means 6 is transmitted to the temperature control means 8. The temperature control unit 8 feedback-controls the output of the component heating unit 5 based on the temperature detected by the temperature detection unit 6.

  The pin probes 7a and 7b are needle-like electrodes, respectively, and are configured to be able to move in the test chamber 2 in the X, Y, and Z directions following the component heating means 5 in the same manner as the temperature detection means 6. . The pin probe 7a is an electrode for making contact with the pin p1 of the electronic component P, and the pin probe 7b is an electrode for making contact with the conductive portion s2 provided on the surface of the substrate S. Both the pin probes 7 a and 7 b are electrically connected to the determination means 10.

  The determination means 10 is provided for measuring or determining the conduction state between the pin probes 7a and 7b. The determination unit 10 includes a constant voltage power supply 25, an ammeter 26, and a determination unit 27. The determination means 10 detects the current flowing between the pin probes 7a and 7b when the constant voltage power supply 25 is turned on by the ammeter 26, and based on the detection result, the determination unit 27 determines between the pin probes 7a and 7b. It is set as the structure which can determine a conduction | electrical_connection state.

  Subsequently, a detection method for detecting a bonding failure in the substrate S arranged on the substrate placement surface 20 of the thermostatic means 3 by the bonding failure detection device 1 of the present embodiment, or a flowchart shown in FIG. Will be described in detail with reference to FIG.

  When the bonding failure detection device 1 detects a bonding failure between the electronic component P and the conductive portion s2 of the substrate S, first, as shown in FIG. 3, in step 1, the control means (not shown) conducts the conduction of the substrate S. Information on a portion (detection point) where a bonding failure should be detected on the portion s2 is input. More specifically, in the example shown in FIG. 1, the position information of the portion (solder joint A1, A2) where the pin P1 is soldered onto the conductive portion s2 of the substrate S and the number of detection points (in FIG. 1). In the example, data such as 2 places) is input. More specifically, by inputting data such as a circuit diagram, CAD data, and thickness of the board S on which the component P is mounted using some input means (not shown), X and Y related to the detection point. The position information of the detection points and the number of detection points are input to the above-described control means by specifying the position information in the Z direction and arbitrarily inputting the position information in the X, Y, and Z directions related to the detection points. . Thereafter, the control flow proceeds to step 2.

  When the control flow shifts to step 2, the control means brings the thermostatic means 3 into an operating state at a predetermined timing (time t1 in FIG. 2A). At this time, the output of the constant temperature means 3 is adjusted so that the surface temperature of the substrate arrangement surface 20 becomes the set temperature Th. The set temperature Th is set to an arbitrary temperature lower than room temperature (room temperature to −65 ° C.). Accordingly, as shown in FIG. 2C, the temperature of the substrate S (substrate temperature Ts) disposed on the substrate placement surface 20 and the temperature of the package part p2 of the electronic component P (package part temperature Tp2) are timed. It gradually becomes lower than room temperature from t1 to t2.

  On the other hand, in step 2, as shown in FIG. 1, the control means moves the component heating means 5 and the temperature detection means 6 above the package part p2 of the electronic component P to be detected as a bonding failure. At this time, when a plurality of electronic components P are attached to the substrate S, one electronic component P is selected from the plurality of electronic components P, and the component heating means 5 and the temperature detecting means 6 are moved above this. State.

  Further, the control means moves the pin probes 7a and 7b to a position corresponding to one of the detection points set in step 1. More specifically, in step 2, the pin probes 7a and 7b are moved to the vicinity of the solder joint A1. Then, the pin probe 7a contacts the pin P1 of the electronic component P joined at the solder joint A1, and is in a state where it can be energized between the pin P1. Further, the pin probe 7b is in a state where it is in contact with the conductive portion s2 of the substrate S in the vicinity of the solder joint portion A1, and is in a state where it can be energized with the conductive portion s2.

  As described above, when the component heating means 5, the temperature detection means 6, and the pin probes 7a and 7b are set at predetermined positions, the presence or absence of a solder joint failure is determined for the solder joint portion A1 between the electronic component P and the conductive portion s2. Detectable state. When the preparation is completed in this way, the control flow shifts to Step 3, and it is confirmed whether the substrate temperature Ts and the package part temperature Tp2 are in a constant temperature state near the set temperature Th (in the range of ± 3 ° C.). Is done. Here, when it is confirmed that the substrate temperature Ts and the package portion temperature Tp2 are in a constant temperature state near the set temperature Th, the control flow is step 4 and step at that time (time t2 in FIG. 2C). Then, the determination means 10 confirms the electrical characteristics of the solder joint A1 over a period M1 (5 seconds in the present embodiment) from time t2 to time t3.

  More specifically, as shown in FIG. 2C, when the temperature Ts of the substrate S and the temperature Tp2 of the package part p2 reach a constant temperature near the set temperature Th at time t2, as shown in FIG. The constant voltage power supply 25 provided in the determination means 10 is turned on for a period M1 (5 seconds in the present embodiment) between times t2 and t3. At this time, the determination unit 27 of the determination means 10 confirms the conduction state between the pin probes 7a and 7b when the electronic component P is in the non-heated state based on the current value detected by the ammeter 26.

  When the period M1 elapses and time t3 is reached, the measurement of electrical characteristics is terminated. Then, the control flow moves to step 6 and the component heating means 5 is turned on. Thereby, the package part p2 of the electronic component P is heated to a predetermined heating set temperature Tp (see FIG. 2B). As a result, the package temperature Tp2 rises as shown in FIG. At this time, the substrate temperature Ts also rises to some extent like the package part temperature Tp2. However, as shown in FIG. 2A, the constant temperature means 3 remains on even after the component heating means 5 is turned on, and the cooling of the substrate S is continued. Therefore, even when the component heating means 5 is turned on, the temperature rise of the substrate S is more gradual than the temperature rise of the package part p2. Therefore, as shown in FIG. 2C, after the component heating means 5 is turned on, the package portion temperature Tp2 and the substrate temperature Ts are reached when the temperature of the package portion p2 reaches the heating set temperature Tp. And the temperature difference D is greatly opened.

  When the heating of the package part p2 is started as described above, the control flow moves to step 7, and it is confirmed whether or not the package part temperature Tp2 reaches the heating set temperature Tp and is stable. When it is confirmed that the package part temperature Tp2 reaches the predetermined heating set temperature Tp and is stable, as shown in FIG. 2D, a period M2 from time t4 to time t5 (this embodiment) The constant voltage power supply 25 is turned on for 5 seconds. Accordingly, the electrical characteristics of the solder joint A1 are confirmed in the same manner as described above (Steps 8 to 9).

  At time t6 after the elapse of the above-described period M2, the control flow proceeds to step 10 and heating of the package part p2 by the component heating means 5 is stopped as shown in FIG. Accordingly, as shown in FIG. 2C, the package portion temperature Tp2 and the substrate temperature Ts are gradually cooled, and approach the set temperature Th of the substrate placement surface 20.

  When heating of the package part p2 by the component heating means 5 is stopped in step 10, the control flow shifts to step 11, and a series of control flows from step 2 to step 10 are performed for all detection points set in step 1. It is confirmed whether or not a solder joint failure has been detected. Here, if there is a detection point that has not yet detected a solder joint failure, the control flow is returned to step 2 and a solder joint failure is detected at a detection point different from the above.

  More specifically, when there are two detection points (solder joints A1 and A2) as in the example shown in FIG. 1, detection of a solder joint failure at the solder joint A2 at time t6 in FIG. Is not complete. Therefore, in this case, the control flow is returned to step 2, and a solder joint failure is detected in the solder joint portion A2 in the same manner as described above.

  That is, when the control flow returns to step 2, the pin probes 7a and 7b move to the position of the solder joint A2, and the pin p1 joined to the solder joint A2 and the conduction part s2 near the solder joint A2 respectively. It will be in contact. At this time, as shown in FIG. 2A, the constant temperature means 3 is maintained in the ON state. The component heating means 5 and the temperature detection means 6 are also moved onto the electronic component P to be detected as necessary. In the example shown in FIG. 1, since the solder joint failure is detected for the same electronic component P in both the solder joint portions A1 and A2, the component heating means 5 and the temperature detection means 6 do not move from the electronic component P.

  When the pin probes 7a and 7b, the component heating means 5 and the temperature detection means 6 are set at predetermined positions in step 2, the control flow shifts to step 3. When it is confirmed in step 3 that the package part temperature Tp2 and the substrate temperature Ts are stable in the range of Th ± 3 [° C.], in a period M3 (5 seconds) from that time (time t8) to time t9. The electrical characteristics of the solder joint A1 are measured (Step 4 to Step 5). Thereafter, at time t9, the control flow proceeds to step 6 and the component heating means 5 is turned on. As a result, when the package part temperature Tp2 reaches the set temperature Tp in step 7 and is confirmed to be stable, the solder joint A1 is in the period M4 (5 seconds) from that time (time t10) to time t11. Are measured (steps 8 to 9). After the measurement of the electrical characteristics in the period M4, at time t12, the component heating unit 5 is turned off as shown in FIG. 2B, and the control flow proceeds to step 11.

  Here, in the example shown in FIG. 1, there are two detection points of the solder joints A1 and A2, and the detection of the solder joint failure is completed for all the detection points when the control flow moves to step 11 at time t12. It will be in the state. Therefore, in step 11, when it is confirmed that the detection of the solder joint failure is completed for all previously set detection points, the control flow moves to step 12 and the thermostatic means 3 is turned off. The measurement operation is completed.

  When the series of measurement operations shown in FIG. 3 is completed, the solder joint portion is compared by comparing the data on the electrical characteristics measured in the periods M1 and M3 with the data on the electrical characteristics measured in the periods M2 and M4. It is determined whether or not A1 causes a bonding failure.

  More specifically, the determination means 10 uses the current values (I1, I2) measured by the ammeter 26 in the above-described periods M1, M2, or the resistance values (R1, R2) derived based on the current values (I1, I2). Compare. The determination unit 10 determines whether the current value I2 measured in the period M2 is extremely smaller than the current value I1 measured in the period M1, or the resistance value R2 derived in the period M2 is derived in the period M1. On the condition that it is extremely large with respect to the value R1, it is determined that a bonding failure has occurred at a portion (solder bonding portion A1) where the conductive portion s2 of the substrate S and the pin P1 are solder bonded. More specifically, the determination unit 10 generates a solder joint failure in the solder joint A1 on condition that the current value I1 and the resistance value R2 are 200% or more (twice or more) of the current value I2 and the resistance value R1. Judge that you are doing.

  Similarly, the determination unit 10 compares the current values (I3 and I4) measured by the ammeter 26 in the periods M3 and M4 or the resistance values (R3 and R4) derived based on the current values. The determination means 10 is that a solder joint failure has occurred in the solder joint A1 on condition that the current value I3 and the resistance value R4 are 200% or more (twice or more) of the current value I4 and the resistance value R3. to decide.

  When the measurement operation is completed for the solder joint portion A1 as described above, or when the determination about the presence or absence of the joint failure is completed, another portion where the other pin p1 of the electronic component P is joined (solder joint portion) When the measurement operation is not completed for A2), or when the measurement operation is not completed for the portion where the pin p1 of another electronic component P mounted on the substrate S is joined, the solder of the pin p1 As for the joint portion, the measurement operation and the determination of the joint failure can be performed in the same manner as described above. When the determination is made in this way, and when a bonding failure with respect to another pin p1 of the same electronic component P as described above is detected, the pin probe 7a, 7b moves. In addition, when detecting a bonding failure with respect to the pin p1 of the electronic component P different from that described above, the component heating means 5 and the temperature detecting means 6 in addition to the pin probes 7a and 7b are added to the electronic component P to be inspected. Move to the corresponding position.

  As described above, according to the bonding failure detection device 1 of the present embodiment, the electronic component P is heated to the predetermined heating set temperature Tp by the component heating means 5, and the substrate S is within the temperature range equal to or lower than the heating set temperature Tp. In the maintained state, an electrical conduction state between the pin probes 7a and 7b can be detected, and a bonding failure of the electronic component P to the conductive portion s2 can be detected based on the detection result. Therefore, according to the bonding failure detection device 1, a large temperature difference can be given to the portion where the electronic component P and the conductive portion s2 of the substrate S are bonded, and the electronic component P mounted on the substrate S is energized to generate heat. This situation can be faithfully reproduced, and in this case, it is possible to accurately grasp the possibility of occurrence of bonding failure in the solder joint A1 or the like, or to accurately reproduce the state of occurrence of bonding failure.

  As described above, in the bonding failure detection device 1 of the present embodiment, the component heating means 5 and the pin probes 7a and 7b can freely move in the X, Y, and Z directions. Therefore, according to the bonding failure detection apparatus 1, a large number of electronic components P are mounted on the substrate S, or the substrate S having a large number of bonding portions can be accurately grasped for the possibility of occurrence of bonding failure. It is possible to accurately reproduce the state of occurrence of bonding failure.

  As described above, in this embodiment, the temperature of the substrate S is adjusted within a predetermined temperature range as in the above-described periods M1 and M3, and the electronic component P is heated to a high temperature as in the periods M2 and M4. Meanwhile, the electrical continuity between the electronic component P and the conductive portion s2 is compared in both of the states where the substrate S is maintained at a low temperature, and a bonding failure is detected based on the comparison result. Therefore, according to the bonding failure detection device 1, the electronic component P and the substrate S before and after thermal stress acts on the bonding portion between the electronic component P and the conductive portion s2 of the substrate S as the electronic component P is energized. While faithfully reproducing the electrical continuity state between the conductive portion s2 and the electronic component P and the conductive portion s2, it is possible to grasp the possibility of occurrence of a bonding failure and accurately reproduce the occurrence state of the bonding failure. be able to.

  As described above, in this embodiment, the pin p1 of the electronic component P and the substrate are used twice as shown in the timing chart of FIG. 2 and the flowchart of FIG. 3 in order to detect a bonding failure at one solder joint A1. It is configured to detect an electrical continuity state with the conductive portion s2 of S. Therefore, if a bonding failure is detected as in this embodiment, a bonding failure such as the solder bonding portion A1 can be accurately detected.

  In the above-described embodiment, a configuration in which a bonding failure is detected twice for one solder joint A1 in a series of flows is exemplified, but the present invention is not limited to this, and once per location. Even if it is the structure which detects a joining failure only, it is good also as a structure which detects a joining failure many times.

  As described above, in the bonding failure detection apparatus 1 according to the present embodiment, the constant temperature means 3 is operated when detecting bonding failures such as the solder bonding portions A1, A2, and the substrate placement surface 20 and the substrate S placed on the substrate placement surface 20 are detected. Is set to a set temperature Th lower than room temperature. Therefore, depending on the dew point of a gas such as air existing in the test chamber 2, the substrate placement surface 20 and the substrate S may condense and the detection accuracy of the bonding failure may be reduced. Therefore, when using the bonding failure detection device 1 to detect a bonding failure, when the set temperature Th is set to a low temperature below the dew point of the gas present in the test chamber 2, for example, nitrogen gas is introduced from the gas inlet 15. It is desirable to introduce a gas having a dew point lower than the set temperature Th such as dry air or to replace the gas existing in the test chamber 2.

  In the above embodiment, an example in which the gas introduction port 15 is provided in the test chamber 2 is illustrated. However, the present invention is not limited to this, and a configuration without the gas introduction port 15 may be used. Good. In the case of such a configuration, there is a possibility that dew condensation may occur when a bonding failure is detected, but the device configuration can be simplified by the amount that the gas inlet 15 is not provided.

It is sectional drawing which shows the use condition of the structure of the joining failure detection apparatus concerning one Embodiment of this invention, and the said joining failure detection apparatus. It is a timing chart at the time of detecting a joint failure by the joint failure detection apparatus shown in FIG. It is a flowchart at the time of detecting a joining failure by the joining failure detection apparatus shown in FIG.

DESCRIPTION OF SYMBOLS 1 Bonding defect detection apparatus 2 Test chamber 3 Constant temperature means 5 Component heating means 6 Temperature detection means 7a Pin probe (component side contact means)
7b Pin probe (substrate side contact means)
DESCRIPTION OF SYMBOLS 10 Determination means 15 Gas inlet 20 Board | substrate arrangement | positioning surface S Board | substrate s2 Conductive part P Electronic component p1 Pin L Plane Tp Heating preset temperature A1, A2 Solder junction part

Claims (5)

  An electronic component mounted on a substrate having a conductive part capable of conducting electricity, and a defective joint detection device capable of detecting a defective joint between the conductive part and the conductive part. The component-side contact means that can be contacted, the substrate-side contact means that can be electrically contacted with the conductive portion of the substrate, the component heating means that can heat the electronic component to a predetermined heating set temperature, and the temperature of the substrate Constant temperature means that can be maintained in a temperature range lower than the heating set temperature, and detects electrical continuity between the component side contact means and the substrate side contact means, and sets the substrate temperature to a predetermined value. An electrical conduction state between the electronic component and the conductive portion of the substrate in a state adjusted within a temperature range, and the substrate is heated to a predetermined heating set temperature or less while heating the electronic component to a predetermined heating set temperature by the component heating means. In a state maintained within the specified temperature range A detection means capable of comparing an electrical continuity between the electronic component and the conductive portion of the substrate and detecting a bonding failure of the electronic component to the conductive portion based on the comparison result. Characteristic bonding failure detection device. The substrate can be arranged on a predetermined plane, and the component heating unit and the component side contact unit intersect the first direction in the plane, the second direction intersecting the first direction, and the predetermined plane. movable der in a third direction is, the electronic component is electrically between the electronic component and the conductive portion of the substrate in a state where the a is and the temperature of the substrate unheated state is adjusted to within a predetermined temperature range Between the electronic component and the conductive portion of the substrate in a conductive state and in a state where the electronic component is heated to a predetermined heating set temperature by the component heating means and the substrate is maintained within a predetermined temperature range below the heating set temperature. joint failure detecting apparatus according to claim 1, characterized that you compare the electrical conduction state. Has can accommodate test chamber substrate, and wherein the dew point of the gas present in the test chamber on condition that it is a substrate holding temperature above the dew point is introduced into the chamber test gas below the substrate holding temperature The joint failure detection device according to claim 1 or 2.   A bonding failure detection method for detecting a bonding failure between an electronic component mounted on a substrate having a conductive portion capable of conducting electricity and a bonding portion between the conductive portion and electrically contacting the electronic component The electrical conduction state between the possible component side contact means and the board side contact means capable of electrical contact with the conductive portion of the board is detected, and the temperature of the board is adjusted within a predetermined temperature range. In an initial state, the electrical conduction state between the electronic component and the conductive portion of the substrate is detected, and the component is heated to a predetermined heating set temperature by the component heating means, and the substrate is heated to the heating set temperature or lower. An electrical continuity state between the electronic component and the conductive portion of the substrate in a component heating state maintained within a predetermined temperature range is detected, and electricity between the electronic component and the conductive portion of the substrate in an initial state is detected. Conduction and component heating And detecting a bonding failure of the electronic component to the conductive portion based on a result of the comparison between the electronic component and the conductive portion of the substrate in the state. .   The test is performed with the substrate housed in a predetermined test chamber, and a gas whose dew point is lower than the substrate holding temperature is introduced into the test chamber on condition that the dew point of the gas existing in the test chamber is equal to or higher than the substrate holding temperature. The bonding failure detection method according to claim 4.

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