JP2010118472A - Method of testing connecting conditions of electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of testing connecting conditions of an electronic device for detecting not only open failure but also non-wetting failure with higher accuracy. <P>SOLUTION: The method of testing connecting conditions can test electrical connecting conditions between connecting portions of a solder bump and a land in the electronic device where a plurality of solder bumps arranged at a surface of an electronic component and a plurality of lands formed on electronic component loading surface of a wiring circuit board corresponding to the solder bumps are connected and electronic components are loaded at the upper part of the wiring circuit board. A connecting portion for testing included in the connecting portions is formed of the solder bump for testing formed adjacent to the solder bump at the one surface of the electronic component and the land for testing formed on the wiring circuit board corresponding to the solder bump for testing. This connecting portion, however, does not provide an electrical connecting function. Moreover, a resistance value of the connecting portion for testing can be measured under the condition that an external force is applied to at least one of the electronic component and wiring circuit board in the direction where the electronic component and wiring circuit board at the connecting portion for testing are separated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention connects a plurality of solder bumps arranged on one surface of an electronic component and a plurality of lands formed corresponding to the solder bumps on the electronic component mounting surface of the wiring board, and mounts the electronic component on the wiring board. The present invention relates to a connection state inspection method for inspecting an electrical connection state of a connection portion between a solder bump and a land.

Conventionally, as shown in Patent Documents 1 and 2, for example, a plurality of solder bumps arranged on one surface of an electronic component and a plurality of lands formed on the electronic component mounting surface of the wiring board corresponding to the solder bump are provided. There has been proposed a method for inspecting an electrical connection state of a connection portion between a solder bump and a land in an electronic device in which electronic components are connected and mounted on a wiring board.
JP-A-8-37357 JP 2003-264259 A

  By the way, in an electronic component or a wiring board, in particular, an electronic component, warping is likely to occur due to heat treatment when forming a connection site. For example, in an electronic component, a semiconductor chip is mounted on a rewiring board (so-called interposer), the periphery of the chip is sealed with resin, and solder bumps such as solder balls are arranged on the back surface of the chip mounting surface of the rewiring board. This is because, for example, the linear expansion coefficient is different between the sealing resin and the rewiring board. In this way, warping occurs due to the difference in linear expansion coefficient between adjacent members.

  Conventionally, an inspection solder bump and an inspection land are provided at a place where warpage is likely to occur, and an inspection connection portion made of these (not connected electrically to other connection portions but having an electrical connection function) The electrical connection state of all the connection parts was ensured by inspecting the conduction state of the connection part (not provided). In this inspection method, if the inspection solder bump and the inspection land (the solder paste is disposed on the surface of the land) are in an open state (non-contact state), the connection is poor. It can be easily detected.

  However, as a connection failure, in addition to an open failure, a so-called non-wetting failure may occur. The non-wetting defect means that at least a part of the connection portion between the solder bump and the land (or solder paste) is not in a joined state (no metal bond is formed) and is in a contact state. When the present inventor has scrutinized, in such non-wetting failure, electrical continuity is ensured in at least a part of the contact part, and the continuity state of the connection part for inspection, and thus the resistance value is simply measured. Then, it became clear that it might be impossible to determine whether or not a defect occurred. In particular, when a part of the connection site is in a joined state, it is difficult to determine whether the connection is good or not by measuring the resistance value. Such a non-wetting defect is not preferable because it may open in a short time due to a temperature cycle load or the like.

  In view of the above problems, an object of the present invention is to provide an electronic device connection state inspection method capable of accurately detecting not only open defects but also non-wetting defects.

  In order to achieve the above object, the invention described in claim 1 includes a plurality of solder bumps arranged on one surface of an electronic component and a plurality of solder bumps formed on the electronic component mounting surface of the wiring board corresponding to the solder bump. A connection state inspection method for inspecting an electrical connection state of a connection part between a solder bump and a land in an electronic device in which an electronic component is mounted on a wiring board and an electronic component is mounted on the wiring board, As described above, it consists of an inspection solder bump formed adjacent to the solder bump on one surface of the electronic component and an inspection land formed on the wiring board corresponding to the inspection solder bump, and does not provide an electrical connection function. The test is performed with an external force applied in a direction in which the electronic component and the wiring board at the inspection connecting part are separated from each other at least one of the electronic component and the wiring board. And measuring the resistance of the connection site of use.

  According to the present invention, when the connection part for inspection has a non-wetting defect in which conduction by contact is ensured at least partly, the contact area between the inspection solder bump and the inspection land is applied by applying the external force. As a result, the resistance value can be decreased and the resistance value can be increased as compared with before the external force is applied. Therefore, the non-wetting defect can be detected with higher accuracy than before. Further, according to the above method, an open defect can also be detected by measuring the resistance value.

  In addition, a non-wetting defect and an open defect can be detected by comparing the resistance value measured with an external force applied with a reference value having a predetermined tolerance. However, preferably, as described in claim 2, it is preferable to measure the resistance value of the connection part for inspection in a state before the external force is applied and compare the resistance value with the resistance value in the external force applied state. As described above, in the case of non-wetting failure, the resistance value varies before and after the application of external force. Therefore, when the resistance value varies, it can be determined that the inspection connection part is non-wetting.

  A configuration in which the solder bump for inspection is formed in at least one of the peripheral region and the central region on one surface of the electronic component may be applied. A warp of an electronic component or a wiring board is generally a warp in which a central region is convex or concave with respect to a counterpart. Therefore, according to the above arrangement, when the connection part for inspection is the part where the facing distance between the electronic component and the wiring board is the longest, and the connection part for inspection is in the joined state, all the connected parts are in the joined state. It can be judged that there is. The central area refers to a predetermined partial area including the center of the formation area of the solder bump including the inspection solder bump on one surface of the electronic component.

  For example, as described in claim 4, when the electronic component warps with the central region protruding from the wiring board, the inspection solder bumps may be formed in the peripheral region on one surface of the electronic component. Then, if a test pad that is electrically connected to the test land is formed on a part other than the part on the electronic component mounting surface of the wiring board, the tester terminal can be brought into contact with the test pad. Thus, the resistance value of the connection part for inspection can be measured while applying a downward external force to the wiring board. In this case, application of external force and measurement of resistance value can be performed at once by a tester. Therefore, the inspection procedure and the apparatus configuration can be simplified.

  Further, as described in claim 5, when the electronic component warps with the central region being concave with respect to the wiring board, the inspection solder bumps may be formed in the central region on one surface of the electronic component. Then, if a test pad electrically connected to the test land is formed on the back side of the electronic component mounting surface of the wiring board except for the part corresponding to the electronic component mounting part, the terminal of the tester is connected. By making contact with the inspection pad, it is possible to measure the resistance value of the connection portion for inspection while applying an upward external force to the wiring board. Also in this case, application of external force and resistance value measurement can be performed at once by the tester. Therefore, the inspection procedure and the apparatus configuration can be simplified.

  According to a sixth aspect of the present invention, it is preferable that a plurality of inspection solder bumps are formed apart from each other on the electronic component, and the resistance value is sequentially measured for each connection portion corresponding to the inspection solder bump. According to this, even if the warping is not uniform, it is possible to detect a connection failure such as a non-wetting failure, and it is possible to increase the reliability with which the joining state of all the connection parts is ensured. For example, when solder bumps including inspection solder bumps are arranged in a grid shape with a flat rectangular outer periphery, inspection solder bumps are formed at the four corners of the peripheral region, and resistance is sequentially applied to the inspection connection portions at the four corners. What is necessary is just to measure a value.

  Next, the invention according to claim 7 connects the plurality of solder bumps arranged on one surface of the electronic component and the plurality of lands formed on the electronic component mounting surface of the wiring board corresponding to the solder bump. A connection state inspection method for inspecting an electrical connection state of a connection portion between a solder bump and a land in an electronic device in which an electronic component is mounted on a wiring board, wherein the solder is applied to one surface of the electronic component as the connection portion. It consists of inspection solder bumps formed adjacent to the bumps and inspection lands formed on the wiring board corresponding to the inspection solder bumps, including a connection part for inspection that does not provide an electrical connection function, Due to the difference in coefficient of linear expansion between the electronic component and the wiring board, at least one of the electronic component and the wiring board is deformed in a direction in which the electronic component and the wiring board are separated from each other at the inspection connection site Degree is varied from room temperature while being changed, and measuring the resistance of the connecting portion for inspection.

  In the present invention, since the ambient temperature is changed in the direction of increasing the warp based on the difference in linear expansion coefficient between the electronic component and the wiring board, the contact area between the solder bump for inspection and the inspection land is reduced to some extent, and consequently The resistance value can be increased not less than before the external force is applied. Therefore, the non-wetting defect can be detected with higher accuracy than before. Further, according to the above method, an open defect can also be detected by measuring the resistance value.

  In addition, a non-wetting defect or an open defect can be detected by comparing the resistance value measured with the ambient temperature changed with a reference value having a predetermined tolerance. However, preferably, as described in claim 8, the resistance value of the connection part for inspection is measured in a state before changing the ambient temperature (room temperature), and the resistance value in the state of changing the ambient temperature is measured. Compared with. As described above, in the case of non-wetting failure, the resistance value varies between before the ambient temperature change (room temperature) and when it is changed. Therefore, when the resistance value varies, it can be determined that the inspection connection part is non-wetting.

  Since the effect of the invention according to claim 9 is the same as that of the invention according to claim 3, the description is omitted.

  For example, as described in claim 10, when the electronic component is warped with the central region protruding from the wiring substrate, the inspection solder bumps may be formed in the peripheral region on one surface of the electronic component. And the resistance value of the connection part for a test | inspection should just be measured in the state which raised ambient temperature from room temperature. Further, as described in claim 11, when the electronic component is warped with the central region being concave with respect to the wiring board, the inspection solder bumps may be formed in the central region on one surface of the electronic component. And the resistance value of the connection part for a test | inspection should just be measured in the state which lowered ambient temperature from room temperature. In either case, the stress due to the difference in linear expansion coefficient acts in the direction in which the electronic component is separated from the wiring board at the inspection connection site, in other words, in the direction in which the warp increases. Therefore, non-wetting can be detected with high accuracy.

  Next, the invention described in claim 12 connects a plurality of solder bumps arranged on one surface of the electronic component and a plurality of lands formed on the mounting surface of the electronic component on the wiring board corresponding to the solder bump. A connection state inspection method for inspecting an electrical connection state of a connection portion between a solder bump and a land in an electronic device in which an electronic component is mounted on a wiring board, wherein the solder is applied to one surface of the electronic component as the connection portion. It consists of inspection solder bumps formed adjacent to the bumps and inspection lands formed on the wiring board corresponding to the inspection solder bumps, including a connection part for inspection that does not provide an electrical connection function, In this vibration period, at least one of the electronic component and the wiring board is vibrated continuously for a predetermined time, and the resistance value of the connection part for inspection is monitored during this vibration period.

  As described above, the non-wetting defect is a defect in which at least a part of the connection portion is in a conductive state by contact instead of joining. In the present invention, at least one of the electronic component and the wiring board is vibrated continuously for a predetermined time, so that the vibration changes the contact area (contact state) between the non-wetting test solder bump and the test land. be able to. Therefore, by monitoring the resistance value of the inspection connection part during the vibration period, if the resistance value varies, it can be determined that the inspection connection part is non-wetting. Further, according to the above method, an open defect can also be detected by the resistance value.

  According to a thirteenth aspect of the present invention, the lands and the inspection lands may include solder paste disposed on the back surface of the land and the inspection lands facing the wiring board. In this case, the land and the inspection land come into contact with the corresponding solder bump and inspection solder bump through the solder paste. In addition to this, a configuration may be adopted in which the solder paste is not provided, and the land and the inspection land are in direct contact with the corresponding solder bump and the inspection solder bump.

  One possible cause of non-wetting failure is a partial remaining of the oxide film due to a lack of flux (cleaning agent) for making the solder bump and the solder paste wet with each other. Note that the remaining oxide film has a non-uniform thickness and partially remains at the connection site, so that at least a part of the contact site is considered to be in an electrically conductive state. Therefore, as described in claim 14, it is preferable that the amount of solder paste on the inspection land is smaller than the amount of solder paste on the land. Since flux is contained in the solder paste, according to the above, the flux in the solder paste is less at the connection part for inspection than at other connection parts, thereby making it easier to cause non-wetting defects. Can do. Thereby, the detection precision of a non-wetting defect can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of the electronic device according to the first embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of the electronic component. FIG. 3 is a plan view showing a schematic configuration of the wiring board, in which resist and solder paste are omitted for convenience. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a plan view showing a schematic configuration of a screen when a solder paste is applied to the wiring board. FIG. 6 is a cross-sectional view illustrating an inspection method for inspecting an electrical connection state of an electronic device.

  As shown in FIG. 1, an electronic device 100 is obtained by mechanically and electrically connecting an electronic component 10 and a wiring board 20 via a solder connection part 30 as a connection part.

  As shown in FIG. 2, the electronic component 10 has a semiconductor chip 11 fixed on one surface 12a (hereinafter simply referred to as a chip mounting surface 12a) of the rewiring board 12, and the chip mounting surface 12a of the rewiring board 12 is fixed. A plurality of solder bumps 13 are formed on the back surface 12b side.

  The semiconductor chip 11 includes, for example, a semiconductor substrate made of single crystal silicon, an element formed on the semiconductor substrate by impurity diffusion, and a wiring layer formed on the semiconductor substrate. A memory circuit, an A / D conversion circuit, an amplifier circuit, a mixed circuit thereof, or the like is configured. In the present embodiment, a substantially rectangular semiconductor chip 11 is bonded and fixed to the chip mounting surface 12a of the rewiring board 12, and an electrode pad (not shown) is provided on the back surface of the semiconductor chip 11 facing the rewiring board 12. A plurality of are formed.

  The rewiring board 12 is a so-called interposer, and is configured by arranging a wiring pattern made of a conductive material such as copper on a base material mainly made of resin or ceramics. A plurality of lands 14 are formed on the chip mounting surface 12 a of the rewiring substrate 12, and these lands 14 are electrically connected to the electrode pads of the semiconductor chip 11. In the present embodiment, a plurality of lands 14 are arranged along each side of the substantially rectangular planar semiconductor chip 11 in a peripheral region surrounding the chip mounting region on the chip mounting surface 12a of the planar substantially rectangular rewiring substrate 12. Has been. Then, it is electrically connected to the electrode pad of the semiconductor chip 11 through the wire 15.

  On the other hand, a plurality of lands 16 are also formed on the back surface 12 b of the rewiring board 12. The plurality of lands 16 are arranged in a lattice pattern, and include lands 16a that perform an electrical connection function and inspection lands 16b (hereinafter simply referred to as inspection lands 16b). The land 16 a is electrically connected to the land 14 formed on the chip mounting surface 12 a via wiring (not shown) formed on the rewiring board 12. In this embodiment, all the lands 16 have a circular outer periphery and have the same diameter, and the land 16 is disposed in the land 16 corresponding to the land 22 of the wiring board 20 shown in FIG. Has an annular region arranged in an annular shape and a rectangular inner region arranged with a gap in the annular region. The inner area of the land 16 is substantially square in plan with nine lands 16 a, and the annular area of the land 16 is rectangular with three rows (three stages) of lands 16. One inspection land 16b is arranged at each of the four corners of the outermost periphery in the annular region, and lands 16a are arranged at the other corners. In addition, the inspection land 16b is electrically connected to a wiring having a GND potential among the wirings formed on the rewiring board 12. In other words, in the electronic device 100, the inspection land 16b is electrically connected to the GND pattern formed on the wiring board 20 through the other land 16a fixed to the GND potential and the solder bump 13a.

  A solder bump 13 is formed on each land 16. That is, solder bumps 13 are formed in a lattice shape corresponding to the lands 16 on the back surface 12 b of the rewiring board 12. Here, among the solder bumps 13, those located on the lands 16 a that provide an electrical connection function are referred to as solder bumps 13 a, and those located on the inspection lands 16 b are referred to as inspection solder bumps 13 b (hereinafter simply referred to as “solder bumps 13 b”). (Indicated as a solder bump for inspection 13b). In the present embodiment, solder balls formed in a spherical shape (ball shape) using a solder material having a tin (Sn) -silver (Ag) composition are employed as the solder bumps 13. Further, the outer sizes of the solder bumps 13a and the inspection solder bumps 13b are substantially equal, that is, all the solder bumps 13 have the same shape and size.

  Thus, the electronic component 10 is a so-called BGA (Ball Grid Array) type electronic component. Such a BGA type electronic component 10 is used, for example, in an electronic device such as a portable information terminal device such as a mobile phone, a memory module, or a CPU module.

  The semiconductor chip 11 and the wire 15 are sealed with a sealing resin 17 formed on the chip mounting surface 12a side of the rewiring substrate 12. In addition, as a constituent material of the sealing resin 17, a well-known material such as an epoxy resin to which a phenolic curing agent, silicone rubber, and a filler are added can be employed. Moreover, the code | symbol 18 shown in FIG. 2 is a resist.

  Next, the wiring board 20 is configured by arranging a wiring pattern made of a conductive material such as copper on a base material 21 mainly made of resin or ceramics. In the present embodiment, a wiring pattern made of copper is arranged in multiple layers on a base material 21 mainly composed of an epoxy resin, thereby forming a multilayered wiring board 20. As shown in FIGS. 3 and 4, a plurality of lands 22 are formed on one surface 20a (hereinafter simply referred to as an electronic component mounting surface 20a) of the wiring substrate 20 (base material 21) as end portions of the wiring pattern. ing. The lands 22 are formed corresponding to a plurality of lands 16 (a plurality of solder bumps 13) formed on the back surface 12b of the rewiring board 12 constituting the electronic component 10. The plurality of lands 22 include a land 22a that performs an electrical connection function, and an inspection land 22b that does not provide an electrical connection function (hereinafter simply referred to as an inspection land 22b). In this embodiment, all the lands 22 employ flat lands having the same diameter, and as shown in FIG. 3, the land 22 is arranged in an annular region in which the lands 22 are annularly arranged, And a rectangular inner region arranged with a gap in the annular region. The inner area of the land 22 is substantially square in plan with nine lands 22 a, and the annular area of the land 22 is rectangular with three rows (three stages) of lands 22. Then, one inspection land 22b is arranged at each of the four corners of the outermost periphery in the annular region, and lands 22a are arranged at the other corners.

  In addition to the lands 22, test pads 23 and 24 for performing an electrical test using a tester are formed on the electronic component mounting surface 20 a of the wiring board 20. These test pads 23 and 24 are formed outside the electronic component mounting area 10a (area surrounded by a broken line in FIG. 3) on the electronic component mounting surface 20a. In the present embodiment, the inspection pads 23 are formed diagonally outside in the annular region of the planar rectangular land 22 with respect to each inspection land 22b, and are formed on the electronic component mounting surface 20a. It is electrically connected to the corresponding inspection land 22b via the wiring portion 25 (wiring pattern in the example shown in FIG. 3). That is, for each of the four inspection lands 22b formed at the four corners, the inspection pads 23 are formed on the diagonally outer side. On the other hand, one test pad 24 is formed on each of the central outer sides of two opposing sides in the annular region of the substantially rectangular annular land 22. Then, it is electrically connected to a solid GND pattern disposed inside the wiring substrate 20 (base material 21) via a connection via or wiring pattern (not shown) in which a conductive material is embedded in the via hole. Yes. That is, the inspection pad 24 is electrically connected to the inspection land 16b (inspection solder bump 13b) of the electronic component 10 through the GND pattern and the solder connection portion 30a. In FIGS. 1 and 6, the test land 16b and the test pad 24 are electrically connected to each other so as to be at the GND potential.

  A solder paste 26 is disposed on each land 22. Here, among the solder pastes 26, those located on the lands 22a that provide an electrical connection function are referred to as solder pastes 26a, and those located on the inspection lands 22b are referred to as inspection solder pastes 26b (hereinafter simply referred to as "solder pastes 26b"). And a solder paste 26b for inspection). In this embodiment, as the solder paste 26, a solder paste is used which is adjusted to a predetermined viscosity by kneading Sn-Ag composition solder particles, resin binder, solvent, flux, inorganic frit and the like, similar to the solder bump 13. .

  Further, in the present embodiment, as shown in FIG. 4, the test solder paste 26b is less loaded on the land 22 than the solder paste 26a. More specifically, the height is low and the width is narrow. In other words, the solder paste for inspection 26b has a smaller amount of flux than the solder paste 26a. As described above, as a method of adjusting the loading amount of the solder paste 26, for example, as shown in FIG. 5, there is a method of adjusting the opening degree (opening) of the screen 101 (metal mask). In the present embodiment, the size (opening area) of the opening 102b on the inspection solder paste 26b side is smaller than the size of the opening 102a on the solder paste 26a side. If this screen 101 is used during screen printing, the width of the solder paste for inspection 26b becomes narrow due to the difference in opening area. Further, since the removal of the solder paste 26 is inferior on the opening 102b side than the opening 102a, the height is also reduced. Therefore, the solder paste 26a and the inspection solder paste 26b having different loading amounts can be formed by a single screen printing. In addition, the height of the solder paste for inspection 26b is a height in contact with the corresponding solder bump for inspection 13b in the positioning state of the electronic component 10 and the wiring board 20 before the heat treatment. Moreover, the code | symbol 27 shown in FIG. 4 is a resist.

  Then, heat treatment (reflow) is performed in a state where the lands 16 of the electronic component 10 and the lands 22 of the corresponding wiring board 20 face each other, that is, in a state where the solder bumps 13 and the solder paste 26 are in contact with each other. Thus, the electronic device 100 shown in FIG. 1 is configured. That is, the solder connection portion 30 is constituted by the solder bump 13 and the solder paste 26. Of the solder connection portions 30, one that electrically connects the lands 16a and 22a is referred to as a solder connection portion 30a, and one that electrically connects the inspection lands 16b and 22b is referred to as an inspection solder connection portion 30b. To do.

  Next, a method for manufacturing the electronic device 100 will be described. First, the electronic component 10 and the wiring board 20 configured as described above are prepared. Then, the electronic component 10 is positioned and placed on the electronic component mounting surface 20 a of the wiring board 20 so that the lands 16 and 22 corresponding to each other face each other and the solder bump 13 contacts the solder paste 26.

  Next, the wiring board 20 on which the electronic component 10 is mounted is transported to a reflow furnace (not shown) and subjected to heat treatment. In this heat treatment, the solder bumps 13 and the solder particles of the solder paste 26 are melted and solidified by cooling to form the solder connection portions 30. At this time, if the solder bumps 13 and the solder paste 26 are mixed with each other to form a metal bond, that is, they are joined, the electronic component 10 is electrically and mechanically connected to the wiring board 20. The electronic device 100 is formed through the above steps.

  Next, a connection state inspection method for the electronic device 100 according to the present embodiment will be described. When the electronic device 100 described above is formed, the electronic component 10 and the wiring substrate 20, particularly the electronic component 10, are likely to warp due to the heat treatment when the solder connection portion 30 is formed. The electronic component 10 has many components such as the semiconductor chip 11, the rewiring substrate 12, and the sealing resin 17, and usually has different linear expansion coefficients. Also, the linear expansion coefficient is different between the electronic component 10 and the wiring board 20. When the linear expansion coefficients are different between members adjacent to each other as described above, for example, the expansion amount is different between adjacent members, and thus warpage occurs in the course of the heat treatment. In the present embodiment, the rewiring board 12 and the sealing resin 17 expand due to the heat treatment, and the warpage of the electronic component 10 having a convex center with respect to the wiring board 20 occurs due to the difference between these linear expansion coefficients. Further, although warping is reduced by contraction during cooling after heating, as shown in FIG. 1, in the state of the electronic device 100, warping with a convex center on the wiring substrate 20 remains in the electronic component 10. ing.

  When warping occurs due to expansion during heating as described above, the solder bump 13 and the solder paste 26 may be separated from each other until the solder bump 13 and the solder paste 26 are melted and mixed with each other. In this case, if the solder bump 13 and the solder paste 26 are separated from each other even after cooling, an open failure occurs. On the other hand, due to cooling after heating, for example, the rewiring board 12 contracts and warpage is reduced, and when the solder bumps 13 and the solder paste 26 come into contact with each other in a solidified state without being mixed with each other, a conductive state by contact is secured. It becomes non-wetting failure. In this non-wetting defect, at least part of the contact portion between the solder bump 13 and the solder paste 26 has a thin (or non-existing) portion of the surface oxide film, thereby ensuring a conductive state at the contact portion. it is conceivable that.

  Further, since the flux for removing the oxide film on the surface of the solder bump 13 and the solder paste 26 is insufficient, only a part of the contact portion between the solder bump 13 and the solder paste 26 is in a joined state, and the rest is in a contact state only. It is also considered that non-wetting failure occurs. Also in this case, at the part where the solder bump 13 and the solder paste 26 are in contact with each other, at least part of the surface oxide film is thin (or does not exist), so that the conductive state at the contact part (excluding the joint part) is achieved. It is considered to be secured. Such non-wetting defects are particularly likely to occur due to warpage caused by expansion during heating, thereby reducing the contact area between the solder bumps 13 and the solder paste 26, thereby resulting in insufficient flux at the contact site. It is considered to be.

  In addition, in the non-wetting failure, it has been confirmed by the present inventor that electrical continuity is ensured in at least a part of the contact part (excluding the joining part). That is, it may not be possible to determine whether or not a non-wetting defect has occurred by simply measuring the conduction state of the inspection solder connection portion 30b and thus the resistance value. In particular, when a part of the inspection solder connection portion 30b is in a joined state, it is difficult to determine whether or not it is a non-wetting defect even by measuring the resistance value.

  Therefore, in the present embodiment, an external force is applied to at least one of the electronic component 10 and the wiring board 20 in the direction in which the electronic component 10 and the wiring board 20 in the test solder connection portion 30b are separated from each other. The resistance value of the inspection solder connection portion 30b is measured. Specifically, the resistance value of the test solder connecting portion 30b between the test lands 16b and 22b is measured by bringing the terminals 103a and 103b of the tester 103 into contact with both test pads 23 and 24. .

  Since the external force is applied in this manner, when the inspection solder connection portion 30b is not wetted, the area of the contact portion (excluding the bonding portion) between the inspection solder bump 13b and the inspection solder paste 26b is small. Therefore, the resistance value can be increased not less than the state before the external force is applied. Thereby, the non-wetting defect can be detected with higher accuracy than in the past. Further, since the resistance value is measured, it is possible to detect an open failure that is in a non-contact state.

  In addition, a non-wetting defect and an open defect can be detected by comparing the resistance value measured with an external force applied with a reference value having a predetermined tolerance. However, in the present embodiment, the resistance value of the inspection solder connection portion 30b is measured in a state before the external force is applied, and then the resistance value of the inspection solder connection portion 30b measured in the external force application state is the previous resistance value. By comparing, the presence or absence of non-wetting failure is determined. According to this, the presence / absence of non-wetting failure can be determined by the presence / absence of a change in resistance value before and after the application of external force. Therefore, it is possible to detect the non-wetting defect with higher accuracy than in comparison with a reference value having a predetermined tolerance.

  In the present embodiment, the electronic component 10 is warped with a convex central region with respect to the wiring board 20 due to the heat treatment. Therefore, the inspection lands 16b (and the inspection solder bumps 13b) are moved away from the back surface of the rewiring board 12. It is the outermost periphery as the peripheral region of the land arrangement regions in 12b, and is formed at the four corners. In addition, an inspection pad 23 electrically connected to the inspection land 22b is formed at a portion of the electronic component mounting surface 20a of the wiring board 20 excluding the electronic component mounting area 10a. More specifically, an inspection pad 23 is formed on each of the inspection lands 22b formed at the four corners on the outer side in the diagonal direction in the annular region of the substantially rectangular annular land 22.

  Therefore, as shown in FIG. 6, by bringing one terminal 103 a of the tester 103 into contact with the inspection pad 23, a downward external force is applied to the electronic component mounting surface 20 a of the wiring board 20, and the inspection solder connection portion A resistance value of 30b can be measured. When applying an external force, the electronic component 10 may be fixed, or at least a part of the electronic component mounting region 10a on the back surface of the wiring board 20 may be fixed. In this case, since the external force can be applied and the resistance value can be measured simultaneously by the tester 103, the inspection procedure and the apparatus configuration can be simplified. In the present embodiment, the inspection pads 24 with which the terminals 103b of the tester 103 are brought into contact are also formed in a portion of the electronic component mounting surface 20a of the wiring board 20 excluding the electronic component mounting area 10a. In the present embodiment, one inspection pad 24 is formed for two inspection pads 23.

  In the present embodiment, as the solder connection portion 30, four inspection solder connection portions 30b are separated from each other. And the resistance value of each solder connection part 30b for a test | inspection is measured sequentially. According to this, even if the warpage of the electronic component 10 is not uniform at the four inspection solder connection portions 30b, it is possible to detect a connection failure such as a non-wetting failure. That is, it is possible to increase the reliability with which the joining state of all the solder connection portions 30 is ensured.

  In the present embodiment, the amount of the inspection solder paste 26b on the inspection land 22b is made smaller than the amount of the solder paste 26a on the land 22a. That is, the non-wetting defect due to the lack of flux is more likely to occur in the inspection solder connection portion 30b than in the other solder connection portions 30a. Further, the positions of the inspection lands 16b and 22b are the four outer corners of the lands 16 and 22 which are easily separated from the wiring board 20 due to the warp of the electronic component 10, and four corners of the rectangle. Therefore, the detection accuracy of non-wetting failure can be increased by these effects.

  In the example shown in FIGS. 1 and 6, non-wetting failure occurs at one of the inspection solder connection portions 30b between the inspection lands 16b and 22b provided at the four corners. In addition, in the solder connection portion 30a, a portion including the solder connection portion 30a adjacent to the inspection solder connection portion 30b in which the non-wetting failure has occurred has a non-wetting failure. Thus, by sequentially measuring the resistance value of the test solder connection portion 30b shown in FIG. 6, the connection state of the solder connection portion 30a that provides an electrical connection function can be ensured.

  In the present embodiment, the inspection pads 23 and 24 are both formed on the electronic component mounting surface 20a of the wiring board 20, and one of the inspection pads 24 is set to the GND potential together with the inspection land 16b of the electronic component 10. The example (connected with the GND pattern of the wiring board 20) is shown. However, the configuration for measuring the resistance value of the inspection solder connection portion 30b is not limited to the above example.

  For example, as shown in FIG. 7, the inspection pad 19 that is electrically connected to the inspection land 16 b and exposed from the sealing resin 17 is formed on the chip mounting surface 12 a of the rewiring substrate 12 of the electronic component 10. The inspection pad 23 formed and electrically connected to the inspection land 22b may be formed on the wiring board 20 as described above. In this case, as shown in FIG. 7, a downward force is applied to the wiring substrate 20 while the terminal 103 a of the tester 103 is in contact with the inspection pad 23, and the terminal 103 b is in contact with the inspection pad 19. Thus, the resistance value of the solder connection portion 30b for inspection is measured. FIG. 7 is a cross-sectional view showing a modification of the electronic device, and corresponds to FIG. In the example shown in FIG. 7, all of the inspection solder connection portions 30b are in a good connection state (joined state).

  In addition, one current path is constituted by the plurality of inspection solder connection portions 30b, inspection pads are provided at both ends of the current path, and the resistance value of the current path including the plurality of inspection solder connection portions 30b by the tester 103. It is also possible to determine whether or not there is a connection failure by measuring. For example, in the example shown in FIG. 8, two adjacent inspection lands 22b are formed for each corner on the electronic component mounting surface 20a of the wiring board 20, and the wiring portion 25 (the wiring pattern in the example shown in FIG. 8) is formed. ), An inspection pad 23a is connected to one inspection land 22b, and an inspection pad 23b is connected to the other inspection land 22b. Although not shown, two inspection lands 16b corresponding to the inspection lands 22b are formed on the back surface 12b of the rewiring board 12 in the electronic component 10 for each corner, and these two inspection lands 16b are formed. They are electrically connected via a wiring portion provided on the rewiring board 12. The resistance value of the current path including the two test solder connection portions 30b is measured by bringing the terminals 103a and 103b of the tester 103 into contact with the two test pads 23a and 23b. FIG. 8 is a plan view showing a modification of the electronic device, and shows a wiring board of the electronic device. FIG. 8 corresponds to FIG. Although FIG. 8 shows an example in which two inspection pads 23a and 23b are provided on the wiring board 20 side, two inspection pads may be provided on the rewiring board 12 side.

  Further, in the present embodiment, an example in which an external force is applied to the wiring board 20 by the terminal 103a of the tester 103 is shown. However, an external force may be applied to at least one of the electronic component 10 and the wiring board 20 by a member different from the tester 103. That is, the resistance value of the test solder connection portion 30b may be measured by the tester 103 in a state where an external force is applied by a member different from the tester 103. Further, the portion corresponding to the inspection land 16b in the electronic component 10 may be pulled upward while the wiring board 20 is fixed.

  Further, in the present embodiment, the inspection lands 16b and 22b are illustrated as being formed at the four corners in the rectangular annular land arrangement region in the rewiring board 12 and the wiring board 20, respectively. However, the peripheral region in the land arrangement region is not limited to the four corners. For example, it is good also as a structure formed in the center between mutually adjacent corners.

  Further, in the present embodiment, an example in which the electronic component 10 warps with the center protruding from the wiring board 20 is shown. However, as shown in FIG. 9, the above-described connection state inspection method can be applied even when the center is warped with a concave. FIG. 9 is a cross-sectional view illustrating a modification of the electronic device. FIG. 10 is a plan view showing a schematic configuration of a wiring board in the electronic device shown in FIG. 9, and a resist and a solder paste are omitted for convenience. In the example shown in FIG. 9, only four lands 22 are the inspection lands 22b among the nine inner lands 22 as the central region surrounded by the annular region. Corresponding to the inspection land 22b, the inspection wiring 16b is also formed on the rewiring board 12 of the electronic component 10, that is, the inspection solder bumps 13b are also formed in the central region on the back surface 12b of the rewiring board 12. Is formed. Then, inspection pads 23 and 24 are formed on the back surface 20b of the electronic component mounting surface 20a of the wiring board 20 except for the portion corresponding to the electronic component mounting area 10a. The inspection pad 23 is connected to the inspection land 22b via the wiring portion 25 (in the example shown in FIG. 9, a through portion 25a penetrating the wiring substrate 20 and a wiring pattern 25b connected to one end of the through portion). Electrically connected. Similarly to the above, one inspection pad 24 is formed outside the center of two opposite sides in the annular region of the land 22, and a connection via or wiring (not shown) in which a conductive material is embedded in the via hole. It is electrically connected to a solid GND pattern disposed inside the wiring board 20 (base material 21) via a pattern or the like. That is, the inspection pad 24 is electrically connected to the inspection land 16b (inspection solder bump 13b) of the electronic component 10 through the GND pattern and the solder connection portion 30a. Therefore, also in the example shown in FIGS. 9 and 10, the resistance value of the test solder connection portion 30 b can be measured by bringing the terminals 103 a and 103 b of the tester 103 into contact with the test pads 23 and 24. In the example shown in FIGS. 9 and 10, the resistance value of the test solder connection portion 30b is applied while applying an upward external force to the wiring board 20 by bringing the terminal 103a of the tester 103 into contact with the test pad 23. Can be measured. In the example shown in FIG. 9, all nine solder connection portions 30a and 30b in the inner region are non-wetting defects.

  In addition, the center area | region of a land arrangement | positioning area | region shows the one part area | region including the center in a land arrangement | positioning surface (the back surface 12b of the rewiring board | substrate 12, the electronic component mounting surface 20a of the wiring board 20). As described above, in the configuration having the inner region, at least a part of the inner region as the central region may be the inspection lands 16b and 22b. In the configuration having only the annular region, at least a part of the annular innermost lands 16 and 22 as the central region may be used as the inspection lands 16b and 22b. Furthermore, in the land arrangement area, in the configuration in which the lands 16 and 22 are arranged in a lattice shape without gaps, at least a part of the lands 16 and 22 in a partial area as a central area including the center of the land arrangement surface is used as the inspection land. 16b and 22b may be used.

  The inspection lands 16b and 22b may be formed in both the central region in the land arrangement region and the peripheral region surrounding the central region. According to this, even if the electronic component 10 is warped, the connection state of the remaining solder connection portions 30a can be ensured by measuring the resistance value of the test solder connection portions 30b.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a cross-sectional view illustrating an inspection method for inspecting an electrical connection state of the electronic device according to the second embodiment.

  Since the connection state inspection method for the electronic device according to the second embodiment is often in common with that shown in the first embodiment, the detailed description of the common parts will be omitted below, and different parts will be described with emphasis. . In addition, the same code | symbol shall be provided to the element same as the element shown in 1st Embodiment.

  In the first embodiment, an example in which the resistance value of the inspection solder connection portion 30b is measured in the state in which the external force is applied in the direction in which the electronic component 10 and the wiring board 20 are separated from each other in the inspection solder connection portion 30b is shown. It was. However, in the present embodiment, the electronic component 10 and the wiring substrate 20 are separated in the direction in which the electronic component 10 and the wiring substrate 20 are separated from each other in the solder connection portion 30b for inspection due to the difference in linear expansion coefficient between the electronic component 10 and the wiring substrate 20. The ambient temperature is changed from room temperature RT so that at least one of them is deformed, and the resistance value of the connection part for inspection is measured in the changed temperature state. Other points are the same as those in the above-described embodiment (including the modified example).

  In the example shown in FIG. 11, the linear expansion coefficient α1 of the electronic component 10 (rewiring board 12) is smaller than the linear expansion coefficient α2 of the wiring board 20, and the electronic component 10 is connected to the wiring in the state of the electronic device 100. The center of the substrate 20 is warped. Then, the ambient temperature T is changed from room temperature RT to T1 (for example, 100 ° C.) higher than RT, and the resistance value of the test solder connection portion 30b is measured in this temperature state T1. The configuration of the electronic device 100 is the same as that shown in FIGS. 1 to 4 shown in the first embodiment.

  As described above, when the linear expansion coefficient α1 of the electronic component 10 is smaller than the linear expansion coefficient α2 of the wiring board 20, the lower surface of the electronic component 10 is changed when the ambient temperature T is changed to T1 higher than the room temperature RT. In the (wiring board facing surface) and the back surface (upper surface), the lower surface side is pulled by the expansion of the wiring substrate 20 having a large linear expansion coefficient, and the expansion amount increases. Then, the electronic component 10 tends to be deformed in a direction in which warpage increases, that is, a direction in which the electronic component 10 and the wiring board 20 in the inspection solder connection portion 30b are separated from each other. As a result, if the inspection solder connection portion 30b is non-wetting, the contact area between the inspection solder bump 13b and the inspection solder paste 26b is reduced to a small extent, and the resistance value is increased. Therefore, the non-wetting defect can be accurately detected by measuring the resistance value of the test solder connection portion 30b in the temperature state T1. Also, open defects can be detected by measuring the resistance value.

  In connection failure detection, as in the first embodiment, non-wetting failure and open failure are detected by comparing the resistance value measured with the temperature changed with a reference value having a predetermined tolerance. Also good. Preferably, the resistance value of the inspection solder connection portion 30b is measured in the state before the temperature change (RT), and then the resistance value of the inspection solder connection portion 30b measured in the state where the temperature is changed (T1). It is preferable to determine the presence or absence of non-wetting defects by comparing with the previous resistance value.

  In the example shown in FIG. 11, an example in which the electronic component 10 warps with respect to the wiring board 20 with the center as a convex is shown. However, the present invention can also be applied to a configuration in which the electronic component 10 warps with the center being concave with respect to the wiring board 20. For example, in the example shown in FIG. 12, the configuration of the electronic device 100 is the same as that of the modification example (FIG. 9) shown in the first embodiment, and the electronic component 10 warps with respect to the wiring board 20 with the center being concave. Yes. The linear expansion coefficient α1 of the electronic component 10 (rewiring board 12) is smaller than the linear expansion coefficient α2 of the wiring board 20. As described above, when the linear expansion coefficient α1 of the electronic component 10 is smaller than the linear expansion coefficient α2 of the wiring board 20, the electronic temperature is changed when the ambient temperature T is changed to T2 (for example, −30 ° C.) lower than the room temperature RT. On the lower surface (surface facing the wiring board) and the back surface (upper surface) of the component 10, the lower surface side is pulled by the contraction of the wiring substrate 20 having a large linear expansion coefficient, and the contraction amount increases. Then, the electronic component 10 tends to be deformed in a direction in which warpage increases, that is, a direction in which the electronic component 10 and the wiring board 20 in the inspection solder connection portion 30b are separated from each other. As a result, if the inspection solder connection portion 30b is non-wetting, the contact area between the inspection solder bump 13b and the inspection solder paste 26b is reduced to a small extent, and the resistance value is increased. Therefore, the non-wetting defect can be accurately detected by measuring the resistance value of the test solder connection portion 30b in the temperature state T2. Also, open defects can be detected by measuring the resistance value. FIG. 12 is a cross-sectional view showing a modification of the inspection method for inspecting the electrical connection state of the electronic device.

  Even if the temperature change from the room temperature RT shown in the present embodiment and the application of the external force shown in the first embodiment are simultaneously performed, the resistance value of the test solder connection portion 30b is measured in that state. good.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 13 is a cross-sectional view illustrating an inspection method for inspecting an electrical connection state of the electronic device according to the third embodiment.

  Since the connection state inspection method for the electronic device according to the third embodiment is often in common with that shown in each of the above-described embodiments, a detailed description of the common parts will be omitted, and the different parts will be mainly described below. To do. In addition, the same code | symbol shall be provided to the element same as the element shown to said each embodiment.

  The present embodiment is characterized in that at least one of the electronic component 10 and the wiring board 20 is vibrated continuously for a predetermined time, and the resistance value of the test solder connection portion 30b is monitored during this vibration period. Other points are the same as those in the above-described embodiment (including the modified example).

  In the example shown in FIG. 13, the electronic device 100 has the same configuration as that shown in the first embodiment (see FIGS. 1 to 4). Then, in a state where the ultrasonic vibrator 104 is in contact with the back surface of the electronic component mounting surface 20a of the wiring board 20, the ultrasonic vibrator 104 is driven to vibrate the wiring board 20. Then, this vibration is maintained for a certain period, and the resistance value of the inspection solder connection portion 30b during the vibration period is detected by the tester 103 in which the terminals 103a and 103b are in contact with the inspection pads 23 and 24. .

  As described above, the non-wetting defect is a defect in which at least a part of the connection portion is in a conductive state by contact instead of joining. Therefore, when the wiring board 20 is vibrated, the contact area (contact state) between the non-wetting test solder bump 13b and the test solder paste 26b can be changed by the vibration. Since the resistance value of the inspection solder connection portion 30b is monitored (continuously measured) during the vibration period, if the resistance value varies, it is determined that the inspection solder connection portion 30b is non-wetting. be able to. Also, open defects can be detected by measuring the resistance value.

  In the example shown in FIG. 13, the example in which the ultrasonic transducer 104 is brought into contact with the back surface side of the wiring board 20 is shown, but the contact position is not limited to the above example. For example, it may be brought into contact with the electronic component mounting surface 20a of the wiring board 20, or may be brought into contact with the electronic component 10. Moreover, how to make it vibrate is not limited to the said example. For example, you may utilize the vibration after applying external force with jigs, such as a hammer.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above-described embodiment, the solder paste 26 is applied onto the lands 22 of the wiring board 20, and the lands 16 of the electronic component 10 are connected to the lands 16 of the electronic component 10 via the solder connection portions 30 formed by the solder bumps 13 and the solder paste 26 on the electronic component 10 side. A configuration example in which the lands 22 of the wiring board 20 are electrically connected is shown. However, the solder connection part 30 may be configured only by the solder bumps 13 without applying the solder paste 26 on the lands 22 of the wiring board 20. That is, the land 16 of the electronic component 10 and the land 22 of the wiring board 20 may be electrically connected via the solder bump 13.

1 is a cross-sectional view of a schematic configuration of an electronic device according to a first embodiment. It is sectional drawing which shows schematic structure of an electronic component. It is a top view which shows schematic structure of a wiring board. It is sectional drawing which follows the IV-IV line of FIG. It is a top view which shows schematic structure of the screen at the time of apply | coating solder paste to a wiring board. It is sectional drawing which shows the test | inspection method which test | inspects the electrical connection state of an electronic device. It is sectional drawing which shows the modification of an electronic device. It is a top view which shows the modification of an electronic device, and has shown the wiring board of the electronic devices. It is sectional drawing which shows the modification of an electronic device. FIG. 10 is a plan view illustrating a schematic configuration of a wiring board in the electronic device illustrated in FIG. 9. It is sectional drawing which shows the test | inspection method which test | inspects the electrical connection state of the electronic device which concerns on 2nd Embodiment. It is sectional drawing which shows the modification of the test | inspection method which test | inspects the electrical connection state of an electronic device. It is sectional drawing which shows the test | inspection method which test | inspects the electrical connection state of the electronic device which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electronic component 13 ... Solder bump 13b ... Inspection solder bump 16 ... Land 16b ... Inspection land 20 ... Wiring board 22 ... Land 22b ... Inspection land 23, 24 ... Inspection pad 26 ... Solder paste 26 ... Inspection solder paste 30 ... Solder connection part (connection part)
30b ... Solder connection for inspection (connection part for inspection)
100 ... electronic device 103 ... tester

Claims (14)

A plurality of solder bumps arranged on one surface of the electronic component and a plurality of lands formed on the mounting surface of the electronic component on the wiring board corresponding to the solder bump are connected, and the electronic In an electronic device in which a component is mounted, a connection state inspection method for inspecting an electrical connection state of a connection portion between the solder bump and the land,
The connection portion includes an inspection solder bump formed adjacent to the solder bump on one surface of the electronic component, and an inspection land formed on the wiring board corresponding to the inspection solder bump. Including a connection part for inspection that does not provide a general connection function,
The resistance value of the inspection connection part is measured with an external force applied in a direction in which the electronic component and the wiring board in the inspection connection part are separated from each other on at least one of the electronic component and the wiring board. A method for inspecting a connection state of an electronic device.   2. The electronic device according to claim 1, wherein the resistance value of the connection portion for inspection is measured even in a state before the external force is applied, and the resistance value is compared with the resistance value in the external force applied state. Connection state inspection method.   3. The method for inspecting a connection state of an electronic device according to claim 1, wherein the inspection solder bump is formed in at least one of a peripheral region and a central region on one surface of the electronic component. The electronic component is warped with the central region convex with respect to the wiring board,
The inspection solder bump is formed in a peripheral region on one surface of the electronic component,
An inspection pad that is electrically connected to the inspection land is formed in a portion other than the electronic component mounting portion on the electronic component mounting surface of the wiring board,
The electronic device according to claim 3, wherein a resistance value of the connection portion for inspection is measured while applying a downward external force to the wiring board by bringing a terminal of the tester into contact with the inspection pad. Connection state inspection method. The electronic component is warped with the central region being concave with respect to the wiring board,
The inspection solder bump is formed in a central region on one surface of the electronic component,
An inspection pad electrically connected to the inspection land is formed on a portion of the back side of the electronic component mounting surface of the wiring board except for a portion corresponding to the electronic component mounting portion,
The electronic device according to claim 3, wherein a resistance value of the connection portion for inspection is measured while an upper external force is applied to the wiring board by bringing a terminal of the tester into contact with the inspection pad. Connection state inspection method. In the electronic component, a plurality of the inspection solder bumps are formed apart from each other,
6. The method for inspecting a connection state of an electronic device according to claim 4, wherein a resistance value is sequentially measured for each connection portion corresponding to the solder bump for inspection. A plurality of solder bumps arranged on one surface of the electronic component and a plurality of lands formed on the mounting surface of the electronic component on the wiring board corresponding to the solder bump are connected, and the electronic component is connected to the wiring board. In a mounted electronic device, a connection state inspection method for inspecting an electrical connection state of a connection portion between the solder bump and the land,
The connection portion includes an inspection solder bump formed adjacent to the solder bump on one surface of the electronic component, and an inspection land formed on the wiring board corresponding to the inspection solder bump. Including a connection part for inspection that does not provide a general connection function,
Due to the difference in coefficient of linear expansion between the electronic component and the wiring board, at least one of the electronic component and the wiring board should be deformed in a direction in which the electronic component and the wiring board are separated from each other at the inspection connection site. A method for inspecting a connection state of an electronic device, comprising: changing an ambient temperature from room temperature, and measuring a resistance value of the connection part for inspection in the changed temperature state.   The resistance value of the connection part for inspection is measured even in a state before the ambient temperature is changed, and the resistance value is compared with the resistance value in the ambient temperature change state. Method for checking the connection state of electronic devices.   The electronic device connection state inspection method according to claim 7 or 8, wherein the inspection solder bump is formed in at least one of a peripheral region and a central region on one surface of the electronic component. The electronic component is warped with the central region convex with respect to the wiring board,
The inspection solder bump is formed in a peripheral region on one surface of the electronic component,
10. The method for inspecting a connection state of an electronic device according to claim 9, wherein the resistance value of the inspection connection portion is measured in a state where the ambient temperature is higher than room temperature. The electronic component is warped with the central region being concave with respect to the wiring board,
The inspection solder bump is formed in a central region on one surface of the electronic component,
10. The method for inspecting a connection state of an electronic device according to claim 9, wherein the resistance value of the inspection connection portion is measured in a state where the ambient temperature is lower than room temperature. A plurality of solder bumps arranged on one surface of the electronic component and a plurality of lands formed on the mounting surface of the electronic component on the wiring board corresponding to the solder bump are connected, and the electronic component is connected to the wiring board. In a mounted electronic device, a connection state inspection method for inspecting an electrical connection state of a connection portion between the solder bump and the land,
The connection portion includes an inspection solder bump formed adjacent to the solder bump on one surface of the electronic component, and an inspection land formed on the wiring board corresponding to the inspection solder bump. Including a connection part for inspection that does not provide a general connection function,
A method for inspecting a connection state of an electronic device, wherein at least one of the electronic component and the wiring board is vibrated continuously for a predetermined time, and the resistance value of the connection part for inspection is monitored during the vibration period.   The electronic device according to claim 1, wherein the land and the inspection land include a solder paste disposed on a back surface of a surface facing the wiring board in the land and the inspection land. Connection state inspection method.   14. The method for inspecting a connection state of an electronic device according to claim 13, wherein the amount of solder paste on the inspection land is made smaller than the amount of solder paste on the land.

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