JP2013195384A - Inspection device, inspection method, and method for manufacturing electronic component - Google Patents

Abstract

An inspection apparatus, an inspection method, and an electronic component manufacturing method for inspecting flatness of a flat surface capable of reducing tact time.
According to an embodiment, a measurement unit capable of detecting positions of a plurality of measurement points on a planar inspection surface formed by a plurality of members, and a position of the plurality of measurement points measured by the measurement unit. , A reference plane formed by any three of the plurality of measurement points is derived, an evaluation height from the reference plane to the plurality of measurement points is derived, and the derived evaluation height is calculated by the inspection surface. And a control unit that determines that the flatness of the detection surface is the predetermined flatness when the evaluation height is within the threshold as compared with a threshold that provides the predetermined flatness.
[Selection] Figure 1

Description

  FIELD Embodiments described herein relate generally to an inspection apparatus, an inspection method, and an electronic component manufacturing method for inspecting flatness of a plane.

  When the grounding surface of a component formed by a combination of a plurality of members is fixed in contact with the grounded surface of another component, the grounding surface and the grounded surface depend on the flatness of the grounding surface formed by the plurality of members. May be partially separated. If the grounding surface and the grounded surface are separated from each other, the components may be inclined and fixed. Further, when another member such as an adhesive or a sheet material is interposed between the grounding surface and the grounded surface, the thickness of the adhesive or the sheet material may be partially different.

  As such a component, for example, an electronic component such as a semiconductor device in which a plurality of IC chips are sandwiched and mounted on a plurality of bus bars is known. In this semiconductor device, for example, a ground surface composed of a plurality of bus bars is fixed to a flat grounded surface of a heat sink via an insulating sheet.

  However, if the distance between the ground surface and the grounded surface composed of a plurality of bus bars is different in each part, the thickness of the insulating sheet interposed between the bus bar and the heat sink is different in each part. As a result, in the semiconductor device, there is a possibility that the heat dissipation of the bus bar may vary.

  Therefore, as a technique for detecting the flatness of the ground contact surface composed of a plurality of members, the ground contact surface is scanned by a measuring means such as a laser displacement meter, and the difference between the maximum value and the minimum value of the ground contact surface is set as the evaluation height. Techniques for detecting are known. This technique is an inspection method in which a threshold value that is an acceptable flatness of the ground plane is compared with a calculated evaluation height, and if the evaluation height is within the threshold value, a predetermined flatness is obtained.

Japanese Patent Laid-Open No. 07-113980

  An object of the present invention is to provide an inspection apparatus, an inspection method, and an electronic component manufacturing method for inspecting flatness of a flat surface, which can reduce the tact time.

  According to the embodiment, the inspection apparatus according to the embodiment includes a measurement unit capable of detecting positions of a plurality of measurement points on a planar inspection surface formed by a plurality of members, and a plurality of measurement points measured by the measurement unit. From the position, a reference plane formed by any three of the plurality of measurement points is derived, an evaluation height from the reference surface to the plurality of measurement points is derived, and the derived evaluation height is And a control unit that determines that the flatness of the detection surface is a predetermined flatness when the evaluation height is within the threshold compared to a threshold at which the inspection surface has a predetermined flatness.

Explanatory drawing which shows typically the structure of the inspection apparatus which concerns on one Embodiment. The perspective view which shows typically the structure of the electronic component from which flatness is detected with the inspection apparatus. The perspective view which shows typically the test | inspection surface of the same electronic component. The flowchart which shows one of the manufacturing methods of the electronic component using the same inspection apparatus.

Hereinafter, an inspection apparatus 1 according to the present embodiment, a method for inspecting flatness of the electronic component 100 using the inspection apparatus 1, and a method for manufacturing the electronic component 100 will be described with reference to FIGS.
FIG. 1 is an explanatory diagram schematically illustrating the configuration of an inspection apparatus 1 according to an embodiment of the present embodiment, and FIG. 2 is a perspective view schematically illustrating the configuration of an electronic component 100 whose flatness is detected by the inspection apparatus 1. 3 is a perspective view showing an inspection surface 120 of the electronic component 100. FIG. 4 is a flowchart showing one method for manufacturing the electronic component 100 using the inspection apparatus 1. FIG. In FIGS. 1 to 3, arrows X, Y, and Z indicate three axial directions that are orthogonal to each other.

  The inspection apparatus 1 is formed so as to be able to inspect the flatness of a plane of the electronic component 100 that is an inspection object. The inspection apparatus 1 includes a fixing unit 11 that fixes the electronic component 100, a moving unit 13, a measuring unit 13 that can measure the distance to the inspection surface 120, and a control unit 14.

  Here, the electronic component 100 is an inspection object whose flatness of the planar inspection surface 120 is inspected by the inspection apparatus 1. In the electronic component 100, the inspection surface 120 is formed of a plurality of members. The electronic component 100 is a semiconductor module such as an IGBT (Insulate Gate Bipolar Transistor) module.

  Specifically, as shown in FIGS. 2 and 3, the electronic component 100 is interposed between a VCM (Vertical Chip Mount) 101, a heat sink 102 for fixing the VCM 101, and between the VCM 101 and the heat sink 102. And an insulating sheet 103 that can be fixed to the heat radiating plate 102.

  The VCM 101 includes a plurality of rectangular parallelepiped bus bars 111 and a semiconductor device 112 such as an IC chip mounted between the bus bars 111. In the VCM 101, a semiconductor device 112 is mounted between adjacent bus bars 111, and a plurality of bus bars 111 are fixed apart by a thickness of the semiconductor device 112. The VCM 101 is composed of, for example, three rectangular parallelepiped bus bars 111 having the same shape. The VCM 101 includes a ground plane 120 fixed to the heat sink 102 by three bus bars 111.

  The ground surface 120 is fixed in contact with the grounded surface of the heat sink 102 via the insulating sheet 103. The ground contact surface 120 is an inspection surface 120 that is formed by a plurality of members (bus bars 111) and whose flatness is detected by the inspection device 1.

  As shown in FIG. 3, the ground contact surface (inspection surface) 120 is formed discontinuously by the adjacent one surface 111 a of the three bus bars 111. Note that the inspection surface 120 of the VCM 101 is inspected in one part of the manufacturing process of the electronic component 100 that is an inspection object.

  The fixing unit 11 fixes the VCM 101 with the inspection surface 120 facing the measuring unit 13.

  The moving means 12 is formed so that at least one of the fixing means 11 and the measuring means 13 is movable in two orthogonal directions along substantially the same direction as the surface direction of the inspection surface 120. Specifically, the moving unit 12 includes a first moving unit 21 that reciprocates the measuring unit 13 in one direction, for example, the X-axis direction in FIG. 1, and a direction in which the measuring unit 13 moves by the first moving unit 21. And a second moving means 22 for reciprocating the measuring means 13 in a direction orthogonal to the (X-axis direction), for example, the Y-axis direction in FIG. Here, the X-axis direction and the Y-axis direction are horizontal directions, for example, and are arranged along the surface direction of the inspection surface 120 of the VCM 101 fixed to the fixing means 11. The Z-axis direction is the height direction (vertical direction), and is arranged along a direction orthogonal to the surface direction of the VCM 101 fixed to the fixing means 11.

  The measuring unit 13 is disposed to face the inspection surface 120 of the VCM 101 fixed to the fixing unit 11. As the measuring means 13, for example, a laser displacement meter is used. The measuring means 13 is formed so as to be able to detect the positions of a plurality of measurement points of the VCM 101 fixed to the fixing means 11.

  Specifically, the measuring unit 13 is positioned in the surface direction (X axis direction and Y axis direction) of the inspection surface 120 at each measurement point of the inspection surface 120 of the VCM 101 fixed to the fixing unit 11, and in the surface direction. The distance in the direction perpendicular to the height (Z-axis direction) can be detected.

  The control unit 14 includes a storage unit 31, an output unit 32, and a control unit 33. The storage unit 31 measures the height in the Z-axis direction measured at each measurement point on the inspection surface 120 by the measuring unit 13 and the surface direction (X-axis direction and Y-axis direction) of the inspection surface 120 at the measurement point. The position can be stored.

  The storage unit 31 stores a threshold value D for evaluating the inspection surface 120. The threshold value D is a value at which the inspection surface (grounding surface) 120 formed by the plurality of bus bars 111 of the VCM 101 as a product has a predetermined flatness. The output unit 32 is configured to be able to output information on the inspection surface 120 to the outside. For example, the output unit 32 is a display unit such as a display that can display information, or a printing unit that can print information on paper sheets.

  The control unit 33 is connected to the measuring unit 13, the first moving unit 21, and the second moving unit 22 via a signal line 98. The control unit 33 is connected to the storage unit 31 and the output unit 32 via the bus line 99 or the like.

  The control unit 33 is configured to be able to move the measuring unit 13 to an arbitrary measurement point for measuring the inspection surface 120 by controlling the first moving unit 21 and the second moving unit 22. The control unit 33 controls the measurement unit 13 so that the height of the inspection surface 120 fixed to the fixing unit 11 at the measurement point can be measured when the measurement unit 13 moves to an arbitrary measurement point. Has been.

The control unit 33 has the following functions (1) to (4).
(1) A function of measuring the heights of the measurement points of all the bus bars 111 forming the inspection surface 120 and storing them in the storage unit 31.

  (2) A function for deriving the reference plane 90 from three measured points at three measured points.

  (3) A function for deriving a reference plane 90 to be evaluated.

  (4) A function of determining the flatness of the reference surface 90.

Next, these functions (1) to (4) will be described.
Function (1) controls the measuring means 13, the first moving means 21, and the second moving means 22, measures the heights of all measurement points of the three bus bars 111 forming the reference plane 90, and measures each of the measured values. This is a function for storing the height at the measurement point and the position of the measurement point in the storage unit 31. The measurement point to be measured is the position of the inspection surface 120 that may come into contact with the grounded surface of the heat sink 102.

  In the present embodiment, the measurement points are the corners of the bus bar 111, and the plane has a square shape, so that one bus bar 111 has four measurement points. In addition, since the VCM 101 is configured by the three bus bars 111, the measurement points are 12 locations that are all corners of the three bus bars 111.

  Function (2) derives a triangular reference plane 90 indicated by a two-dot chain line in FIG. 3 from any three measurement points among all measurement points measured in function (1). Function (2) performs all combinations of three measurement points of all measured measurement points. For example, in the present embodiment where four corners of three bus bars 111 are measured, all 220 combinations of three measurement points are obtained.

In addition, the reference plane 90 is calculated | required by the following numerical formula (1) which is the general formula which calculates | requires the positional information on three places, and a plane.

  Function (3) is a function for deriving a reference plane 90 to be evaluated from all the reference planes 90 derived in function (2). Specifically, the reference surface 90 to be evaluated is a reference surface 90 that may form the ground contact surface 120 among a plurality of reference surfaces 90 formed from three measured measurement points, A reference surface 90 that can be grounded to the grounded surface of the heat sink 102 when the VCM 101 is brought into contact with the heat sink 102 is shown. In the present embodiment, the reference surface 90 to be evaluated is a reference surface 90 that satisfies the following conditions (1) and (2).

  Condition (1) is that the center of gravity of the VCM 101, that is, the center of gravity of the ground contact surface (inspection surface) 120 formed by the three bus bars 111 is located within the range of the triangular reference surface 90 derived in the function (2). That is. When the VCM 101 is grounded to the heat sink 102, the normal line of the ground plane 120 passing through the center of gravity of the VCM 101 passes through a triangular virtual plane formed by any three points of the four ground points of the ground plane 120. For this reason, it is determined that the reference plane 90 that satisfies the condition (1) may form the ground plane 120. Further, it is determined that the reference surface 90 that does not satisfy the condition (1) does not form the ground contact surface 120.

  Condition (2) is that the height of the other measurement points excluding the three measurement points forming the reference surface 90 is higher than that of the reference surface 90. That is, when the grounding surface 120 of the VCM 101 is grounded to the heat sink 102, the grounding point of the grounding surface 120 is at a position lower than the other parts of the grounding surface 120. For this reason, the reference surface 90 that may form the ground contact surface 120 is at a position where the other measurement points are higher in the height direction than the reference surface 90.

The height (hereinafter referred to as “evaluation height”) H from the reference plane 90 to be evaluated under the condition (2) is a general expression for deriving the distance between the point and the plane. Is required.

  The evaluation height H of the measurement point obtained from Expression (2) is higher than the plane (H> 0), and it is determined that the reference plane 90 that satisfies the condition (2) may form the ground plane 120. . Further, it is determined that the reference plane 90 that does not satisfy the condition (2) does not form the ground plane 120.

  As described above, the function (3) satisfies the condition (1) and the condition (2) from the plurality of reference surfaces 90 obtained in the function (2) and may form the ground surface 120. This is a function for determining 90.

  Function (4) is a function for determining the flatness of the reference surface 90. Specifically, the function (4) is a threshold value indicating whether the flatness is within a predetermined flatness among all the reference surfaces 90 that may form the ground contact surface 120 derived in the function (3). This is a function for judging that the ground contact surface 120 has a predetermined flatness when judged from D and within the range of the threshold value D.

  In the function (4), the evaluation height H derived in the function (3) is a target for determining the flatness from the threshold value D. In the function (4), when the evaluation height H of the measurement point of the reference plane 90 that may form the ground contact surface 120 derived in the function (3) is within the range of the threshold D (D> H), The ground plane 120 is determined to be a ground plane having a predetermined flatness.

Next, the manufacturing method of the electronic component 100 using such an inspection apparatus 1 will be described with reference to the flowchart shown in FIG.
The electronic component 100 is a semiconductor module including the VCM 101, the heat sink 102, and the insulating sheet 103 described above. The method of manufacturing the electronic component 100 described below is one of the electronic components 100, and the flatness of the ground plane 120 of the VCM 101 is predetermined when the VCM 101 is connected to the heat sink 102 via the insulating sheet 103. It is a flatness inspection process for determining pass or fail of whether or not the heat dissipation function is flat.

  The flatness inspection process, which is one of the methods for manufacturing the electronic component 100, is a secondary side of the process of manufacturing the VCM 101 using three rectangular parallelepiped bus bars 111 and a plurality of semiconductor devices 112 mounted between the bus bars 111. The VCM 101 and the heat radiating plate 102 are performed on the primary side of the step of fixing the insulating sheet 103 with the insulating sheet 103 interposed therebetween.

  First, the manufactured VCM 101 is fixed to the fixing means 11. Next, the control unit 33 derives a measurement point on the inspection surface 120 (step ST11). Note that the measurement points are twelve corners of all corners of the three bus bars 111 of the VCM 101.

  Next, the control unit 33 controls the measuring unit 13, the first moving unit 21, and the second moving unit to measure the heights of all measurement points derived from the inspection surface 120 (step ST12). The height of the measurement point is stored in the storage unit 31.

  Next, the control unit 33 derives a triangular reference plane 90 from the position information measured at any three of the 12 measurement points using Equation (1) (step ST13). Next, the control unit 33 determines whether or not the center of gravity of the VCM 101 is located within the derived reference plane 90 (step ST14). When the center of gravity of the VCM 101 is located in the reference plane 90 (YES in step ST14), the control unit 33 next evaluates the reference plane 90 and each measurement point, assuming that the condition (1) is satisfied. Height H is derived from equation (2) (step ST15).

  Next, the control unit 33 determines whether or not all the derived evaluation heights H are higher than the reference plane 90 (step ST16). When the evaluation height H is higher than the reference surface 90 (H> 0) (step ST16), the control unit 33 satisfies the conditions (1) and (2) and the contact surface 90 satisfies the conditions (1) and (2). It is determined that the reference surface 90 is likely to form the ground 120, and is stored in the storage unit 31 (step ST17).

  In step ST14, when the center of gravity of the VCM 101 is not located in the reference plane 90 (NO in step ST14), the control unit 33 does not satisfy the condition (1), and the reference plane 90 forms the ground plane 120. Therefore, the reference plane 90 is excluded (step ST18). In step ST16, when the evaluation height H is the same position as or lower than the reference plane 90 (H ≦ 0) (NO in step ST16), the control unit 33 does not satisfy the condition (2), It is determined that the reference surface 90 does not form the ground contact surface 120, and the reference surface 90 is excluded (step ST18).

  Next, the control unit 33 evaluates the reference surface 90 that satisfies the conditions (1) and (2), that is, the inspection surface 120, from all the reference surfaces 90 of all combinations of the three measurement points. It is determined whether 90 is derived (step ST19). When the reference plane 90 to be evaluated has not been derived from all the reference planes 90 (NO in step ST19), the process returns to step ST13, the reference plane 90 is derived from the measurement point, and the subsequent steps after step ST14 are performed.

  When the reference plane 90 to be evaluated is derived from all the reference planes 90 (YES in step ST19), the control unit 33 evaluates all the measurement points of the reference plane 90 to be evaluated stored in the storage unit 31. It is determined whether H is within the range of the threshold value D stored in the storage unit 31 (step ST20).

  When the evaluation heights H of all the measurement points are within the range of the threshold value D (D> H) (YES in step ST20), the control unit 33 determines whether the inspection surface 120 can form the electronic component 100. It judges that it has flatness and performs a pass judgment (step ST21). That is, the control unit 33 determines that the inspection surface 120 is formed to have a flatness that can fix the VCM 101 and the heat sink 102, that is, a flatness that can obtain a predetermined heat dissipation function by the VCM 101 and the heat sink 102. To do.

  When at least one of the evaluation heights H is equal to or greater than the threshold value D (D ≦ H) (NO in step ST20), the control unit 33 has a predetermined flatness that allows the inspection surface 120 to form the electronic component 100. It judges that it has not carried out, and a failure determination is performed (step ST22). That is, in the control unit 33, the inspection surface 120 is formed to have a flatness that can fix the VCM 101 and the heat sink 102, more specifically, a flatness that the VCM 101 and the heat sink 102 cannot obtain a predetermined heat dissipation function. Judge.

  Next, the control unit 33 outputs the information of the VCM 101 that has made these determinations from the output unit 32 to the outside. Based on the output of the output unit 32, the VCM 101 having the ground plane 120 with a predetermined flatness is transported to the next process, the subsequent processes are performed, and the electronic component 100 is manufactured. Further, the VCM 101 that has been determined to be rejected is repaired and the flatness is inspected again.

  According to the inspection apparatus 1, the flatness inspection method, and the electronic component 100 manufacturing method configured as described above, the flatness of the ground plane 120 formed by the bus bar 111 that is a plurality of members can be inspected. It becomes possible. In particular, the measurement points are corners that can serve as contact points of the plurality of bus bars 111. Since the reference plane 90 is obtained from these measurement points and the flatness is derived, the number of measurement points to be measured is small. That is, it is not necessary to scan the entire inspection surface 120 and measure the flatness in order to inspect the flatness. For this reason, it becomes possible to shorten the detection time of flatness, and it becomes possible to detect the flatness and shorten the tact time of manufacturing the electronic component 100.

  As described above, according to the inspection apparatus 1 according to the present embodiment, the inspection method for inspecting the flatness of the inspection surface (grounding surface) 120 formed by a plurality of members (bus bars 111), and the method for manufacturing the electronic component 100 For example, the inspection time for the flatness of the inspection surface 120 can be shortened, and the tact time can be reduced.

  In addition, the inspection apparatus 1 of this embodiment is not limited to the structure mentioned above. For example, the electronic component 100 of the above-described embodiment has been described using a semiconductor module that fixes the VCM 101 provided with the three bus bars 111 to the heat sink 102, but is not limited thereto.

  For example, the electronic component 100 may have a configuration in which the VCM 101 is configured by combining two or four or more bus bars 111. The electronic component 100 may be an electronic component other than the semiconductor module. Further, the inspection surface 120 for inspecting the flatness by the inspection apparatus 1 described above may be other than the electronic component 100.

  In the above-described example, as a method for manufacturing the electronic component 100, the configuration in which the inspection surface 120 determines whether or not the flatness having a predetermined heat dissipation function when the VCM 101 is fixed to the heat sink 102 has been described. However, it is not limited to this. That is, the inspection apparatus 1, the inspection method, and the manufacturing method of the electronic component 100 are configured to inspect the flatness of a plane made of a member other than the bus bar 111 if the flatness of the plane made of a plurality of members can be inspected. May be.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Inspection apparatus, 11 ... Fixing means, 12 ... Measuring means, 13 ... Moving means, 14 ... Control means, 21 ... Moving means, 22 ... Moving means, 31 ... Memory | storage part, 32 ... Output part, 33 ... Control part, 98 ... signal line, 99 ... bus line, 100 ... electronic component, 101 ... VCM, 102 ... heat sink, 103 ... insulating sheet, 111 ... bus bar, 112 ... semiconductor device, 120 ... inspection surface (grounding surface).

Claims (10)

Measuring means capable of detecting the positions of a plurality of measurement points on a planar inspection surface formed by a plurality of members;
A reference plane formed by any three of the plurality of measurement points is derived from the positions of the plurality of measurement points measured by the measuring unit, and an evaluation height from the reference plane to the plurality of measurement points is derived. Then, the derived evaluation height is compared with a threshold value at which the inspection surface has a predetermined flatness, and when the evaluation height is within the threshold value, the flatness of the detection surface is determined as the predetermined flatness. A control unit,
An inspection apparatus comprising:   The inspection apparatus according to claim 1, wherein the plurality of measurement points are corner portions of the member.   The inspection apparatus according to claim 1, wherein the reference plane for deriving the evaluation height has a center of gravity of the plurality of members located therein.   The reference plane for deriving the evaluation height is characterized in that the measurement points excluding three of the plurality of measurement points forming the reference plane are positioned higher than the plane direction. The inspection device described. Detecting the position of a plurality of measurement points on a planar inspection surface composed of a plurality of members by a measuring means;
Deriving a reference plane formed by any three of the plurality of measurement points from the positions of the plurality of measurement points measured by the measurement means;
Deriving evaluation heights from the reference plane to the plurality of measurement points;
The derived evaluation height is compared with a threshold value that forms a predetermined flatness of the detection surface, and when the evaluation height is within the threshold value, the flatness of the inspection surface is determined as the predetermined flatness. An inspection method characterized by comprising:   6. The inspection method according to claim 5, wherein the reference plane for deriving the evaluation height has the centers of gravity of the plurality of members positioned therein.   The reference plane for deriving the evaluation height is characterized in that the measurement points excluding three of the plurality of measurement points forming the reference plane are located higher than the plane direction. The inspection method described. Forming an electronic component having a planar inspection surface by combining a plurality of members;
Detecting the position of a plurality of measurement points on the inspection surface by a measuring means;
Deriving a reference plane formed by any three of the plurality of measurement points from the positions of the plurality of measurement points measured by the measurement means;
Deriving evaluation heights from the reference plane to the plurality of measurement points;
Comparing the derived evaluation height with a threshold value forming a predetermined flatness of the detection surface;
And when the evaluation height is within the threshold value, the flatness of the inspection surface is determined to be a predetermined flatness.   The method for manufacturing an electronic component according to claim 8, wherein the reference plane for deriving the evaluation height has a center of gravity of the plurality of members positioned therein.   The reference plane for deriving the evaluation height is characterized in that the measurement points excluding three of the plurality of measurement points forming the reference plane are located higher than the plane direction. The manufacturing method of the electronic component of description.

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