Inspection equipment

Abstract

To provide an inspection device that can improve the inspection accuracy of electrical components. [Solution] The inspection device has a plurality of contact pieces having contacts at their tips arranged in the width direction of the contact pieces, and the electrical circuit that is electrically connected to one terminal of the electrical component to be inspected is formed by dividing it in the width direction by the plurality of contact pieces.

Description

Technical Field

[0001] The present invention relates to an inspection apparatus for electrical components such as semiconductor modules, and particularly to a technique suitable for inspecting power semiconductor modules.

Background Art

[0002] Conventionally, an inspection apparatus called an IC socket has been used for inspecting electrical components such as semiconductor modules. The IC socket has a contact portion that contacts the module terminals of the electrical component to be inspected and electrically connects, for example, the electrical component and the inspection circuit board.

[0003] In particular, for an inspection apparatus for power semiconductor modules, it is required that the contact portion can handle a large current. Specifically, the contact portion preferably has a large cross-sectional area to suppress heat generation during energization and has contact points that can obtain stable contact performance with the module terminals.

[0004] For example, Patent Document 1 discloses a contact probe for power semiconductor measurement. Also, for example, contact components with contacts arranged side by side are known. This contact is suitable for inspection applications of power semiconductor modules in that it can secure an electric circuit cross-sectional area and obtain stable contact performance through multi-point contact.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] During the testing of power semiconductor modules, large currents flow through the contact area, which easily generates significant noise in the output signal. In recent years, in order to improve the reliability of power semiconductor modules, the acceptable level of noise in the output signal has tended to decrease compared to the past.

[0007] The objective of the present invention is to provide an inspection device that can improve the inspection accuracy of electrical components. [Means for solving the problem]

[0008] The inspection apparatus according to the present invention is Multiple contact pieces, each having a contact point at its tip, are arranged in a line in the width direction of the contact piece. The electrical circuit that is electrically connected to one terminal of the electrical component to be inspected is formed by dividing it in the width direction by a plurality of contact pieces. [Effects of the Invention]

[0009] According to the present invention, noise generated in the output signal can be significantly reduced, and the inspection accuracy of electrical components can be improved. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view showing an inspection apparatus according to the first embodiment of the present invention. [Figure 2] Figures 2A and 2B show examples of contact components. [Figure 3] Figure 3 shows the shape of the contact area of ​​the contact piece. [Figure 4] Figures 4A and 4B show the electrical circuit density at the tip of the contact area and the electrical circuit density at the spring section. [Figure 5] Figure 5 shows an example of a contact portion according to the second embodiment. [Figure 6] Figure 6 shows another example of the contact portion according to the second embodiment. [Figure 7] Figure 7 shows another example of the contact portion according to the second embodiment. [Figure 8] Figure 8 shows another example of the contact portion according to the second embodiment. [Figure 9] Figure 9 shows another example of the contact portion according to the second embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, elements common to all are denoted by the same reference numerals, and redundant descriptions of them will be omitted.

[0012] Figure 1 is a perspective view showing an inspection device 1 according to a first embodiment of the present invention. Figure 1 mainly shows the configuration related to the contact portion 10 of the inspection device 1.

[0013] The inspection device 1 is a so-called IC socket for testing the electrical characteristics of the electrical component 100. The electrical component 100 is, for example, a power semiconductor module that controls and converts power and can handle high voltage (e.g., 500V) and high current (e.g., 1000A). The electrical component 100 includes module terminals 101 to 103 for power input and output and a module body 107. The electrical component 100 may also include terminals (not shown) for signal input and output.

[0014] In the following, the direction of pressure applied when the electrical component 100 is mounted to the inspection device 1 will be described as "first direction D1", the direction of alignment of the module terminals 101 as "second direction D2", and the direction perpendicular to the first direction D1 and the second direction D2 as "third direction D3".

[0015] As shown in Figure 1, the inspection device 1 comprises a contact portion 10 and a base portion 20. The inspection device 1 may also be equipped with a module holding portion (not shown) on the base portion 20, which includes a pressing mechanism and a locking mechanism, etc., for holding the electrical components 100 in a stable position.

[0016] The contact part 10 electrically connects the electrical component 100 and the test circuit board. In the test apparatus 1, two contact parts 11 and 12 are arranged along the second direction D2 at one end in the third direction D3, and two contact parts 13 are arranged at the other end. The contact parts 11 to 13 correspond to the module terminals 101 to 103 of the electrical component 100 to be tested.

[0017] The contact parts 11 to 13 each have a contact component 30 and a contact fixing part 40. The contact component 30 is detachably fixed to the contact fixing part 40, for example. The contact component 30 is fixed so that its longitudinal direction coincides with the third direction D3 and its width direction coincides with the second direction D2, for example. The contact component 30 is formed of a conductive material such as a copper alloy. The contact component 30 forms an electric circuit through which current flows during the inspection of the electrical component 100.

[0018] Each contact component 30 contacts the module terminals 101 to 103 of the electrical component 100. The contact component 30 is electrically connected to the test circuit board (not shown) through a lead wire (not shown) connected to the contact fixing part 40, for example.

[0019] In the inspection of the electrical component 100, the module terminals 101 to 103 of the electrical component 100 and the contact components 30 of the contact parts 11 to 13 elastically contact each other with a predetermined contact load applied.

[0020] FIG. 2A and FIG. 2B are diagrams showing an example of the contact component 30. FIG. 2A is a perspective view of the contact component 30, and FIG. 2B is a front view of the contact component 30.

[0021] As shown in Figures 2A and 2B, the contact component 30 is a contact having a contact base 31 and contact pieces 32 to 34. The contact component 30 is formed, for example, by wire cutting a conductive plate-shaped base material. In this case, the thickness of the base material becomes the width of the contact component 30. In this embodiment, the contact component 30 is provided with three contact pieces 32 to 34, but the number of contact pieces may be two or four or more.

[0022] The contact base 31 is the part that is attached to the contact fixing part 40. The contact base 31 has an inverted T shape in a front view so as to ensure the spring length of the contact pieces 32 to 34 while suppressing the longitudinal length of the contact component 30. However, the shape of the contact base 31 is not limited to this, and may be a simple rectangular parallelepiped, for example.

[0023] The contact pieces 32-34 are formed to branch from the contact base 31 in the height direction and extend in the longitudinal direction. The contact pieces 32-34 have a plate shape with a constant plate thickness t. The contact pieces 32-34 have a cantilever beam structure in which one end (the end of the spring portion 51) is connected to the contact base 31.

[0024] In the following, when distinguishing between contact pieces 32 to 34, they will be referred to as "proximal contact piece 32," "intermediate contact piece 33," and "distal contact piece 34." The proximal contact piece 32 is the contact piece whose contact with module terminals 101 to 106 is closest to the contact base 31. The distal contact piece 34 is the contact piece whose contact is furthest distal to the contact base 31. The intermediate contact piece 33 is the contact piece sandwiched between the proximal contact piece 32 and the distal contact piece 34.

[0025] Each of the contact pieces 32 to 34 has a spring portion 51 and a contact portion 52. The tip surface 52a of the contact portion 52 makes contact with the module terminals 101 to 103 of the electrical component 100 (hereinafter referred to as the "contact surface 52a"). The contact pieces 32 to 34 are arranged such that their respective spring portions 51 and contact portions 52 are aligned in the thickness direction, that is, the contact surface 52a exhibits a comb-like shape.

[0026] The spring portion 51 extends longitudinally from the contact base 31 and exerts a biasing force when the electrical component 100 is installed. The direction of extension of the spring portion 51 (the longitudinal direction of the contact component 30) intersects with the pressing direction when the electrical component 100 is installed. The spring portion 51 does not have to have a straight shape along the longitudinal direction; for example, it may have an inclined portion 54. The length and shape of the spring portion 51 are set appropriately to satisfy the required spring characteristics (contact load) of the spring portion 51. In addition, the spacing between the spring portions 51 in the contact pieces 32-34 is set to allow for the deflection that occurs in the spring portion 51 when the contact pieces 32-34 are pressed in when the electrical component 100 is installed.

[0027] The contact portion 52 is a part that bends upward from the spring portion 51 in an L-shape and extends generally along the height direction. The contact portion 52 does not exert a biasing force when the electrical component 100 is installed, or its biasing force is negligible compared to that of the spring portion 51, so functionally it can be called a "non-spring portion".

[0028] The contact component 30 is suitable for inspection equipment 1 for power semiconductor modules that handle high voltage and high current because it can secure the cross-sectional area of ​​the circuit with three contact pieces 32 to 34 and can make multi-point contact with each of the module terminals 101 to 103.

[0029] The number of contact pieces 32-34, the contact area (width, thickness) per piece, and the gap (pitch) between contact pieces 32-34 are designed taking into account the cumulative tolerance of misalignment relative to the module terminals 101-106.

[0030] Figure 3 shows the shape of the contact portion 52 of the contact pieces 32 to 34.

[0031] In conventional contacts, multiple contact pieces have a constant thickness and are arranged parallel to each other at equal intervals, which can make it difficult to accommodate a narrow contactable area while ensuring sufficient cross-sectional area of ​​the electrical circuit. In contrast, in the contact component 30 of this embodiment, as shown in Figure 3, the contact pieces 32 to 34 have a constant thickness, but are not arranged parallel to each other at equal intervals.

[0032] Specifically, the contact portions 52 of the proximal contact piece 32 and the intermediate contact piece 33 have inclined portions 53 that are bent in a crank shape to approach the distal contact piece 34. The inclination angle of the inclined portion 53 of the proximal contact piece 32 (angle relative to the extending direction of the distal contact 34) is greater than the inclination angle of the inclined portion 53 of the intermediate contact piece 33. On the other hand, the contact portion 52 of the distal contact 34 is formed in a straight shape.

[0033] In other words, in this embodiment, as shown in Figure 3, the distance L1 between the tip ends of the contact portions 52 in adjacent contact pieces 32 to 34 is different from the distance L3 between the spring portions 51.

[0034] Furthermore, the above embodiments are merely examples, and the present invention is not limited thereto. For example, the distal contact piece 34 may have an inclined portion, and its inclination angle (angle with respect to the extending direction of the proximal contact 32) may be greater than the inclination angle of the inclined portion of the intermediate contact piece 33, while the contact portion of the proximal contact 32 may be formed in a straight shape. Moreover, the intermediate contact piece 33 may be formed in a straight shape, and the proximal contact piece 32 and distal contact piece 34 may be formed in a crank-like bend so as to approach the intermediate contact piece 33.

[0035] The electrical circuit density at the tip of the contact portion 52 is different from that of the spring portion 51. The electrical circuit density at the tip of the contact portion 52 represents the ratio of the effective electrical circuit area (sum of the cross-sectional areas of the contact pieces 32 to 34) to the area S1 of the contact region at the tip of the contact portion 52 (see Figure 4A). The area S1 of the contact region is the area of ​​the outer edge shape including the three contact surfaces 52a of the contact pieces 32 to 34. The electrical circuit density in the spring portion 51 represents the ratio of the effective electrical circuit area (sum of the cross-sectional areas of the contact pieces 32 to 34) to the area S2 of the spring portion 51 (see Figure 4B). The area of ​​the spring portion 51 is the area of ​​the outer edge shape including the three spring portions 51 of the contact pieces 32 to 34.

[0036] Specifically, the spacing L1 at the tip of the contact portion 52 is narrower than the spacing L3 of the spring portion 51. The spacing L1 at the tip of the contact portion 52 is typically the spacing of the contact surfaces 52a. It can also be said that the electrical circuit density at the tip of the contact portion 52 is greater than the electrical circuit density of the spring portion 51.

[0037] In this case, the area S1 of the contact region at the tip of the contact portion 52 is smaller than the area S2 of the spring portion 51. That is, the contact component 30 has the same effective circuit area as a conventional contact, but the contact region area S1 is smaller because the gap is smaller. Therefore, the contact component 30 can accommodate a narrow contactable area while ensuring the circuit cross-sectional area.

[0038] Here, the gap at the tip of the contact portion 52 is formed using a thin wire having a first wire diameter. On the other hand, the gap in the spring portion 51 is formed using a large-diameter wire having a second wire diameter that is larger than the first wire diameter. Generally, wire cutting using thin wires takes longer than wire cutting using large-diameter wires.

[0039] Therefore, in this embodiment, the gap L1 at the tip of the contact portion 52 is narrower than the gap L2 at the base of the contact portion 52. The gap L2 at the base of the contact portion 52 is the gap near the bent portion connected to the spring portion 51, and is typically the same as the gap L3 of the spring portion 51. It can also be said that the electrical circuit density at the tip of the contact portion 52 is smaller than the electrical circuit density at the base of the contact portion 52. The gap at the base of the contact portion 52 is formed using a large-diameter wire, similar to the gap in the spring portion 51. Therefore, compared to the case where the gap of the contact portion 52 is formed using a small-diameter wire along its entire length, the processing time can be reduced.

[0040] Furthermore, on the contact surface 52a of the contact pieces 32-34, the proximal edge 52b closest to the contact base 31 is rounded. When the electrical components 100 are installed in the inspection device 1 and the contact pieces 32-34 are pressed in, the spring portion 51 bends downward with the connection point with the contact base 31 as the fixed end. As a result, the contact surface 52a of the contact pieces 32-34 rotates while rubbing (also called wiping) against the module terminals 101-103. The contact between the contact surface 52 and the module terminals 101-103 transitions from surface contact to point contact at the edge 52b.

[0041] Edge 52b rubs against module terminals 101-103, and as this rubbing progresses, there is a risk that contact performance will deteriorate over time. By applying a rounded edge (R) to edge 52b, deterioration due to rubbing with module terminals 101-103 can be prevented, and stable contact performance can be ensured.

[0042] As described above, the contact component 30 according to the embodiment is equipped with the following features individually or in appropriate combinations.

[0043] In other words, the contact component 30 is a contact component having a plurality of contact pieces 32 to 34 branching from a contact base 31, and each contact piece 32 to 34 includes a spring portion 51 connected to the contact base 31 and a contact portion 52 having a contact surface 52a (contact) at its tip. The spacing L1 at the tip side of the contact portions 52 in adjacent contact pieces 32 to 34 is different from the spacing L3 of the spring portions 51. It can also be said that the electrical circuit density at the tip side of the contact portions 52 is different from the electrical circuit density of the spring portions 51.

[0044] The contact component 30 improves the design flexibility to reduce the contact area that contacts the module terminals 101-103 while ensuring sufficient contact load and circuit cross-sectional area.

[0045] Specifically, in the contact component 30, the spacing L1 at the tip of the contact portion 52 is narrower than the spacing L3 of the spring portion 51. It can also be said that the electrical circuit density at the tip of the contact portion 52 is greater than that of the spring portion 51. This makes it easy to accommodate a narrow contactable area.

[0046] In the contact component 30, the spacing L1 at the tip of the contact portion 52 is narrower than the spacing L2 at the base of the contact portion 52. It can also be said that the electrical circuit density at the tip of the contact portion 52 is greater than the electrical circuit density at the base of the contact portion 52. The processing area by wire cutting using a thin wire can be reduced, shortening processing time and improving productivity.

[0047] In the contact component 30, the contact portion 52 has an inclined portion 53 formed by a crank-like bend, and the spacing L4 between the inclined portions 53 of adjacent contact pieces 32-34 gradually narrows from the base side to the tip side. It can also be said that the electrical circuit density in the inclined portion 53 gradually increases from the base side to the tip side. Since the gap at the tip side and the gap at the base side of the contact portion 52 are smoothly connected without the formation of a step, it results in an electrically advantageous structure.

[0048] In the contact component 30, the inclination angles of the inclined portions 53 of adjacent contact pieces 32 to 34 are different from each other. By appropriately setting the inclination angle, the distance L1 at the tip of the contact portion 52 can be easily adjusted.

[0049] In the contact component 30, the contact surfaces 52a (contacts) of the multiple contact pieces 32 to 34 elastically contact one of the module terminals 101 to 106 of the electrical component 100 being inspected. Since multiple contact surfaces 52a elastically make multi-point contact with one of the module terminals 101 to 103, stable contact performance can be obtained.

[0050] In the contact component 30, the spring portion 51 and the contact portion 52 each have a plate shape, and the multiple contact pieces 32 to 34 are arranged such that their respective spring portions 51 and contact portions 52 are aligned in the plate thickness direction. The shape of the contact area easily conforms to the shape of the module terminals 101 to 103, and efficient contact can be made with the contactable area of ​​the module terminals 101 to 103.

[0051] In the contact component 30, the gap at the tip of the contact portion 52 between adjacent contact pieces 32-34 and the gap in the spring portion 51 are formed using wires of different diameters. This makes it easy to create gaps with different spacings.

[0052] [Second Embodiment] In the inspection device 1 of the first embodiment, each contact section 10 (11-13) has one contact component 30. That is, for one of the module terminals 101-103, the contact pieces 32-34 are arranged in a single row in the width direction.

[0053] In contrast, in the second embodiment, as shown in Figure 5, the contact section 10 has four contact components 30. The four contact components 30 are arranged side by side within the width range of one of the module terminals 101 to 103. That is, for one of the module terminals 101 to 103, the contact pieces 32 to 34 are arranged in four rows in the width direction, and all the contact pieces 32 to 34 are electrically connected in parallel. In other words, the circuit electrically connected to one of the module terminals 101 to 103 is formed by dividing it in the width direction by the four contact components 30.

[0054] By electrically connecting multiple contact pieces 32-34 in parallel to one of the module terminals 101-103, the overall inductance of the contact section 10 is reduced, significantly reducing noise generated in the output signal. Therefore, the inspection accuracy of the electrical component 100 can be improved.

[0055] The configuration of the contact component 30 is, for example, the same as the contact component 30 shown in the first embodiment. In the second embodiment, a conventional comb-tooth contact may be used as the contact component 30.

[0056] In the contact portion 10 of the second embodiment, the contact pieces 32 to 34 are arranged in four rows in the width direction and three rows in the thickness direction of the contact pieces. In other words, the contact points of the contact portion 10 can make contact at 4 x 3 points. If the contact pieces are arranged in N rows in the width direction and M rows in the thickness direction, then N x M points of contact will be achieved.

[0057] Furthermore, it is sufficient that the contact pieces 32-34 of the four contact components 30 are arranged in a line in the width direction, and all the contact pieces 32-34 may be formed by branching from a single contact base 31.

[0058] In the contact section 10, the widths of each contact component 30 may be different (see Figure 6). In this case, the inductance reduction effect is enhanced, and the generation of noise in the output signal can be suppressed more effectively.

[0059] Furthermore, a metal shielding plate 60 may be placed between adjacent contact components 30 in the contact section 10. Preferably, the shielding plate 60 is grounded. In this case, the influence of mutual inductance between adjacent contact components 30 can be reduced, and the generation of noise in the output signal can be suppressed more effectively.

[0060] Furthermore, as shown in Figures 8 and 9, the multiple contact components 30 arranged in the width direction may be arranged with alternating offsets in the longitudinal direction or in the height direction. In this case as well, the influence of mutual inductance between adjacent contact components 30 can be reduced, and the generation of noise in the output signal can be suppressed more effectively.

[0061] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0062] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0063] 1. Inspection device 10 Contact section 20 Base section 30 Contact parts 31 Contact base 32-34 Contact pieces 40 Contact fixing part 51 Spring section 52 Contact area 53 Slope 100 Electrical Components

Claims

1. Multiple contact pieces, each having a contact point at its tip, are arranged in a line in the width direction of the contact piece. The electrical circuit electrically connected to one terminal of the electrical component to be inspected is formed by dividing it in the width direction by a plurality of contact pieces. Inspection device.

2. Multiple contact pieces are arranged side by side within the width of one terminal of the electrical component. The inspection apparatus according to claim 1.

3. The aforementioned contact piece is a plate-shaped member, Multiple contact pieces are arranged in N rows in the width direction of the plate-like member and in M ​​rows in the thickness direction of the plate-like member. Multiple contacts are capable of making contact with one terminal of the electrical component at multiple points in an N × M range. The inspection apparatus according to claim 1.

4. The plurality of contact pieces arranged in the width direction have different widths. The inspection apparatus according to claim 1.

5. A metal shielding plate is positioned between a plurality of contact pieces arranged in the width direction. The inspection apparatus according to claim 1.

6. The plurality of contact pieces arranged in the width direction are positioned alternately in the axial direction. The inspection apparatus according to claim 1.

7. The plurality of contact pieces arranged in the width direction are positioned alternately in the height direction. The inspection apparatus according to claim 1.

Images