Electrical connection device

Abstract

This enables proper electrical connection between the wafer pad and the printed circuit board. [Solution] The system comprises a printed circuit board 4, a probe head 1 that holds a plurality of probes 11 having a base end that electrically connects to the printed circuit board 4 and a tip that contacts a wafer (object under inspection) 21, and a fix base 6 that is located below the printed circuit board 4 and is partially fixed to the upper surface of the probe head 1, wherein the fix base 6 and the printed circuit board 4 are provided so as to be able to move relative to each other in response to thermal expansion. Specifically, the fix base 6 is made of a material and thickness such that its thermal expansion is equal to that of the wafer (object under inspection) 21.

Description

Technical Field

[0001] The present invention relates to an electrical connection device used for inspecting the electrical characteristics of an inspection object.

Background Art

[0002] An electrical connection device for electrically connecting an inspection object and an inspection device is used to measure the electrical characteristics of an inspection object such as an integrated circuit. The electrical connection device has a configuration in which a probe head holding probes is attached to a printed circuit board on which lands electrically connected to the probes are arranged.

[0003] By bringing each probe held by the probe head into contact with the wafer pad of the test object, the electrical characteristics of the test object can be measured. Also, a space transformer is installed between the probe head and the printed circuit board to convert the wiring pitch between each probe and the printed circuit board.

[0004] The space transformer is fixed by a fixing member connected to the printed circuit board, and further the probe head is fixed to the space transformer (see, for example, Patent Document 1). Therefore, the electrical characteristics of the test object are measured in a state where the printed circuit board, the space transformer, and the probe head are fixed to each other. In measuring the electrical characteristics of the test object, the measuring instrument may generate heat due to Joule heat or the like and reach a high temperature state. Also, there is a so-called burn-in measurement in which the temperature of the test object is deliberately raised.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In conventional space transformer support structures, the printed circuit board and probe head are fixed to the space transformer. However, because the probe head and space transformer have different thermal expansion rates, a problem arises where misalignment occurs between the probe and the contact terminals provided on the printed circuit board.

[0007] Furthermore, because wafer pads and printed circuit boards have different thermal expansion rates, there was a problem in aligning the probe with the wafer pad.

[0008] The present invention has been made to solve these conventional problems, and its objective is to provide an electrical connection device that can enable appropriate electrical connection between a wafer pad and a printed circuit board. [Means for solving the problem]

[0009] An electrical connection device according to one aspect of the present invention is: Printed circuit board and A probe head that holds multiple probes, each having a base end that electrically connects to the printed circuit board and a tip end that contacts the object to be inspected, The printed circuit board is provided with a fixed base located below it and partially fixed to the upper surface of the probe head, The fixed base and the printed circuit board are provided so as to be able to move relative to each other in response to thermal expansion. [Effects of the Invention]

[0010] According to the present invention, it is possible to enable appropriate electrical connections between wafer pads and printed circuit boards. [Brief explanation of the drawing]

[0011] [Figure 1]This is a cross-sectional view showing the configuration of an electrical connection device according to an embodiment of the present invention. Figure 1(a) shows the state of the electrical connection device in a steady state (low temperature state), and Figure 1(b) shows the state of the electrical connection device in a high temperature state. [Figure 2] This is a perspective view of an electrical connection device according to an embodiment of the present invention, viewed from below. [Figure 3] This figure illustrates a structure for an electrical connection device according to an embodiment of the present invention, in which a fixed base and a printed circuit board are provided so as to be able to move relative to each other in response to thermal expansion. Figure 3(a) is a plan view, and Figure 3(b) is a view showing cross-section AA in Figure 3(a). [Figure 4] This is an explanatory diagram illustrating the through-holes in a printed circuit board provided in an electrical connection device according to an embodiment of the present invention. (a) is a plan view of the printed circuit board, (b) is an enlarged view of the through-hole provided in region A1 in (a), and (c) is an enlarged view of the through-hole 41 provided in region A2 in (a). [Figure 5] This figure shows a modified example of a support member included in an electrical connection device according to an embodiment of the present invention. [Figure 6] This is an explanatory diagram illustrating the connection between a printed circuit board and an interposer in an electrical connection device according to an embodiment of the present invention. (a) is a side view at low temperature, (b) is a side view at high temperature, (c) is an enlarged plan view of the contact state at low temperature, and (d) is an enlarged plan view of the contact state at high temperature. [Figure 7] (a) is an enlarged plan view of the contact state between the printed circuit board and the interposer at low temperatures in the electrical connection device according to Modification 1 of the present invention, (b) is an enlarged plan view of the contact state at high temperatures, (c) is an enlarged plan view of the contact state between the printed circuit board and the interposer at low temperatures in the electrical connection device according to Modification 2 of the present invention, and (d) is an enlarged plan view of the contact state at high temperatures. [Modes for carrying out the invention]

[0012] Next, embodiments of the present invention will be described with reference to the drawings. In the following drawings, identical or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the dimensional ratios of each part may differ from those of reality. Furthermore, it goes without saying that there are parts in the drawings where the dimensional relationships and ratios differ from those of other parts. The embodiments shown below are illustrative examples of devices for realizing the technical idea of ​​the present invention, and the embodiments of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to those described below.

[0013] [Description of Embodiments] Figure 1 is a cross-sectional view showing the configuration of an electrical connection device 100 according to an embodiment of the present invention. Figure 1(a) shows the state of the electrical connection device 100 in a steady state (low temperature state), and Figure 1(b) shows the state of the electrical connection device 100 in a high temperature state. Figure 2 is a perspective view of the electrical connection device 100 according to an embodiment of the present invention, viewed from below.

[0014] As shown in Figures 1(a) and 1(b), the electrical connection device 100 comprises a probe head 1, a space transformer 2, an interposer 3, a printed circuit board 4, a reinforcing plate 5, and a fixed base 6. As shown in Figure 2, the printed circuit board 4, the reinforcing plate 5, and the fixed base 6 are formed in a disc shape. In the following description, the side with the reinforcing plate 5 in Figure 1 (upper side in the figure) is considered the upward direction, and the opposite side (lower side in the figure) is considered the downward direction. The direction of the plane perpendicular to the vertical direction is considered the planar direction. In Figure 1, the left side of the paper is the center side of each disc-shaped component in the planar direction, and the right side of the paper is the outside of the circle.

[0015] The probe head 1 holds a plurality of probes 11. The tip of each probe 11 is connected to each pad 21a of the wafer 21 serving as the inspection target. That is, in the electrical inspection of the wafer 21 in the electrical connection device 100, for example, with the wafer 21 held on a chuck table (not shown), the probe head 1 and the wafer 21 are aligned, and an electrical signal is passed through each probe 11, whereby the electrical connection state of the wafer 21 serving as the inspection target can be inspected. That is, the probe head 1 holds a plurality of probes having a base end portion electrically connected to the printed circuit board 4 and a tip portion contacting the inspection target (pad 21a).

[0016] The inside of the probe head 1 has a hollow structure. A plurality of through holes through which the probes 11 are inserted are formed in the upper surface member and the lower surface member. The base end portion of the probe 11 inserted into the through hole is connected to the wiring of the space transformer 2, and the base end portion of the inserted probe 11 is connected to each pad 21a of the wafer 21 serving as the inspection target.

[0017] The space transformer 2 is interposed between the printed circuit board 4 and the probe head 1 and converts the wiring pitch of the base end portions of the respective probes 11 held by the probe head 1. The lower surface of the space transformer 2 is in contact with the base end portion of the probe 11. The upper surface of the space transformer 2 faces the printed circuit board 4 with the interposer 3 interposed therebetween.

[0018] The interposer 3 is a substrate for providing electrical continuity between the upper and lower surfaces, and electrically connects the wiring 2a disposed in the space transformer 2 and the printed circuit board 4 by contactors 31. As the contactors 31, for example, elastic members such as pogo pins or conductive rubber can be used. Note that the contactors 31 are not limited to elastic members, and wirings or the like may be used.

[0019] The printed circuit board 4 is a base for inspecting the electrical connection state of the wafer 21 to be inspected. The printed circuit board 4 is provided with through holes 41 that penetrate vertically for the insertion of a suspension member 7, which will be described later.

[0020] The reinforcing plate 5 is made of, for example, stainless steel, and is provided so that its lower surface is in contact with the upper surface of the printed circuit board 4. This allows the printed circuit board 4 to be reinforced in terms of strength. The reinforcing plate 5 is provided with a through hole 51 that penetrates vertically at the same position as the through hole 41, for which the suspension member 7, which will be described later, is inserted.

[0021] The Fix Base 6 is fixed to the lower end of the suspension member 7, which is provided by passing through the through-hole 51 of the reinforcing plate 5 (described later) and the through-hole 41 of the printed circuit board 4. The Fix Base 6 is suspended and supported by the suspension member 7 with a predetermined gap provided on the underside of the printed circuit board 4. In addition, a part of the lower surface of the Fix Base 6 is fixed to a part of the upper surface of the probe head 1.

[0022] The fix base 6 is made of a material and thickness such that its thermal expansion is equal to that of the wafer 21 being inspected. The thickness of the fix base 6 is selected in light of the thermal expansion coefficients of the fix base 6 and the wafer 21 so that the thermal expansion of both components is equal. In selecting the thickness of the fix base, the amount of radiant heat from the chuck table on which the wafer 21 is held is taken into consideration. Note that the thermal expansion coefficients of the printed circuit board 4 and the reinforcing plate 5 are greater than those of the fix base 6.

[0023] As shown in Figure 1(a), in a steady state (low temperature state), the probe head 1 and the wafer 21 are aligned so that the tip of each probe 11 is connected to each pad 21a of the wafer 21 which is to be inspected.

[0024] As shown in Figure 1(b), under high-temperature conditions, each component of the electrical connection device 100 expands thermally from the center of the circle outward (to the right side of the paper). Here, since the fix base 6 and the printed circuit board 4 are provided so as to be able to move relative to each other in response to thermal expansion, the fix base 6 and the probe head 1 fixed to the fix base 6 expand thermally in accordance with the thermal expansion of the wafer 21, so that the tip of each probe 11 can maintain a state of being connected to each pad 21a of the wafer 21. Furthermore, since the thermal expansion coefficients of the printed circuit board 4 and the reinforcing plate 5 are greater than those of the fix base 6, under the high-temperature conditions shown in Figure 1(b), the suspension member 7 will move closer to the left wall surface (towards the center) inside the through hole 41.

[0025] Figure 3 illustrates the structure for which the fixed base 6 and the printed circuit board 4 are provided so as to be able to move relative to each other in accordance with thermal expansion in an electrical connection device 100 according to an embodiment of the present invention. Figure 3(a) is a plan view, and Figure 3(b) is a view showing the cross section AA in Figure 3(a). Note that in Figure 3(a), for explanatory purposes, the suspension member 7 and the configuration provided above the reinforcing plate 5 are omitted. Figure 4 is an explanatory diagram illustrating the through-hole 41 of the printed circuit board 4 provided in the electrical connection device 100 according to an embodiment of the present invention. Figure 4(a) is a plan view of the printed circuit board 4, Figure 4(b) is an enlarged view of the through-hole 41 (hereinafter referred to as through-hole 41A) provided in region A1 in Figure 4(a), and Figure 4(c) is an enlarged view of the through-hole 41 (hereinafter referred to as through-hole 41B) provided in region A2 in Figure 4(a).

[0026] As shown in Figure 3(b), the lid 8 is positioned above the reinforcing plate 5 with a predetermined gap, and the lid 8 is fixed to the reinforcing plate 5 from above with fixing bolts 52. In this case, to create a gap between the reinforcing plate 5 and the lid 8, an elastic material 81 may be placed between the reinforcing plate 5 and the lid 8 and fixed with fixing bolts 52, after which the elastic material 81 may be removed or left in place.

[0027] As described above, the reinforcing plate 5 is provided with through holes 51 that penetrate in the vertical direction, and the printed circuit board 4 is provided with through holes 41 that penetrate in the vertical direction at the same positions as the through holes 51 in the planar direction.

[0028] As shown in Figure 3(a), the cross-sectional shapes of the through holes 41 and 51 are elliptical, with the direction of thermal expansion of the fix base 6 (left-right direction on the plane of the paper) as the major axis, so that they can slide in accordance with the thermal expansion of the fix base 6. The inner diameter of the major axis of the ellipse is Φ21.

[0029] In Figure 4(a), the thermal expansion direction of the fix base 6 is outward from the center of the circle on the printed circuit board 4. Specifically, in the through hole 41 (denoted here as through hole 41A) provided in region A1 in Figure 4(a), the direction of arrow Y1 is the thermal expansion direction of the fix base 6, as shown in Figure 4(b). In the through hole 41 (denoted here as through hole 41B) provided in region A2 in Figure 4(a), the direction of arrow Y2 is the thermal expansion direction of the fix base 6, as shown in Figure 4(c).

[0030] As shown in Figure 4(b), the cross-sectional shape of the through hole 41A is an ellipse with an inner diameter of Φ21, where the major axis is in the Y1 direction, which is the thermal expansion direction of the fix base 6. As shown in Figure 4(c), the cross-sectional shape of the through hole 41B is an ellipse with an inner diameter of Φ21, where the major axis is in the Y2 direction, which is the thermal expansion direction of the fix base 6.

[0031] As shown in Figure 3(b), the suspension member 7 is inserted into the through holes 41 and 51 and has a main body portion 7a with an outer diameter Φ11 that is sufficiently smaller than the inner diameter Φ21 so that it can slide in the direction of thermal expansion of the fix base 6 (left-right direction on the plane of the paper) when inserted, and a top portion 7b with an outer diameter Φ12 that is larger than the inner diameter Φ21.

[0032] Three support members 71, each having a hemispherical top, are positioned near the through-hole 51. The lower part of the top 7b of the suspension member 7 is in contact with the tops of the three support members 71, thereby providing suspension support.

[0033] In the electrical connection device 100 with this configuration, when the fixed base 6 expands due to heat at high temperatures, the main body 7a of the suspension member 7 fixed to the fixed base 6 slides within the inner diameter Φ21 in the direction of thermal expansion. The probe head 1 fixed to the fixed base 6 also expands due to heat to follow the thermal expansion of the wafer 21, so that the spacing between each probe 11 held on the probe head 1 also follows the thermal expansion of the wafer 21. This allows the tip of each probe 11 held on the probe head 1 to remain electrically connected to each pad 21a of the wafer 21. In this way, the electrical connection device 100 can properly perform electrical measurements of circuits formed on the wafer 21 even at high temperatures.

[0034] In the example shown in Figure 3(b), the steady position 7A, which is the position of the suspension member 7 in a steady state (low temperature state), and the expanded position 7B, which is the position of the suspension member 7 in a high temperature state, are shown. When the fix base 6 undergoes thermal expansion, the suspension member 7 slides from the steady position 7A to the expanded position 7B, in accordance with the amount of thermal expansion of the fix base 6.

[0035] In this description, three support members 71, each having a hemispherical top, are positioned near the through-hole 51, and the suspension member 7 is suspended and supported by the lower part of its top 7b contacting the tops of the three support members 71. However, the support members 71 are not limited to this shape.

[0036] For example, as shown in Figure 5(a), the support member 72 may have a cylindrical shape that can roll in the direction of thermal expansion (left-right direction on the plane of the paper). Furthermore, the number of support members 72 is not limited to three; three or more may be provided as long as they can lift and support the suspension member 7. In addition, although the support member 72 is configured to have a cylindrical shape that can roll in the direction of thermal expansion (left-right direction on the plane of the paper), it may of course also be spherical.

[0037] Furthermore, as shown in Figure 5(b), the suspension member 7 may be suspended and supported by a support member 73, which is a biasing means, so that it can slide in the direction of thermal expansion (left-right direction on the paper).

[0038] Figure 6 is an explanatory diagram illustrating the connection between the printed circuit board 4 and the interposer 3, which are part of the electrical connection device 100 according to an embodiment of the present invention. Figure 6(a) is a side view at low temperature, Figure 6(b) is a side view at high temperature, Figure 6(c) is an enlarged plan view of the contact state at low temperature, and Figure 6(d) is an enlarged plan view of the contact state at high temperature.

[0039] As shown in Figures 6(a) and 6(b), lands 42 are provided on the underside of the printed circuit board 4. Here, the land 42 located in Figure 6(a) is denoted as land 42A(42), and the land 42 located in Figure 6(b) is denoted as land 42B(42).

[0040] The lower end of the contact 31 is in contact with the upper end of the wiring 2a located inside the space transformer 2. Furthermore, the upper part of the contact 31 is provided with a tip 31a, which is electrically connected to the land 42 and is designed to slide along with the upper end of the wiring 2a due to the thermal expansion of the probe head 1. Here, the contact 31 located in Figure 6(a) is denoted as contact 31A(31), the tip 31a as tip 31aA(31a), the contact 31 located in Figure 6(b) is denoted as contact 31B(31), and the tip 31a as tip 31aB(31a).

[0041] The land 42 is molded to maintain contact even when the tip 31a of the contact element 31 slides in the direction of thermal expansion due to the thermal expansion of the probe head 1.

[0042] Specifically, as shown in Figures 6(a) and (c), at low temperatures, the tip portion 31aA(31a) of the contact element 31A(31) and the land 42A(42) are in contact at the leftmost end in the left-right direction of the paper. As shown in Figures 6(b) and (d), at high temperatures, when the tip portion 31aB(31a) of the contact element 31B(31) slides in the direction of thermal expansion (rightward direction of the paper) due to the thermal expansion of the probe head 1, the tip portion 31aB(31a) of the contact element 31B(31) and the land 42B(42) are in contact at the rightmost end in the left-right direction of the paper.

[0043] Thus, the land 42 is molded in such a shape that the contact position with the contact element 31 at low temperatures and the contact position with the contact element 31 at high temperatures are located at the ends of each other. As a result, the land 42 can maintain contact even when the tip portion 31a of the contact element 31 slides in the direction of thermal expansion due to the thermal expansion of the probe head 1.

[0044] In this description, the land 42 is molded in such a way that the contact position with the contact element 31 at low temperatures and the contact position with the contact element 31 at high temperatures are located at the ends of each other, but this is not the only example.

[0045] Figure 7(a) is an enlarged plan view of the contact state between the printed circuit board 4 and the interposer 3 of the electrical connection device 100 according to Modification 1 of the present invention at low temperatures, and Figure 7(b) is an enlarged plan view of the contact state at high temperatures.

[0046] As shown in Figure 7(a), at low temperatures, the tip 31aA(31a) of the contact element 31A(31) and the land 42A(42) are in contact at the center in the left-right direction of the paper. As shown in Figure 7(b), at high temperatures, when the tip 31aB(31a) of the contact element 31B(31) slides in the direction of thermal expansion (rightward direction of the paper) due to the thermal expansion of the probe head 1, the tip 31aB(31a) of the contact element 31B(31) and the land 42B(42) are in contact at the rightmost end in the left-right direction of the paper.

[0047] Figure 7(c) is an enlarged plan view of the contact state between the printed circuit board 4 and the interposer 3 at low temperatures in the electrical connection device 100 according to Modification 2 of the present invention, and Figure 7(d) is an enlarged plan view of the contact state at high temperatures.

[0048] As shown in Figures 7(c) and 7(d), the land 43 is molded to have an elliptical shape with the direction of thermal expansion of the probe head 1 (here, the left-right direction of the paper) as its major axis. Here, the contact 31 located in Figure 7(c) is denoted as contact 31A(31), the tip portion 31a is denoted as tip portion 31aA(31a), the contact 31 located in Figure 7(d) is denoted as contact 31B(31), and the tip portion 31a is denoted as tip portion 31aB(31a). In addition, the land 43 located in Figure 7(c) is denoted as land 43A(43), and the land 43 located in Figure 7(d) is denoted as land 43B(43).

[0049] As shown in Figure 7(c), at low temperatures, the tip portion 31aA(31a) of the contact element 31A(31) and the land 43A(43) are in contact at the leftmost end in the left-right direction of the paper. As shown in Figure 7(d), at high temperatures, when the tip portion 31aB(31a) of the contact element 31B(31) slides in the direction of thermal expansion (rightward direction of the paper) due to the thermal expansion of the probe head 1, the tip portion 31aB(31a) of the contact element 31B(31) and the land 43B(43) are in contact at the rightmost end in the left-right direction of the paper.

[0050] As a result, the land 43 can maintain contact even when the tip 31a of the contact element 31 slides in the direction of thermal expansion due to the thermal expansion of the probe head 1.

[0051] Although the present invention has been described by the embodiments described above, the descriptions and drawings that constitute part of this invention should not be understood as limiting the invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure. [Explanation of Symbols]

[0052] 1 probe head 2 Space Transformers 2a wiring 3 Interposer 4 Printed circuit boards 5. Reinforcement plate 6. Fix Base 7. Suspension member 7a Main body 7b Top of head 8 Lid 11 probes 21 wafers 21a pad 31 Contactor 41 Through hole 42,43 Rand 51 Through hole 52 Fixing bolts 71-73 Support members 81 Elastic material 100 Electrical connection device

Claims

1. Printed circuit board and A probe head that holds multiple probes, each having a base end that electrically connects to the printed circuit board and a tip end that contacts the object to be inspected, The printed circuit board is provided with a fixed base located below it and partially fixed to the upper surface of the probe head, The fixed base and the printed circuit board are provided so as to be able to move relative to each other in response to thermal expansion. An electrical connection device characterized by the following features.

2. The fixed base is formed of a material and thickness such that its thermal expansion is equal to that of the object being inspected. The electrical connection device according to claim 1, characterized by its features.

3. The printed circuit board is provided with through holes that penetrate in the vertical direction. The system further comprises a suspension member whose lower end is fixed to the fixed base and which is inserted into the through hole and suspended. The electrical connection device according to claim 1, characterized by its features.

4. The cross-sectional shape of the through-hole is an ellipse with the direction of thermal expansion of the fixed base as its major axis, so that it can slide in accordance with the thermal expansion of the fixed base. The electrical connection device according to claim 3.

5. The suspension member is suspended and supported so as to be slidable relative to the printed circuit board in the direction of thermal expansion of the fixed base. The electrical connection device according to feature 4.

6. A space transformer interposed between the printed circuit board and the probe head, having wiring for changing the wiring pitch of each probe, The system further comprises a contact that electrically connects the upper end of the wiring to a land provided on the lower surface of the printed circuit board, and is provided to slide together with the upper end of the wiring due to the thermal expansion of the probe head, The land is molded to maintain contact even when the tip of the contact slides in the direction of thermal expansion due to the thermal expansion of the probe head. The electrical connection device according to claim 1, characterized in that...

7. The land is molded in such a shape that the contact position with the contact element at low temperatures and the contact position with the contact element at high temperatures are located at the ends of each other. The electrical connection device according to claim 6.

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