Probe structure and inspection device

Abstract

The invention provides a probe structure and an inspection device capable of obtaining matching of characteristic impedance of a connection terminal as a signal circuit relay point. The present invention provides a probe structure for transmitting and receiving a high-frequency signal to and from an object to be inspected via a contact portion that electrically contacts an electrode of the object to be inspected, the probe structure being characterized by being provided with: a main body portion; a substrate holding part which is provided with a wiring substrate on one surface and is fixed on the main body part on the other surface; a connector that is joined to the wiring board of the board holding member and that connects the wiring of the wiring board and the coaxial cable via a connection terminal; and an impedance adjustment unit that adjusts a gap between the impedance adjustment unit and the connection terminal to perform impedance matching.

Description

Technical Field

[0001] This invention relates to a probe structure and inspection device, for example, a probe structure and inspection device applicable to the inspection of electrical characteristics of high-frequency devices such as semiconductor integrated circuits. Background Technology

[0002] For example, when inspecting the electrical characteristics of semiconductor integrated circuits on a semiconductor wafer, a probe alignment device is used. In particular, to inspect the electrical characteristics of high-frequency devices, high-frequency probes that transmit and receive high-frequency signals to and from the high-frequency devices are used.

[0003] Figure 2 This is a diagram illustrating the structure of a probe used in the examination of existing high-frequency test subjects.

[0004] exist Figure 2 In the existing probe structure 90, there is a lower ground plane 91, a probe substrate 92, a mounting portion 93, a coaxial connector 95, and an upper ground plane 99. The probe structure 90 is assembled by screwing screws 96 into the mounting through hole 93a and threaded hole 91a. When the coaxial cable connected to the coaxial connector 95 comes into contact with the contact pad (also called "input / output signal terminal") 951, an electrical connection is established.

[0005] Existing technical documents

[0006] Patent documents

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2006-194765 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, when there are components connected to ground (GND) near the input / output signal terminals, the characteristic impedance of the input / output signal terminals decreases, which can sometimes affect high-frequency measurements.

[0010] Therefore, in view of the above-mentioned problems, the present invention aims to provide a probe structure and inspection device capable of obtaining a matching characteristic impedance at the connection terminal that serves as a relay point in a signal circuit.

[0011] Technical means to solve the problem

[0012] To address the aforementioned problems, the first technical solution of the present invention is a probe structure that transmits and receives high-frequency signals between itself and the subject of examination via a contact portion that makes electrical contact with the electrodes of the subject. The probe includes: a main body; a substrate holding member having a wiring substrate on one side and the other side fixed to the main body; a connector engaging with the wiring substrate of the substrate holding member and connecting the wiring of the wiring substrate to a coaxial cable via a connection terminal; and an impedance adjustment portion that adjusts the gap between itself and the connection terminal to achieve impedance matching.

[0013] The second technical solution of the present invention is an inspection device that uses high-frequency signals to inspect the electrical characteristics of the object being inspected. It has a probe structure, wherein the probe structure makes the contact part electrically contact the electrode of the object being inspected, and transmits and receives high-frequency signals between the probe structure and the object being inspected. The probe structure is the same as the probe structure of the first technical solution.

[0014] The effects of the invention

[0015] According to the present invention, it is possible to achieve matching of characteristic impedance at the connection terminal that serves as a relay point in a signal circuit. Attached Figure Description

[0016] Figure 1 This is a configuration diagram showing the external structure of the probe structure in the embodiment.

[0017] Figure 2 This is a diagram of the probe structure mounted on an existing high-frequency detector device.

[0018] Figure 3 This is an explanatory diagram illustrating the connection structure of an existing probe structure.

[0019] Figure 4 This is an overall configuration diagram showing the overall structure of the semiconductor inspection apparatus according to the implementation method.

[0020] Figure 5 This is an explanatory diagram illustrating the connection configuration of the probe structure in the implementation method.

[0021] Figure 6 It is a diagram showing the equivalent circuit of the transmission path and the impedance of the existing input and output signal terminals.

[0022] Figure 7 This is a diagram showing the impedance of the input and output signal terminals before and after the adjustment in the implementation method.

[0023] Figure 8 This is a graph showing the return loss waveforms before and after impedance adjustment in the implementation method. Detailed Implementation

[0024] (A) Implementation Method

[0025] Hereinafter, embodiments of the probe structure and inspection device of the present invention will be described in detail with reference to the accompanying drawings.

[0026] In this embodiment, as an example of the inspection apparatus of the present invention, a semiconductor inspection apparatus applied to inspect the electrical characteristics of high-frequency devices on a semiconductor wafer is illustrated.

[0027] In addition, as an example of the probe structure of the present invention, a case of a high-frequency probe structure applied to a semiconductor inspection device is illustrated.

[0028] Furthermore, the probe structure and inspection device of the present invention are not limited to the high-frequency probe structure and semiconductor inspection device described in the embodiments.

[0029] (A-1) Composition of a semiconductor inspection device

[0030] Figure 4 This is an overall configuration diagram showing the overall structure of the semiconductor inspection apparatus according to the implementation method.

[0031] Furthermore, while each figure illustrates the main constituent components, it is not limited to those shown; additional components not shown may also be included. In each figure, identical or corresponding constituent elements are labeled with the same or corresponding symbols. Each figure is schematic; note that the dimensions, thicknesses, etc., of each constituent element differ from the actual dimensions. Additionally, the dimensions and proportions of corresponding constituent elements may differ between the figures. The embodiments shown below illustrate apparatus and methods for embodying the technical concept of the present invention and do not limit the material, shape, structure, or arrangement of the constituent elements of the present invention.

[0032] exist Figure 4 In this context, the X, Y, and Z directions are defined. Figure 4 In the diagram, the X direction (first direction) is the left-right direction of the paper, the Y direction (second direction) is the depth direction of the paper, and the Z direction (third direction) is the up-down direction of the paper.

[0033] exist Figure 4 In the embodiment, the semiconductor inspection apparatus 1 includes a base 2, a frame 3, an object to be inspected 4, a moving device 5, a stage 6, a top plate 7, a robot arm 8, a high-frequency probe structure mounting part 9, and a high-frequency probe structure 10.

[0034] Furthermore, the semiconductor inspection device 1 is not limited to Figure 4 The configuration shown can also be applied, for example, to detectors that do not have a base portion 2 and a frame portion 3, or to detectors constructed with simpler components that replace the base portion 2 and the frame portion 3. Additionally, microscopes, laser cutting devices, etc., can also be included.

[0035] The semiconductor inspection apparatus 1 uses a high-frequency device (semiconductor integrated circuit) formed on a semiconductor wafer as the object under inspection 4, and makes contact portion (also called "contact" or "contact pin") 14 make electrical contact with the electrode terminals of the object under inspection 4 to inspect the electrical characteristics of the object under inspection 4. The semiconductor inspection apparatus 1 is also called a detector.

[0036] During inspection, the contact portion 14 of the high-frequency probe structure 10 is electrically contacted with the electrode terminals of the device under inspection 4. The semiconductor inspection apparatus 1 provides a high-frequency signal to the device under inspection 4 via the contact portion 14 and acquires a response signal from the device under inspection 4 via the contact portion 14. In this way, the electrical characteristics of the high-frequency device are inspected. For example, the semiconductor inspection apparatus 1 uses a high-frequency signal from a coaxial cable to inspect the electrical characteristics of the high-frequency device.

[0037] The stage 6 is used to place semiconductor chips, wafers, etc., which are the objects to be inspected 4. In addition, the stage 6 may also have a temperature adjustment function to adjust the temperature of the object to be inspected 4 to a high or low temperature.

[0038] The moving device 5 moves the stage 6 on which the object to be inspected 4 is placed, thereby positioning the electrode terminals and contact portions 14 of the object to be inspected 4. For example, the moving device 5 has an X-axis moving part that moves the stage 6 in the X-axis direction, a Y-axis moving part that moves in the Y-axis direction, a Z-axis moving part that moves in the Z-axis direction, and a θ-axis moving part that rotates in the θ-axis direction, enabling movement along the XYZθ axes. Furthermore, the moving device 5 is not limited to moving in four axial directions.

[0039] The high-frequency probe structure 10 has a contact portion 14 that makes electrical contact with the electrodes of the object being examined, and transmits and receives high-frequency signals between itself and the object being examined 4 via the contact portion 14. In this example, a case with two high-frequency probe structures 10 is illustrated.

[0040] The high-frequency probe structure 10 is mounted on the high-frequency probe structure mounting part 9 of the robot arm 8 and connected to the coaxial cable. The robot arm 8 is operated to align the contact part 14 with the electrode of the object being inspected.

[0041] The robotic arm 8 is mounted on the top plate 7 to align the high-frequency probe structure 10. The robotic arm 8 can be a manual robotic arm operated by an operator or an automatically controlled robotic arm.

[0042] (A-2) High-frequency probe structure

[0043] Figure 1 This is a configuration diagram showing the external structure of the high-frequency probe structure 10 according to the embodiment.

[0044] exist Figure 1In the embodiment, the high-frequency probe structure 10 has a main body 11 as the main body, an FPC holder 12 as a substrate holding member, an FPC 13 as a wiring substrate, a contact portion 14, connectors 15A and 15B, and impedance adjustment portions 16A and 16B.

[0045] The main body 11 is the main component that serves as the base of the high-frequency probe structure 10. The main body 11 is, for example, a plate component made of metal such as iron, and is a bent structure formed by bending. The bent structure of the main body 11 has a first plate portion 111 and a second plate portion 112.

[0046] The first plate portion 111 of the main body portion 11 is mounted on the high-frequency probe structure mounting portion 9. In order to be mounted to the high-frequency probe structure mounting portion 9, the first plate portion 111 has three holes 111a and one hole 111b arranged in a row.

[0047] The second plate portion 112 of the main body portion 11 is the portion that electrically connects the wiring pattern of the coaxial cable that can be connected via connectors 15A and 15B and the FPC 13 held by the FPC holder 12.

[0048] An elongated hole is provided on the second plate portion 112, and the first support portion (the portion where the contact portion 14 is provided) 121 of the curved FPC holder 12 is inserted into the elongated hole. Thus, the first support portion 121 of the curved FPC holder 12 is inserted into the elongated hole of the main body portion 11 and the FPC holder 12 is held.

[0049] Furthermore, with the FPC retainer 12 inserted and installed in the main body 11, the first surface 112a of the second plate portion 112 and the second support portion 122 of the FPC retainer 12 are overlapped, and connectors 15A and 15B are installed and fixed thereon. Thus, the FPC retainer 12 can be fixed by clamping it between the first surface 112a of the second plate portion 112 of the main body 11 and connectors 15A and 15B. Since the FPC 13, made of flexible material, is held on the FPC retainer 12, connectors 15A and 15B are pressed against the FPC 13 to engage through contact pressure. Alternatively, other fixing methods can also be applied.

[0050] Connectors 15A and 15B are connected to the coaxial cable.

[0051] FPC13 has a wiring pattern formed on a flexible substrate and is disposed on the first surface 12a of FPC holder 12. The wiring pattern of FPC13 is connected to the contact portion 14. As described later, when connectors 15A and 15B are fixed, input / output signal terminals 151 are connected to the wiring pattern on FPC13, and coaxial cable and wiring pattern on FPC13 can be connected via input / output signal terminals 151.

[0052] The FPC retainer 12 is used to hold the FPC 13, such as a sheet component made of materials like stainless steel. The FPC retainer 12 is a bent structure formed by bending into approximately right angles. The FPC 13 is bonded to the first surface 12a of the FPC retainer 12 to hold the FPC 13 and support the contact portion 14.

[0053] The curved FPC cage 12 has a first support portion 121 and a second support portion 122.

[0054] The first support portion 121 of the FPC cage 12 is a member on the side of the top end that supports the contact portion 14. The first support portion 121 has a generally triangular base portion 121a whose width (length in the Y-axis direction) decreases from the main body portion 11 side to the top end side, an alignment portion 121c that serves as the top end of the base portion 121a and aligns the contact portion 14, and an elongated portion 121b between the base portion 121a and the alignment portion 121c.

[0055] The base portion 121a is shaped approximately triangular to facilitate the alignment of the contact portion 14 with the electrode terminals of the object being inspected 4. Similarly, as Figure 1 As shown, the alignment portion 121c is rectangular (approximately rectangular) because two high-frequency probe structures 10 are usually used for inspection, and the rectangular ends of a pair of alignment portions 121c are positioned opposite each other as a reference for alignment, thus facilitating the alignment of the contact portion 14.

[0056] The second support portion 122 of the FPC holder 12 is fixed to the main body portion 11 on one side. The second support portion 122 is fixed to the main body portion 11 and supports the first support portion 121, and is a component on the side where the input / output signal terminals 151 of connectors 15A and 15B are connected to the FPC 13.

[0057] Impedance adjustment units 16A and 16B are used to adjust the decrease in impedance generated near the input / output signal terminal 151, which serves as a connection terminal.

[0058] The detailed configuration of impedance adjustment units 16A and 16B will be described below. For example, impedance matching is achieved by adjusting the distance between the input / output signal terminals 151 and the impedance adjustment units 16A and 16B. Impedance adjustment units 16A and 16B are rod-shaped members (e.g., screws) with end faces at their top ends, and the distance between these rod-shaped members and the input / output signal terminals 151 is adjusted. Furthermore, impedance adjustment units 16A and 16B are connected to ground (GND).

[0059] For example, the FPC holder 12 is provided with an adjustment hole 20 for adjusting impedance. Additionally, the main body 11 is provided with a through hole 115 for inserting impedance adjustment parts 16A and 16B, which are screws. By adjusting the spacing between the impedance adjustment parts 16A and 16B inserted into the through hole 115 and the input / output signal terminals 151, impedance matching can be achieved.

[0060] In addition, impedance adjustment sections 16A and 16B are provided for each connector 15A and 15B respectively.

[0061] Figure 5 This is an explanatory diagram illustrating the connection configuration of the high-frequency probe structure 10 in the embodiment.

[0062] The connection configurations of connectors 15A and 15B are basically the same. Here, in order to explain the common configuration of connectors 15A and 15B, they will be referred to as "connector 15" and "impedance adjustment part 16".

[0063] The FPC cage 12, the main body 11, and the connector 15 are connected to ground. In addition, the impedance adjustment unit 16 is connected to ground via the main body 11.

[0064] exist Figure 5 In the embodiment, a through hole 115 is provided on the main body 11, and an impedance adjustment part 16 is inserted into the through hole 115 of the main body 11. The impedance adjustment part 16 can be pushed and pulled in the through hole 115.

[0065] Alternatively, the impedance adjustment unit 16 may also include a force-applying member 17 such as a helical spring to prevent loosening. When pressed into the main body 11, the impedance adjustment unit 16 can move toward the main body 11 while being subjected to force.

[0066] In the FPC retainer 12, an adjustment hole 20 is provided at a position corresponding to the through hole 115 of the main body 11. This allows the top end 161 of the impedance adjustment part 16, which passes through the through hole 115 of the main body 11, to reach the adjustment hole 20. Here, the top end of the impedance adjustment part 16 is cut into a flat cross-section; that is, the top end 161 is a cut surface. This facilitates adjustment of the size of the adjustment hole 20.

[0067] The adjustment hole 20 passes through the FPC retainer 12 but not through the FPC 13. Therefore, the adjustment hole 20 is a space enclosed by the FPC 13, the main body 11, the walls of the FPC retainer 12, and the top end 161 of the impedance adjustment part 16. The size of the space of the adjustment hole 20 changes depending on the position of the push-pull impedance adjustment part 16. By changing the size of this adjustment hole 20, the impedance can be adjusted.

[0068] Here, the decrease in characteristic impedance of the input / output signal terminal 151 of the high-frequency probe structure 10 will be explained.

[0069] In the high-frequency probe structure 10, the contact portion 14 is connected to the input / output signal terminal 151 of the high-frequency signal. At this time, it is necessary to design the impedance (output impedance) of the high-frequency circuit side to be equal to the impedance (input impedance) of the contact portion 14.

[0070] In the past, such as Figure 3 As shown, opposite to the input / output signal terminal 951, there is an FPC cage and main body (equivalent to) that are connected to ground. Figure 3 The probe substrate 92 and the lower ground plane 91 are used to reduce the characteristic impedance in the input / output signal terminal 951, which affects the high-frequency measurement.

[0071] For example, to prevent the generation of standing waves due to reflections that obstruct the transmission of high-frequency signals, a design was implemented to ensure that the input and output impedance values ​​(e.g., 50Ω) are consistent. The characteristic impedance Z0 of the high-frequency probe transmitting high-frequency signals is represented by equation (1).

[0072] [Formula 1]

[0073]

[0074] In equation (1), C represents capacitance (static capacitance), and L represents inductance. The characteristic impedance Z0 is directly proportional to L and inversely proportional to C.

[0075] Figure 6 (A) is the transmission path equivalent circuit. In the input / output signal terminal 951, an FPC holder and a main body (equivalent to...) are located near the input / output signal terminal 951. Figure 3 The probe substrate 92 and the lower ground plane 91 have a large capacitance C, therefore the characteristic impedance Z0 is smaller (reference). Figure 6 (B) of Z).

[0076] In view of the problems of the prior art mentioned above, such as Figure 5 As shown, in this embodiment, an adjustment hole 20 is provided on the FPC holder 12 to separate the input / output signal terminal 151 from the gap between the FPC holder 12 and the main body 11. Furthermore, an impedance adjustment section 16 is provided to change the size of the adjustment hole 20. In other words, the gap between the input / output signal terminal 151 and the impedance adjustment section 16 is changed. This allows for a reduction in capacitance C and adjustment of the characteristic impedance Z0.

[0077] Figure 7 This is a diagram showing the impedance of the input / output signal terminals 151 of the impedance adjustment unit 16 before and after adjustment in the embodiment.

[0078] Before adjustment, without the impedance adjustment section 16, an adjustment hole 20 is provided on the FPC holder 12 to reduce the value of capacitor C, and a through hole 115 is provided on the main body 11 by tapping. The central axis of the through hole 115 and the central axis of the input / output signal terminal 151 are coaxial. Figure 5 (P-axis). For example Figure 7 As shown, the value of impedance Z0 increases at this time.

[0079] Afterwards, the impedance adjustment unit 16 can obtain the GND signal from the through hole 115 of the main body 11, and adjust the impedance Z0 by pushing and pulling the impedance adjustment unit 16, which is a screw.

[0080] For example, if the impedance adjustment section 16 is pushed into the through hole 115, narrowing the gap between the input / output signal terminal 151 and the impedance adjustment section 16, the value of the capacitor C increases. Figure 7 As shown, the impedance value can be designed as the input and output impedance (e.g., 50Ω).

[0081] Figure 8 This is a diagram showing the return loss waveforms before and after impedance adjustment in the implementation method.

[0082] When processing high-frequency signals, all impedances are designed together to reduce reflections. For example, the input and output impedances are designed to be the same, say 50Ω. If there is an impedance change in the middle of the signal path, a portion of the signal will not be transmitted to the receiving side but will return to the transmitting side, resulting in reflection.

[0083] according to Figure 8 The results show that if we observe the return loss before and after adjustment, the reflection is reduced after adjustment compared to before adjustment, which can improve the characteristics.

[0084] (A-3) Effects of the implementation method

[0085] As described above, according to this embodiment, the gap between the impedance adjustment part and the input / output signal terminals can be adjusted by pushing and pulling the through hole of the main body, thereby achieving the matching of the characteristic impedance of the connection terminal that serves as a relay point in the signal circuit.

[0086] (B) Other implementation methods

[0087] Various modified embodiments have been mentioned in the above embodiments, but the present invention can also be applied to the following modified embodiments.

[0088] (B-1) In the above embodiment, a high-frequency probe structure with two connectors is illustrated, but it can also be applied to a case with one or more connectors. Even in this case, the connection structure of each connector still adopts the connection structure described in the above embodiment, and the same effect can be obtained.

[0089] (B-2) Generally, impedance matching in circuits using high-frequency signals requires a highly precise control of the connection structure. However, in this embodiment, since a rod-shaped member such as an adjusting screw can be pushed and pulled, impedance can be controlled with a simple structure. The central axis of the input / output signal terminals and the axis of the impedance adjustment section are preferably coaxial, but impedance can be adjusted even if the axes are not perfectly aligned.

[0090] Symbol Explanation

[0091] 1…Semiconductor inspection apparatus, 2…Base section, 3…Frame section, 4…Inspected object, 5…Moving device, 6…Stage, 7…Top plate, 8…Robot, 9…Probe structure mounting section, 10…High-frequency probe structure, 11…Main body section, 111…First plate section of the main body section, 111a and 111b…Hole section, 112…Second plate section of the main body section, 112a…First surface of the second plate section of the main body section, 115…Through hole, 12…FPC holder, 12a…First surface of the FPC holder, 121…First support section of the FPC holder, 1 21b…Base portion of FPC cage, 121c…Alignment portion of FPC cage, 122…Second support portion of FPC cage, 13…FPC, 14…Contact portion, 15 (15A and 15B)…Connector, 151…Input / output signal terminal, 16 (16A and 16B)…Impedance adjustment portion, 161…Top portion of impedance adjustment portion, 17…Force application member, 20…Adjustment hole, 90…Probe structure, 91…Main body, 92…FPC cage, 93…FPC, 94…Contact portion, 951…Input / output signal terminal.

Claims

1. A probe structure that transmits and receives high-frequency signals with respect to a subject via a contact portion that is in electrical contact with an electrode of the subject, the probe structure being characterized by comprising: Main body; A substrate holding member has a wiring substrate on one side and is fixed to the main body on the other side; A connector that engages with the wiring substrate of the substrate holding member and connects the wiring of the wiring substrate to a coaxial cable via connection terminals; and The impedance adjustment section adjusts the gap between itself and the connection terminal to achieve impedance matching.

2. The probe structure according to claim 1, characterized in that, The substrate holding member has a space around the connection terminal. The main body has a through hole at a position corresponding to the space provided on the substrate holding member. The impedance adjustment section has a rod-shaped member that can be pushed and pulled through the through hole of the main body to adjust the gap between the connection terminal and the rod-shaped member.

3. The probe structure according to claim 1, characterized in that, The substrate holding member, the main body, the connector, and the impedance adjustment part are all grounded.

4. The probe structure according to claim 2, characterized in that, The top end of the rod-shaped member in the impedance adjustment section is an end face.

5. The probe structure according to claim 1, characterized in that, The wiring substrate of the substrate holding member is a flexible substrate.

6. An inspection device that uses a high-frequency signal to inspect the electrical characteristics of an object being inspected, characterized in that... It has a probe structure that makes electrical contact between the contact portion and the electrodes of the object being inspected, and transmits and receives high-frequency signals between the probe structure and the object being inspected. The probe structure is the probe structure according to any one of claims 1 to 5.

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