Wiring Substrate and Probe Card

Abstract

To provide a wiring board capable of realizing good contact with a contact conductor, and a probe card .SOLUTION: A wiring board includes an insulating substrate having a first surface and a second surface located on the opposite side of the first surface, and a plurality of wiring conductors located on the first surface and the second surface. When the first surface is divided into two regions, a circular first region located in the center of the first surface, and a second region surrounding the first region and having the same area as the first region, the plurality of wiring conductors include a plurality of first wiring conductors located in the first region and a plurality of second wiring conductors located in the second region, and the thickness of the plurality of second wiring conductors is larger than that of the plurality of first wiring conductors.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a wiring board and a probe card.

Background Art

[0002] Patent Document 1 describes a wiring board for a probe card.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A wiring board for a probe card has a plurality of probe pins joined to the lower surface and a plurality of wiring conductors on the upper surface. A plurality of contact conductors respectively contact the plurality of wiring conductors on the upper surface, and the wiring board and another circuit board are electrically connected via the contact conductors. A good contact property with the contact conductors (a contact that can obtain good electrical conduction with an appropriate pressure) is desired for the wiring board.

[0005] An object of the present disclosure is to provide a wiring board and a probe card that can achieve good contact property with contact conductors.

Means for Solving the Problems

[0006] The wiring board according to the present disclosure includes an insulating substrate having a first surface and a second surface located on the opposite side of the first surface, a plurality of wiring conductors located on the first surface and the second surface, and when the first surface is divided into two regions, a circular first region located at the center of the first surface and a second region surrounding the first region and having the same area as the first region, The plurality of wiring conductors includes a plurality of first wiring conductors located in the first region and a plurality of second wiring conductors located in the second region. The thickness of the plurality of second wiring conductors is greater than the thickness of the plurality of first wiring conductors.

[0007] The probe card according to the present disclosure is the above wiring substrate, a plurality of probe pins electrically connected to the plurality of wiring conductors located on the second surface, respectively, and includes.

[0008] Another aspect of the probe card according to the present disclosure is provided with one or more bonding metal films located on the first surface, more than half of the total number of the bonding metal films is the above wiring substrate located in the first region, a plurality of probe pins electrically connected to the plurality of wiring conductors located on the second surface, respectively, a metal member bonded to the bonding metal film, and includes.

Advantages of the Invention

[0009] According to the present disclosure, a wiring substrate and a probe card capable of realizing good connectivity with a connection conductor can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0012] (Embodiment 1) FIG. 1 is a plan view showing a wiring conductor according to Embodiment 1 of the present disclosure. FIG. 2 is a longitudinal sectional view (A) showing the wiring conductor of Embodiment 1, and partial enlarged views (B) and (C). FIG. 3 is a longitudinal sectional view showing a probe card according to Embodiment 1 of the present disclosure. FIGS. 2(A) and 3 show schematic views in which simplifications in drawing such as reducing the number of wiring conductors 12, 13, and 14 are made. In FIGS. 2(A) and 3, the aspect ratio of each component, the amount of warping of the insulating substrate 11, the thicknesses of the wiring conductors 12 and 13, the inclination angle of the wiring conductor 12 with respect to the first surface S1, etc. are exaggeratedly shown. Hereinafter, the description will be made with the first surface S1 side of the wiring substrate 10 being the upper side and the second surface S2 side being the lower side. FIG. 1 shows the first surface S1 side of the wiring substrate 10.

[0013] The wiring substrate 10 of Embodiment 1 may be a wiring substrate 10 for a probe card. The wiring substrate 10 includes an insulating substrate 11 having a first surface S1 and a second surface S2 located on the opposite side of the first surface S1, a plurality of wiring conductors 12 located on the first surface S1, a plurality of wiring conductors 13 located on the second surface S2, and a wiring conductor 14 located inside the insulating substrate 11.

[0014] The material of the insulating substrate 11 may be mullite ceramic or other ceramics. The wiring substrate 10 and the insulating substrate 11 may be a regular polygonal shape having eight or more corners or a circular shape in a plan view. By adopting such a shape, stress can be dispersed at the edge of the insulating substrate 11, and thus the strength of the wiring substrate 10 can be improved. The wiring substrate 10 and the insulating substrate 11 may have a size corresponding to a wafer (such as a silicon wafer) to be inspected by the probe card 1. When the wiring substrate 10 is used as the probe card 1, the first surface S1 of the wiring substrate 10 may be a surface facing the circuit board 20 (FIG. 3) connected to the inspection apparatus. The second surface S2 of the wiring substrate 10 may be a surface facing the object to be inspected (such as a silicon wafer).

[0015] The wiring conductors 12, 13, 14 (FIG. 2(A)) may be conductors for exchanging (sending and receiving) signals or power supply voltages between the first surface S1 and the second surface S2.

[0016] The plurality of wiring conductors 12 on the first surface S1 may be conductors electrically connected to the circuit board 20 via the contact conductors 31 (FIG. 3). The plurality of wiring conductors 12 may be electrode pads. The contact conductor 31 has the action of a spring and may be configured to be in conduction with the wiring conductor 12 by contacting the wiring conductor 12 using the repulsive force of the spring. The wiring conductor 12 may be a conductor formed by forming a thin film of a pattern corresponding to the wiring conductor 12 on the first surface S1 by a thin film forming process such as a sputtering process and then plating the thin film by an electrolytic plating process.

[0017] The plurality of wiring conductors 13 on the second surface S2 may be conductors to which the probe pins 41 (FIG. 3) are joined. The plurality of wiring conductors 13 may be electrode pads. The wiring conductor 13 may be a conductor formed by forming a thin film of a pattern corresponding to the wiring conductor 13 on the second surface S2 by a thin film forming process such as a sputtering process and then plating the thin film by an electrolytic plating process.

[0018] The wiring conductor 14 may be a conductor that electrically connects the wiring conductor 12 on the first surface S1 and the wiring conductor 13 on the second surface S2. The insulating substrate 11 has a laminated structure in which a plurality of insulating layers are laminated, and the wiring conductor 14 may include a film-like or linear metallized conductor located between the plurality of insulating layers and a via conductor extending across the insulating layers.

[0019] <Details of the wiring conductor 12 on the first surface S1 and the wiring conductor 13 on the second surface S2> Hereinafter, the first surface S1 will be described by dividing it into two regions: a circular first region R1 located at the center of the first surface S1 and a second region R2 surrounding the first region R1 and having the same area as the first region R1. In FIG. 1, the boundary between the first region R1 and the second region R2 is indicated by a dashed-dotted line. The center point of the first region R1 may coincide with the center point of the first surface S1. Hereinafter, the wiring conductor 12 located in the first region R1 will be denoted as "first wiring conductor 12a", the wiring conductor 12 located in the second region R2 will be denoted as "second wiring conductor 12b", and the wiring conductor 13 located on the second surface S2 will be denoted as "third wiring conductor 13".

[0020] As shown in FIG. 2(A), the thicknesses of the plurality of second wiring conductors 12b are larger than the thicknesses of the plurality of first wiring conductors 12a. The thickness T1aa (FIG. 2(B)) of each first wiring conductor 12a may not be constant. Similarly, the thickness T2aa (FIG. 2(C)) of each second wiring conductor 12b may not be constant. The thicknesses of the plurality of first wiring conductors 12a may be the average thickness of all the first wiring conductors 12a, the median thickness, the average value, the maximum value, or the minimum value of the thicknesses after excluding 3% of the first wiring conductors 12a with larger thicknesses and 3% of the first wiring conductors 12a with smaller thicknesses in order to exclude extreme values. Similarly, the thicknesses of the plurality of second wiring conductors 12b may be the average thickness of all the second wiring conductors 12b, the median thickness, the average value, the maximum value, or the minimum value of the thicknesses after excluding 3% of the second wiring conductors 12b with larger thicknesses and 3% of the second wiring conductors 12b with smaller thicknesses in order to exclude extreme values. When comparing the thicknesses, the same definition may be applied to the thicknesses of the first wiring conductor 12a and the second wiring conductor 12b.

[0021] The thickness of the first wiring conductor 12a and the thickness of the second wiring conductor 12b may be controlled by applying electrolytic plating as a plating process for forming the wiring conductor 12 and adjusting the current flowing through the pattern of the first wiring conductor 12a and the current flowing through the pattern of the second wiring conductor 12b during electrolytic plating.

[0022] According to the above configuration, when connecting the plurality of wiring conductors 12 and the plurality of contact conductors 31 (FIG. 3), the distance between the surface of the first wiring conductor 12a in the first region R1 and the contact conductor 31 becomes relatively large. On the other hand, the distance between the surface of the second wiring conductor 12b in the second region R2 and the contact conductor 31 becomes relatively small. Therefore, the pressure applied from the contact conductor 31 to the first wiring conductor 12a can be reduced, and the pressure applied from the contact conductor 31 to the second wiring conductor 12b in the second region R2 can be increased. Therefore, the contact property between the second wiring conductor 12b and the contact conductor 31 is improved. Further, the wiring conductors 12 tend to gather more in the first region R1 on the first surface S1. Thus, if the pressure applied from each contact conductor 31 to each first wiring conductor 12a is large, the total pressure applied to the first region R1 becomes excessive, and the stress generated in the wiring conductor 12 increases. However, according to the above configuration of Embodiment 1, since the total pressure applied to the first region R1 is reduced, the stress generated in the wiring board 10 can be reduced. Therefore, good contact property between the wiring conductor 12 and the contact conductor 31 can be obtained in both the first region R1 and the second region R2.

[0023] The wiring conductors 12 (the first wiring conductor 12a and the second wiring conductor 12b) on the first surface S1 may be configured such that the thickness gradually decreases as it gets closer to the center. With this configuration, the pressure applied from the contact conductor 31 to the wiring conductor 12 can be made larger as it gets closer to the edge of the first surface S1, and the contact property between the wiring conductor 12 located near the edge of the first surface S1 and the contact conductor 31 can be further improved. Further, the total pressure applied from the plurality of contact conductors 31 to the central portion of the first surface S1 becomes low, and the stress generated in the wiring board 10 can be reduced. Therefore, the contact property between the wiring conductor 12 and the contact conductor 31 at the central portion can be made better.

[0024] In a plan view, the total area of the plurality of first wiring conductors 12a may be larger than the total area of the plurality of second wiring conductors 12b. In such a configuration, if the thickness of the first wiring conductor 12a and the thickness of the second wiring conductor 12b are the same, the total pressure applied from the contact conductor 31 to the first region R1 becomes larger than the total pressure applied from the contact conductor 31 to the second region R2. Therefore, in such a configuration, by making the thickness of the first wiring conductor 12a smaller than the thickness of the second wiring conductor 12b, the total pressure in the first region R1 is reduced, and good contact property can be obtained in the first region R1.

[0025] When a plurality of types of wiring boards 10 having different patterns are prepared, the difference between the total area of the plurality of first wiring conductors 12a and the total area of the plurality of second wiring conductors 12b may be set so that the difference between the thickness (average thickness) of the plurality of first wiring conductors 12a and the thickness (average thickness) of the plurality of second wiring conductors 12b becomes larger. With such a configuration, in any of the plurality of types of wiring boards 10, the total pressure applied from the contact conductor 31 to the first region R1 can be set to a good magnitude, and the contact property in the first region R1 can be improved.

[0026] In a plan view, the total area of the plurality of first wiring conductors 12a and the plurality of second wiring conductors 12b may be larger than the total area of the plurality of third wiring conductors 13. In such a configuration, due to the difference in the expansion rate between the conductor and the insulating substrate 11, a warp in which the first surface S1 becomes convex is likely to occur. The warp acts to increase the total pressure applied from the contact conductor 31 to the first region R1. Therefore, the action based on the fact that the thickness of the first wiring conductor 12a is smaller than the thickness of the second wiring conductor 12b (the action of reducing the total pressure in the first region R1) functions effectively, and the contact property in the first region R1 can be improved.

[0027] In a plan view, the total area of the plurality of first wiring conductors 12a may be 55% or more and 76% or less of the total area of the plurality of wiring conductors 12 (the first wiring conductors 12a and the second wiring conductors 12b) located on the first surface S1. With this configuration, it is easy to provide an appropriate thickness difference between the first wiring conductors 12a and the second wiring conductors 12b, and the contact property between the contact conductors 31 and the first wiring conductors 12a and the second wiring conductors 12b can be improved by this thickness difference.

[0028] The following relational table 1 shows an example of the relationship between the conductor area ratio (the ratio of the total area of the plurality of first wiring conductors 12a located in the first region R1 to the total area of the plurality of wiring conductors 12 located on the first surface S1), the thickness of the first wiring conductors 12a for which good contact property can be obtained, the thickness of the second wiring conductors 12b, and the thickness difference.

[0029] <Relational Table 1>

Table 1

[0030] (Probe Card) As shown in FIG. 3, the probe card 1 according to Embodiment 1 of the present disclosure includes the above-described wiring substrate 10 and a plurality of probe pins 41 respectively joined to the plurality of wiring conductors 13 on the second surface S2. The probe pins 41 may be joined to the wiring conductors 13 via a joining material such as solder.

[0031] The probe card 1 may further include a circuit board 20 connected to an inspection device (not shown), a frame body 22 that supports the wiring substrate 10, and a plurality of contact conductors 31 interposed between the circuit board 20 and the wiring substrate 10. The frame body 22 may be configured to support the edge portion of the wiring substrate 10 from below. The frame body 22 may be fixed to the circuit board 20, and the wiring substrate 10 and the circuit board 20 may be integrated. Each of the plurality of contact conductors 31 may electrically connect the electrode pads 21 and the wiring conductors 12 associated with each other by contacting a plurality of electrode pads 21 located on the lower surface of the circuit board 20 and the plurality of wiring conductors 12 of the wiring substrate 10.

[0032] The plurality of contact conductors 31 may be integrally supported at their central portions on an insulating board or insulating sheet (not shown). The plurality of integrated contact conductors 31 may be referred to as an interposer.

[0033] According to the probe card 1 of this configuration, the probe pins 41 of the probe card 1 are connected to the electrodes on the silicon wafer to be inspected. Then, an inspection device (not shown) connected to the circuit board 20 can inspect the object to be inspected by exchanging one or both of a signal and a power supply voltage with the object to be inspected via the circuit board 20, the plurality of contact conductors 31, the wiring board 10, and the probe pins 41.

[0034] According to the probe card 1 of Embodiment 1, good contact between the wiring board 10 and the contact conductors 31 is realized, so good exchange of one or both of a signal and a power supply voltage can be realized between the inspection device and the object to be inspected.

[0035] (Embodiment 2) FIG. 4 is a plan view showing a wiring conductor according to Embodiment 2 of the present disclosure. FIG. 5 is a longitudinal sectional view showing a probe card according to Embodiment 2 of the present disclosure. FIG. 5 shows a schematic view with simplification in drawing.

[0036] The wiring board 10A and the probe card 1A of Embodiment 2 are different in that another element is added to the configuration in which the circuit board 20A supports the wiring board 10A, and other components may be the same as those in Embodiment 1.

[0037] The wiring board 10A of Embodiment 2 may further include a bonding metal film 16 for bonding a support metal member 24, as shown in FIG. 4, in addition to the components similar to those in Embodiment 1. The bonding metal film 16 may be located on the first surface S1. The wiring board 10A may include a plurality of bonding metal films 16, but the bonding metal film 16 may be one. The bonding metal film 16 may have an area larger than that of the individual wiring conductors 12 and 13 in plan view. The bonding metal film 16 may be polygonal, circular, or elongated in one direction in plan view.

[0038] The bonding metal film 16 may be a conductor formed by forming a thin film of a pattern corresponding to the bonding metal film 16 on the first surface S1 by a thin film forming process such as a sputtering process and then plating the thin film by an electrolytic plating process.

[0039] In the probe card 1A, a metal member 24 is joined to the bonding metal film 16, and the metal member 24 supports the wiring board 10A from above (see FIG. 5). That is, the metal member 24 exerts a force in a direction to pull up the bonding metal film 16. The force counteracts the force in the direction in which the plurality of contact conductors 31 press the wiring board 10A, and acts to counteract the distortion of the wiring board 10A due to the pressure of the plurality of contact conductors 31.

[0040] All of the bonding metal film 16 may be located in the first region R1 as shown in FIG. 4, or more than half of the total area may be located in the first region R1. According to this configuration, since most of the bonding metal film 16 is included in the first region R1 where the pressure of the plurality of contact conductors 31 increases, the action of counteracting the distortion of the bonding metal film 16 acts on the first region R1, and the stress of the wiring board 10A in the first region R1 can be relaxed. Further, around the bonding metal film 16, the force for pulling up the wiring board 10A in the bonding metal film 16 and the force for pushing down the wiring board 10A by the plurality of contact conductors 31 cancel each other out. Therefore, it is possible to alleviate the concentration of stress around the bonding metal film 16.

[0041] The probe card 1A of Embodiment 2 may further include a metal member 24 (for example, a bolt and a nut) and a support portion (such as a through hole) 26 located on the circuit board 20A in addition to the components similar to those of Embodiment 1. The metal member 24 may be joined to the bonding metal film 16 via a joining member 8 such as a brazing material. Then, the circuit board 20A may support the wiring board 10A via the metal member 24 by engaging another part of the metal member 24 with the support portion 26 of the circuit board 20A.

[0042] According to the wiring board 10A of Embodiment 2, good contact between the plurality of wiring conductors 12 on the first surface S1 and the contact conductor 31 can be realized, and the stress generated in the wiring conductors 12 can be relaxed. According to the probe card 1A of Embodiment 2, good communication of one or both of the signal and the power supply voltage can be realized between the inspection device and the inspection object by the wiring board 10A that can obtain the above actions.

[0043] As described above, each embodiment of the present disclosure has been described. However, the wiring board and the probe card of the present disclosure are not limited to the above embodiments. The details shown in the embodiments can be appropriately changed without departing from the gist of the invention.

Description of Signs

[0044] 1, 1A Probe card 8 Joining member 10, 10A Wiring board 11 Insulating substrate 12, 14 Wiring conductor 12a First wiring conductor 12b Second wiring conductor 13 Wiring conductor (third wiring conductor) 16 Metallic film for joining R1 First region R2 Second region T1aa, T2aa Thickness 20, 20A Circuit board 21 Electrode pad 22 Frame 24 Metal member 26 Support part 31 Contact conductor 41 Probe pin

Claims

1. An insulating substrate having a first surface and a second surface located on the opposite side of the first surface; A plurality of wiring conductors located on the first surface and the second surface; Comprising; When the first surface is divided into two regions, a circular first region located at the center of the first surface and a second region surrounding the first region and having the same area as the first region, The plurality of wiring conductors include a plurality of first wiring conductors located in the first region and a plurality of second wiring conductors located in the second region, The thickness of the plurality of second wiring conductors is greater than the thickness of the plurality of first wiring conductors, A wiring substrate.

2. In a plan view, the total area of the plurality of first wiring conductors is larger than the total area of the plurality of second wiring conductors, The wiring substrate according to Claim 1.

3. The plurality of wiring conductors include a plurality of third wiring conductors located on the second surface, In a plan view, the total area of the plurality of first wiring conductors and the plurality of second wiring conductors is larger than the total area of the plurality of third wiring conductors, The wiring substrate according to Claim 1 or Claim 2.

4. In a plan view, the total area of the plurality of first wiring conductors is 55% or more and 76% or less of the total area of the plurality of wiring conductors located on the first surface, The wiring substrate according to any one of Claims 1 to 3.

5. The insulating substrate is a regular polygonal shape having 8 or more corners or a circular shape in a plan view, The wiring substrate according to any one of Claims 1 to 4.

6. Comprising one or more bonding metal films located on the first surface, In a plan view, more than half of the total area of the bonding metal film is located in the first region, The wiring substrate according to any one of Claims 1 to 5.

7. The wiring substrate according to any one of Claims 1 to 6, A plurality of probe pins electrically connected to the plurality of wiring conductors located on the second surface respectively, A probe card comprising.

8. The wiring substrate according to Claim 6, A plurality of probe pins electrically connected to the plurality of wiring conductors located on the second surface respectively, A metal member joined to the bonding metal film, A probe card comprising.

Images