JP5361314B2 - Multilayer wiring board and probe card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem, wherein when stress, such as thermal stress is added toward an insulating board from a conductive member and when stress is added to a conductive member from an insulating board by adding stress externally to a ceramic board, stress concentrates on a part of the interface between the conductor part and the ceramic board, resulting in the possibility of exfoliation of a conductor part from the ceramic board. <P>SOLUTION: In the wiring board including a first insulating board; a second insulating board deployed on the first insulating board to prepare a via hole; and a conductive member filled in the via hole, when a cross-section of the second insulating board is viewed; the via hole is formed; such that the diameter of an aperture on the back surface side of the second insulating board is made larger than the diameter of top of obverse surface side of the second insulating board, and the surface is formed to become a curvilinear shape, with the surface being convex on the inward side. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a wiring board used for a probe card. The probe card is used in an evaluation test for measuring electrical characteristics of a semiconductor element or a semiconductor integrated circuit formed on a semiconductor wafer.

  Conventionally, as a wiring board used for a probe card, a first insulating substrate having a main surface, a main surface of the first insulating substrate, and a main surface, a back surface, and a main surface are provided. What has the 2nd insulating board | substrate provided with the via hole penetrated to the back surface, and the electrically-conductive member arrange | positioned in the via hole is used.

  When a probe card is manufactured using such a wiring board, there is a difference in thermal expansion coefficient between the insulating substrate and the conductive member in the heat treatment process such as the probe pin mounting process. Thermal stress is applied from the surface toward the insulating substrate. At this time, if the conductive member is a columnar body, thermal stress is applied radially from the center of the conductive member in a direction parallel to the main surface of the first insulating substrate, so that a crack is formed in a part of the wiring substrate. Could have occurred.

Therefore, it has been proposed to disperse the thermal stress in the direction of stacking of the substrates by using a substantially truncated cone-shaped conductor as in the ceramic substrate described in Patent Document 1. In the ceramic substrate described in Patent Document 1, by using a substantially truncated cone-shaped conductor, the thermal stress applied from the conductive member toward the insulating substrate is inclined down to the main surface or the back surface side of the first ceramic substrate. Can be in the direction. Therefore, it is possible to reduce the possibility of cracks occurring in a part of the wiring board.
JP 2007-324419 A

  In the ceramic substrate described in Patent Document 1, the interface between the conductor portion and the ceramic substrate is linear in a cross section perpendicular to the main surface of the ceramic substrate. Therefore, when stress is applied from the conductive member to the insulating substrate as in the above-described thermal stress, and when stress is applied from the outside to the ceramic substrate, the stress is applied from the insulating substrate to the conductive member. In addition, there is a possibility that stress concentrates on a part of the interface between the conductor portion and the ceramic substrate, and the conductor portion peels off from the ceramic substrate.

  In recent years, as semiconductor wafers have been increased in size, semiconductor elements have been narrowed in pitch and fine wiring. Along with this, finer wiring of conductor patterns is also progressing in probe cards and wiring boards used therefor. Therefore, since the bonding area between the conductive member and the insulating substrate is small, the conductive member is easily peeled from the insulating substrate.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a wiring board with improved electrical reliability by improving the bonding property between a conductive member and an insulating board.

A multilayer wiring board of the present invention is provided on a main surface of a first insulating substrate having a main surface and the first insulating substrate, and penetrates from the main surface to the back surface and from the main surface to the back surface. A second insulative substrate having a via hole and a conductive member disposed in the via hole. When the second insulating substrate is viewed in cross section in a cross section perpendicular to the main surface of the second insulating substrate, the via hole has an upper end on the main surface side of the second insulating substrate. The diameter of the lower end portion of the second insulating substrate on the back surface side is larger than the diameter of the portion, and the via hole has a curved shape in which the surface of the via hole protrudes inward. The center of the upper end portion of the via hole on the main surface side is shifted in the direction along the main surface with respect to the center of the lower end portion of the via hole on the back surface side. In the cross section perpendicular to the surface, the via hole is such that the center of the upper end portion on the main surface side of the via hole is closer to the side surface of the second insulating substrate than the center of the lower end portion on the back surface side of the via hole. A third insulating substrate having a shape of a wiring substrate, a main surface of the second insulating substrate, and a second via hole penetrating from the main surface to the back surface. Including. Further, when the third insulating substrate is viewed in cross section in a cross section perpendicular to the main surface of the third insulating substrate, the second via hole is formed on the main surface of the third insulating substrate. The second insulating substrate has a curved shape in which the diameter of the lower end portion on the back surface side of the third insulating substrate is larger than the diameter of the upper end portion on the side, and the surface of the second via hole is inwardly convex. When the via hole of the conductive substrate is the first via hole, the radius of curvature of the first via hole is larger than the radius of curvature of the second via hole.

According to the multilayer wiring board of the present invention, when the second insulating substrate is viewed in cross section in a cross section perpendicular to the main surface of the second insulating substrate, the via hole is the main hole of the second insulating substrate. It has a curved shape in which the diameter of the lower end portion on the back surface side of the second insulating substrate is larger than the diameter of the upper end portion on the surface side, and the surface of the via hole is convex inward. As a result, the bonding area between the conductive member and the insulating substrate increases. Further, the via hole has a curved shape in which the surface is convex inward. In addition, the center of the upper end portion on the main surface side of the via hole is shifted in the direction along the main surface with respect to the center of the lower end portion on the back surface side of the via hole, and the via hole is in relation to the main surface of the second insulating substrate. In the vertical cross section, the center of the upper end portion on the main surface side is closer to the side surface of the second insulating substrate than the center of the lower end portion on the back surface side. Thereby, even when stress is applied from the conductive member toward the insulating substrate and when stress is applied from the insulating substrate toward the conductive member, the insulating substrate and the conductive member are not easily deformed. As a result, the bondability between the conductive member and the insulating substrate is improved, and the electrical reliability is improved. Also, a large stress locally applied to the interface between the third insulating substrate and the conductive member
And the stress applied to the interface between the second insulating substrate and the conductive member is further spread over the interface between the second insulating substrate and the conductive member. Can be dispersed. In other words, a strong stress applied locally can be dispersed stepwise. Therefore, the durability of the entire multilayer wiring board can be improved.

  Hereinafter, the wiring board of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the wiring substrate 1 according to the first embodiment of the present invention includes a first insulating substrate 3 having a main surface 3 a and a main surface 3 a of the first insulating substrate 3. A second insulating substrate 5 provided on the upper surface and provided with a main surface 5a, a back surface 5b opposite to the main surface 5a, and a via hole 7 penetrating from the main surface 5a to the back surface 5b; The conductive member 9 is provided. When the second insulating substrate 5 is viewed in a cross section perpendicular to the main surface 5a of the second insulating substrate 5, the via hole 7 is formed on the main surface 5a side of the second insulating substrate 5. The diameter R2 of the lower end portion on the back surface 5b side of the second insulating substrate 5 is larger than the diameter R1 of the upper end portion, and the surface of the via hole 7 has a curved shape that protrudes inward.

  Thus, since the via hole 7 in the wiring board 1 of the present embodiment has a curved shape in which the surface of the via hole 7 protrudes inward, the via hole 7 has a large joint surface between the second insulating substrate 5 and the conductive member 9. Even when a stress is applied, the stress is dispersed over a wide range of the joint surface between the second insulating substrate 5 and the conductive member 9, and the second insulating substrate 5 is moved to the main surface 5 a side or the back surface 5 b side. Stress can be released. For this reason, the insulating substrate and the conductive member 9 are not easily deformed, so that the bonding property between the conductive member 9 and the insulating substrate is improved, and the electrical reliability is improved.

  The via hole 7 may have a constricted shape in which the diameter of the central portion in the thickness direction of the second insulating substrate 5 is smaller than the diameter of the upper end portion on the main surface 5a side and the lower end portion on the back surface 5b side. It is preferable that the diameter gradually increases from the upper end portion on the 5a side toward the lower end portion on the back surface 5b side. Even when a large stress is applied to the joint surface between the second insulating substrate 5 and the conductive member 9, it is possible to suppress the stress from being accumulated in the central portion in the thickness direction of the second insulating substrate 5, and This is because stress can be released to the main surface 5a side or the back surface 5b side of the second insulating substrate 5.

  The first insulating substrate 3 of the present embodiment includes a main surface 3a. As the first insulating substrate 3, a member having good insulation may be used. Specifically, a ceramic member and a resin can be used.

  The second insulating substrate 5 of the present embodiment is disposed on the main surface 3 a of the first insulating substrate 3. Further, the second insulating substrate 5 of the present embodiment includes a main surface 5a, a back surface 5b opposite to the main surface 5a, and a via hole 7 penetrating from the main surface 5a to the back surface 5b. As the second insulating substrate 5, like the first insulating substrate 3, a member having good insulation may be used. Specifically, a ceramic member and a resin can be used.

  The second insulating substrate 5 is arranged on the main surface 3a of the first insulating substrate 3 so that the main surface 5a of the second insulating substrate 5 is in contact with the main surface 3a of the first insulating substrate 3. The second insulating substrate 5 may be provided so that the back surface 5b of the second insulating substrate 5 is in contact with the main surface 3a of the first insulating substrate 3 as in the present embodiment. It is preferable to dispose on the main surface 3 a of one insulating substrate 3. This is because the stress applied to the second insulating substrate 5 from above the second insulating substrate 5 can be easily distributed over a wide area below the second insulating substrate 5.

  When the wiring board 1 of the present embodiment is used for the probe card 21, in consideration of the contact with the semiconductor element that is the object to be measured, a highly rigid ceramic member is used as the first insulating substrate 3 and the first is used. It is preferable to use a resin that can easily increase the pitch accuracy as the second insulating substrate 5.

  The conductive member 9 of this embodiment is disposed in the via hole 7 of the second insulating substrate 5. The conductive member 9 may be filled in the entire via hole 7, but it is preferable that the conductive member 9 is in contact with the surface of the via hole 7 and has a gap or a recess. This is because stress can be absorbed by these portions when there are voids and recesses, so that the bondability between the conductive member 9 and the second insulating substrate 5 can be improved. As the conductive member 9, a member having good electrical conductivity may be used. Specifically, metal conductors such as Sn, Ag, Au, and Cu can be used. It is particularly preferable to use a metal conductor having a high melting point such as W, Mo and Mn.

  Next, a wiring board 1 according to a second embodiment of the present invention will be described.

  As shown in FIG. 3, the wiring board 1 according to the present embodiment has a cross section perpendicular to the main surface 5 a of the second insulating substrate 5 as compared with the wiring board 1 according to the first embodiment. The center of the upper end portion of the via hole 7 on the main surface 5a side is closer to the side surface of the second insulating substrate 5 than the center of the lower end portion of the via hole 7 on the back surface 5b side. Thereby, the effect of dispersing stress on the side surface side of the wiring board 1 can also be enhanced.

  Next, a multilayer wiring board according to an embodiment of the present invention will be described.

  As shown in FIGS. 4 and 5, the multilayer wiring board 11 of this embodiment is disposed on the main surface 5 a of the wiring board 1 typified by the above-described embodiment and the second insulating substrate 5. A third insulating substrate 13 including a surface 13a, a back surface 13b, and a second via hole 15 penetrating from the main surface 13a to the back surface 13b is provided. In addition, when the third insulating substrate 13 is viewed in a cross section in a cross section perpendicular to the main surface 13 a of the third insulating substrate 13, the second via hole 15 has the main via of the third insulating substrate 13. The diameter of the lower end portion on the back surface 13b side of the third insulating substrate 13 is larger than the diameter of the upper end portion on the surface 13a side, and the second via hole 15 has a curved shape in which the surface is convex inward. The curvature radius of the first via hole 7 in the second insulating substrate 5 is larger than the curvature radius of the second via hole 15.

  By forming the first via hole 7 and the second via hole 15 as described above, the bonding property between the conductive member 9 and the insulating substrate is enhanced, and the electrical reliability is enhanced. Since the first via hole 7 has a shape in which the diameter of the lower end portion on the back surface 5b side of the second insulating substrate 5 is larger than the diameter of the upper end portion on the main surface 5a side of the second insulating substrate 5, The stress applied to the interface between the second insulating substrate 5 and the conductive member 9 due to the stress applied to the second insulating substrate 5 from the main surface 5a side of the second insulating substrate 5 is changed to the second insulating substrate 5. And the conductive member 9 can be dispersed over a wide range.

  The second via hole 15 has a shape in which the diameter of the lower end portion on the back surface 13b side of the third insulating substrate 13 is larger than the diameter of the upper end portion on the main surface 13a side of the third insulating substrate 13. Thus, the stress applied to the interface between the third insulating substrate 13 and the conductive member 9 due to the stress applied to the third insulating substrate 13 from the main surface 13a side of the third insulating substrate 13 is changed to the third insulating property. It can be dispersed over a wide range of the interface between the substrate 13 and the conductive member 9.

  At this time, since the third insulating substrate 13 is disposed on the main surface 5 a of the second insulating substrate 5, the third insulating substrate 13 is more locally located than the second insulating substrate 5. Large stress is easily applied. However, in the wiring board 1 according to the present embodiment, the radius of curvature of the first via hole 7 in the second insulating substrate 5 is larger than the radius of curvature of the second via hole 15, so that the third insulating substrate A large stress locally applied to the interface between the first insulating substrate 13 and the conductive member 9 is dispersed over a wide range of the interface between the third insulating substrate 13 and the conductive member 9, and the second insulating substrate 5 and the conductive member 9 The stress applied to the interface can be dispersed over a wider range of the interface between the second insulating substrate 5 and the conductive member 9. In other words, a strong stress applied locally can be dispersed stepwise. Therefore, the durability of the entire multilayer wiring board 11 can be improved.

  Moreover, it is preferable to interpose an adhesive layer between the second insulating substrate 5 and the third insulating substrate 13. This is because the bondability between the second insulating substrate 5 and the third insulating substrate 13 can be improved, and the durability of the multilayer wiring substrate 11 can be improved.

  Next, the manufacturing method of the wiring board of this invention is demonstrated.

  As shown in FIGS. 6 and 7, the method of manufacturing the wiring board 1 according to the first embodiment of the present invention includes a first insulating substrate 3 having a main surface 3a, a main surface 5a, and a back surface 5b. A step of preparing the provided second insulating substrate 5 (first step); a via hole 7 penetrating from the main surface 5a to the back surface 5b is formed in the second insulating substrate 5; A step of disposing the member 9 (second step), a step of disposing the second insulating substrate 5 on the main surface 3a of the first insulating substrate 3 (third step), A step of pressing the second insulating substrate 5 from the main surface 5a side to the back surface 5b side of the second insulating substrate 5 using the first pressing member 17 (fourth step); The second pressing member 19 having a hardness lower than that of the member 17 is used to move the second insulating substrate 5 from the main surface 5a side toward the back surface 5b side. It has a step of pressing the edge of the substrate 5 (the fifth step), a.

  Thus, the manufacturing method of the wiring board 1 according to the present embodiment includes a step of pressing the two second insulating substrates 5, the fourth step and the fifth step. In the fourth step, the first insulating substrate 3 and the second insulating substrate 5 can be positioned. In the fifth step, since the second pressing member 19 having a lower hardness than the first pressing member 17 is used, the second pressing member 19 is in close contact with the second insulating substrate 5. The bondability between the first insulating substrate 3 and the second insulating substrate 5 can be improved.

  In the case where the step of pressing the second insulating substrate 5 is only the fifth step, there is a possibility that a displacement occurs between the first insulating substrate 3 and the second insulating substrate 5, By including the fourth step and the fifth step as in this embodiment, it is possible to suppress the occurrence of misalignment between the first insulating substrate 3 and the second insulating substrate 5. .

  Furthermore, since the second pressing member 19 is in close contact with the second insulating substrate 5, it is possible to apply a pressing force with small variation over a wide range of the second insulating substrate 5. Therefore, the stress applied to the second insulating substrate 5 is likely to be applied not only to the first insulating substrate 3 positioned below the second insulating substrate 5 but also to the conductive member 9. Therefore, in the fifth step, the diameter of the lower end portion on the back surface 5b side of the second insulating substrate 5 is larger than the diameter of the upper end portion on the main surface 5a side of the second insulating substrate 5, and the surface is inside. It is possible to easily form a curved via hole 7 that is convex. As a result, the bonding surface of the second insulating substrate 5 and the conductive member 9 can be formed in a curved shape that protrudes toward the center of the via hole 7, so that the bondability between the conductive member 9 and the second insulating substrate 5 can be achieved. And electrical reliability is enhanced.

  More specifically, first, in the first step, a first insulating substrate 3 having a main surface 3a and a second insulating substrate 5 having a main surface 5a and a back surface 5b are prepared. . In the second step, a via hole 7 penetrating from the main surface 5 a to the back surface 5 b is formed in the second insulating substrate 5, and the conductive member 9 is disposed in the via hole 7. Further, as the third step, the second insulating substrate 5 is disposed on the main surface 3 a of the first insulating substrate 3.

  At this time, the third step may be performed after the second step, or the second step may be performed after the third step. That is, after disposing the second insulating substrate 5 on the main surface 3 a of the first insulating substrate 3, the via hole 7 is formed in the second insulating substrate 5, and the conductive member 9 is placed in the via hole 7. Alternatively, a via hole 7 is formed in the second insulating substrate 5, and the conductive member 9 is disposed in the via hole 7, and then the first insulating substrate 3 has a first surface on the main surface 3 a. Two insulating substrates 5 may be provided.

  Further, as a fourth step, as shown in FIG. 6, the second insulating substrate 5 is used from the main surface 5 a side to the back surface 5 b side of the second insulating substrate 5 using the first pressing member 17. Press. As the first pressing member 17, a member having relatively higher hardness than the second pressing member 19 may be used. Specifically, a glass plate or a metal plate can be used.

  Finally, as the fifth step, as shown in FIG. 7, the second pressing member 19 having a hardness lower than that of the first pressing member 17 is used to reverse the back surface from the main surface 5 a side of the second insulating substrate 5. The second insulating substrate 5 is pressed toward the 5b side. As the second pressing member 19, a member having a relatively low hardness as compared with the first pressing member 17 may be used, and specifically, a soft member such as a resinous sheet can be used.

  In the step of forming the via hole 7, the via hole 7 is formed in which the diameter of the opening on the back surface 5 b side of the second insulating substrate 5 is larger than the diameter of the upper end portion on the main surface 5 a side of the second insulating substrate 5. It is preferable. As a result, the pressing force in the fifth step is easily transmitted to the bonding surface between the second insulating substrate 5 and the conductive member 9, so that the bonding surface of the second insulating substrate 5 and the conductive member 9 is formed on the via hole 7. It is because it becomes easy to form by the curve shape which becomes convex to the center side.

  The second pressing member 19 preferably has a hardness lower than that of the conductive member 9 and higher than that of the second insulating substrate 5. Accordingly, the deformation in the thickness direction of the second insulating substrate 5 can be promoted while suppressing the deformation in the thickness direction of the conductive member 9, so that the joint surface between the second insulating substrate 5 and the conductive member 9 is formed in the via hole. This is because it can be easily deformed into a curved shape that is convex toward the center side of 7.

  Next, a probe card according to an embodiment of the present invention will be described.

  As shown in FIG. 8, the probe card 21 of this embodiment includes the wiring board 1 typified by the above embodiment, and includes a measurement wiring board 23 having a main surface and a back surface, and a measurement wiring board 23. A measurement terminal 25 disposed on the main surface and a connection terminal 27 disposed on the back surface of the measurement wiring board 23 are provided.

  In the present embodiment, the measurement terminal 25 is electrically connected to the conductive member 9 via a wiring conductor 29 disposed on the main surface of the measurement wiring board 23. Further, the connection terminal 27 is electrically connected to the conductive member 9 via a through conductor 31 that penetrates the first insulating substrate 3.

  In the probe card 21 of the present embodiment, the terminal of the semiconductor element that is the object to be measured is electrically connected to the measurement terminal 25 of the probe card 21, and the semiconductor element is energized. Here, energizing is intended not only to apply a voltage but also to input a signal to a semiconductor element. The quality of the semiconductor element can be determined by measuring the output taken out via the connection terminal 27 and comparing it with the expected value.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a perspective view which shows the wiring board in the 1st Embodiment of this invention. It is sectional drawing of the wiring board shown in FIG. It is sectional drawing which shows the wiring board in the 2nd Embodiment of this invention. It is a perspective view which shows the multilayer wiring board concerning one Embodiment of this invention. It is sectional drawing of the multilayer wiring board shown in FIG. It is sectional drawing which shows the manufacturing method of the wiring board concerning one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the wiring board concerning one Embodiment of this invention. It is sectional drawing which shows the probe card concerning one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wiring board 3 ... 1st insulating substrate 3a ... Main surface 5 ... 2nd insulating substrate 5a ... Main surface 5b ... Back surface 7 ... Via hole (1st 1 via hole)
9 ... conductive member 11 ... multilayer wiring board 13 ... third insulating substrate 13a ... main surface 13b ... back surface 15 ... second via hole 17 ... first press Member 19 ... second pressing member 21 ... probe card 23 ... measurement wiring board 25 ... measurement terminal 27 ... connection terminal 29 ... wiring conductor 31 ... penetrating conductor

Claims (4)

A first insulating substrate having a main surface, and a second insulating layer disposed on the main surface of the first insulating substrate, and having a main surface, a back surface, and a via hole penetrating from the main surface to the back surface. of an insulating substrate, and have a conductive member disposed within the via hole,
When the second insulating substrate is viewed in cross section in a cross section perpendicular to the main surface of the second insulating substrate, the via hole is formed at the upper end portion on the main surface side of the second insulating substrate. The diameter of the lower end of the back surface side of the second insulating substrate is larger than the diameter, and the via hole has a curved shape in which the surface of the via hole is convex inward.
The center of the upper end portion on the main surface side of the via hole is shifted in the direction along the main surface with respect to the center of the lower end portion on the back surface side of the via hole,
In the cross section perpendicular to the main surface of the second insulating substrate, the via hole has the center of the upper end portion of the via hole on the main surface side than the center of the lower end portion of the via hole on the back surface side. a wiring substrate Ru shape der close to the side surface of the second insulating substrate,
Multi-layer wiring provided on the main surface of the second insulating substrate, and including a third insulating substrate having a main surface, a back surface, and a second via hole penetrating from the main surface to the back surface A substrate,
When the third insulating substrate is viewed in cross section in a cross section perpendicular to the main surface of the third insulating substrate, the second via hole is formed on the main surface side of the third insulating substrate. The diameter of the lower end portion on the back side of the third insulating substrate is larger than the diameter of the upper end portion, and the second via hole has a curved shape in which the surface is convex inward,
A multilayer wiring board characterized in that when the via hole of the second insulating substrate is a first via hole, the radius of curvature of the first via hole is larger than the radius of curvature of the second via hole . The multilayer wiring board according to claim 1, wherein the conductive member in the wiring board is in contact with the surface of the via hole and has a gap or a recess. 2. The wiring board according to claim 1, wherein a diameter of the via hole in the wiring board gradually increases from an upper end portion on the main surface side toward a lower end portion on the back surface side. A measurement wiring board comprising the multilayer wiring board according to claim 1 and having a main surface and a back surface; a measurement terminal disposed on the main surface of the measurement wiring board; A probe card comprising a connection terminal disposed on the surface.

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