JP6100617B2 - Multi-layer wiring board and probe card board - Google Patents

Description

  The present invention relates to a multilayer wiring board in which a plurality of resin insulation layers and thin film conductor layers are provided on a ceramic substrate, and a probe card substrate using the multilayer wiring board.

  Conventionally, a semiconductor device is connected to a terminal on the upper surface, and a connection pad on the lower surface electrically connected to the terminal is electrically connected to an external electric circuit as a wiring substrate (space transformer substrate) on a ceramic substrate. A multilayer wiring board provided with a thin film wiring portion made of a resin insulating layer and a thin film conductor layer is used. The multilayer wiring board is used as, for example, a so-called probe card board that performs electrical inspection of semiconductor elements.

  In a multilayer wiring board, a thin film conductor layer made of a copper plating layer or the like is provided between a plurality of resin insulation layers. A via conductor that penetrates the resin insulating layer in the thickness direction is provided. The end portion of the via conductor is connected to the thin film conductor layer. The upper and lower thin film conductor layers are electrically connected to each other via via conductors.

  The ceramic substrate is provided with a wiring conductor from the upper surface to the lower surface, for example. A thin film conductor layer is electrically connected to a portion of the wiring conductor located on the upper surface of the ceramic substrate. Through this wiring conductor, the thin film conductor layer is electrically led to the lower surface of the ceramic substrate and is electrically connected to an external electric circuit.

JP 2007-173429 A

  In the multilayer wiring board, a resin insulating layer made of a resin material having a smaller coefficient of thermal expansion than that in the past in order to suppress peeling of the resin insulating layer due to a difference in coefficient of thermal expansion between the resin insulating layer and the ceramic substrate. Has come to be used.

  However, in this case, since the thermal expansion coefficient of the resin insulating layer is smaller than the thermal expansion coefficient of the via conductor, for example, the via conductor tends to expand more than the resin insulating layer due to heat applied during operation as a probe card. To do. Due to the difference in expansion, there is a problem that stress that peels the resin insulating layer upward between the plurality of resin insulating layers is generated, and peeling between the layers is likely to occur. Since the ceramic substrate exists below the thin-film wiring portion and the via conductor is blocked from extending, the direction in which the via conductor extends is mainly upward. Therefore, upward stress is generated.

A multilayer wiring board according to one aspect of the present invention includes a ceramic substrate, a plurality of resin insulating layers stacked on the ceramic substrate, a thin film conductor layer provided between the plurality of resin insulating layers, and the plurality of the plurality of resin insulating layers. Via conductors penetrating the resin insulation layer in the thickness direction. A part of the thin film conductor layer is directly connected to an end portion of the via conductor, and one of the resin insulation layers adjacent to the upper and lower layers is a surface portion between the plurality of resin insulation layers. The thin film is in the form of a groove in plan view and is directly connected to the via conductor.
It is adjacent to the conductor layer and surrounds the via conductor, and a part of the other resin insulation layer enters the recess.

A probe card substrate according to one aspect of the present invention includes a multilayer wiring substrate having the above-described configuration, a terminal formed of a thin film conductor layer provided on the upper surface of the uppermost resin insulating layer, and a probe connected to the terminal. Is provided.

  According to the multilayer wiring board of one aspect of the present invention, between the resin insulating layers, one of the resin insulating layers adjacent in the vertical direction has a concave portion on the surface portion, and the concave portion Since a part of the surface portion of the other resin insulation layer enters inside, the bonding area between the upper and lower resin insulation layers increases. For this reason, the bonding strength between the upper and lower resin insulating layers is increased, and peeling between the layers is suppressed.

It is sectional drawing which shows the multilayer wiring board of embodiment of this invention, and the board | substrate for probe cards. It is sectional drawing which expands and shows the principal part of the multilayer wiring board shown in FIG. 1, and the board | substrate for probe cards. It is sectional drawing which shows the principal part in the modification of the multilayer wiring board shown in FIG. 1, and the board | substrate for probe cards. It is sectional drawing which shows the principal part in the other modification of the multilayer wiring board shown in FIG. 1, and the board | substrate for probe cards. It is sectional drawing which shows the principal part in the other modification of the multilayer wiring board shown in FIG. 1, and the board | substrate for probe cards.

  A multilayer wiring board and a probe card board according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a multilayer wiring board and a probe card board according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a main part in FIG.

  The multilayer wiring board includes a ceramic substrate 10, a plurality of resin insulation layers 1 laminated on the ceramic substrate 1, a thin film conductor layer 2 provided between the plurality of resin insulation layers 1, and a plurality of resin insulation layers 1. And a via conductor 3 penetrating in the thickness direction. A thin film conductor layer (not shown) similar to the thin film conductor layer 2 is also provided on the upper surface of the uppermost resin insulating layer 1 of the multilayer wiring board, and a terminal 2a is formed by this thin film conductor layer. A probe card substrate is formed by connecting a probe 21 to the terminal 2a.

  In the multilayer wiring board and the probe card substrate, one resin insulating layer among the resin insulating layers 1 adjacent to each other between the plurality of resin insulating layers 1 has a recess 1a on the surface portion. A part of the other resin insulating layer 1 enters 1a. Part of the resin insulating layer 1 that has entered fills the recess 1a. The area of the bonding surface between the upper and lower resin insulation layers 1 is increased by the recess 1a. Therefore, the bonding strength between the upper and lower insulating layers 1 is improved, and the possibility that peeling or the like occurs between the insulating layers 1 is reduced.

  The ceramic substrate 10 is a part that ensures the mechanical strength of the entire multilayer wiring board. The ceramic substrate 10 is provided on the main surface of the ceramic insulating layer 11 and a ceramic insulating base (not indicated) in which a ceramic insulating layer 11 made of an aluminum oxide sintered body or a mullite sintered body is laminated. And a through conductor 13 penetrating the ceramic insulating layer 11 in the thickness direction.

  The wiring conductor 12 provided on the upper surface of the ceramic substrate 10 is electrically connected to the thin film conductor layer 2, and the wiring conductor 12 provided on the lower surface of the ceramic substrate 10 is electrically connected to an external electric circuit (not shown). Connected.

  If the ceramic substrate 10 is made of, for example, a mullite sintered body, it can be manufactured as follows. That is, a ceramic green sheet is produced by forming a raw material powder containing mullite as a main component into a sheet together with an appropriate organic binder and an organic solvent, and then the ceramic green sheet is cut and punched into an appropriate shape and It can be produced by sizing and baking at a temperature of about 1300-1500 ° C.

  The wiring conductor 12 is formed of a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, or platinum, or an alloy containing these metal materials as a main component. These metal materials and the like are formed on a predetermined portion of the ceramic substrate 10 by a method such as a metallization method or a plating method.

  If the wiring conductor 6 is made of tungsten, for example, a paste of tungsten is applied or filled on the surface of the ceramic green sheet to be the ceramic substrate 10 or the inside of a through-hole formed in advance. It can be formed by co-firing.

  The resin insulating layer 1 functions as a base material for forming the thin film conductor layer 2. The resin insulating layer 1 functions as an insulating material for ensuring electrical insulation between the thin film conductor layers 2. The resin insulating layer 1 is, for example, a rectangular shape such as a rectangular shape or a square shape, or a circular shape, and is formed in a layer shape having a thickness of about 25 μm.

  The resin insulating layer 1 is made of, for example, a thermoplastic resin such as liquid crystal polymer, polyimide, polyetherimide resin, or polyamideimide resin, or a resin material such as epoxy resin, polyamideimide resin, or polyimide resin. Examples of the liquid crystal polymer include polyester-based liquid crystal polymers.

  If the laminated body of the plurality of resin insulation layers 1 is made of, for example, a thermosetting resin, it is produced by molding and laminating an uncured product of the resin material into a predetermined layer shape, and then curing it. Can do. If the resin insulating layer 1 is made of a thermoplastic resin, the resin insulating layer 1 can be produced by laminating a plurality of thermoplastic resins such as a film to be the resin insulating layer 1 and heating them to adhere to each other.

The thin film conductor layer 2 forms part of a conductive path that electrically conducts the multilayer wiring board in the thickness direction. The thin film conductor layer 2 electrically connects, for example, a probe 21 electrically connected to the thin film conductor layer 2 and an external electric circuit electrically connected to the wiring conductor 12 provided on the lower surface of the ceramic substrate 1. A part of the conductive path connected to is formed. A semiconductor wafer as a test object electrically connected to the probe 21 is electrically connected to an external electric circuit via the probe 21, the thin film conductor layer 2, the through conductor 3, and the wiring conductor 21. The external electric circuit in this case is, for example, an inspection circuit that inspects the operation of the semiconductor wafer, and thereby inspects whether or not each semiconductor element of the semiconductor wafer operates normally.

  The thin film conductor layer 2 also functions as a land for improving the ease of connection and the reliability when the end portions of the via conductors 3 provided in the upper and lower resin insulation layers 1 are electrically connected to each other. You can also In the case of the thin film conductor layer 2 as a land, for example, it may be provided in a circular pattern such as a concentric circle with respect to the circular via conductor 3 in plan view.

The thin film conductor layer 2 is made of a metal material such as copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cobalt, or titanium. The thin film conductor layer 2 may be made of an alloy material of these metal materials.

  The thin film conductor layer 2 is formed by depositing the above metal material on the main surface of the resin insulating layer 1 by a sputtering method, a vapor deposition method, a plating method, or the like, and performing a trimming process such as masking or etching as necessary. , Can be formed on the surface of the resin insulating layer 1 in a predetermined pattern.

  The resin insulating layer 1 is provided with via conductors 3 that penetrate the resin insulating layer 1 in the thickness direction. The upper and lower thin film conductor layers 2 are electrically connected to each other via the via conductor 3. The upper end portion of the via conductor 3 is directly connected to the lower surface of the upper thin film conductor layer 2. The lower end portion of the via conductor 3 is directly connected to the upper surface of the lower thin film conductor layer 2.

  The via conductor 3 is made of, for example, solder such as tin-silver, metal material such as copper, silver, tin, bismuth, indium, chromium, nickel, titanium, or an alloy material of these metal materials.

The via conductor 3 is a through-hole that penetrates in the thickness direction in a part of the resin insulating layer 1 by drilling such as laser processing using a CO ₂ laser or YAG laser, RIE (reactive ion etching) or etching using a solvent, A via hole (not shown) is formed, and a conductive material to be a via conductor is filled in the through hole by a sputtering method, a vapor deposition method, a plating method, a method of filling a conductor paste, or the like.

  A thin film conductor layer 2 is provided between the plurality of laminated resin insulation layers 1, and the upper and lower thin film conductor layers 2 are electrically connected to each other via via conductors 3, so that a thin film portion A of the multilayer wiring board 1 is provided. Is basically formed.

  The multilayer wiring board having such a configuration is manufactured, for example, as follows. If the resin insulating layer 1 is made of a thermoplastic resin, first, a sheet (film or the like) of a thermoplastic resin such as a polyimide resin is prepared, and then a copper foil is attached to the upper surface of the resin insulating layer 1. After that, the copper foil is processed into a predetermined pattern of the thin film conductor layer 2 by pattern processing means such as masking and etching, and then a hard substrate having a flat surface is placed on the upper surface of the pattern of the thin film conductor layer 2 and hot pressing is performed. Thus, the thin film conductor layer 2 is embedded in the insulating resin layer 2. Then, after a through hole is formed at a predetermined position from the side opposite to the surface on which the thin film conductor layer 2 is embedded, for example, a conductor paste is filled in the through hole by a printing method. Then, the thermoplastic resin sheet used as the other resin insulation layer 1 is laminated | stacked, and it pressurizes up and down, heating this laminated body, and the sheets of thermoplastic resin are mutually adhere | attached. At this time, a copper foil having a predetermined pattern, that is, a thin film conductor layer 2 is provided between the upper and lower thermoplastic resin sheets (resin insulating layer 1) which are in close contact with each other.

  The resin insulating layer 1 is made of a resin material having the same thermal expansion coefficient as that of the aluminum oxide sintered body or the mullite sintered body in order to suppress a difference in thermal expansion coefficient with respect to the ceramic substrate 10.

  Between the resin insulation layers 1, one (the lower layer in the example of FIG. 2) of the resin insulation layers 1 adjacent to each other in the vertical direction has a recess 1 a on the surface portion, and the inside of the recess 1 a A part of the other (insulating layer in the example of FIG. 2) resin insulating layer 1 enters.

  Between the resin insulation layers 1, one of the resin insulation layers 1 adjacent to the top and bottom has a recess 1 a on the surface, and the other resin insulation layer 1 is in the recess 1 a. Since a part of the surface portion is intruded, for example, the bonding area between the upper and lower resin insulating layers 1 is increased according to the bonding area between the upper and lower resin insulating layers 1 in the recess 1a. Therefore, the bonding strength between the upper and lower resin insulation layers 1 is increased, and peeling between layers is suppressed.

  In the example shown in FIG. 2, the recess 1 a is adjacent to the thin film conductor layer 2. The stress that causes peeling between the upper and lower resin insulation layers 1 is a thermal stress caused by the difference in thermal expansion coefficient between the resin insulation layer 1 and the via conductor 3 and the thin film conductor layer 2. Is particularly large in a portion adjacent to the thin film conductor layer 2 or the via conductor 3. In the portion where the thin film conductor layer 2 is located between the layers, the portion adjacent to the thin film conductor layer 2 is particularly large. Since the strength of the bonding between the upper and lower insulating layers 1 is improved at the portion where the thermal stress is large, peeling between the upper and lower resin insulating layers 1 is more effectively suppressed.

  Moreover, when the recessed part 1a surrounds the via conductor 3, the strength of bonding between the upper and lower resin insulating layers 1 can be increased more effectively. In this case, the strength of the bonding between the resin insulating layers 1 is improved by the recesses 1a around the via conductor 3 which is a portion where the stress generated between the upper and lower resin insulating layers 1 is relatively large. Accordingly, the bonding strength between the resin insulating layers 1 is further increased, and peeling between the resin insulating layers 1 is more effectively suppressed.

  When the recess 1 a surrounds the via conductor 3, the recess 1 a does not necessarily have to be adjacent to the via conductor 3. For example, if the thin film conductor layer 2 is connected to the end of the via conductor 3 as in the example shown in FIG. 2, it is difficult for the recess 1 a to directly contact the via conductor 3. In such a case, the recess 1a is adjacent to the thin film conductor layer 2 connected to the end of the via conductor 3, and surrounds the via conductor 3 with a certain distance from the via conductor 3 in plan view. It does not matter if it is provided.

  Further, for example, as in the example shown in FIG. 3, the recess 1 a may be adjacent to the end of the via conductor 3. FIG. 3 is an enlarged cross-sectional view showing a main part in a modified example of the multilayer wiring board shown in FIGS. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the example shown in FIG. 3, the thin film conductor layer 2 is not connected to the end of one via conductor 3 among the plurality of via conductors 3. In this example, the recess 1a is adjacent to the via conductor 3 in plan view. In the case where the recess 1a not only surrounds the via conductor 3 in a plan view but is adjacent to the recess 1a, it results from a difference in thermal expansion coefficient between the via conductor 3 and the resin insulating layer 1. The strength of the bonding between the upper and lower resin insulation layers 1 is more effectively improved at a portion where the thermal stress is particularly large. Therefore, peeling between the resin insulating layers 1 can be more effectively suppressed.

  In addition, about the via conductor 3, when what was provided in the some resin insulation layer 1 is connected up and down, it is advantageous in reducing the area which the via conductor 3 occupies in the multilayer wiring board in planar view. is there. However, in this case, since the plurality of via conductors 3 included in the plurality of resin insulation layers 1 expands vertically at the same position, the stress that causes peeling between the layers of the resin insulation layer 1 tends to concentrate around the via conductors 3. . Even in such a case, if the bonding strength between the resin insulating layers 1 around the via conductor 3 is improved as described above, peeling between the layers can be suppressed.

  The concave portion 1a is formed by polishing the surface of the resin insulating layer 1 (thermoplastic resin sheet) provided with a copper foil or the like to be the thin film conductor layer 2 together with the copper foil or the like. It can be formed by increasing the polishing amount in a part of the part adjacent to the foil or the like as compared with the other part.

FIG. 4 is an enlarged cross-sectional view showing a main part of another modification of the multilayer wiring board and the probe card board shown in FIGS. 4, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals. In the example of FIG. 4, a recess 1b is included in the inner surface of the recess 1a.

  The recessed portion 1b is a portion in which a part of the inner surface of the recess 1a protrudes in the direction opposite to the inside (outer side) of the recess 1a. In this case, it can also be considered that a part of the inner surface of the recess 1 protrudes in the direction of the interior of the recess 1a, and the periphery of the protruding portion is a recess 1a.

  The other resin insulation layer 1 (the upper resin insulation layer 1 or the like) laminated on the one resin insulation layer 1 (the lower resin insulation layer 1 or the like) provided with the recess 1a in the recess 1b. Part of it is getting filled. The joint area between the resin insulating layers 1 is increased by the amount of the recessed portion 1b, and the bonding strength between the resin insulating layers 1 is increased. Therefore, peeling between the resin insulating layers 1 is more effectively suppressed.

  Note that, as in the example shown in FIG. 4, the indented portion 1 b may be a portion in which the resin insulating layer 1 is recessed in the recessed portion 1 a (the shape of the recessed portion 1 a on the left side in FIG. 4). It may be a part of which is recessed (in the form of the recess 1a on the right side in FIG. 4). In addition, the via conductor 3 may be recessed (not shown) in the recess 1a. For example, as shown in FIG. 4, the inner surface of the recess 1a is the surface of the resin insulating layer 1 and the thin film conductor layer 2 in the recess 1a. When the recess 1a is adjacent to the via conductor 3, the surface (not shown) of the via conductor 3 in the recess 1a is also the inner surface of the recess 1a.

  FIG. 5 is an enlarged cross-sectional view showing a main part in another modification of the multilayer wiring board and the probe card board shown in FIGS. 5, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the example of FIG. 5, the recess 1 a is provided at a position apart from both the thin film conductor layer 2 and the via conductor 3 between the upper and lower resin insulation layers 1. Even in such a case, since a part of the upper resin insulating layer 1 enters the recess 1a, the bonding area between the upper and lower resin insulating layers 1 is increased, and the bonding strength is improved. Therefore, peeling between the layers of the resin insulating layer 1 can be suppressed.

  In addition, when the recessed part 1a is provided in such a position, it is not necessary to consider the deformation | transformation etc. of the thin film wiring conductor 2 or the via conductor 3 accompanying presence of the recessed part 1a. Further, the space and the degree of freedom for providing the recess 1a in a plan view are relatively large. Therefore, it is advantageous in increasing the area or number of the recesses 1a in plan view.

  Moreover, in the example shown in FIG. 5, the inner surface of the recessed part 1a is curving in circular arc shape. A part of the curved inner surface includes a portion that intersects with the direction of action (vertical direction) of stress such as thermal stress to peel the upper and lower resin insulation layers 1 up and down. Therefore, peeling between the upper and lower resin insulation layers 1 due to the stress can be more effectively suppressed.

  As described above, the multilayer wiring board as described above is, for example, a probe card substrate in which the probe 21 is connected to the terminal 2a made of a thin film conductor layer exposed on the upper surface of the uppermost resin insulating layer 1. . The probe card substrate is electrically connected to an electrode of a semiconductor element (not shown) via a probe 21. In addition, the wiring conductor 12 provided on the lower surface of the ceramic substrate 10 is electrically connected to an external electric circuit (not shown) for measuring the electric characteristics, etc., and inspecting the electric characteristics of the semiconductor element, etc. Is done.

Examples of semiconductor elements include semiconductor integrated circuit elements such as ICs and LSIs, and micromachines (so-called MEMS elements) in which a minute electromechanical mechanism is formed on the surface of a semiconductor substrate. The electrical inspection of the semiconductor element is, for example, confirmation of whether or not calculation, storage, mechanical operation, and the like are normally performed.

  The ceramic substrate 10 has a function of ensuring the rigidity of the entire multilayer wiring board when used, for example, as a probe card substrate. By providing the resin insulating layer 1 and the thin film conductor layer 2 on the ceramic substrate 10, fine wiring that can correspond to the electrodes of the semiconductor element is formed on the highly rigid substrate. A multilayer wiring board that can be used as a substrate or the like is formed.

  The multilayer wiring board and the like of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, the recess 1a as shown in FIG. 1 and the recess 1a as shown in FIG. 5 may be used together in one multilayer wiring board or the like. Moreover, the recessed part 1b may be provided in each of these recessed parts 1a. Further, a plating layer (not shown) such as nickel and gold may be applied to the exposed portion of the wiring conductor 12 or the like.

  Further, the upper resin insulating layer 1 may have a concave portion 1a on the surface portion, and a part of the lower resin insulating layer 1 may enter the concave portion 1a.

DESCRIPTION OF SYMBOLS 1 ... Resin insulating layer 1a ... Recessed part 1b ... Recessed part 2 ... Thin film conductor layer 3 ... Via conductor
10 ... Ceramic substrate
11 ... Ceramic insulation layer
12 ... Wiring conductor
13 ... Penetration conductor
21 ... Probe

Claims (4)

A ceramic substrate;
A plurality of resin insulation layers laminated on the ceramic substrate;
A thin film conductor layer provided between the plurality of resin insulation layers;
A via conductor penetrating the plurality of resin insulation layers in the thickness direction,
A portion of the thin film conductor layer is directly connected to the end of the via conductor;
Between the resin insulation layers, one of the resin insulation layers adjacent to the top and bottom has a recess in the surface portion,
The recess, in plan view, a groove-like, surrounds the via conductor as well as adjacent to the thin film conductor layer is directly connected to the via conductor,
Multi-layer wiring board, characterized in that enters the portion of the other resin insulating layer in the recess. Some of the recess in plan view, a multilayer wiring board according to claim 1, characterized in that adjacent to the via conductor wherein thin conductive layer on the end portion is not connected. 3. The multilayer wiring board according to claim 1, wherein a concave portion is included in an inner surface of the concave portion, and the concave portion is filled with a part of the other resin insulating layer. 4. The multilayer wiring board according to any one of claims 1 to 3 ,
A terminal comprising a thin film conductor layer provided on the upper surface of the uppermost resin insulation layer;
A probe card substrate comprising: a probe connected to the terminal.

Images