JP2007318032A - Wiring substrate and semiconductor device mounting structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring substrate which has a low linear expansion coefficient close to a linear expansion coefficient of a semiconductor device, and a semiconductor device mounting structure which has a high performance. <P>SOLUTION: The wiring substrate includes: a first woven cloth where a plurality of first fiber bundles which are located along a first direction, and a plurality of a second fiber bundles which are located along a second direction different from the first direction and have a sectional area smaller and/or an array space larger than that of the first fiber, are woven to form a textile; a resin board which holds the first woven cloth inside; and a plurality of wiring conductors which are located on the resin board. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wiring board used in various audio visual (abbreviated as AV: Audio Visual) devices, home appliances, communication devices, computer devices and peripheral devices, and a mounting structure of a semiconductor element using the same. It is.

  Conventionally, resin wiring boards have been used as wiring boards on which semiconductor elements such as IC (Integrated Circuit) and LSI (Large Scale Integration) are mounted.

  However, a resin wiring board has a larger linear expansion coefficient than that of a semiconductor element due to the characteristics of the resin. For this reason, when a semiconductor element is mounted on a resin wiring board, a large thermal stress is applied between the two due to the difference in coefficient of linear expansion between the two, and the connection state between the wiring board and the semiconductor element becomes unstable. There is a concern about the yield drop.

  Therefore, it is required to realize a wiring board having a low linear expansion coefficient close to that of the semiconductor element and a semiconductor element mounting structure.

  The first wiring board of the present invention is arranged along a plurality of first fiber bundles arranged along a first direction and a second direction different from the first direction, and is smaller than the first fiber bundle. A first woven fabric formed by weaving a plurality of second fiber bundles having a cross-sectional area, a resin plate that accommodates the first woven fabric therein, and a plurality of wiring conductors disposed on the resin plate And.

  The first wiring board of the present invention includes a plurality of third fiber bundles arranged along a third direction different from the first direction, the second direction, and the first wiring board in the first wiring board. A plurality of fourth fiber bundles arranged along a fourth direction different from the three directions and having a smaller cross-sectional area than the third fiber bundle, and are accommodated in the resin plate. A second woven fabric is further provided.

  Furthermore, in the first wiring board of the present invention, in the first wiring board, the third fiber bundle has a smaller linear expansion coefficient than the fourth fiber bundle.

  In the first wiring board of the present invention, in the first wiring board, the first fiber bundle has a smaller coefficient of linear expansion than the second fiber bundle.

  Furthermore, in the first wiring board of the present invention, in the first wiring board, the first direction and the fourth direction are arranged substantially parallel to each other, and the second direction and the third direction are It arrange | positions substantially parallel.

  In the first wiring board of the present invention, the number of the first woven cloths is equal to the number of the second woven cloths in the first wiring board.

  Furthermore, in the first wiring board of the present invention, in the first wiring board, the width of the intersecting region between the first fiber bundle and the second fiber bundle may be the first fiber bundle and the second fiber bundle. The width of the intersection region between the third fiber bundle and the fourth fiber bundle is larger than the width of the non-intersection region between the third fiber bundle and the fourth fiber bundle. large.

  In the first wiring board of the present invention, in the first wiring board, the first fiber bundle to the fourth fiber bundle are spaced from each other along a direction substantially orthogonal to the longitudinal direction. The arrangement pitch of the second fiber bundle is set larger than the arrangement pitch of the first fiber bundle, and the arrangement pitch of the fourth fiber bundle is set larger than the arrangement pitch of the third fiber bundle. ing.

  On the other hand, the second wiring board of the present invention is arranged along the first direction, and a plurality of first fiber bundles arranged at intervals in a direction substantially orthogonal to the first direction, and the first direction A plurality of second fiber bundles arranged along a second direction different from the second direction and arranged at intervals in a direction substantially orthogonal to the second direction, and the arrangement of the second fiber bundles A first woven fabric in which the pitch is set larger than the arrangement pitch of the first fiber bundles, a resin plate that houses the first woven fabric, and a plurality of wiring conductors disposed on the resin plate; It has.

  Further, the second wiring board of the present invention is arranged along a third direction different from the first direction in the second wiring board, and is arranged with an interval in a direction substantially orthogonal to the third direction. A plurality of third fiber bundles, and a plurality of third fiber bundles arranged along a fourth direction different from the second direction and the third direction, and arranged at intervals in a direction substantially orthogonal to the fourth direction. A second woven fabric that is configured by weaving a fourth fiber bundle, and in which the arrangement pitch of the fourth fiber bundle is set larger than the arrangement pitch of the third fiber bundle, and is accommodated inside the resin plate. And.

  Furthermore, in the second wiring board of the present invention, in the second wiring board, the third fiber bundle has a smaller linear expansion coefficient than the fourth fiber bundle.

  In the second wiring board of the present invention, in the second wiring board, the first fiber bundle has a smaller coefficient of linear expansion than the second fiber bundle.

  Furthermore, in the second wiring board of the present invention, in the second wiring board, the first direction and the fourth direction are arranged substantially parallel to each other, and the second direction and the third direction are It arrange | positions substantially parallel.

  In the second wiring board of the present invention, the number of the first woven cloths is equal to the number of the second woven cloths in the second wiring board.

  Furthermore, the second wiring board of the present invention is the above-mentioned second wiring board, wherein the width of the intersecting region between the first fiber bundle and the second fiber bundle is the first fiber bundle and the second fiber bundle. The width of the intersection region between the third fiber bundle and the fourth fiber bundle is larger than the width of the non-intersection region between the third fiber bundle and the fourth fiber bundle. large.

  The semiconductor element mounting structure of the present invention includes the first or second wiring board described above and a semiconductor element connected to the wiring conductor of the wiring board.

  According to the present invention, it is possible to reduce the linear expansion coefficient of a wiring board made of a resin plate. Further, it is possible to suppress the variation due to the direction with respect to the linear expansion coefficient in the wiring board. As a result, a high-performance semiconductor element mounting structure with a good connection state is realized.

  The present inventor applies a woven fabric formed by weaving a plurality of fiber bundles arranged in different directions, and uses the woven fabric as a resin plate made of a resin material such as an epoxy resin, and a wiring conductor formed on the resin plate. And a wiring board having the following. In such a wiring board, the expansion of a resin plate having a large linear expansion coefficient is suppressed by a woven fabric made of a material having a small linear expansion coefficient, and the linear expansion coefficient of the entire wiring board is reduced.

  However, it has been found that the linear expansion coefficient of the wiring board is not only related to the constituent material of the woven fabric, but is greatly related to the shape and arrangement pitch of the fiber bundles constituting the woven fabric. Was devised. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
1 is a cross-sectional view of a semiconductor element mounting structure according to an embodiment of the present invention, FIG. 2A is a plan view of a woven fabric used for the wiring board shown in FIG. 1, and FIG. These are AA sectional view taken on the line of the woven fabric shown to (a). Note that FIG. 2A shows only one woven fabric for convenience.

  The semiconductor element mounting structure according to the present embodiment is generally composed of a wiring board 1 and a semiconductor element 6 such as an IC or LSI mounted on the wiring board 1. Here, the semiconductor element 6 is flip-chip mounted on the wiring substrate 1 via a bonding material 7 such as solder. Hereinafter, the wiring board 1 will be mainly described.

  The wiring board 1 is used for electronic devices such as various audio visual (AV: Audio Visual) devices, home appliances, communication devices, computer devices, and peripheral devices thereof, and includes a plurality of woven fabrics 2, It has a configuration including a resin plate 3 that accommodates the woven fabric 2 and a wiring conductor 4 formed on the resin plate 3.

The woven fabric 2 includes a plurality of fiber bundles 2x arranged substantially parallel to the x direction and a plurality of fiber bundles 2y arranged substantially parallel to the y direction. Each fiber bundle 2x is alternately arranged on the upper surface side and the lower surface side of the fiber bundle 2y as shown in FIG. 2 (b), and as a whole wavy in the z direction. Is formed. On the other hand, as shown in FIG. 2B, the fiber bundles 2y are alternately arranged periodically on the upper surface side and lower surface side of the fiber bundle 2x, and are formed in a wavy shape as a whole in the z direction. It is assumed that the x direction, the y direction, and the z direction are orthogonal to each other.

  Such a woven fabric 2 is housed inside the resin plate 3 in a stacked manner in the z direction, suppresses expansion and contraction of the resin plate 3 having a large linear expansion coefficient, and reduces the linear expansion coefficient of the wiring board 1. Is for. Although a part of the woven fabric 2 may be exposed from the surface of the resin plate 3, if the wiring conductor 4 is formed on the resin plate 3 with respect to the exposed portion of the woven fabric 2, the wiring conductor 4 is more than the resin plate 3. It is preferable that the woven fabric 2 is completely accommodated in the resin plate 2 because it is easy to peel off.

The number of fabric 2 may be singular, the volume ratio of the woven fabric 2 against the resin plate 3 (the volume V ₂ of the fabric 2, when the volume V ₃ of the resin plate 3, V 2 _/ V ₃₎ Is preferably set to 45% or more and 70% or less. When the volume ratio of the woven fabric 2 is less than 45%, the force by which the woven fabric 2 suppresses the elongation of the resin plate 2 becomes small. On the other hand, when the volume ratio of the woven fabric 2 exceeds 70%, Since the volume is insufficient, a large number of voids not filled with resin may occur between the fiber bundles 2x and 2y or between the plurality of single fibers 5 constituting the fiber bundles 2x and 2y. This is because defective insulation and swelling of the resin plate are likely to cause failure.

  As shown in FIG. 3, the fiber bundles 2x and 2y constituting the woven fabric 2 are formed by bundling a plurality of single fibers 5 each made of a material having a smaller linear expansion coefficient than the resin plate 3. The arrangement pitch in the y direction of the bundle 2x and the arrangement pitch in the x direction of the fiber bundle 2y are set to be approximately equal. On the other hand, the cross-sectional area of the fiber bundle 2y is set smaller than the cross-sectional area of the fiber bundle 2x.

  Here, the arrangement pitch of the fiber bundles refers to an interval between the central axes of adjacent fiber bundles (the maximum interval when the interval between the pair of adjacent fiber bundles is not uniform). Considering the case where the arrangement pitch of each fiber bundle varies within the woven cloth 2 as in the woven cloth shown in FIG. 11, the arrangement pitch basically means the average value of the arrangement pitch between the fiber bundles. However, the average value of the arrangement pitches of the fiber bundles in arbitrary 10 pieces arranged in succession may be adopted without measuring all the arrangement pitches.

  The cross-sectional area of the fiber bundle refers to the cross-sectional area parallel to the z-direction (the cross-sectional area is the maximum when the cross-sectional area is not uniform for one fiber bundle), and basically takes an average value. However, you may employ | adopt the average value of the cross-sectional area of the arbitrary five fiber bundles arranged continuously.

  In order to set the cross-sectional area of the fiber bundle 2y to be smaller than the cross-sectional area of the fiber bundle 2x, the number of single fibers 5 is made smaller in the fiber bundle 2y than the fiber bundle 2x, or the cross-sectional area of the single fiber 5 is set to fiber. What is necessary is just to make it small with the fiber bundle 2y rather than the bundle 2x.

  In this way, instead of simply using fiber bundles having the same cross-sectional area in the x and y directions, the cross-sectional area of the fiber bundle 2y is smaller than that of the fiber bundle 2x. The undulation in the z direction of the fiber bundle 2x is reduced. When the undulation is small, the spring property of the fiber bundle is impaired, and as a result, the force with which the fiber bundle tries to extend in the x direction becomes small. Therefore, the elongation in the x direction of the fiber bundle 2x is reduced, and the linear expansion coefficient of the woven fabric 2 in the x direction can be reduced.

  The ratio Sx / Sy of the cross-sectional area Sx of the fiber bundle 2x to the cross-sectional area Sy of the fiber bundle 2y is preferably set in the range of 3-100. When Sx / Sy is smaller than 3, the waviness of the fiber bundle 2x in the z direction cannot be reduced so much, and the constituent material of the fiber bundle 2x is made of a material having a relatively low linear expansion coefficient. On the other hand, if Sx / Sy is larger than 100, the force that the fiber bundle 2y holds the fiber bundle 2x becomes relatively weak, so that the fiber bundle 2y and the fiber bundle 2x are displaced from each other. It becomes easy and a phenomenon called so-called misalignment occurs. When misalignment occurs, nonuniform deformation of the substrate occurs at this portion, making it difficult to form fine and highly accurate wiring.

Further, as shown in FIG. 4, the width of the fiber bundles 2x and 2y is formed wider in the intersecting region C where the fiber bundles 2x and 2y intersect than in the non-intersecting region where the fiber bundles 2x and 2y do not intersect. ing. That is, the widths 2xw ₁ and 2yw ₁ of the fiber bundles 2x and 2y in the intersecting region C are formed wider than the widths 2xw ₂ and 2yw ₂ of the fiber bundles 2x and 2y in the non-intersecting region. In this case, since the contact area of the intersecting region C is increased, the adhesion strength between the fiber bundle 2x and the fiber bundle 2y is increased, and the strength of the woven fabric 2 can be maintained high over a long period of time. Therefore, the width of the fiber bundles 2x and 2y is preferably formed wider in the intersecting region C where the fiber bundles 2x and 2y intersect than in the non-intersecting region.

  As a material of the single fiber 5 constituting the fiber bundles 2x and 2y, a material having a Young's modulus of 10 GPa or more is preferably applied. Furthermore, the linear expansion coefficient (25 ° C. or more and 200 ° C. or less) in the longitudinal direction of the single fiber 5 is preferably −10 ppm / ° C. or more and 0 ppm / ° C. or less.

  The lower the linear expansion coefficient in the longitudinal direction of the single fiber 5, the lower the linear expansion coefficient in the longitudinal direction of the fiber bundles 2x and 2y, and the greater the effect of suppressing the elongation of the resin plate 3, so the linear expansion coefficient is 0 ppm / It is preferable that it is below ℃.

  In addition, since the cross-sectional area of the fiber bundle 2x is larger than the cross-sectional area of the fiber bundle 2y, the smaller the linear expansion coefficient of the fiber bundle 2y, the smaller the linear expansion coefficient of the fiber bundle 2y, the viewpoint that the linear expansion coefficient of the woven fabric 2 is reduced. Is preferable.

  The material constituting the single fiber 4a having a Young's modulus of 10 GPa or more and a linear expansion coefficient in the longitudinal direction (25 ° C. or more and 200 ° C. or less) of −10 ppm / ° C. or more and 0 ppm / ° C. or less includes wholly aromatic polyester fibers and wholly aromas. Organic fibers mainly composed of a group polyamide, polybenzoxazole, and a liquid crystal polymer are preferably used. When the woven fabric is formed of a material other than resin, the Young's modulus is 10 GPa or more, and the longitudinal linear expansion coefficient (25 ° C. or more and 200 ° C. or less) is −10 ppm / ° C. or more and 0 ppm / ° C. or less as S glass, It is also possible to apply T-glass. Although E glass can also be applied, it is preferable to use S glass or T glass because the linear expansion coefficient is larger than that of S glass or T glass.

-The resin board 3 which coat | covers the resin board woven fabric 2 is formed with the epoxy resin which contains 20 to 80 wt% of nonmetallic inorganic fillers (for example, spherical silica), for example. With this configuration, a linear expansion coefficient of 20 ppm / ° C. to 60 ppm / ° C. and a Young's modulus of 2 GPa to 5 GPa can be realized. The resin plate 3 may be a single layer or may be composed of a plurality of layers.

  The lower the linear expansion coefficient of the resin plate 3 is, the better. However, a resin plate having a linear expansion coefficient smaller than 10 ppm / ° C. is not commercially available and has not been tested. Therefore, at the present time, the linear expansion coefficient of the resin plate 3 is preferably 10 ppm / ° C. or more and 60 ppm / ° C. or less. This is because if the linear expansion coefficient of the resin plate 3 exceeds 60 ppm / ° C., it is difficult to make the thermal expansion coefficient of the entire wiring board 1 equal to that of silicon. Moreover, since the expansion of the resin plate 5 becomes easy to be suppressed by the single fiber 4a, the Young's modulus is preferably 5 GPa or less. Further, if the Young's modulus of the resin plate 5 is too small, the rigidity of the wiring board tends to be insufficient, so that the Young's modulus of the resin plate 5 is preferably 0.05 GPa or more.

  In the present embodiment, an epoxy resin is used as the material of the resin plate 5, but of course it is not limited to the epoxy resin. For example, a resin material such as cyanate resin or bismaleimide triazine can be used as a material for the resin plate. However, for the Young's modulus and the linear expansion coefficient, the same numerical ranges as those applied with the epoxy resin are suitable ranges. The amount of the nonmetallic inorganic filler is appropriately changed according to the type of resin material constituting the resin plate 5. In addition to silica, materials such as aluminum hydroxide, aluminum oxide, magnesium hydroxide, and calcium hydroxide can be used as the nonmetallic inorganic filler.

-Measuring method of Young's modulus The Young's modulus of the single fiber 5, the fiber bundles 2x, 2y, and the resin plate 3 can be measured by the following method. The Young's modulus of the single fiber 5 is a unit cross-sectional area obtained by loosening the fiber bundles 2x and 2y constituting the woven fabric 2, taking out one single fiber 5, and measuring the single fiber 5 with a tensile tester. It can be measured by dividing the tensile stress per unit by the elongation of the single fiber. The Young's modulus of the fiber bundles 2x and 2y can be measured by dividing the tensile stress per unit cross-sectional area obtained by measuring the fiber bundles 2x and 2y with a tensile tester by the elongation amount of the fiber bundles 2x and 2y. . In the case of the resin plate 3, a unit piece obtained by cutting a film prepared by curing under the same conditions as the wiring board 1 into a rectangular test piece and measuring the test piece with a tensile tester. It can be measured by dividing the tensile stress per area by the amount of elongation of the resin. Moreover, it can also measure using a conventionally well-known nanoindentation method.

  On the other hand, the Young's modulus of the single fiber 5 and the resin plate 3 can be measured from the state in which the wiring board 1 is formed. The Young's modulus of the single fiber 5 is determined by removing the resin plate 3 and taking out the fiber bundles 2x and 2y, then loosening the fiber bundles 2x and 2y, and taking out one single fiber 5, and subjecting the single fiber 5 to a tensile test. It can be measured by dividing the tensile stress per unit cross-sectional area obtained by measuring with a machine by the amount of elongation of the fiber. The Young's modulus of the fiber bundles 2x and 2y is the tensile stress per unit cross-sectional area obtained by measuring the fiber bundles 2x and 2y taken out after removing the resin plate 3 with a tensile tester as the amount of elongation of the fibers. It can be measured by dividing. The Young's modulus of the resin plate 3 is obtained from the load applied to the indenter and the projected area under the indenter at the time when the resin plate 3 is cut into a thin piece and an indenter such as a square pole or a triangular pyramid is pushed into the surface of the thin piece. The Young's modulus of the fiber bundles 2x and 2y is determined by measuring the Young's modulus of the resin plate 3 measured in advance and the Young's modulus in the state of the composite of the resin plate 3 and the single fiber 5, and the Young's modulus of this composite. From the Young's modulus of the resin plate 3, the Young's modulus of the fiber bundles 2x and 2y can be measured by simulation.

-Measuring method of linear expansion coefficient Moreover, the linear expansion coefficient of the longitudinal direction of the single fiber 5 and fiber bundle 2x, 2y and the linear expansion coefficient of the resin board 3 are measurable with the following method. The linear expansion coefficient of the single fiber 5 is determined by taking out the single fiber 5 from the fiber bundles 2x and 2y, attaching it to a probe for measuring dimensions, raising the temperature while applying a load in the direction of pulling the single fiber 5, and measuring the dimension due to the temperature change. It can be measured by measuring the change. The linear expansion coefficient of the fiber bundles 2x and 2y is determined by attaching the fiber bundles 2x and 2y to a dimensional measurement probe, increasing the temperature while applying a load in the direction of pulling the fiber bundles 2x and 2y, and measuring the dimensional change due to the temperature change. Can be measured. The linear expansion coefficient of the resin plate 3 can be measured, for example, by cutting out a test piece of 2 mm × 3 mm × 15 mm, raising the temperature while contacting the test piece with a dimensional measurement probe, and measuring the dimensional change due to the temperature change. .

  On the other hand, the linear expansion coefficients of the single fibers 5, the fiber bundles 2 x and 2 y and the resin plate 3 can be measured from the state where the wiring board 1 is formed. The linear expansion coefficient of the single fiber 5 is such that after removing the resin plate 3 and taking out the fiber bundles 2x and 2y, the single fiber 5 is taken out from the fiber bundles 2x and 2y, and the single fiber 5 is attached to a probe for measuring dimensions. It can be measured by increasing the temperature while applying a load in the direction of pulling the single fiber 5 and measuring the dimensional change due to the temperature change. The linear expansion coefficient of the fiber bundles 2x and 2y is determined by removing the resin plate 3 and taking out the fiber bundles 2x and 2y, attaching the probe for measuring the dimensions of the fiber bundles 2x and 2y, and pulling the fiber bundles 2x and 2y. It can be measured by raising and measuring the dimensional change due to temperature change. The linear expansion coefficient of the resin plate 3 is determined by cutting the resin plate 3 into a thin piece of appropriate size, attaching the thin piece as a test piece to a dimensional measurement probe, and increasing the temperature while applying a load in the direction of pulling the test piece. It can be measured by measuring a dimensional change due to a temperature change. The linear expansion coefficient of the fiber bundles 2x and 2y is determined in advance by measuring the linear expansion coefficient of the resin plate 3 and measuring the linear expansion coefficient in the state of the composite of the resin plate 3 and the fiber bundles 2x and 2y. From the linear expansion coefficient of the body and the linear expansion coefficient of the resin plate 3, the linear expansion coefficients of the fiber bundles 2x and 2y can be measured by simulation.

-Wiring conductor The wiring conductor 4 is also formed on the upper surface and inside of the resin plate 3 and in some cases on the lower surface. It is formed in a predetermined pattern by a conductive material such as silver, gold, aluminum, nickel, or chromium. The wiring conductor 4 is electrically connected to a semiconductor element such as an IC or LSI mounted on the wiring board 1 and functions as a power supply wiring for supplying power to the semiconductor element. The wiring conductor 4 may include a through-hole conductor and an electrode pad.

-Wiring board manufacturing method The wiring board 1 according to the present embodiment is manufactured through the following steps, for example.

  (1) First, the woven fabric 2 is formed. The woven fabric 2 forms fiber bundles 2x and 2y having different cross-sectional areas by bundling the single fibers 5 into a thread shape. Next, the fiber bundles 2x and 2y are woven into a plain weave using a loom so that the arrangement pitches of the fiber bundles 2x and 2y are substantially equal to each other, and the fiber bundles 2x and 2y are knitted to form the woven fabric 2. When it is desired to increase the width of the fiber bundles 2x and 2y in the intersecting region of the fiber bundles 2x and 2y, the woven fabric 2 is heated and pressed in the z direction using a press device or the like. The woven fabric 2 is completed by the above method.

  (2) Next, a resin material (for example, a precursor of an epoxy resin) constituting the resin plate 3 is prepared, and a varnish is prepared by mixing a spherical silica powder that has been previously subjected to silane coupling treatment and a solvent. . And the produced varnish is impregnated in the woven fabric 2, and a resin sheet (prepreg) is produced.

  (3) Subsequently, a plurality of the obtained resin sheets are laminated, and a metal foil (for example, a copper foil) is deposited on the front and back, and this is heated and pressed in the thickness direction of the resin sheet. A three-hole conductor is formed by electroless plating, electroplating or the like on the through-hole formed by, for example. Then, the copper substrate is processed into a predetermined pattern by photolithography and etching that are conventionally known, thereby completing the wiring substrate 1 having the resin plate 2 in which the woven fabric 2 is accommodated.

  Thereafter, a resin layer and a wiring layer may be laminated on the obtained wiring board by a build-up method to produce a multilayer board, or a semiconductor element such as an IC or LSI may be mounted on the wiring board 1, and the semiconductor An element mounting structure may be formed.

(Second Embodiment)
FIG. 5 is a plan view showing a woven fabric of a wiring board according to the second embodiment. In the following, the configuration of the present embodiment that is different from that of the first embodiment will be mainly described, and the description of the common configuration will be omitted in principle.

  In the woven fabric 2 in the present embodiment, the cross-sectional areas of the fiber bundles 2x and 2y are substantially equal, and the arrangement pitch of the fiber bundles 2x is set smaller than the arrangement pitch of the fiber bundles 2y. With this configuration, the number of the fiber bundles 2x per unit length can be increased, and the force for suppressing the elongation of the resin plate 3 in the x direction is equal to the arrangement pitch of the fiber bundles 2x and 2y. It becomes possible to enlarge compared with the case where it does. As a result, the linear expansion coefficient of the entire woven fabric 2 can be reduced.

  The ratio Px / Py of the arrangement pitch Px of the fiber bundle 2x to the arrangement pitch Py of the fiber bundle 2y is preferably set in the range of 1/100 to 1/3. When Px / Py is smaller than 1/100, the number of undulations in the z direction of the fiber bundle 2y increases, the spring property of the fiber bundle 2y increases, and the effect of reducing the linear expansion coefficient may be reduced. On the other hand, when Px / Py is larger than 1/3, the effect of reducing the linear expansion coefficient in the x direction of the fiber bundle 2x is not so remarkable. Therefore, when the linear expansion coefficient of the entire wiring board 1 is significantly reduced. Therefore, it is necessary to sufficiently consider the selection material of the fiber bundle 2x, and the width of the selection material of the fiber bundle 2x becomes narrow.

(Third embodiment)
FIG. 6 is a plan view showing a woven fabric of a wiring board according to the third embodiment. In the following, the configuration of the present embodiment that is different from that of the first embodiment will be mainly described, and the description of the common configuration will be omitted in principle.

  In the woven fabric 2 in this embodiment, the cross-sectional area relationship between the fiber bundles 2x and 2y is set to be smaller than the cross-sectional area of the fiber bundle 2x, as in the first embodiment. The arrangement pitch of the fiber bundle 2x is set smaller than the arrangement pitch of the fiber bundle 2y. By setting it as this structure, the number of the fiber bundles 2x per unit length can be increased, suppressing the wave | undulation to the z direction of the fiber bundle 2x small. As a result, the force that suppresses the resin plate 3 that tries to extend in the x direction is greater than that in the first and second embodiments, which leads to a reduction in the linear expansion coefficient of the entire woven fabric 2.

(Fourth embodiment)
FIG. 7 is a plan view showing a woven fabric of a wiring board according to the fourth embodiment. In the following, the configuration of the present embodiment that is different from that of the first embodiment will be mainly described, and the description of the common configuration will be omitted in principle.

  In the wiring board in the present embodiment, a woven fabric 2B having a configuration substantially the same as that of the woven fabric 2A is placed on the woven fabric 2A corresponding to the woven fabric 2 in the first embodiment at about 90 degrees (± 10 degrees, ie, The woven fabrics 2 </ b> A and 2 </ b> B are accommodated inside the resin plate 3 and arranged in a form rotated in the right direction (clockwise). That is, the fiber bundles 2Ax and 2Ay constituting the woven fabric 2A have substantially the same arrangement pitch, and the cross-sectional area of the fiber bundle 2Ay is set smaller than the cross-sectional area of the fiber bundle 2Ax, but constitutes the woven fabric 2B. The fiber bundles 2Bx and 2By have substantially the same arrangement pitch, but the cross-sectional area of the fiber bundle 2By is set larger than the cross-sectional area of the fiber bundle 2Bx, and the cross-sectional area of the fiber bundle is woven with the woven fabric 2A. The cloth 2B is reversed.

  The reason for adopting such a configuration is as follows. That is, when the woven fabric 2 according to the first embodiment is laminated in the z direction as it is, the linear expansion coefficient of the entire wiring board can surely be reduced, but the linear expansion coefficient of the wiring board 1 with respect to the x direction and the wiring with respect to the y direction. The difference from the linear expansion coefficient of the substrate 1 tends to increase. Such a tendency causes the distortion of the wiring board 1, but such a tendency becomes particularly strong when the wiring board 1 is used for a multilayer wiring board. Therefore, it is desired to reduce the difference between the linear expansion coefficient of the wiring board 1 in the x direction and the linear expansion coefficient of the wiring board 1 in the y direction while keeping the linear expansion coefficient of the wiring board 1 low.

  Therefore, the wiring board 1 according to the present embodiment can reduce the linear expansion coefficient of the wiring board 1 in the x direction with the woven cloth 2A, and can reduce the linear expansion coefficient of the wiring board 1 in the y direction with the woven cloth 2B. it can. As a result, while reducing the linear expansion coefficient of the entire wiring board, the distortion of the wiring board 1 due to the difference between the linear expansion coefficients in the x direction and the y direction is satisfactorily suppressed. Therefore, it is particularly effective when the wiring board is used as a multilayer wiring board or a wiring board for flip chip mounting of semiconductor elements.

(Fifth embodiment)
FIG. 8 is a plan view showing a woven fabric of a wiring board according to the fifth embodiment. In the following, the configuration of the present embodiment that is different from that of the fourth embodiment will be mainly described, and the description of the common configuration will be omitted in principle.

  The wiring board according to the fourth embodiment is the wiring board according to the fourth embodiment in that the woven cloth 2B is arranged on the woven cloth 2A in a form in which the woven cloth 2A is rotated 45 degrees rightward (clockwise). The configuration is different. Even with such a configuration, the difference between the linear expansion coefficients in the x direction and the y direction can be reduced as in the fourth embodiment, but the effect of the fourth embodiment is greater.

  The rotation angle of the woven fabric 2B with respect to the woven fabric 2A is not necessarily 45 degrees, but it is preferable to rotate it by 10 degrees or more. Further, as is clear from the fourth embodiment, it is more preferable to rotate it by 80 degrees to 100 degrees. When rotated more than 100 degrees, the woven fabrics 2A and 2B have the same configuration as that rotated at an angle of less than 80 degrees because they have an axisymmetric structure. 100 degrees is most preferred.

(Sixth embodiment)
FIG. 9 is a plan view showing a woven fabric of a wiring board according to the sixth embodiment. In the following, the configuration of the present embodiment that is different from that of the fourth embodiment will be mainly described, and the description of the common configuration will be omitted in principle.

  The wiring board in the present embodiment is different from the fourth embodiment in that the woven fabrics 2A and 2B are equivalent to the woven fabric in the second embodiment. The point that the woven fabric 2A and the woven fabric 2B are arranged in a relationship rotated by about 90 degrees is common.

  Even in such a configuration, the same effects as in the fourth embodiment are obtained. Needless to say, the rotation angle of the woven fabrics 2A and 2B is not limited to 90 degrees.

(Seventh embodiment)
FIG. 10 is a plan view showing a woven fabric of a wiring board according to the seventh embodiment. In the following, the configuration of the present embodiment that is different from that of the fourth embodiment will be mainly described, and the description of the common configuration will be omitted.

  The wiring board in this embodiment is different from that in the fourth embodiment in that the woven fabrics 2A and 2B are equivalent to the woven fabric in the third embodiment. The point that the woven fabric 2A and the woven fabric 2B are arranged in a relationship rotated by about 90 degrees is common.

  Even in such a configuration, the same effect as that of the fourth embodiment is obtained, but the effect of reducing the linear expansion coefficient for each of the woven fabrics 2A and 2B is larger than that of the fourth embodiment, and therefore, compared with the fourth embodiment. Is more effective. Needless to say, the rotation angle of the woven fabrics 2A and 2B is not limited to 90 degrees.

(Other embodiments)
The present invention is not particularly limited to the first to seventh embodiments described above, and various modifications and improvements can be made.

  For example, as in the first to third embodiments, when the woven fabric 2 having a linear expansion coefficient smaller in the x direction than in the y direction is stacked in the z direction, the linear expansion coefficient of the wiring board 1 is larger than that in the y direction. Although it decreases in the x direction, the longitudinal direction of the wiring conductor 4 formed on the resin plate 3 is made substantially parallel to the x direction in order to alleviate the difference in the linear expansion coefficient of the wiring board 1 between the x direction and the y direction. Is preferred. Since the wiring conductor 4 has a large linear expansion coefficient, if such a configuration is adopted, an increase in the linear expansion coefficient in the y direction of the wiring board 1 due to the wiring conductor 4 can be suppressed and the distortion of the wiring board 1 can be reduced. An increase can be prevented satisfactorily.

  In the fourth to seventh embodiments, it is preferable that the numbers of the woven fabric 2A and the woven fabric 2B are equal. This is because if the number of the woven fabrics 2A and 2B is different, the difference between the linear expansion coefficients in the x direction and the y direction is increased according to the difference in the number. Further, the arrangement of the woven cloth 2A and the woven cloth 2B is preferably symmetrical with respect to the z direction. In this case, the difference between the linear expansion coefficients in the x direction and the y direction can be further reduced.

  Furthermore, in the first to seventh embodiments, the fiber bundles are arranged in two directions in the x and y directions, but this arrangement direction is not limited to only two directions. For example, there may be a case where fiber bundles are arranged in three or more directions and knitted together. In this case, the rigidity strength of the wiring board can be increased as compared with those arranged in two directions. In addition, fiber bundles arranged in two directions may be perpendicular to the z direction but may not intersect perpendicularly.

It is sectional drawing which shows the mounting structure of the semiconductor element which concerns on the 1st Embodiment of this invention. (A) is a top view which shows the woven fabric used for the wiring board shown in FIG. 1, (b) is the sectional view on the AA line of the woven fabric shown in (a). It is sectional drawing of a fiber bundle. It is an enlarged plan view of the intersection area C of the fiber bundles 2x and 2y. It is a top view which shows the woven fabric of the wiring board which concerns on the 2nd Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on the 3rd Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on the 4th Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on the 5th Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on the 6th Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on the 7th Embodiment of this invention. It is a top view which shows the woven fabric of the wiring board which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wiring board 2, 2A, 2B ... Woven cloth 2x, 2Ax, 2Bx ... Fiber bundle 2y, 2Ay, 2By ... Fiber bundle 3 ... Resin board 4 ... Wiring conductor 5. ..Single fiber 6 ... Semiconductor element C ... Intersection region

Claims (16)

A plurality of first fiber bundles arranged along the first direction and a plurality of second fiber bundles arranged along a second direction different from the first direction and having a smaller cross-sectional area than the first fiber bundle. And a first woven fabric configured by weaving,
A resin plate for accommodating the first woven fabric therein;
A plurality of wiring conductors disposed on the resin plate;
Wiring board equipped with. The wiring board according to claim 1,
A plurality of third fiber bundles arranged along a third direction different from the first direction, and arranged along a fourth direction different from the second direction and the third direction, from the third fiber bundle A wiring board further comprising a second woven fabric, which is formed by weaving a plurality of fourth fiber bundles having a small cross-sectional area, and is arranged so as to be accommodated in the resin plate. The wiring board according to claim 2,
The third fiber bundle is a wiring board having a smaller linear expansion coefficient than the fourth fiber bundle. In the wiring board according to any one of claims 1 to 3,
The first fiber bundle is a wiring board having a smaller linear expansion coefficient than the second fiber bundle. In the wiring board according to any one of claims 2 to 4,
The first direction and the fourth direction are arranged substantially parallel to each other;
A wiring board in which the second direction and the third direction are arranged substantially parallel to each other. In the wiring board according to any one of claims 2 to 5,
A wiring board in which the number of the first woven fabric and the number of the second woven fabric are equal. The wiring board according to any one of claims 2 to 6,
The width of the intersecting region between the first fiber bundle and the second fiber bundle is larger than the width of the non-intersecting region between the first fiber bundle and the second fiber bundle,
The width of the intersection region between the third fiber bundle and the fourth fiber bundle is larger than the width of the non-intersection region between the third fiber bundle and the fourth fiber bundle. The wiring board according to any one of claims 2 to 7,
The first fiber bundle to the fourth fiber bundle are each arranged at intervals along a direction substantially orthogonal to the longitudinal direction thereof,
The wiring board in which the arrangement pitch of the second fiber bundle is set larger than the arrangement pitch of the first fiber bundle, and the arrangement pitch of the fourth fiber bundle is set larger than the arrangement pitch of the third fiber bundle. A plurality of first fiber bundles arranged along the first direction and arranged at intervals in a direction substantially perpendicular to the first direction, and arranged along a second direction different from the first direction; A plurality of second fiber bundles arranged at intervals in a direction substantially perpendicular to the second direction, and the arrangement pitch of the second fiber bundles is greater than the arrangement pitch of the first fiber bundles. A first woven fabric set large,
A resin plate for accommodating the first woven fabric therein;
A plurality of wiring conductors disposed on the resin plate;
A wiring board comprising: The wiring board according to claim 9,
A plurality of third fiber bundles arranged along a third direction different from the first direction and arranged at intervals in a direction substantially orthogonal to the third direction; the second direction and the third direction; Are arranged along different fourth directions, and are knitted with a plurality of fourth fiber bundles arranged at intervals in a direction substantially orthogonal to the fourth direction. And a second woven fabric having an arrangement pitch set larger than the arrangement pitch of the third fiber bundle and housed inside the resin plate. The wiring board according to claim 10,
The wiring board according to claim 3, wherein the third fiber bundle has a smaller linear expansion coefficient than the fourth fiber bundle. The wiring board according to any one of claims 9 to 11,
The wiring board, wherein the first fiber bundle has a smaller linear expansion coefficient than the second fiber bundle. The wiring board according to any one of claims 9 to 12,
The first direction and the fourth direction are arranged substantially parallel to each other;
The wiring board, wherein the second direction and the third direction are arranged substantially parallel to each other. The wiring board according to any one of claims 9 to 13,
A wiring board in which the number of the first woven fabric and the number of the second woven fabric are equal. The wiring board according to any one of claims 9 to 14,
The width of the intersecting region between the first fiber bundle and the second fiber bundle is larger than the width of the non-intersecting region between the first fiber bundle and the second fiber bundle,
The width of the intersection region between the third fiber bundle and the fourth fiber bundle is larger than the width of the non-intersection region between the third fiber bundle and the fourth fiber bundle. A mounting structure for a semiconductor element, comprising: the wiring board according to claim 1; and a semiconductor element connected to a wiring conductor provided on the wiring board.

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