JP5350829B2 - Manufacturing method of wiring board with reinforcing material, wiring board for wiring board with reinforcing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a wiring board with a reinforcing material, which has almost no warpage while securing rigidity. <P>SOLUTION: A wiring board 11 with a reinforcing material includes a wiring board 40 and a stiffener 31. The wiring board 40 has a substrate main surface 41 and a substrate rear surface 42, and is formed by laminating a plurality of resin insulating layers 43-46 and a plurality of conductor layers 51, without including a core substrate. The stiffener 31 is joined only to the substrate main surface 41 side of the wiring board 40. When the thermal expansion coefficient of the wiring board 40 is larger than that of the stiffener 31, a wiring board 40 having warpage that the substrate main surface 41 side becomes a recess is formed and the stiffener 31 is bonded to the substrate main surface 41 of the wiring board 40 having the warpage. The wiring board 11 with a reinforcing material is thus manufactured. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method of manufacturing a wiring board with a reinforcing material provided with a reinforcing material for preventing warping of the wiring board, and a wiring board for a wiring board with a reinforcing material.

  In recent years, semiconductor integrated circuit elements (IC chips) used as computer microprocessors and the like have become increasingly faster and more functional, with an accompanying increase in the number of terminals and a tendency to narrow the pitch between terminals. . In general, a large number of terminals are densely arranged on the bottom surface of an IC chip, and such a terminal group is connected to a terminal group on the motherboard side in the form of a flip chip. However, it is difficult to connect the IC chip directly on the mother board because there is a large difference in the pitch between the terminals on the IC chip side terminal group and the mother board side terminal group. For this reason, a method is generally adopted in which a semiconductor package is prepared by mounting an IC chip on an IC chip mounting wiring board, and the semiconductor package is mounted on a motherboard (see, for example, Patent Document 1).

  The IC chip is generally formed using a semiconductor material (for example, silicon) having a thermal expansion coefficient of about 2.0 ppm / ° C. to 5.0 ppm / ° C. On the other hand, the IC chip mounting wiring board is often a resin wiring board formed using a resin material having a considerably larger thermal expansion coefficient. As an example of this resin wiring board, a structure in which a buildup layer is formed on the front surface and the back surface of a core substrate has been put into practical use. In this resin wiring substrate, for example, a resin substrate (glass epoxy substrate or the like) in which a reinforcing fiber is impregnated with a resin is used as a core substrate. Then, by utilizing the rigidity of the core substrate, a resin layer and a conductor layer are alternately laminated on the front surface and the back surface of the core substrate, thereby forming a buildup layer. That is, in this resin wiring substrate, the core substrate plays a role of reinforcement and is formed much thicker than the build-up layer. In addition, wiring (specifically, a through-hole conductor or the like) is formed through the core substrate for conduction between buildup layers formed on the front surface and the back surface.

  By the way, in recent years, with the increase in the speed of semiconductor integrated circuit elements, the signal frequency used has become a high frequency band. In this case, the wiring penetrating the core substrate contributes as a large inductance, leading to transmission loss of high-frequency signals and circuit malfunction, which hinders speeding up. In order to solve this problem, it has been proposed that the resin wiring substrate is a substrate that does not have a core substrate (see, for example, Patent Document 2). Since this substrate is obtained by shortening the overall wiring length by omitting a relatively thick core substrate, the transmission loss of high-frequency signals is reduced, and the semiconductor integrated circuit element can be operated at high speed. .

  However, if the core substrate is omitted, the resin wiring board is thinned, and thus the rigidity of the resin wiring board is inevitably lowered. In this case, when the solder used for flip chip connection is cooled, the resin wiring board tends to warp to the chip mounting surface side due to the influence of thermal stress caused by the difference in thermal expansion coefficient between the chip material and the substrate material. Become. As a result, cracks occur in the chip bonding portion, and open defects are likely to occur. That is, when a semiconductor package is configured using the above IC chip, there arises a problem that high yield and reliability cannot be realized.

  In order to solve the above problem, a semiconductor package 100 is proposed in which an annular metal stiffener 105 (reinforcing material) is attached to one side of the resin wiring substrate 101 (the mounting surface 102 of the IC chip 106 or its back surface 103). (See FIG. 14).

JP 2002-26500 A (FIG. 1 and the like) Japanese Unexamined Patent Publication No. 2002-26171 (FIG. 5 etc.)

  However, in the semiconductor package 100, the thermal expansion coefficient of the resin wiring substrate 101 is larger than the thermal expansion coefficient of the metal stiffener 105. For this reason, when heat is applied when the metal stiffener 105 is bonded to the resin wiring board 101, the resin wiring board 101 is warped due to the influence of thermal stress caused by the difference in thermal expansion coefficient (FIG. 15). reference). In this case, since the flatness of the chip mounting surface 102 cannot be ensured sufficiently, it is difficult to mount the IC chip 106 and the product reliability is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a wiring board with a reinforcing material with less warping while ensuring rigidity, and a wiring board for the wiring board with the reinforcing material. There is.

As a means for solving the above problems (means 1), it has a structure in which a plurality of resin insulation layers and a plurality of conductor layers are laminated without including a core substrate, including a substrate main surface and a substrate back surface. A plurality of main surface side connection terminals to which a semiconductor integrated circuit chip can be connected are bonded to the wiring substrate disposed on the substrate main surface only on the substrate main surface side, and the plurality of main surface side connection terminals A wiring board with a reinforcing material, comprising a reinforcing material having an opening through which the opening is exposed, wherein the thermal expansion coefficient of the plurality of resin insulation layers having the largest number of layers is the heat of the reinforcing material. When the expansion coefficient is larger than that, a wiring board having a warp in which the substrate main surface side is concave is manufactured, and the thermal expansion coefficient of the plurality of resin insulating layers having the largest number of layers is the thermal expansion coefficient of the reinforcing material. If the substrate back side is smaller than Manufacturing a wiring board with a reinforcing material, comprising: a wiring board manufacturing process for manufacturing a wiring board having a warping; and an adhesion process for bonding the reinforcing material to the substrate main surface of the wiring board having a warping. There is a way.

  Therefore, according to the invention described in the means 1, since the wiring board is formed without including the core board, sufficient rigidity cannot be secured by itself. For this reason, a reinforcing material is joined to the board main surface side of the wiring board, and a wiring board with a reinforcing material is manufactured. In the wiring board with a reinforcing material, when the thermal expansion coefficient of the wiring board is larger than the thermal expansion coefficient of the reinforcing material, a warp in which the back surface side of the board becomes concave due to the thermal expansion coefficient difference occurs. In this case, after a wiring board having a warp in which the substrate main surface side is concave is prepared in advance in the wiring board preparation step, a reinforcing material is bonded to the substrate main surface side of the wiring substrate having warpage in the bonding step. On the other hand, when the thermal expansion coefficient of the wiring board is smaller than the thermal expansion coefficient of the reinforcing material, a warp in which the board main surface side becomes concave due to the difference in thermal expansion coefficient occurs. In this case, after a wiring board having a warp in which the back side of the board is concave is created in advance in the wiring board creating process, a reinforcing material is bonded to the main surface side of the wiring board having the warping in the bonding process. If it does in this way, it deform | transforms in the direction which eliminates the curvature of a wiring board by the thermal expansion coefficient difference of a wiring board and a reinforcing material, and can manufacture the wiring board with a reinforcing material of a flat shape with few curvature. As a result, the semiconductor integrated circuit chip can be easily mounted on the wiring board with the reinforcing material, and the product yield of the wiring board can be improved.

  Although the magnitude | size of the said curvature of the said wiring board before the said adhesion process is not limited, For example, you may be 100 micrometers or more and 500 micrometers or less. In this case, although the magnitude | size of the said curvature of the said wiring board after the said adhesion process is not limited, For example, you may be 0 micrometer or more and 50 micrometers or less.

  The wiring board has a substrate main surface and a substrate back surface, has a structure in which a plurality of resin insulating layers and a plurality of conductor layers are laminated without including a core substrate, and can connect a semiconductor integrated circuit chip. A structure in which a plurality of main surface side connection terminals are arranged on the main surface of the substrate is used. In the wiring board, it is preferable that a plurality of via conductors are formed in the plurality of resin insulation layers, and the plurality of via conductors are expanded in the same direction in each layer of the plurality of resin insulation layers. In this way, a coreless wiring board that does not include a core board can be reliably manufactured.

  When the thermal expansion coefficient of the wiring board is larger than the thermal expansion coefficient of the reinforcing material, in the wiring board manufacturing process, from a material having a relatively small thermal expansion coefficient compared to the other of the plurality of resin insulating layers. It is preferable to perform lamination by arranging at least one resin insulating layer on the side to be the back surface of the substrate. If it does in this way, the wiring board which has the curvature from which the board | substrate principal surface side becomes concave can be easily produced by applying a thermal stress using the thermal expansion coefficient difference of each resin insulating layer.

  When the thermal expansion coefficient of the wiring board is smaller than the thermal expansion coefficient of the reinforcing material, in the wiring board manufacturing process, from a material having a relatively small thermal expansion coefficient compared to the other of the plurality of resin insulating layers. It is preferable that at least one resin insulating layer is disposed on the side to be the main surface of the substrate for lamination. If it does in this way, the wiring board which has the curvature by which a board | substrate back surface side becomes concave can be easily produced by applying a thermal stress using the thermal expansion coefficient difference of each resin insulating layer.

  It is preferable that at least one resin insulating layer made of a material having a relatively small coefficient of thermal expansion compared to the other of the plurality of resin insulating layers is made of a composite material containing an inorganic material in the resin material. . By using such a composite material, it is possible to reliably form a wiring board having the warp. Moreover, the rigidity of a wiring board can be improved by using the composite material which contained the inorganic material in the resin material.

  In the present invention, “thermal expansion coefficient” of the reinforcing material and the wiring board means a thermal expansion coefficient in a direction (XY direction) perpendicular to the thickness direction (Z direction), and is 0 ° C. to 100 ° C. It means the value measured with TMA (thermomechanical analyzer) between ℃. “TMA” refers to thermomechanical analysis, such as that defined in JPCA-BU01.

  The resin insulation layer can be appropriately selected in consideration of insulation, heat resistance, moisture resistance, and the like. Preferred examples of the polymer material for forming the resin insulation layer include thermosetting resins such as epoxy resin, phenol resin, urethane resin, silicone resin, polyimide resin, polycarbonate resin, acrylic resin, polyacetal resin, polypropylene resin, etc. And other thermoplastic resins. In addition, composite materials of these resins and organic fibers such as glass fibers (glass woven fabrics and glass nonwoven fabrics) and polyamide fibers, or three-dimensional network fluorine-based resin base materials such as continuous porous PTFE, epoxy resins, etc. A resin-resin composite material impregnated with a thermosetting resin may be used.

  The conductor layer and the main surface side connection terminal are mainly made of copper, and are formed by a known method such as a subtractive method, a semi-additive method, or a full additive method. Specifically, for example, techniques such as etching of copper foil, electroless copper plating, or electrolytic copper plating are applied. After forming a thin film by a method such as sputtering or CVD, etching is performed to form a conductor layer or a main surface side connection terminal, or a conductor layer or main surface side connection terminal is formed by printing a conductive paste or the like. It is also possible to do.

  As the semiconductor integrated circuit chip connectable to the plurality of main surface side connection terminals, an IC chip used as a microprocessor of a computer, an IC such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory). A chip can be mentioned.

  The reinforcing material is preferably more rigid than the resin material constituting the wiring board. The reason is that if the reinforcing material itself is given high rigidity, it can be given high rigidity to the wiring board by surface bonding, and becomes stronger against externally applied stress. In addition, if the reinforcing material has high rigidity, the wiring board can be provided with sufficiently high rigidity even if the reinforcing material is thinned, so that the thinning of the entire wiring board with reinforcing material is not hindered.

  The reinforcing material is preferably formed using, for example, a highly rigid metal material or ceramic material. For example, the reinforcing material may be formed of a composite material containing an inorganic material in a resin material.

  Examples of the metal material constituting the reinforcing material include iron, gold, silver, copper, copper alloy, iron nickel alloy, silicon, and gallium arsenide. Examples of the ceramic material constituting the reinforcing material include low-temperature fired materials such as alumina, glass ceramic, and crystallized glass, aluminum nitride, silicon carbide, and silicon nitride. As the resin material constituting the reinforcing material, epoxy resin, polybutene resin, polyamide resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polyimide resin, bismaleimide / triazine resin, polycarbonate resin, polyphenylene ether resin, acrylonitrile butadiene styrene copolymer There is a coalescence (ABS resin).

  The reinforcing material is bonded to the main surface of the wiring board, but the bonding method is not particularly limited, and a well-known method suitable for the nature, shape, etc. of the material forming the reinforcing material is adopted. be able to. For example, the joining surface of the reinforcing material is preferably joined to the substrate main surface via an adhesive. In this way, the reinforcing material can be reliably and easily joined to the wiring board. Examples of the adhesive include an acrylic adhesive, an epoxy adhesive, a cyanoacrylate adhesive, and a rubber adhesive.

Further, as another means (means 2) for solving the above-mentioned problem, a plurality of resin insulating layers and a plurality of conductor layers are laminated without including a core substrate, having a substrate main surface and a substrate back surface. A plurality of main surface side connection terminals that have a structure and can be connected to a semiconductor integrated circuit chip are disposed on the main surface of the substrate, and have openings that expose the plurality of main surface side connection terminals. A wiring board to which a material is to be bonded, having a warp of 100 μm or more and 500 μm or less, wherein a plurality of via conductors are formed in the plurality of resin insulating layers, and the plurality of via conductors are the plurality of via conductors. In each layer of the resin insulation layer, the diameter is expanded in the same direction, and the resin insulation layer has at least one resin insulation layer made of a material having a relatively small thermal expansion coefficient compared to the other of the plurality of resin insulation layers. For circuit board with reinforcing material There is a wiring board.

  Therefore, according to the invention described in Means 2, since the wiring board is formed without including the core board, sufficient rigidity cannot be secured by itself, so that the reinforcing material is bonded to the board main surface side. Used as a reinforcing wiring board with a reinforcing material. Here, the wiring board before the reinforcing material is bonded has a warp with a size of 100 μm or more and 500 μm or less, a plurality of via conductors are formed in the plurality of resin insulating layers, and the plurality of via conductors are a plurality of via conductors. In each layer of the resin insulating layer, the diameter is expanded in the same direction. When a reinforcing material is joined to a wiring board having warpage, it can be deformed in a direction to eliminate the warping of the wiring board due to the difference in thermal expansion coefficient between the wiring board and the reinforcing material. A wiring board can be manufactured.

1 is a schematic cross-sectional view illustrating a schematic configuration of a semiconductor package according to an embodiment. The schematic plan view which shows a semiconductor package. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. Explanatory drawing which shows the manufacturing method of a wiring board with a stiffener. The perspective view which shows the semiconductor package of a prior art. Similarly, the schematic sectional drawing which shows a semiconductor package.

  Hereinafter, an embodiment in which the present invention is embodied in a wiring board with a reinforcing material will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the semiconductor package 10 of this embodiment includes a BGA (ball grid) including a stiffener-equipped wiring substrate 11 (a wiring substrate with a reinforcing material) and an IC chip 21 (semiconductor integrated circuit chip). Array). Note that the form of the semiconductor package 10 is not limited to BGA alone, and may be PGA (pin grid array), LGA (land grid array), or the like. The IC chip 21 is a rectangular flat plate having a length of 15.0 mm, a width of 15.0 mm, and a thickness of 0.8 mm, and is made of silicon having a thermal expansion coefficient of 4.2 ppm / ° C.

  The wiring board 11 with a stiffener includes a wiring board 40 and a wiring board stiffener (hereinafter referred to as “stiffener”) 31 that is a reinforcing material. The wiring substrate 40 of the present embodiment has a substrate main surface 41 and a substrate back surface 42 and is formed in a substantially rectangular shape in plan view of 50.0 mm long × 50.0 mm wide × 0.4 mm thick. The wiring board 40 is a coreless wiring board formed without including a core board, and is composed of four resin insulation layers 43, 44, 45, 46 made of epoxy resin and conductor layers 51 made of copper alternately. It has a laminated structure.

  In the wiring substrate 40 of the present embodiment, the first resin insulating layer 43 that is the lowest layer is made of a composite material in which a glass cloth 48 (inorganic material) is contained in an epoxy resin. The resin insulation layers 44 to 46 of the layers to the fourth layer are made of an epoxy resin that does not include the glass cloth 48. Therefore, the first resin insulating layer 43 has a smaller thermal expansion coefficient than the other resin insulating layers 44 to 46. Specifically, the thermal expansion coefficient of the first resin insulating layer 43 is about 16 ppm / ° C., and the thermal expansion coefficients of the second to fourth resin insulating layers 44 to 46 are about 30 ppm / ° C. It has become. The thermal expansion coefficient of the conductor layer 51 is about 17 ppm / ° C.

  As shown in FIG. 1, terminal pads 52 (main surface side connection terminals) are arranged in an array on the substrate main surface 41 of the wiring substrate 40 (on the surface of the fourth resin insulating layer 46). Yes. Furthermore, a plurality of main surface side solder bumps 54 are disposed on the surface of the terminal pad 52. Each main surface side solder bump 54 is electrically connected to the surface connection terminal 22 of the IC chip 21. That is, the IC chip 21 is mounted on the substrate main surface 41 side of the wiring substrate 40. In addition, the area | region in which each terminal pad 52 and each main surface side solder bump 54 is formed is the IC chip mounting area 23 in which the IC chip 21 can be mounted.

  On the other hand, BGA pads 53 are arranged in an array on the substrate rear surface 42 of the wiring substrate 40 (on the lower surface of the first resin insulating layer 43). A plurality of backside solder bumps 55 for connecting the motherboard are disposed on the surface of each BGA pad 53, and the wiring board 40 is mounted on the motherboard (not shown) by each backside solder bump 55. The

  Each resin insulation layer 43 to 46 is provided with a via hole 56 and a via conductor 57. Each via hole 56 has a truncated cone shape, and is formed by drilling the resin insulation layers 43 to 46 using a YAG laser or a carbon dioxide gas laser. Each via conductor 57 is a conductor whose diameter increases toward the back side 42 of the substrate (downward in FIG. 1), and electrically connects each conductor layer 51, the terminal pad 52 and the BGA pad 53 to each other. ing.

  As shown in FIGS. 1 and 2, the stiffener 31 has a rectangular frame shape in plan view of 50.0 mm long × 50.0 mm wide × 2.0 mm thick. The stiffener 31 is formed thicker than the wiring board 40 using a metal material (for example, copper). Therefore, the stiffener 31 is more rigid than the wiring board 40. Furthermore, the thermal expansion coefficient of the stiffener 31 is about 17 ppm / ° C., which is smaller than the thermal expansion coefficient (about 30 ppm / ° C.) of the resin insulating layers 44 to 46 constituting the wiring board 40.

  The stiffener 31 has a bonding surface 32 bonded to the wiring substrate 40 and a non-bonding surface 33 located on the opposite side of the bonding surface 32. The bonding surface 32 can come into surface contact with the outer peripheral portion of the substrate main surface 41 (that is, the region excluding the IC chip mounting region 23 in the substrate main surface 41).

  The stiffener 31 is formed with a rectangular opening 35 penetrating in a plan view opening at the center of the joint surface 32 and the center of the non-joint surface 33. The opening 35 exposes the terminal pad 52 and the main surface side solder bump 54. Specifically, the opening 35 is a hole having a substantially square shape in cross section having a radius of 1.5 mm at four corners with a length of 20 mm × width of 20 mm.

  As shown in FIG. 1, the bonding surface 32 of the stiffener 31 is surface bonded (bonded and fixed) to the outer peripheral portion of the substrate main surface 41 via an adhesive 30 (for example, an epoxy-based adhesive). If the stiffener-equipped wiring board 11 is configured in this way, the stiffener 31 can impart high rigidity to the wiring board 11.

  Next, the manufacturing method of the wiring board 11 with a stiffener is demonstrated.

  In the preparation step, the wiring board 40 and the stiffener 31 are prepared and prepared in advance.

  The wiring board 40 is manufactured through the following wiring board manufacturing process. In the wiring substrate manufacturing process, first, as shown in FIG. 3, a support substrate 70 having sufficient strength such as a glass epoxy substrate is prepared. Next, a base resin insulating layer 71 is formed by pasting a sheet-like insulating resin base material made of epoxy resin on the support substrate 70 to form a base material 69 made of the support substrate 70 and the base resin insulating layer 71. obtain. Then, as shown in FIG. 4, the laminated metal sheet body 72 is disposed on one surface of the base material 69 (specifically, the upper surface of the base resin insulating layer 71). Here, by disposing the laminated metal sheet body 72 on the base resin insulating layer 71, adhesiveness is secured to such an extent that the laminated metal sheet body 72 is not peeled off from the base resin insulating layer 71 in the subsequent manufacturing process. The laminated metal sheet body 72 is formed by closely attaching two copper foils 73 and 74 in a peelable state. Specifically, the laminated metal sheet body 72 is formed by laminating the copper foils 73 and 74 via metal plating (for example, chromium plating).

  Thereafter, as shown in FIG. 5, a sheet-like insulating resin base material 75 is disposed so as to wrap the laminated metal sheet body 72, and is heated under pressure using a vacuum press-bonding hot press (not shown). As a result, the insulating resin base material 75 is cured to form the fourth resin insulating layer 46. Here, the resin insulating layer 46 is in close contact with the laminated metal sheet body 72, and in close contact with the base resin insulating layer 71 in the peripheral region of the laminated metal sheet body 72, thereby sealing the laminated metal sheet body 72.

  Then, as shown in FIG. 6, laser processing is performed to form via holes 56 at predetermined positions of the resin insulating layer 46, and then desmear processing is performed to remove smears in the via holes 56. Then, via conductors 57 are formed in each via hole 56 by performing electroless copper plating and electrolytic copper plating according to a conventionally known method. Further, the conductor layer 51 is patterned on the resin insulating layer 46 by performing etching by a conventionally known method (for example, semi-additive method) (see FIG. 7).

  The first to third resin insulation layers 43 to 45 and the conductor layer 51 are also formed by the same method as the above-described fourth resin insulation layer 46 and conductor layer 51, and the resin insulation layer 46 is formed on the resin insulation layer 46. Laminate to. However, in this embodiment, when the second to fourth resin insulation layers 44 to 46 are formed, a general build-up material (Ajinomoto: ABF-GX13) that does not include the glass cloth 48 is used as the insulation resin group. Used as material 75. In addition, a build-up material (Ajinomoto: ABF-GX13-PP) obtained by impregnating a glass cloth 48 with an epoxy resin is used as an insulating resin base material only when the first resin insulating layer 43 is formed. Thus, by using different buildup materials, the thermal expansion coefficient of the first resin insulation layer 43 is about 16 ppm / ° C., and the thermal expansion coefficients of the second to fourth resin insulation layers 44 to 46 are About 30 ppm / ° C.

  The laminated body 80 which laminated | stacked the laminated metal sheet body 72, the resin insulating layers 43-46, and the conductor layer 51 on the base material 69 is formed by the above process (refer FIG. 8). As shown in FIG. 8, a region located on the laminated metal sheet body 72 in the laminated body 80 is a wiring laminated portion 81 to be the wiring board 40.

  The laminated body 80 is cut by a dicing device (not shown), and the peripheral area of the wiring laminated portion 81 in the laminated body 80 is removed. At this time, as shown in FIG. 8, the substrate 69 (the support substrate 70 and the base resin insulating layer 71) below the wiring laminated portion 81 is cut at the boundary between the wiring laminated portion 81 and the peripheral portion 82. By this cutting, the outer edge portion of the laminated metal sheet body 72 sealed with the resin insulating layer 46 is exposed. That is, due to the removal of the peripheral portion 82, the close contact portion between the base resin insulating layer 71 and the resin insulating layer 46 is lost. As a result, the wiring laminated portion 81 and the base material 69 are connected via the laminated metal sheet body 72 only.

  Here, as shown in FIG. 9, the wiring laminated portion 81 is separated from the base material 69 by peeling at the interface between the two copper foils 73 and 74 in the laminated metal sheet body 72. Then, as shown in FIG. 10, by patterning by etching the copper foil 73 on the lower surface of the wiring laminated portion 81 (resin insulating layer 46), terminal pads are formed on the outermost resin insulating layer 46. 52 is formed.

  In the subsequent solder bump forming step, main surface side solder bumps 54 for IC chip connection are formed on the plurality of terminal pads 52 formed on the outermost resin insulation layer 46 (see FIG. 11). Specifically, a solder ball is placed on each terminal pad 52 using a solder ball mounting device (not shown), and then the solder ball is heated to a predetermined temperature and reflowed, whereby the main surface is placed on each terminal pad 52. Side solder bumps 54 are formed. Similarly, back-side solder bumps 55 are formed on the plurality of BGA pads 53 formed on the resin insulating layer 43.

  Here, in the wiring board 40, the resin insulating layer 43 and the resin insulating layers 44 to 46 have different thermal expansion coefficients. For this reason, when the solder bumps 54 and 55 are formed, as a result of applying thermal stress due to the difference in thermal expansion coefficient, the wiring substrate 40 is deformed and warpage occurs in which the substrate main surface 41 side becomes concave (see FIG. 11). The warp of the wiring board 40 is about 200 μm to 300 μm.

  The stiffener 31 is processed into a rectangular shape by cutting a copper plate using a conventionally known cutting device. Further, the opening 35 of the stiffener 31 is formed by drilling using a countersink cutter, a mechanical drill, a punching device, or the like.

  In the bonding step, the stiffener 31 is bonded to the substrate main surface 41 of the wiring substrate 40 having warpage. Specifically, as shown in FIG. 12, after applying the adhesive 30 to the joint surface 32 of the stiffener 31, the stiffener 31 is disposed on the substrate main surface 41 of the wiring substrate 40, and the joint surface 32 is formed on the substrate main surface 41. Contact the surface 41. In this state, if the adhesive 30 is solidified by performing a heat treatment (curing) at about 150 ° C., for example, the adhesive 30 is cooled to room temperature after the heat treatment, and the stiffener 31 is attached to the substrate main surface 41. It is bonded and fixed via the adhesive 30 (see FIG. 13). At this time, when the thermal stress resulting from the difference in thermal expansion coefficient between the wiring board 40 and the stiffener 31 is applied, the wiring board 40 is deformed in a direction to eliminate the warp. Thereby, the warp of the wiring board 40 is reduced to 50 μm or less, and the flat-stiffened wiring board 11 with less warpage is formed.

  Thereafter, the IC chip 21 is mounted on the IC chip mounting area 23 of the wiring board 40. At this time, the surface connection terminals 22 on the IC chip 21 side and the main surface side solder bumps 54 on the wiring board 40 side are aligned. Then, by heating and reflowing the main surface side solder bumps 54, the surface connection terminals 22 and the main surface side solder bumps 54 are joined, and the IC chip 21 is mounted on the wiring board 40 (see FIG. 1). .

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In this embodiment, after the wiring board 40 having a warp in which the substrate main surface 41 side is concave is created in advance in the wiring board creation process, the substrate main of the wiring board 40 having a warp is produced in the bonding process. A stiffener 31 is bonded and fixed to the surface 41 side. In this way, the wiring board 11 with a reinforcing material having a flat shape with less warping can be manufactured by deforming the wiring board 40 in a direction to eliminate the warping due to the difference in thermal expansion coefficient between the wiring board 40 and the stiffener 31. it can. As a result, the IC chip 21 can be reliably mounted on the wiring board 11 with the reinforcing material, and the yield of the product can be improved and its reliability can be ensured.

  (2) In the wiring board manufacturing process of the present embodiment, the resin insulating layer 43 made of a material having a relatively small thermal expansion coefficient as compared with the other of the plurality of resin insulating layers 43 to 46 is used as the substrate back surface 42. The resin insulating layers 43 to 46 are stacked on the side to be disposed. If it does in this way, the wiring board 40 which has the curvature by which the board | substrate main surface 41 side becomes concave can be easily produced by applying the thermal stress resulting from the thermal expansion coefficient difference of each resin insulation layers 43-46.

  (3) By forming the resin insulating layer 43 using a build-up material obtained by impregnating a glass cloth 48 (inorganic material) with an epoxy resin like the wiring substrate 40 of the present embodiment, the rigidity of the substrate itself is formed. Can be improved.

  In addition, you may change embodiment of this invention as follows.

  In the above-described embodiment, the wiring board 40 having the warp that the thermal expansion coefficient of the wiring board 40 is larger than the thermal expansion coefficient of the stiffener 31 and the board main surface 41 side is concave is manufactured. On the contrary, when the thermal expansion coefficient of the stiffener 31 is large and the thermal expansion coefficient of the wiring board 40 is small, the wiring board 40 having a warp in which the back surface 42 side of the substrate is concave is produced, and the wiring having the warp is produced. The stiffener 31 may be bonded and fixed on the substrate main surface 41 of the substrate 40. Even in this case, the wiring board 11 with a stiffener having a flat shape without warping can be manufactured by deforming the wiring board 40 in a direction to eliminate the warping due to the difference in thermal expansion coefficient between the wiring board 40 and the stiffener 31. it can. When manufacturing the wiring board 40 having a warp in which the substrate back surface 42 side is concave, the wiring board 40 is made of a material having a relatively small thermal expansion coefficient compared to the other of the plurality of resin insulating layers 43 to 46. The resin insulating layer 46 is disposed on the side that becomes the substrate main surface 41 to perform lamination.

  In the above embodiment, the wiring board 40 is a board formed by laminating four resin insulating layers 43 to 46, but the number of these resin insulating layers may be changed as appropriate. In addition, one resin insulating layer 43 among the plurality of resin insulating layers 43 to 46 is formed of a material having a relatively small coefficient of thermal expansion as compared with the other ones. The insulating layer may be formed of materials having different thermal expansion coefficients.

  In the above embodiment, the wiring substrate 40 having a warp is produced using thermal stress caused by the difference in thermal expansion coefficients of the resin insulating layers 43 to 46. However, the present invention is not limited to this. Absent. For example, you may produce the wiring board 40 which has curvature by embossing using a shaping die. Moreover, in the wiring board which covers the outermost layer of the substrate with the solder resist, the thermal expansion coefficient of the solder resist is made different from the thermal expansion coefficient of the resin insulating layers 43 to 46, and the heat of the solder resist and the resin insulating layer is formed. The wiring board may be warped using a difference in expansion coefficient.

  In the above embodiment, after the wiring board 40 and the stiffener 31 having warpage are individually manufactured, the wiring board 40 and the stiffener 31 are joined to manufacture the wiring board 11 with the stiffener. It is not limited to this. For example, a multi-cavity wiring board in which a plurality of product areas to be the wiring board 40 is formed is manufactured, and the stiffeners 31 are bonded and fixed to the product areas of the multi-cavity wiring board. Then, after the stiffener 31 is bonded and fixed, a plurality of wiring boards 11 with stiffeners may be simultaneously produced by cutting the multi-wiring board. Also in this multi-cavity wiring board, a warp in which the substrate main surface 41 side becomes concave due to the difference in thermal expansion coefficient between the resin insulating layers 43 to 45 and the resin insulating layer 46 is generated. Then, the heat treatment at the time of bonding of the stiffener 31 causes the wiring board to be deformed in a direction to eliminate the warp due to the difference in thermal expansion coefficient between the multi-piece wiring board and the stiffener 31. Even in this manner, the wiring board 11 with a stiffener having a flat shape with little warpage can be manufactured.

  In the wiring board 11 with a stiffener of the above embodiment, the stiffener 31 made of copper is used as a reinforcing material, but a metal stiffener other than copper may be used, or a ceramic stiffener or a resin stiffener is used. It may be used. Furthermore, you may use the stiffener which affixes a metal plate and a ceramic board on the surface of the base material which consists of resin materials.

DESCRIPTION OF SYMBOLS 11 ... Wiring board with a stiffener as a wiring board with a reinforcing material 21 ... IC chip as a semiconductor integrated circuit chip 31 ... Stiffener as a reinforcing material 35 ... Opening 40 ... Wiring board 41 ... Substrate main surface 42 ... Substrate back surface 43-46 ... Resin insulation layer 48 ... Glass cloth as inorganic material 51 ... Conductive layer 52 ... Terminal pad as main surface side connection terminal 57 ... Via conductor

Claims (7)

A plurality of main surface side connections that have a substrate main surface and a substrate back surface, have a structure in which a plurality of resin insulating layers and a plurality of conductor layers are laminated without including a core substrate, and can connect a semiconductor integrated circuit chip. A wiring board having terminals disposed on the board main surface;
A method of manufacturing a wiring board with a reinforcing material, comprising: a reinforcing material that is bonded only to the main surface side of the substrate and has an opening through which the plurality of main surface side connection terminals are exposed;
When the thermal expansion coefficient though out layer highest number of said plurality of resin insulation layer is greater than the thermal expansion coefficient of the reinforcement to produce a wiring board having a warp which the substrate main surface is concave, the plurality When the thermal expansion coefficient of the resin insulation layer having the largest number of layers is smaller than the thermal expansion coefficient of the reinforcing material, a wiring board manufacturing step of manufacturing a wiring board having a warp in which the back side of the substrate is concave,
And a bonding step of bonding the reinforcing material to the main surface of the wiring board having warpage.   The size of the warp of the wiring substrate before the bonding step is 100 μm or more and 500 μm or less, and the size of the warp of the wiring substrate after the bonding step is 0 μm or more and 50 μm or less. A manufacturing method of a wiring board with a reinforcing material according to 1.   The plurality of via conductors are formed in the plurality of resin insulation layers, and the plurality of via conductors are expanded in the same direction in each layer of the plurality of resin insulation layers. The manufacturing method of the wiring board with a reinforcing material of description.   In the wiring board manufacturing step, at least one resin insulating layer made of a material having a relatively small coefficient of thermal expansion compared to the other of the plurality of resin insulating layers is arranged on the side to be the back surface of the substrate and laminated. 4. The method of manufacturing a wiring board with a reinforcing material according to claim 1, wherein a wiring board having a warp in which the main surface side of the board is concave is manufactured.   In the wiring board manufacturing step, at least one resin insulation layer made of a material having a relatively small coefficient of thermal expansion as compared with the other of the plurality of resin insulation layers is disposed on the substrate main surface side. The method of manufacturing a wiring board with a reinforcing material according to any one of claims 1 to 3, wherein a wiring board having a warp in which the back surface side of the board is concave is produced by stacking.   At least one resin insulation layer made of a material having a relatively small coefficient of thermal expansion compared to the other of the plurality of resin insulation layers is made of a composite material containing an inorganic material in the resin material. The manufacturing method of the wiring board with a reinforcing material of Claim 4 or 5. A plurality of main surface side connections that have a substrate main surface and a substrate back surface, have a structure in which a plurality of resin insulating layers and a plurality of conductor layers are laminated without including a core substrate, and can connect a semiconductor integrated circuit chip. A wiring board to which a reinforcing material having terminals disposed on the main surface of the substrate and having openings through which the plurality of main surface side connection terminals are exposed is to be bonded, and having a size of 100 μm or more and 500 μm or less has a warp, the the plurality of resin insulation layer is formed with a plurality of via conductors, the plurality of via conductors are then expanded in the same direction in each layer of the plurality of resin insulation layers, the plurality of resin A wiring board for a wiring board with a reinforcing material, comprising at least one resin insulating layer made of a material having a relatively small coefficient of thermal expansion as compared with the other insulating layers .

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