JP2010021368A - Wiring board with built-in component and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a wiring board with a built-in component capable of unfailingly connecting the built-in component to a conductor layer and improving connection reliability, and to provide the wiring board with the built-in component. <P>SOLUTION: The manufacturing method is provided with: a protruding conductor forming step of forming a protruding conductor 51 by bonding a bonding portion in a metal member equipped with a wire and the bonding portion to external electrodes 121, 122 and then separating the wire; a housing step of housing a capacitor 101 into a housing hole 90 of a core substrate 11; a resin filling/sealing step of filling and sealing a gap in the housing hole 90 of the core substrate 11 in which the capacitor 101 is housed, with an insulative resin (being a resin filling portion 92). Preferably, after the resin filling/sealing step, the manufacturing method is provided with a height aligning step of aligning the height so that tops of a plurality of protruding conductors 51 and a core rear surface 13 of the core substrate 11 may be included in one planar surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a component built-in wiring board in which components such as capacitors are accommodated and a method for manufacturing the same. More specifically, the present invention relates to a method of manufacturing a component-embedded wiring board that can prevent the occurrence of defective products and improve reliability, and a component-embedded wiring substrate manufactured by the method.

  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, since the terminal group on the IC chip side and the terminal group on the motherboard side have a large difference in the pitch between terminals, it is difficult to directly connect the IC chip to the motherboard. Therefore, a method is usually employed in which a package is prepared by mounting an IC chip on an IC chip mounting wiring board, and the package is mounted on a motherboard. In a wiring board for mounting an IC chip constituting this type of package, it has been proposed to provide a capacitor in order to reduce switching noise of the IC chip and stabilize the power supply voltage. As an example, a wiring board is proposed in which chip-shaped capacitors are embedded in a core substrate made of a polymer material, and build-up layers are formed on the front surface and the back surface of the core substrate (for example, see Patent Document 1). ).

An example of the conventional method for manufacturing a wiring board will be described below.
First, a core substrate 204 (see FIG. 27) made of a polymer material having accommodation holes 203 opened on both the core main surface 201 and the core back surface 202 is prepared. In addition, a capacitor 208 (see FIG. 27) is prepared in which a plurality of surface electrodes 207 protrude from the capacitor main surface 205 and the capacitor back surface 206, respectively. Then, the adhesive tape 209 is stuck on the core back surface 202 side, and the opening on the core back surface 202 side of the accommodation hole 203 is closed in advance. Next, the capacitor 208 is accommodated in the accommodation hole 203, and the capacitor back surface 206 is attached to the adhesive surface of the adhesive tape 209 and temporarily fixed (see FIG. 27).

  Thereafter, a resin insulating layer 210 mainly composed of a polymer material is formed on the core main surface 201 and the capacitor main surface 205 (see FIG. 28). At the same time, the gap between the inner wall surface of the accommodation hole 203 and the side surface of the capacitor 208 is filled with a part of the resin insulating layer 210 to fix the capacitor 208 (see FIG. 28). At this point, the adhesive tape 209 is peeled off. Next, a resin insulating layer 211 mainly composed of a polymer material is formed on the core back surface 202 and the capacitor back surface 206 (see FIG. 29). Further, via holes penetrating the resin insulating layers 210 and 211 are formed at a plurality of locations by laser drilling, and the surface electrode 207 is exposed. Thereafter, electroless copper plating is performed on the resin insulating layers 210 and 211 and the inner surfaces of the via holes, then an etching resist is formed, and then electrolytic copper plating is performed. Furthermore, by removing the etching resist and performing soft etching, the conductor layer 213 is patterned on the resin insulating layers 210 and 211, and the via conductor 212 is formed inside each via hole (see FIG. 29). ). Next, a buildup layer is formed by alternately providing a resin insulation layer and a conductor layer on the resin insulation layers 210 and 211. In this way, a wiring board having a predetermined structure can be manufactured.

Japanese Patent Laying-Open No. 2006-351882 (FIG. 1 etc.)

  However, in the manufacturing method described above, the core substrate 204 and the capacitor 208 are likely to have thickness variations due to warpage or the like that occurs during formation, and since the capacitor 208 is usually thinner than the core substrate 204, the core main surface A step is formed between 201 and the capacitor main surface 205. Therefore, variations also occur in the thickness of the resin insulating layers 210 and 211 formed on the core substrate 204 and the capacitor 208 and the depth of the via hole formed in the resin insulating layers 210 and 211. Therefore, when forming via holes at a plurality of locations by laser drilling, laser output adjustment is not easy. That is, when a via hole is formed in a relatively thin portion of the resin insulating layers 210 and 211, the laser light that has passed through the resin insulating layers 210 and 211 is irradiated to the surface electrode 207 with a high output. May cause the surface electrode 207 to generate heat and melt. On the other hand, when a via hole is formed in a relatively thick portion of the resin insulating layers 210 and 211 (for example, a portion on the capacitor main surface 205 of the resin insulating layer 210), the laser light passing through the resin insulating layers 210 and 211 There is a possibility that the resin does not reach the surface electrode 207 and the resin remains on the upper surface of the surface electrode 207 so that the surface electrode 207 cannot be sufficiently exposed. In addition, when a via hole is formed in a relatively thick portion of the resin insulating layers 210 and 211, the via hole becomes deep, so that the aspect ratio of the via hole (via hole depth / diameter) increases and becomes elongated. For this reason, it is not easy to completely fill the via hole with the via conductor paste, and if it is to be completely filled, the productivity is lowered. Further, it may be difficult to connect the end portion of the formed via conductor 212 and the surface electrode 207 with certainty.

  The present invention has been made in view of the above-described conventional situation, and by reliably connecting the component and the core substrate, the occurrence of defective products can be prevented and the reliability can be improved. An object of the present invention is to provide a method for manufacturing a component-embedded wiring board that can be used. It is another object of the present invention to provide a highly reliable component built-in wiring board manufactured by the method of the present invention.

The present invention is as follows.
1. A core substrate having a core main surface and a core back surface, and having at least an accommodation hole opening in the core back surface; a component main surface and a component back surface; and a plurality of external electrodes formed on the component back surface And a component housed in the housing hole, an insulating resin filling the gap in the housing hole in which the component is housed, and the external electrode projecting from the external electrode, and the external electrode is connected to the back surface of the core Or a method of manufacturing a component-embedded wiring board comprising a plurality of projecting conductors led out to the surface of the buildup insulating layer laminated on the back surface of the core, the metal member comprising a wire part and a joint part After the joining portion is joined to the external electrode, the projecting conductor forming step of separating the wire portion to form the projecting conductor, and the component back surface and the core back surface of the component are directed to the same side. In the state, the component is And accommodation step for accommodating manufacturing method of wiring board with a built-in component, characterized in that it comprises a resin being filled step of being filled with an insulating resin to a gap in the accommodation hole portion which the component is accommodated.
2. The above 1. in which the joint portion is substantially spherical. A method for manufacturing a component-embedded wiring board as described in 1.
3. After the resin filling step, a height adjusting step for adjusting the height so that the top portions of the plurality of protruding conductors and the core back surface or the surface of the build-up insulating layer are included in one flat surface. Provided above 1. Or 2. A method for manufacturing a component-embedded wiring board as described in 1.
4). The projecting conductor has a shape of a skirt. To 3. The manufacturing method of the component built-in wiring board in any one of these.
5). The above-mentioned projecting conductor is 1 <R / S <5, where S is the joint diameter with the external electrode and R is the maximum diameter of the projecting conductor. A method for manufacturing a component-embedded wiring board as described in 1.
6). The protruding conductor is composed of copper as a main component. To 5. The manufacturing method of the component built-in wiring board in any one of these.
7). The joining in the projecting conductor forming step is performed by ultrasonic joining while maintaining the temperature of the component at 400 ° C. or lower. To 6. The manufacturing method of the component built-in wiring board in any one of these.
8). The component is a via array capacitor. To 7. The manufacturing method of the component built-in wiring board in any one of these.
9. The protruding conductor forming step and the resin filling step are performed in this order, and the protruding conductor roughening is performed to roughen the surface of the protruding conductor between the protruding conductor forming step and the resin filling step. The above-mentioned 1. comprising the steps. To 8. The manufacturing method of the component built-in wiring board in any one of these.
10. 1. A pressing process for pressing the protruding conductor to adjust the shape of the protruding conductor. Thru 9. The manufacturing method of the component built-in wiring board in any one of these.
11. Above 1. To 10. A wiring board with a built-in component obtained by the method for manufacturing a wiring board with a built-in component according to any one of the above.

  According to the method of manufacturing a component-embedded wiring board of the present invention, the core back surface side of the core substrate is flattened by forming the resin filling portion. Therefore, when the back surface side build-up layer is formed on the core back surface, the surface is formed on the surface. The height of the connecting terminal portion (that is, the BGA pad) is constant. Therefore, the wiring board can be reliably mounted on the mother board, and the reliability of the wiring board is improved. In addition, since the component, for example, the via array capacitor is arranged directly under the IC chip mounted in the IC chip mounting area, the wiring connecting the via array capacitor and the IC chip is shortened, and an increase in the inductance component of the wiring is prevented. Is done. Therefore, the switching noise of the IC chip due to the via array capacitor can be reduced, and the power supply voltage can be stabilized. Furthermore, since the noise that enters between the IC chip and the via array capacitor can be suppressed to a very low level, high reliability can be obtained without causing a malfunction or the like. In addition, since the IC chip mounting area is located in the area directly above the via array capacitor, the IC chip mounted on the IC chip mounting area is supported by the via array capacitor having high rigidity and low thermal expansion coefficient. . Therefore, in the IC chip mounting region, the buildup layer is difficult to be deformed, and the IC chip can be stably supported. Accordingly, it is possible to prevent cracking of the IC chip due to a large thermal stress, poor connection, and the like. As a result, a large IC chip of 10 mm square or more and a low-k (low dielectric constant) brittle IC chip that have a large stress strain due to a difference in thermal expansion, a large calorific value, and a large thermal shock during use. Can be used.

  Moreover, when a junction part is substantially spherical shape, the resin for forming a resin filling part can be made to flow in smoothly, and the position shift of components at the time of filling resin can also be prevented.

Further, after the resin filling step, when a height adjusting step for adjusting the height so that the tops of the plurality of protruding conductors and the back surface of the core or the surface of the buildup insulating layer are included in one flat surface is provided. The top surface of the plurality of protruding conductors and the surface of the core back side conductor layer formed on the core back surface have the same height, and a back side resin insulation layer with small thickness variation can be formed. . Therefore, when forming a plurality of via holes penetrating the back surface side resin insulation layer when forming the via hole, it is possible to easily and reliably form a via hole with a constant laser beam output and a small variation in depth. . In addition, a via conductor can be reliably formed in each via hole. As a result, the projecting conductor and the via conductor can be reliably conducted, the occurrence of defective products can be prevented, and a highly reliable wiring board can be manufactured. Further, in the height adjusting step, the top portion before the height adjustment is polished in a state where the resin filling portion covering the back surface of the capacitor is disposed between the side surfaces of the respective protruding conductors. In this way, since each protruding conductor is fixed by the resin filling portion, even if a large force is applied to the protruding conductor during the height adjustment process, the protruding conductor can be prevented from being damaged. it can. Furthermore, since the resin-filled portions are arranged between the side surfaces of the respective protruding conductors, the recesses between the protruding conductors are filled and flattened, so that the polishing powder generated during polishing of the top surface and the resin-filled portion remains. It becomes difficult to do. In addition, since both the top portion of the protruding conductor and the core back side conductor layer are removed in the height adjusting step, the top portion is not only flattened but also the core back side conductor layer exposed from the resin filling portion. The surface of the substrate can be flattened. Therefore, the variation in the thickness of the backside resin insulation layer formed on the surface of the protruding conductor and the core backside conductor layer is further reduced. As a result, when a plurality of via holes are formed in the back surface side resin insulation layer, the variation in the depth of the via holes becomes smaller, and via conductors can be more reliably formed in each via hole. The conductor and the via conductor can be more reliably conducted, and the reliability can be improved.
Further, when the protruding conductor has a squinted shape, the fitting property between the protruding conductor and the resin filling portion is improved, and peeling between the resin filling portion and the component back surface is prevented.
Further, when the joint diameter of the projecting conductor with the external electrode is S and the maximum diameter of the projecting conductor is R, even when 1 <R / S <5, Is improved, and peeling between the resin filling portion and the back of the component is prevented.
Further, when the projecting conductor is mainly composed of copper, the projecting conductor has a low resistance and can be inexpensive, and the surface can be easily roughened, which is advantageous in terms of the process.
Further, when the joining in the projecting conductor forming step is performed by ultrasonic joining while maintaining the temperature of the component at 400 ° C. or less, the projecting conductor and the external electrode can be joined with high strength.
Also, if the component is a via array capacitor, the IC chip to be mounted is supported by a via array capacitor that is higher in rigidity and has a lower coefficient of thermal expansion than a polymer material. The up layer is difficult to deform, the IC chip is stably supported, and the occurrence of cracks in the IC chip due to large thermal stress, poor connection, and the like can be prevented.
Furthermore, a protruding conductor forming step and a resin filling step are performed in this order, and a protruding conductor roughening step for roughening the surface of the protruding conductor is further provided between the protruding conductor forming step and the resin filling step. In this case, the protruding conductor and the resin filling portion can be more reliably brought into close contact with each other.
In addition, when a pressing process for pressing the projecting conductor to adjust the shape of the projecting conductor is provided, the shape of the projecting conductor can be adjusted, the variation in height can be reduced, and the projecting conductor can be reduced. It is also possible to increase the bonding strength between the conductor and the external electrode.

  According to the component built-in wiring board of the present invention, the height of the connection terminal portion (that is, the BGA pad) formed on the surface of the back-side buildup layer formed on the back surface of the core is constant. Can be reliably mounted on the mother board, and the reliability of the wiring board is improved. In addition, intrusion noise between the component and the IC chip can be suppressed to an extremely low level, and no malfunction or the like can occur. Therefore, high reliability can be obtained. Furthermore, since the IC chip is supported by a part having high rigidity and a low coefficient of thermal expansion, the build-up layer is hardly deformed in the IC chip mounting region, and the IC chip is stably supported. Accordingly, it is possible to prevent the occurrence of cracks in the IC chip due to a large thermal stress, poor connection, and the like.

The present invention will be described in detail below.
The core substrate constituting the component built-in wiring board can be manufactured by a known method. The core substrate is, for example, a plate-like body having a core main surface and a core back surface opposite to the core main surface, and has an accommodating hole for accommodating components. The accommodation hole portion may be a bottomed hole that opens only on the core back surface side, or may be a through hole that opens on both the core main surface side and the core back surface side.

  Although the material of a core board | substrate is not specifically limited, The core board | substrate which has a polymeric material as a main component is preferable. Examples of the polymer material used for forming the core substrate include an epoxy resin, a polyimide resin, a bismaleimide / triazine resin, and a polyphenylene ether resin. In addition, composite materials of these resins and inorganic fibers such as glass fibers and organic fibers such as polyamide fibers can be used.

Parts can also be produced by known methods. This component includes a component main body having a component main surface, a component back surface, and a component side surface. In the present invention, a protruding conductor is provided on an external electrode on the component back surface. The shape of the component is not particularly limited, and for example, a plate-like body in which the area of the component main surface is larger than the area of the side surface of the component can be used. The planar shape of the component is preferably a polygon, and examples of the polygon include a quadrangle, a triangle, a hexagon, and the like, and a quadrangle is particularly preferable.
In addition, a polygon means not only an exact polygon shape but the shape where the corner | angular part was chamfered, and the shape where a part of edge | side is a curve.

  Specific components include, for example, capacitors, IC chips, MEMS (Micro Electro Mechanical Systems) elements manufactured by a semiconductor manufacturing process, and the like. Here, the “IC chip” refers to an element mainly used as a microprocessor of a computer.

  The capacitor includes a chip capacitor, a capacitor main body having a structure in which a plurality of internal electrode layers are stacked via a dielectric layer, a plurality of via conductors in the capacitor connected to the plurality of internal electrode layers, a plurality of For example, a capacitor having a plurality of external electrodes connected to at least an end portion on the component back side of the via conductor in the capacitor may be used. An example of the capacitor having this specific structure is a via array capacitor. In the via array capacitor, inductance can be reduced, and high-speed power supply for noise absorption and power supply fluctuation smoothing can be performed. Further, the entire capacitor can be easily downsized, and as a result, the entire component-embedded wiring board can be easily downsized. In addition, the capacitance can be increased despite the small size, and more stable power supply can be achieved.

  Examples of the dielectric layer of the capacitor include a ceramic dielectric layer, a resin dielectric layer, and a dielectric layer made of a ceramic / resin composite material. Among these, a ceramic dielectric layer that can be a capacitor having high rigidity and a low coefficient of thermal expansion is preferable. As this ceramic dielectric layer, a dielectric layer using a high dielectric constant ceramic sintered body of barium titanate, lead titanate, and strontium titanate lamps can be used as a capacitor having a large capacitance. . Depending on the purpose, among ceramics such as alumina, aluminum nitride, boron nitride, silicon carbide, and silicon nitride, a ceramic sintered body having particularly high rigidity and low thermal expansion coefficient may be used. In addition, a sintered body of a ceramic that can be fired at a low temperature such as a glass ceramic in which an inorganic filler such as alumina is blended with borosilicate glass or lead borosilicate glass can also be used. Furthermore, as the resin dielectric layer, a dielectric layer using a resin such as an epoxy resin or a tetrafluoroethylene resin containing an adhesive is preferable. In addition, as the dielectric layer made of ceramic / resin composite material, barium titanate, lead titanate, strontium titanate, etc. are used as ceramic, and epoxy resin, phenol resin, urethane resin, silicone resin, polyimide are used as resin. Thermosetting resins such as resins and unsaturated polyester resins, and thermoplastic resins such as polycarbonate resins, acrylic resins, polyacetal resins, and polypropylene resins can be used. Furthermore, these resins can be used in combination with rubbers such as nitrile butadiene rubber, styrene butadiene rubber, and fluorine rubber.

  The internal electrode layer, the via conductor in the capacitor, and the external electrode are not particularly limited. For example, when the dielectric layer is a ceramic dielectric layer, it is preferably a metallized conductor. This metallized conductor can be formed by applying a conductive paste containing a metal powder by a known method, for example, a metallized printing method, followed by firing. The ceramic dielectric layer and the metallized conductor can be formed by simultaneous firing. In this case, the melting point of the metal powder contained in the conductor paste is preferably higher than the firing temperature of the unfired ceramic. For example, when the ceramic dielectric layer is a ceramic having a high sintering temperature such as alumina, powders of nickel, tungsten, molybdenum, manganese, etc., and alloys thereof can be used as the metal powder. Further, when the ceramic dielectric layer is a ceramic having a low sintering temperature such as glass ceramic, copper, silver or the like, or a powder of an alloy thereof can be used as the metal powder.

  The plurality of projecting conductors project from the rear surface of the component. The plurality of projecting conductors may be projected on the component main surface in addition to the component back surface (hereinafter, the projecting conductor is projected on the component back surface will be described in detail. The same applies to the case where the main surface is formed.) Furthermore, the plurality of projecting conductors project on a plurality of external electrodes disposed on the back surface of the component. The protruding conductor can be formed of a conductive metal material. Examples of the metal material constituting the protruding conductor include copper, gold, and aluminum.

  The protruding conductor can be formed by separating the wire portion after joining the joint portion of the metal member including the wire portion and the joint portion to the external electrode. The protruding conductor is preferably thicker than the external electrode, and the thickness of the protruding conductor before the height matching step is preferably 50 to 300 μm, particularly preferably 100 to 200 μm. When the thickness of the projecting conductor is less than 50 μm, the projecting conductor is difficult to protrude from the back of the core when a component is accommodated in the housing hole. Therefore, the top of the projecting conductor is removed and the top surface and the conductor are removed. It becomes difficult to match the surface of the layer to the same height. On the other hand, when the thickness of the projecting conductor exceeds 300 μm, it takes a long time to remove the top side of the projecting conductor by polishing or the like, and the productivity of the parts decreases.

  Furthermore, it is preferable that the diameter of the protruding conductor formed on the plurality of external electrodes disposed on the back surface of the component is equal to the diameter of the external electrode. In this way, since the cross-sectional area of the projecting conductor is larger than when the diameter of the projecting conductor is smaller than the diameter of the external electrode, the resistance of the projecting conductor can be reduced, and Not only is the conductivity of the conductor improved, it is also advantageous for the connectivity with the via electrode formed thereafter. In addition, since the diameter of the projecting conductor is equal to the diameter of the surface electrode, when each projecting conductor is projected on a plurality of external electrodes that are usually arranged with a gap between them, adjacent projecting The conductors are always arranged with a gap, and a short circuit due to contact between the protruding conductors can be prevented.

  The material of the resin filling portion that fills the gap in the accommodation hole portion in which the part is accommodated is not particularly limited, and can be appropriately selected in consideration of insulation, heat resistance, moisture resistance, and the like. Examples of the polymer material used for forming the resin-filled portion include thermosetting resins such as epoxy resin, phenol resin, urethane resin, silicone resin, and polyimide resin, and heat such as polycarbonate resin, acrylic resin, polyacetal resin, and polypropylene resin. Examples thereof include a plastic resin. As this polymer material, a thermoplastic resin is preferable. In addition, you may use the material which mix | blended inorganic fillers, such as a glass filler, with these resin.

  It is preferable that the thickness of the resin-filled portion covering the back of the component before the height adjustment is equal to or greater than the thickness of the protruding conductor. That is, the surface of the top portion of the protruding conductor before height adjustment may be exposed on the surface of the resin filling portion, but is preferably covered with the resin filling portion. If the resin-covered part that covers the back of the component is thinner than the protruding conductor, the top of the protruding conductor will protrude from the surface of the resin-covered part, and when a large force is applied to the protruding conductor in the height adjustment process The projecting conductor is easily damaged. If the resin-covered portion that covers the back surface of the component is excessively thicker than the protruding conductor, it takes a long time to remove the resin-covered portion by polishing or the like, and the productivity of the component is reduced.

  In addition, since the resin filling portion covers at least the component back surface and the component side surface, and the resin filling portion covers the component side surface in addition to the component back surface, there is a gap between the inner surface of the housing hole and the component. Even if a large force is applied to the component in the height matching process, the component can be prevented from being damaged. Note that “covering” includes not only the case where the entire surface is covered, but also the case where the covering conductor is partially covered, for example, the protruding conductor is not covered.

  In the housing step, the component is housed in the housing hole with the core back surface and the component back surface facing the same side. The parts must be housed in the housing holes in a completely embedded state. Furthermore, when the accommodation hole is a through hole that opens on both the core main surface side and the core back surface side, the housing step is performed on the core main surface side of the housing hole that opens on both the core main surface and the core back surface. The opening may be carried out with the adhesive surface of the adhesive tape being closed, and the adhesive tape may be removed after the height adjustment step.

  Resin-filling that forms a resin-filled portion on the back surface of the core and the back surface of the component after the housing step and before the height adjusting step, and fills the gap between the inner wall surface of the housing hole portion and the side surface of the component with a part of the resin-filled portion Perform the process and fix the parts. Further, in the height matching step, it is preferable to polish the surface of the top portion of the protruding conductor and simultaneously polish the resin filling portion. Even if polishing is performed at the same time, the parts are fixed in advance by the resin filling part before the height adjustment process, so even if a large force is applied to the parts during the height adjustment process, the parts may be damaged. Can be prevented. In addition, the gap can be filled up to the bottom of the accommodation hole by the resin filling portion, and generation of voids and the like can be prevented. Therefore, a component built-in wiring board with excellent reliability can be manufactured. Furthermore, in the height alignment process, since the resin filling portion is polished simultaneously with the polishing of the top surface of the protruding conductor, the height alignment process is simplified, and the component built-in wiring board can be easily manufactured, Cost can be reduced.

  As a method for forming the resin-filled portion, a method of forming a paste containing a polymer material on the core back surface and the component back surface, allowing the paste to flow into the gap, then drying and heating, and the core back surface and the component back surface After laminating and arranging a mask having a through hole at a position where a resin-filled portion is to be formed, a paste containing a polymer material is printed through the mask, and flows into the gap, and then dried. And a method of forming by heating.

  The component can be fixed by forming a resin filling portion by curing or solidifying the polymer material in a state where the gap is filled with a part of the polymer material. When the polymer material is a thermosetting resin, examples of the method of curing the polymer material include a method of heating an uncured polymer material. In addition, when the polymer material is a thermoplastic resin, a method of cooling and solidifying the heated polymer material can be used. In addition, as an uncured state of a thermosetting resin, the B stage etc. which are the intermediate | middle cured states which reach complete curing are mentioned, for example.

  In the height matching step, the top surface of the projecting conductor and the surface of the conductor layer formed on the back surface of the core are matched to the same height. Thereafter, if the main surface side wiring laminated portion is formed on the core main surface or the back surface side wiring laminated portion is formed on the back surface of the core, the component built-in wiring board is completed.

  In the height adjustment process, as a method of matching the top surface of the protruding conductor and the surface of the conductor layer formed on the back surface of the core to the same height, the top surface and the conductor layer can be reduced by lowering the protruding conductor. The surface of the top and the conductor layer are adjusted to the same height by thinning the conductor layer, the surface of the top and the surface of the conductor layer are adjusted to the same height. Examples thereof include a method of adjusting the surface to the same height, and a method of adjusting the surface of the top and the surface of the conductor layer to the same height by increasing the thickness of the conductor layer. Among these methods, a method of matching the surface of the top portion and the surface of the conductor layer to the same height by lowering the protruding conductor is preferable. In the method of adjusting the top surface and the surface of the conductor layer to the same height by thinning the conductor layer, the originally thin conductor layer must be further thinned, and even if the conductor layer is thinned, the top surface and There is a possibility that the surface of the conductor layer cannot be adjusted to the same height. Also, in the method of adjusting the top surface and the surface of the conductor layer to the same height by increasing the protruding conductor or increasing the thickness of the conductor layer, the top surface of the protruding conductor and the surface of the conductor layer A process such as printing a conductor paste on the substrate is required, which complicates the manufacture of the component built-in wiring board and increases the manufacturing cost. In the method in which the surface of the top and the surface of the conductor layer are adjusted to the same height by lowering the protruding conductor, the component is formed thinner than the core substrate, and the protruding conductor is accommodated in the accommodating hole. It is preferable that the thickness is such that it slightly protrudes from the back surface of the core in the state where it is formed. In this way, the protruding conductor can be reliably lowered by polishing or the like.

  In addition, as a method of adjusting the top surface and the surface of the conductor layer to the same height by lowering the protruding conductor or making the conductor layer thin, at least one of the top portion and the conductor layer is mechanically And a method of chemically removing at least one of the top and the conductor layer. However, in the height matching step, it is preferable to mechanically remove at least one of the top portion and the conductor layer. In this way, the height can be easily adjusted at a lower cost than when chemically removing at least one of the top and the conductor layer.

  As a method for mechanically removing at least one of the top of the protruding conductor and the conductor layer, a method of cutting at least one of a part of the top and a part of the conductor layer, at least one of the surface of the top and the surface of the conductor layer And a method of polishing the surface. As a method of polishing at least one of the top surface and the surface of the conductor layer, polishing with a belt sander device attached with sandpaper, applying an abrasive to the outer peripheral surface of a disk-shaped nonwoven fabric, and rotating the top portion while rotating Examples thereof include buffing that is pressed against the surface or the surface of the conductor layer. The arithmetic average roughness of the sandpaper polishing surface and the particle size of the abrasive are preferably equal to the arithmetic average roughness after polishing of the top surface and the surface of the conductor layer. On the other hand, examples of the method of chemically removing at least one of the top and the conductor layer include a method of removing at least one of the top and part of the conductor layer with an etching solution.

  When the top portion of the protruding conductor is polished in the height adjusting step, it is preferable to polish the surface of the top portion in a state where the cured or solidified resin is disposed between the side surfaces of the plurality of protruding conductors. In this way, since the protruding conductor is fixed by the cured or solidified resin, even if a large force is applied to the protruding conductor during the height adjustment process, the protruding conductor can be prevented from being damaged. it can. Here, resin is resin which comprises the resin filling part which covers a component back surface.

  After the height adjustment process, a back surface side interlayer insulating layer is formed on the core back surface and the component back surface, and then a laser drilling process is performed to form a via hole penetrating the back surface side interlayer insulating layer to form the top of the protruding conductor. The surface can be exposed and then a via conductor can be formed inside the via hole. In this way, the variation in the thickness of the back surface side interlayer insulating layer formed on the back surface of the core and the back surface of the component flattened in the height matching process is reduced, and the variation in the depth of the via hole is also reduced. Therefore, the via conductor can be reliably formed in the via hole, and the protruding conductor and the via conductor can be reliably conducted. Therefore, the generation of defective products can be prevented, and a highly reliable component built-in wiring board can be obtained.

  Further, the resin filling portion and the back surface side interlayer insulating layer may be made of the same material or different materials, but are preferably made of the same material. Thereby, it is not necessary to prepare another material different from the formation of the back surface side interlayer insulating layer in forming the resin filling portion. Therefore, the types of raw materials necessary for manufacturing the component built-in wiring board are reduced, and the cost of the component built-in wiring board can be reduced. The “same material” means a polymer material of the same kind and a material having a large difference in thermal expansion coefficient. If there is no great difference in thermal expansion coefficient, peeling between the resin filling portion and the back surface side interlayer insulating layer can be prevented, and a highly reliable wiring board with built-in components can be obtained. The thermal expansion coefficient is a thermal expansion coefficient in a direction perpendicular to the thickness direction, that is, in the plane direction, and is a value between 0 and 100 ° C. measured by a thermomechanical analyzer.

  The component built-in wiring board of the present invention has a structure in which a core substrate, a component, a main surface side interlayer insulating layer and a main surface side conductor layer are stacked on the core main surface, and a semiconductor integrated circuit on which an IC chip can be mounted. The main surface side wiring laminated portion with the circuit element mounting area set on the front surface, and the connection terminal portion that can be connected to the motherboard has a structure in which the back surface side interlayer insulating layer and the back surface side conductor layer are laminated on the core back surface. A wiring board with a built-in component including a back surface side wiring laminated portion formed on the surface, and the surface of the core back surface side conductor layer and the tops of the plurality of protruding conductors are located on the same plane, and the core back surface It is preferable that the surface of the side conductor layer and the surface of the protruding conductor, particularly the top portion thereof are roughened, and the arithmetic average roughness thereof is rougher than the arithmetic average roughness of the surface of the core main surface side conductor layer. The core back side conductor layer is the core main surface side conductor It can be an aspect that is thinner than. The “arithmetic average roughness” is the arithmetic average roughness Ra defined in JIS B0601. This arithmetic average roughness Ra is a value measured according to JIS B0651.

  In this aspect, if the surface of the protruding conductor before resin filling, particularly the top, is roughened, the protruding conductor and the resin filling portion can be brought into close contact with each other. As a result, the protruding conductor and the component can be stably fixed in the height adjusting process, and even if a large force is applied, the protruding conductor and the component can be prevented from being damaged. Furthermore, in this aspect, since the surface of the core back surface side conductor layer and the top surface of the projecting conductor are located on the same plane, variations in the thickness of the back surface side interlayer insulating layer formed on the core back surface are reduced. Can be small. Therefore, when a plurality of via conductors are formed in the back surface side interlayer insulating layer, since the variation in the depth of the via hole is small, it is easy to form the via conductor, and as a result, the projecting conductor and the via conductor can be securely connected. It can be made conductive. Therefore, the occurrence of defective products can be prevented, and a component built-in wiring board with high reliability can be obtained.

  Furthermore, the back surface side interlayer insulating layer located closest to the core back surface preferably has a thickness variation of 5 μm or less, particularly 2 μm or less. If the variation in thickness is small, the via conductor can be easily formed, and as a result, the protruding conductor and the via conductor can be reliably conducted. Therefore, the occurrence of defective products can be prevented, and a component built-in wiring board with high reliability can be obtained. If the thickness variation exceeds 5 μm, the via hole depth also varies when the via hole is formed, and the projecting conductor and the via conductor cannot be reliably connected to each other, resulting in a defective product. Also, the reliability of the component built-in wiring board tends to decrease.

  The material of the main surface side interlayer insulating layer constituting the main surface side wiring laminated portion and the back surface side interlayer insulating layer constituting the back surface side wiring laminated portion is not particularly limited, and these insulating layers are insulating, heat resistant, It can be appropriately selected in consideration of moisture resistance and the like. Polymer materials for forming the main surface side interlayer insulating layer and the back surface side interlayer insulating layer include thermosetting resins such as epoxy resins, phenol resins, urethane resins, silicone resins, polyimide resins, polycarbonate resins, and acrylic resins. And thermoplastic resins such as polyacetal resin and polypropylene resin. In addition, you may use the material which mix | blended organic fibers, such as inorganic fillers, such as a glass filler, and a polyamide fiber, with these resin. Furthermore, a resin / resin composite material obtained by impregnating a thermosetting resin such as an epoxy resin with a fluororesin base material having a three-dimensional network structure such as porous PTFE can also be used.

Hereinafter, an embodiment of a component built-in wiring board according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a component built-in wiring board (hereinafter referred to as “wiring board”) 10 of this embodiment is a wiring board for mounting an IC chip. The wiring substrate 10 includes a core substrate 11 that is a plate having a substantially rectangular planar shape, and a main surface side buildup layer 31 (main surface side) formed on the core main surface 12 (upper surface in FIG. 1) of the core substrate 11. Wiring laminated portion) and a back side buildup layer 32 (back side wiring laminated portion) formed on the core back surface 13 (lower surface in FIG. 1) of the core substrate 11.

  The main surface side buildup layer 31 formed on the core main surface 12 of the core substrate 11 is composed of two main surface side resin insulation layers 33 and 35 (so-called main surface side) made of thermosetting resin (epoxy resin or the like). Interlayer insulation layer) and main surface side conductor layers 41 made of copper are alternately laminated. Terminal pads 44 are formed in an array at a plurality of locations on the surface of the second-layer main-surface-side resin insulation layer 35. Further, the surface of the main surface side resin insulation layer 35 is almost entirely covered with a solder resist 37, and an opening 46 for exposing the terminal pad 44 is formed at a predetermined position of the solder resist 37. A plurality of solder bumps 45 are provided on the surface of the terminal pad 44. Each solder bump 45 has a rectangular planar shape and is electrically connected to the surface connection terminal 22 of the flat-plate IC chip 21. An area formed by each terminal pad 44 and solder bump 45 is an IC chip mounting area 23 (semiconductor integrated circuit element mounting area) on which the IC chip 21 can be mounted. The IC chip mounting area 23 is on the main surface side. It is set on the surface 39 of the buildup layer 31. Furthermore, via conductors 43 are formed at a plurality of locations in the second-layer main-surface-side resin insulation layer 35. The lower end of each via conductor 43 is connected to the main surface side conductor layer 41 formed on the surface of the main surface side resin insulation layer 33, and the upper end of each via conductor 43 is the main end. It is connected to a terminal pad 44 formed on the surface of the surface side resin insulation layer 35. The via conductor 43 electrically connects the main surface side conductor layer 41 and the terminal pad 44 to each other.

  As shown in FIG. 1, the back side buildup layer 32 formed on the core back side 13 of the core substrate 11 has substantially the same structure as the main surface side buildup layer 31. That is, the back-side buildup layer 32 includes two back-side resin insulation layers 34 and 36 (so-called back-side interlayer insulation layers) made of a thermosetting resin (epoxy resin or the like) and the back-side conductor layer 42. It has an alternately stacked structure. Via conductors 47 are formed at a plurality of positions in the first-layer backside resin insulation layer 34, and the lower end of each via conductor 47 is a backside formed on the surface of the backside resin insulation layer 34. The side conductor layer 42 is connected. In addition, via conductors 43 are formed at a plurality of locations in the second-layer back-side resin insulation layer 36, and vias are provided at the bottom surfaces of the respective via conductors 43 on the bottom surface of the back-side resin insulation layer 36. BGA pads 48 that are electrically connected to the back-side conductor layer 42 via the conductors 43 are formed in a lattice shape. Further, the lower surface of the back side resin insulation layer 36 is almost entirely covered with a solder resist 38, and an opening 40 for exposing the BGA pad 48 is formed at a predetermined position of the solder resist 38. A plurality of solder bumps 49 that can be electrically connected to a mother board (not shown) are disposed on the surface of the BGA pad 48. That is, the BGA pad 48 and the solder bump 49 constitute a connection terminal portion 50 formed on the surface of the back surface side buildup layer 32. 1 is mounted on the mother board by each solder bump 49.

  The core substrate 11 of the present embodiment in FIG. 1 is a plate-like body having a rectangular shape of 25 mm long × 25 mm wide × 0.9 mm thick. The core substrate 11 includes a base material 161 made of glass epoxy, a sub-base material 164 formed on an upper surface and a lower surface of the base material 161 and made of an epoxy resin blended with an inorganic filler such as silica filler, and the base material 161. And a conductor layer 163 made of copper formed on the upper and lower surfaces. In the core substrate 11, a plurality of through-hole conductors 16 are formed so as to penetrate the core main surface 12, the core back surface 13, and the conductor layer 163. The through-hole conductor 16 connects and conducts the core main surface 12 side and the core back surface 13 side of the core substrate 11 and is electrically connected to the conductor layer 163. Note that the inside of the through-hole conductor 16 is filled with a closing body 17 such as an epoxy resin. Furthermore, the upper end of the through hole conductor 16 is electrically connected to a part of the main surface side conductor layer 41 on the surface of the main surface side resin insulation layer 33, and the lower end of the through hole conductor 16 is connected to the back surface side resin. It is electrically connected to a part of the back side conductor layer 42 on the lower surface of the insulating layer 34.

  In addition, a core main surface side conductor layer 61 made of copper is patterned on the core main surface 12 of the core substrate 11, and each core main surface side conductor layer 61 is electrically connected to the through-hole conductor 16. Has been. Similarly, a core back side conductor layer 62 made of copper is patterned on the core back side 13 of the core substrate 11, and each core back side conductor layer 62 is electrically connected to the through-hole conductor 16. Yes. Furthermore, the core back surface side conductor layer 62 is formed thinner than the core main surface side conductor layer 61 (thickness 75 μm), and is 65 μm in this embodiment. In addition, the arithmetic average roughness Ra of the surface of the core back surface side conductor layer 62 and the surface of the top portion 52 of the protruding conductor 51 is the arithmetic average roughness Ra of the surface of the core main surface side conductor layer 61 (0. 5 μm), specifically, 0.8 μm.

  Furthermore, the core substrate 11 has one accommodation hole 90 having a rectangular planar shape that opens at the center of the core main surface 12 and the center of the core back surface 13. That is, the accommodation hole 90 is a through hole. As shown in FIG. 1, the via array capacitor 101 (component) is embedded and accommodated in the accommodation hole 90. The capacitor 101 is accommodated with the capacitor back surface 103 facing the same side as the core back surface 13 of the core substrate 11. The capacitor 101 of the present embodiment is a plate-like body having a rectangular shape of 10.0 mm in length, 10.0 mm in width, and 0.8 mm in thickness. That is, the capacitor 101 is formed thinner than the core substrate 11. In addition, the capacitor 101 is disposed in a region immediately below the IC chip mounting region 23 in the core substrate 11. The area of the IC chip mounting region 23 (the area of the surface on which the surface connection terminals 22 are formed in the IC chip 21) is set to be smaller than the area of the capacitor main surface 102 of the capacitor 101. When viewed from the thickness direction, the capacitor 101 is located in the capacitor main surface 102.

  As shown in FIGS. 1, 2, and 9, the capacitor 101 of this embodiment is a so-called via array type capacitor. The ceramic sintered body 104 (component main body) constituting the capacitor 101 has one capacitor main surface 102 (upper surface in FIG. 1) as a component main surface and one capacitor rear surface 103 (lower surface in FIG. 1) as a component back surface. ) And four capacitor side surfaces 106 (left surface and right surface in FIG. 1) which are component side surfaces.

  As shown in FIG. 2, the ceramic sintered body 104 (component main body) has a structure in which power supply internal electrode layers 141 and ground internal electrode layers 142 are alternately stacked via ceramic dielectric layers 105. Yes. The ceramic dielectric layer 105 is made of a sintered body of barium titanate, which is a kind of high dielectric constant ceramic, and functions as a dielectric (insulator) between the power internal electrode layer 141 and the ground internal electrode layer 142. To do. Each of the power supply internal electrode layer 141 and the ground internal electrode layer 142 is a layer formed mainly of nickel, and is disposed in every other layer in the ceramic sintered body 104.

  As shown in FIGS. 2 and 9 and the like, a large number of via holes 130 are formed in the ceramic sintered body 104. These via holes 130 penetrate the ceramic sintered body 104 in the thickness direction and are arranged in an array over the entire surface of the ceramic sintered body 104. In each via hole 130, a plurality of in-capacitor via conductors 131 and 132 communicating between the capacitor main surface 102 and the capacitor back surface 103 of the ceramic sintered body 104 are formed using nickel as a main material (FIG. 2). 4 and 9). In the present embodiment, since the via hole 130 has a diameter of about 100 μm, the via conductors 131 and 132 in the capacitor also have a diameter of about 100 μm. Each power supply capacitor internal via conductor 131 passes through each power supply internal electrode layer 141 and electrically connects them. Further, each via-capacitor via conductor 132 passes through each ground internal electrode layer 142 and is electrically connected to each other. The capacitor via conductors 131 for power supply and the via conductors 132 for ground capacitor are arranged in an array as a whole. In this embodiment, for convenience of explanation, the via conductors 131 and 132 in capacitors are arranged in 5 columns × 5 columns. Although illustrated, there are actually more columns.

  Further, as shown in FIG. 2 and the like, the capacitor main surface 102 of the ceramic sintered body 104 includes a plurality of main surface side power supply electrodes 111 (external electrodes) and a plurality of main surface side ground electrodes 112 (external electrodes). Is protruding. Each main surface side ground electrode 112 is individually formed on the capacitor main surface 102, but may be formed integrally. The main surface side power supply electrode 111 is directly connected to the end surface of the plurality of power supply capacitor inner via conductors 131 on the capacitor main surface 102 side, and the main surface side ground electrode 112 is connected to a plurality of ground capacitor inner vias. The conductor 132 is directly connected to the end surface of the capacitor main surface 102 side.

  Furthermore, a plurality of back surface side power supply electrodes 121 (external electrodes) and a plurality of back surface side ground electrodes 122 (external electrodes) protrude from the capacitor back surface 103 of the ceramic sintered body 104. Each back surface side ground electrode 122 is individually formed on the capacitor back surface 103, but may be formed integrally. Further, the back surface side power supply electrode 121 is directly connected to the end surface on the capacitor back surface 103 side of the plurality of power supply capacitor internal via conductors 131, and the back surface side ground electrode 122 is connected to the plurality of ground internal capacitor capacitor via conductors 132. Is directly connected to the end surface of the capacitor back surface 103 side. Accordingly, the power supply electrodes 111 and 121 are electrically connected to the power supply capacitor internal via conductor 131 and the power supply internal electrode layer 141, and the ground electrodes 112 and 122 are connected to the ground capacitor internal via conductor 132 and the ground internal electrode layer 142. It will be conducted.

  The external electrodes 111, 112, 121, and 122 are made of nickel as a main material, and the surface is entirely covered with a copper plating layer (not shown). The electrodes 111, 112, 121, and 122 of this embodiment have a diameter of about 500 μm, a thickness of about 50 μm, and a minimum pitch length of about 580 μm.

  As shown in FIGS. 1 and 2, projecting conductors 51 project from the back-side power supply electrode 121 and the back-side ground electrode 122, respectively. The protruding conductor 51 of the present embodiment is a conductor (copper post) formed using a copper wire. Each protruding conductor 51 has a circular cross section, and the central axis of the protruding conductor 51 coincides with the center of the external electrodes 121 and 122. The surface of the top portion 52 of each protruding conductor 51 is circular, and the surface of the top portion 52 is parallel to the capacitor main surface 102. The diameter of the protruding conductor 51 is equal to the diameter of the electrodes 121 and 122, and is larger than the diameter (about 100 μm) of the capacitor via conductors 131 and 132, and is 200 to 250 μm in this embodiment. Furthermore, the thickness of each protruding conductor 51 in a state where the wiring board 10 is completed is 100 μm in the present embodiment. That is, the protruding conductor 51 is formed thicker than the electrodes 121 and 122. Further, the surface of the top portion 52 of the protruding conductor 51 is located on the same plane as the surface of the core back surface side conductor layer 62. The protruding conductors 51 are connected to via conductors 47 formed at a plurality of locations in the back surface side resin insulation layer 34 located closest to the core back surface 13 side. In this embodiment, the thickness of the back surface side resin insulation layer 34 is about 50 μm, and the thickness variation is 5 μm.

  Further, as shown in FIG. 1 and the like, the ceramic sintered body 104 (component main body) is covered with a resin filling portion 92. The resin filling portion 92 covers one capacitor main surface 102, one capacitor back surface 103, and four capacitor side surfaces 106. In a state where the capacitor 101 is built in the wiring substrate 10, the resin filling portion 92 covering the capacitor main surface 102 does not cover the entire surface of the capacitor main surface 102, and the electrodes 111 and 112 are exposed. Similarly, the resin filling portion 92 that covers the capacitor back surface 103 does not cover the entire surface of the capacitor back surface 103, and the surface of the top portion 52 of the protruding conductor 51 that protrudes on the electrodes 121 and 122 is exposed. ing. The thickness of the resin filling portion 92 that covers the capacitor main surface 102 is 50 μm, and the thickness of the resin filling portion 92 that covers the capacitor back surface 103 is 150 μm before height adjustment. Thus, the resin filling portion 92 covering the capacitor back surface 103 is formed thicker than each protruding conductor 51, and the surface of the top portion 52 of the protruding conductor 51 is formed by the resin filling portion 92 before the height adjustment. Covered. The resin filling portion 92 is formed of the same material as the resin insulating layers 33 to 36 (that is, an epoxy resin that is a thermosetting resin). Thereby, the thermal expansion coefficient of the resin filling part 92 also becomes the same value as the thermal expansion coefficient of the resin insulating layers 33 to 36, and is set to about 10 to 60 ppm / ° C. (specifically, about 20 ppm / ° C.). . Further, the thermal expansion coefficient of the resin filling portion 92 is set to a value larger than the thermal expansion coefficient of the ceramic sintered body 104.

  As shown in FIG. 1 and the like, the gap between the inner wall surface 91 of the accommodation hole 90 and the capacitor side surface 106 of the capacitor 101 is filled with a part of the resin filling portion 92. That is, the four capacitor side surfaces 106 are covered with the resin filling portion 92. The resin filling portion 92 has a function of fixing the capacitor 101 to the core substrate 11. Note that the capacitor 101 has a square shape in plan, and has chamfered portions with chamfering dimensions of 0.55 mm or more (in this embodiment, chamfering dimensions of 0.6 mm) at the four corners. Thereby, when the resin filling portion 92 is deformed due to a temperature change, the stress concentration on the corner portion of the capacitor 101 can be relaxed, and the occurrence of cracks in the resin filling portion 92 can be prevented.

  As described above in detail, in the component built-in wiring board of this embodiment, the external electrodes 111 and 112 on the capacitor main surface 102 side are connected to the via conductor 47, the main surface side conductor layer 41, and the via as shown in FIG. It is electrically connected to the IC chip 21 through the conductor 43, the terminal pad 44, the solder bump 45, and the surface connection terminal 22 of the IC chip 21. On the other hand, the external electrodes 121 and 122 on the capacitor back surface 103 side are connected to the mother board (not shown) via the protruding conductor 51, the via conductor 47, the back surface side conductor layer 42, the via conductor 43, the BGA pad 48 and the solder bump 49. Are electrically connected to the electrodes of

  Further, when a current is applied from the motherboard side through the electrodes 121 and 122 and a voltage is applied between the power supply internal electrode layer 141 and the ground internal electrode layer 142, for example, positive charges are generated in the power supply internal electrode layer 141. Accumulating, and negative charges are accumulated in the ground internal electrode layer 142. As a result, the capacitor 101 functions as a capacitor. Further, in the capacitor 101, the power supply capacitor internal via conductor 131 and the ground capacitor internal via conductor 132 are alternately arranged adjacent to each other, and flow through the power supply capacitor internal via conductor 131 and the ground capacitor internal via conductor 132. The current directions are set to be opposite to each other. Thereby, the inductance component can be reduced.

Hereinafter, the manufacturing method of the wiring board 10 of this embodiment is demonstrated in detail.
An intermediate product of the core substrate 11 is prepared in advance by a known method as follows.
First, the copper clad laminated board (refer FIG. 5) by which the copper foil 162 was stuck on both surfaces of the base material 161 of length 350mm * width 375mm * thickness 0.6mm is prepared. Thereafter, the copper foils 162 on both sides of the copper-clad laminate are etched, and the conductor layer 163 is patterned by, for example, a subtractive method (see FIG. 6). Specifically, after the electroless copper plating, electrolytic copper plating is performed using the electroless copper plating layer as a common electrode. Further, a dry film is laminated, the dry film is exposed and developed, and the dry film is formed into a predetermined pattern. In this state, unnecessary electrolytic copper plating layer, electroless copper plating layer and copper foil 162 are removed by etching, and the dry film is peeled off. Next, after roughening the upper and lower surfaces of the substrate 161 and the conductor layer 163, an epoxy resin film (thickness of 80 μm) containing an inorganic filler is thermocompression bonded to the upper and lower surfaces of the substrate 161 to form a sub-group. A material 164 is formed (see FIG. 7).

  Thereafter, the core back surface side conductor layer 62 (thickness: 75 μm) is patterned on the upper surface of the upper sub base material 164, and the core main surface side conductor layer 61 (thickness: 50 μm) is formed on the lower surface of the lower sub base material 164. The pattern is formed. Specifically, after performing electroless copper plating on the upper surface of the upper sub-base material 164 and the lower surface of the lower sub-base material 164, an etching resist is formed, and then electrolytic copper plating is performed. Further, the etching resist is removed and soft etching is performed. Thereafter, the laminated body composed of the base material 161 and the sub-base material 164 is drilled using a router to form through holes to be the accommodation hole portions 90 at predetermined positions, thereby producing an intermediate product of the core substrate 11. (See FIG. 8). The intermediate product of the core substrate 11 is a multi-piece core substrate having a structure in which a plurality of regions to be the core substrate 11 are arranged vertically and horizontally in the plane direction.

In addition, as a component, the via array capacitor 101 having the protruding conductors 51 is prepared in advance by a known method as follows.
First, a ceramic green sheet is formed, and nickel paste for internal electrode layers is screen printed on the green sheet and dried. As a result, in a subsequent process, a power supply internal electrode portion that becomes the power supply internal electrode layer 141 and a ground internal electrode portion that becomes the ground internal electrode layer 142 are formed. After that, the green sheets with the power supply internal electrode portions and the green sheets with the ground internal electrode portions formed are alternately stacked and pressed in the stacking direction to integrate the green sheets. A laminate is formed.

  Next, a large number of via holes 130 are formed through the green sheet laminate using a laser processing machine, and via paste 130 is filled with a via conductor nickel paste using a paste press-fitting and filling device (not shown). Thereafter, the paste is printed on the upper surface of the green sheet laminate, and the back-side power electrode 121 and the back-side ground are covered on the upper surface side of the green sheet laminate so as to cover the upper end surface of the paste filled in the via hole 130. A conductive coating film to be the electrode 122 is formed. Subsequently, the paste is printed on the lower surface of the green sheet laminate, and the main surface side power supply electrode 111 and the main surface are covered so as to cover the lower end surface of the paste filled in the via hole 130 on the lower surface side of the green sheet laminate. A conductive coating film to be the side ground electrode 112 is formed.

  Then, the conductive coating film which becomes the external electrodes 111, 112, 121, 122 formed on the upper and lower surfaces of the green sheet laminate is dried (see FIG. 9). Next, the green sheet laminate is degreased and fired at a predetermined temperature for a predetermined time. As a result, barium titanate and nickel contained in the paste are simultaneously fired, and a sintered ceramic body 104 having a conductor layer and having an electrode serving as an external electrode on the surface is formed. Thereafter, the electrode of the ceramic sintered body 104 is subjected to electroless copper plating (thickness of about 10 μm). As a result, external electrodes 111, 112, 121, and 122 having a diameter of 500 μm and a thickness of 50 μm with copper plating on the upper surface are formed.

  Next, the protruding conductor 51 is formed on the surface of the copper plating layer formed on the upper surfaces of the external electrodes 121 and 122 (see FIG. 10). In this projecting conductor forming step, the projecting conductor 51 holds the capacitor 101 in a predetermined position with the electrodes 121 and 122 facing upward, and in this state, an ultrasonic bonding apparatus (only the capillary 8 is shown) is used. Can be formed. This ultrasonic bonding apparatus includes an alignment mechanism using a CCD camera, and thereby aligns the capillary 8 and the electrodes 121 and 122. Further, bonding is performed while blowing nitrogen gas mixed with a small amount of hydrogen so that the copper plating layers of the external electrodes 121 and 122 and the surface of the joint portion 72 of the metal member 7 are not oxidized. In order to prevent oxidation, bonding may be performed in a vacuum chamber. More specifically, the wire portion 71 of the metal member 7 inserted through the capillary 8 of the ultrasonic bonding apparatus is pulled out from the lower end surface of the capillary 8, and a substantially spherical joint portion 72 is formed at the distal end portion by thermal energy due to discharge. Form (see FIG. 11). At this time, the external electrodes 121 and 122 are heated to a predetermined temperature (400 ° C. or lower is preferable). If the heating temperature is 400 ° C. or lower, the protruding conductor 51 and the external electrodes 121 and 122 can be bonded with high strength, and the thermal load on the ultrasonic bonding apparatus such as the capillary 8 can be reduced. it can. In the present embodiment, a copper wire having a diameter of 75 μm is used as the metal member 7, and the joint portion 72 is formed to have a diameter of about 200 μm. The joint 72 can also be formed using other heating means such as an electric torch.

  When the joining portion 72 of the metal member 7 is formed, the capillary 8 is lowered, the joining portion 72 of the metal member 7 is pressed by the lower end surface of the capillary 8, and ultrasonic energy is applied to bring the joining portion 72 to a predetermined temperature. Bonded to the external electrodes 121 and 122 of the heated capacitor 101 (see FIG. 12). Thereafter, the cut clamp (not shown) is closed, the capillary 8 is raised in a state where the wire portion 71 is sandwiched, and the wire portion 71 is cut from the joint portion 72 (see FIG. 13). At this time, when the capillary 8 is raised, the wire portion 71 is cut so as to be torn off if the bonding strength is larger than its own strength. However, depending on the wire diameter of the metal member 7 and the bonding conditions, the capillary portion 71 is cut. It can also cut | disconnect by sliding 8 to a horizontal direction or moving combining a horizontal direction and an upward direction.

  Thereafter, by repeating the operations of FIGS. 11 to 13, the joint portion 72 to be the protruding conductor 51 is formed on all the external electrodes 121 and 122 of the capacitor 101. As a result, a protruding conductor 51 having a bonding diameter S of about 200 μm, a maximum diameter R of about 250 μm, and a height of about 120 μm is formed on the electrodes 121 and 122 (see FIGS. 10 and 14). The height of the protruding conductor 51 is such that at least the top portion 52 of the protruding conductor 51 before the height adjustment is in the state of accommodating the capacitor 101 in the accommodating hole 90 of the core substrate 11 in the accommodating step described later. It is necessary to have a height that protrudes slightly above the top surface. The material of the metal member 7, the wire diameter of the wire portion 71, the diameter of the joint portion 72, bonding conditions, and the like can be appropriately selected according to the size, shape, and the like of the protruding conductor 51 to be formed.

Here, the shape of the protruding conductor 51 formed on the external electrodes 121 and 122 of the capacitor 101 will be described in detail.
The protruding conductor 51 can be formed so that the cross section is oblong (see FIG. 14). In addition, a shape with a sharp top (see Fig. 15), bonding by double punching, a shape with two long ellipses overlapped (see Fig. 16), a bonding by double punching, and the lower elliptical step and the top The shape can be a shape such as a shape (see FIG. 17) that is overlapped with an upper step portion having a sharp point, a semi-elliptical shape (see FIG. 18), or the like. In the protruding conductor 51 of FIGS. 16 to 17, the height can be increased by hitting twice. 14 to 17 has a maximum diameter between the top end and the joining end, and the projecting conductor 51 in FIG. 18 has a maximum diameter at the joining end, which will be described later. The joining diameter S is the maximum diameter R.

  The projecting conductors 51 of FIGS. 14 to 18 are formed so that the diameter decreases from the maximum diameter portion toward the top end, so that in the resin filling step, the resin used for forming the resin filling portion 92 has a maximum diameter from the top end. It tends to flow toward the part. Further, since the flow resistance is small and the resin smoothly flows in, the capacitor 101 can be prevented from being displaced when the resin is filled, and a gap is generated between the top end and the maximum diameter portion. Can also be prevented. In particular, the protruding conductor 51 in FIGS. 15 and 17 has a sharp pointed top, so that the resin can flow more smoothly. In addition, although the top part of the protruding conductor 51 of FIGS. 15 and 17 is pointed, since the top part is removed by polishing in the height adjusting process to be described later, there is no problem. Furthermore, since the protruding conductor 51 of FIGS. 14 to 17 is formed so that the diameter decreases from the maximum diameter portion toward the joint portion, that is, it is squeezed, it can be fitted to the resin filling portion 92. Can be improved. In addition, since the bonding diameter is small, it is easy to align the electrodes 121 and 122 and the protruding conductor 51.

  Furthermore, it is preferable that the protruding conductor 51 has a bonding diameter that is equal to or less than one times the maximum diameter, that is, the maximum diameter R / the bonding diameter S> 1 (see FIGS. 14 to 17 for R and S). If R / S> 1, the fitting property between the narrowed protruding conductor 51 and the resin filling portion 92 is improved. In addition, the maximum diameter means the diameter of the maximum diameter part in the other part excluding the joint part. On the other hand, if R / S> 5, the bonding area may be reduced, and the connection reliability with the external electrodes 121 and 122 may be reduced. Further, when R / S> 5 after ensuring the required joint diameter, the interval between the adjacent protruding conductors 51 cannot be reduced, and the pitch cannot be reduced. Therefore, it is preferable that the protruding conductor 51 has 1 <R / S <5.

  The formed projecting conductor 51 can be adjusted in shape by a pressing process. That is, the protruding conductor 51 can be pressed by lowering and pressing a press die (not shown) from above the capacitor 101 while the capacitor 101 is placed on and held on the support base. Thereby, the shape of the protruding conductor 51 can be adjusted, and the variation in the height can also be reduced. Further, the bonding strength between the protruding conductor 51 and the external electrodes 121 and 122 can be increased. This pressing step is not essential, and the shape of the protruding conductor 51 may be confirmed visually or the like, and may be performed as necessary. When the pressing is performed, the thickness of each protruding conductor 51 after pressing can be set to about 120 μm, and the core 101 is stored in the storage hole 90 (see FIGS. 19 to 20). It is preferable to form it so as to protrude from the back surface 13.

  In the housing step, the capacitor 101 is housed in the housing hole 90 with the mounting surface (manufactured by Yamaha Motor Co., Ltd., not shown) with the core back surface 13 and the capacitor back surface 103 facing the same side ( (See FIG. 19). In this state, the surface of the top portion 52 before the height adjustment of the protruding conductor 51 is located above the surface of the core back-side conductor layer 62. Further, the opening on the core main surface 12 side of the accommodation hole 90 is closed with a peelable adhesive tape 171, and this adhesive tape 171 is supported by a support base (not shown). On the adhesive surface of the adhesive tape 171, the capacitor 101 is attached and temporarily fixed. Since the capacitor 101 is thinner than the core substrate 11, there is a step between the core back surface 13 and the capacitor back surface 103. Yes.

  In the resin filling step, an uncured resin sheet 176 (thickness: 200 μm) to be the resin filling portion 92 is laminated on the core back surface 13 and the capacitor back surface 103 (see FIGS. 20 to 21). In addition, the gap between the inner wall surface 91 of the accommodation hole 90 and the capacitor side surface 106 is filled with a part of the uncured resin that becomes the resin filling portion 92. Further, after filling the uncured resin, the uncured resin is cured by heat treatment to form the resin filled portion 92, and the capacitor 101 is fixed to the core substrate 11.

  In the height adjusting step, the surface of the top portion 52 of each protruding conductor 51 and the surface of the core back side conductor layer 62 are adjusted to the same height (see FIG. 22). Specifically, by using a belt sander device or the like, the protruding conductor 51 is lowered by polishing the top side of the protruding conductor 51 positioned above the surface of the core back-side conductor layer 62, and at the same time, the capacitor The resin filling portion 92 covering the back surface 103 is polished. Further, the surface of the core back side conductor layer 62 exposed by polishing the resin filling portion 92 is also polished. As a result, a part of the top portion 52 of the protruding conductor 51 and a part of the core back side conductor layer 62 are mechanically removed, the thickness of the protruding conductor 51 becomes 100 μm, and the thickness of the core back side conductor layer 62 is increased. Is 65 μm. The arithmetic average roughness Ra of the polished surface of the sandpaper attached to the belt sander device is equal to the arithmetic average roughness Ra after polishing the top portion 52 of the protruding conductor 51 and the surface of the core back side conductor layer 62. Specifically, it is set to 0.8 μm. At this time, the adhesive tape 171 is peeled off. Note that the surfaces of the external electrodes 111 and 112 and the surface of the core main surface side conductor layer 61 are in contact with the adhesive tape 171, and therefore are positioned at the same height without being polished.

  Next, the main surface side buildup layer 31 is formed on the core main surface 12 and the back surface side buildup layer 32 is formed on the core back surface 13 by a known method. Specifically, a photosensitive epoxy resin is applied to the core main surface 12 and the capacitor main surface 102, and then exposed and developed to form the lower main surface side resin insulation layer 33 (see FIG. 24). ). In addition, as resin to adhere, other resin, such as a liquid crystal polymer, can also be used. Further, a photosensitive epoxy resin is applied to the core back surface 13 and the capacitor back surface 103, and exposure and development are performed, thereby forming a lower back side resin insulation layer 34 (see FIG. 23). In addition, as resin to adhere, other resin, such as a liquid crystal polymer, can also be used.

  Specifically, first, laser drilling is performed using a YAG laser, a carbon dioxide gas laser, or the like to form via holes 181 and 182 at positions where the via conductors 47 are formed (see FIG. 24). That is, a via hole 181 penetrating the main surface side resin insulation layer 33 is formed, and the main surface side power supply electrode 111 and the main surface side ground electrode 112 are exposed. Also, a via hole 182 that penetrates the back surface side resin insulation layer 34 is formed, and protrudes on the surface of the top portion 52 of the protruding conductor 51 protruding on the back surface side power supply electrode 121 and on the back surface ground electrode 122. The surface of the top portion 52 of the protruding conductor 51 provided is exposed (see FIG. 24).

  Further, drilling is performed using a drill machine, and a through hole 191 penetrating the core substrate 11 and the resin insulating layers 33 and 34 is formed in advance at a predetermined position (see FIG. 24). Then, after applying electroless copper plating to the surfaces of the resin insulating layers 33 and 34, the inner surfaces of the via holes 181 and 182 and the inner surfaces of the through holes 191, an etching resist is formed, and then electrolytic copper plating is applied. Then, the etching resist is removed and soft etching is performed. Thereby, the main surface side conductor layer 41 is formed on the main surface side resin insulation layer 33, and the back surface side conductor layer 42 is patterned on the back surface side resin insulation layer 34 (see FIG. 25). At the same time, the through-hole conductor 16 is formed in the through-hole 191 and the via conductor 47 is formed in the via holes 181 and 182. Next, the cavity of the through-hole conductor 16 is filled with an insulating resin material (epoxy resin) to form a closing body 17 (see FIG. 26).

  Thereafter, a photosensitive epoxy resin or the like is applied to the resin insulating layers 33 and 34, exposed and developed, and then a resin having via holes 183 and 184 at positions where via conductors 43 (see FIG. 1) are to be formed. Insulating layers 35 and 36 are formed (see FIG. 26). In addition, as resin to adhere, other resin, such as a liquid crystal polymer, can also be used. In this case, via holes 183 and 184 are formed at positions where the via conductors 43 are to be formed by a laser processing machine or the like, then electrolytic copper plating is performed by a known method, and via conductors are formed inside the via holes 183 and 184. 43, terminal pads 44 are formed on the main surface side resin insulation layer 35, and BGA pads 48 are formed on the back surface side resin insulation layer 36 (see FIG. 1).

  Thereafter, solder resists 37 and 38 are formed by applying and curing a photosensitive epoxy resin or the like on the resin insulating layers 35 and 36. Next, exposure and development are performed in a state where a predetermined mask is arranged, and the openings 40 and 46 are patterned in the solder resists 37 and 38. Further, solder bumps 45 are formed on the terminal pads 44, and solder bumps 49 are formed on the BGA pads 48 (see FIG. 1). In addition, it can be grasped that the product in this state is a multi-cavity wiring board in which a plurality of product regions to be the wiring board 10 are arranged vertically and horizontally along the plane direction. Furthermore, when the multi-cavity wiring board is divided, a large number of wiring boards 10 which are individual products can be manufactured simultaneously.

  In the present invention, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. For example, the protruding conductor 51 is formed on the external electrodes 121 and 122 disposed on the capacitor back surface 103 of the ceramic sintered body 104, and on the external electrodes 111 and 112 disposed on the capacitor main surface 102, The protruding conductor 51 may be formed. In this way, not only can the electrodes 121 and 122 and the via conductors 47 in the back surface side resin insulation layer 34 be reliably connected via the protruding conductors 51, but also the electrodes 111 and 112 and the main surface side resin. The via conductors 47 in the insulating layer 33 can also be reliably connected via the protruding conductors 51, and the wiring board 10 with higher reliability can be obtained. However, from the viewpoint of cost reduction, the protruding conductor 51 is not formed on the electrodes 111 and 112 that are originally at the same height as the core main surface side conductor layer 61 because the adhesive tape 171 is contacted in the height adjusting step. The projecting conductor 51 is preferably formed only on the electrodes 121 and 122.

  Further, the gap between the inner wall surface 91 of the housing hole 90 and the capacitor side surface 106 is filled by a part of the resin filling portion 92 provided separately from the main surface side buildup layer 31. The gap between the inner wall surface 91 of the accommodation hole 90 and the capacitor side surface 106 may be filled with a part of the back surface side resin insulation layer 34 constituting the layer 31. In this way, it is not necessary to perform the resin filling portion forming step, the number of man-hours required for manufacturing the wiring board 10 can be reduced, and the wiring board 10 can be formed easily and at low cost. .

It is a schematic sectional drawing of the wiring board of one Embodiment which actualized this invention. It is a schematic sectional drawing of a via array capacitor. It is a schematic explanatory drawing for demonstrating the connection in the inner layer of a via array capacitor. It is a schematic explanatory drawing for demonstrating the connection in the inner layer of a via array capacitor. It is typical sectional drawing of the copper clad laminated board used for preparation of a core board | substrate. It is typical sectional drawing of the core board intermediate goods by which the conductor layer was patterned. It is typical sectional drawing of the core substrate intermediate | middle product on which the sub-base material in which the conductor layer was patterned was laminated | stacked. It is typical sectional drawing of the core board | substrate with which the accommodation hole part was formed. It is a typical sectional view of a via array capacitor. FIG. 5 is a schematic cross-sectional view of a via array capacitor in which a protruding conductor is formed on an external electrode. It is typical sectional drawing for demonstrating the metal member in which the junction part was formed. It is typical sectional drawing for demonstrating the state which made the junction part contact the external electrode. It is typical sectional drawing for demonstrating the state which cut | disconnected the wire part from the junction part and raised the capillary. It is typical sectional drawing of an example of the shape of a protruding conductor. It is typical sectional drawing of the other example of the shape of a protruding conductor. It is typical sectional drawing of the other example of the shape of a protruding conductor. It is typical sectional drawing of the other example of the shape of a protruding conductor. It is typical sectional drawing of the other example of the shape of a protruding conductor. It is typical sectional drawing for demonstrating the state by which the via array capacitor was accommodated in the accommodation hole part of the core board | substrate. It is typical sectional drawing for demonstrating a mode that the uncured resin sheet for forming a resin filling part was prepared upward. It is typical sectional drawing for demonstrating the state in which the resin filling part was formed. It is typical sectional drawing for demonstrating the state after matching the height of a core back surface conductor layer and a protruding conductor. It is typical sectional drawing for demonstrating the state by which the main surface side and the back surface side resin insulation layer were formed in both surfaces of the core board | substrate. It is typical sectional drawing for demonstrating the state by which the via hole was formed in the resin insulating layer, and the via hole over the full thickness was further formed. It is typical sectional drawing for demonstrating the state by which the conductor layer was formed in the surface of the resin insulating layer, and the via conductor was formed in the via hole. It is explanatory drawing of the manufacturing method of a wiring board. It is typical sectional drawing for demonstrating an example of the manufacturing method of the wiring board in a prior art. It is typical sectional drawing for demonstrating the post process of the manufacturing method of FIG. It is typical sectional drawing for demonstrating the post process of the manufacturing method of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10; Component built-in wiring board (wiring board), 11; Core board | substrate, 12; Core main surface, 13; Core back surface, 21; IC chip as a semiconductor integrated circuit element, 23; IC chip as a semiconductor integrated circuit element mounting area Mounting area, 31; main surface side buildup layer as main surface side wiring laminated portion, 32; back surface side buildup layer as rear surface side wiring laminated portion, 33, 35; main surface side as main surface side interlayer insulating layer Resin insulation layers 34, 36; back side resin insulation layers as back side interlayer insulation layers, 39; surfaces of main surface side wiring laminates, 41; main surface side conductor layers, 42; back surface side conductor layers, 47; vias Conductor, 50; connection terminal portion, 51; protruding conductor, 52; top, 61; core main surface side conductor layer, 62; core back surface side conductor layer as a conductor layer formed on the core back surface, 90; accommodation hole Part, 91; inner wall surface, 92; resin filling part, 1 DESCRIPTION OF SYMBOLS 1; Via array capacitor as components, 102; Capacitor main surface as component main surface, 103; Capacitor back surface as component back surface, 104: Ceramic sintered body as component main body, 106; Capacitor side surface as component side surface, 121 A back-side power supply electrode as a surface electrode; 122; a back-side ground electrode as a surface electrode; 182; a via hole.

Claims (11)

A core substrate having a core main surface and a core back surface, and having at least an accommodation hole opening in the core back surface;
A component having a component main surface and a component back surface, having a plurality of external electrodes formed on the component back surface, and being housed in the housing hole;
An insulating resin that fills the gap in the housing hole in which the component is housed; and
A method of manufacturing a component built-in wiring board comprising: a plurality of projecting conductors that project from the external electrode and lead out the external electrode to the core back surface or the surface of a build-up insulating layer laminated on the core back surface Because
A protruding conductor forming step of forming the protruding conductor by cutting the wire portion after bonding the bonding portion of the metal member including the wire portion and the bonding portion to the external electrode;
A housing step of housing the component in the housing hole with the component back surface and the core back surface of the component facing the same side;
And a resin filling step of filling a gap in the housing hole in which the component is housed with an insulating resin.   The method of manufacturing a component built-in wiring board according to claim 1, wherein the joint portion is substantially spherical.   After the resin filling step, a height adjusting step for adjusting the height so that the top portions of the plurality of protruding conductors and the core back surface or the surface of the build-up insulating layer are included in one flat surface. The manufacturing method of the component built-in wiring board of Claim 1 or 2 provided.   The method of manufacturing a component built-in wiring board according to claim 1, wherein the protruding conductor has a squinted shape.   5. The component built-in wiring board according to claim 4, wherein the protruding conductor has 1 <R / S <5, where S is a bonding diameter with the external electrode and R is a maximum diameter of the protruding conductor. Manufacturing method.   The method for manufacturing a component built-in wiring board according to claim 1, wherein the protruding conductor is mainly composed of copper.   The method for manufacturing a component built-in wiring board according to claim 1, wherein the joining in the projecting conductor forming step is performed by ultrasonic joining while maintaining a temperature of the component at 400 ° C. or lower.   The method of manufacturing a component built-in wiring board according to claim 1, wherein the component is a via array capacitor.   The protruding conductor forming step and the resin filling step are performed in this order, and the protruding conductor roughening is performed to roughen the surface of the protruding conductor between the protruding conductor forming step and the resin filling step. The manufacturing method of the component built-in wiring board in any one of Claims 1 thru | or 8 provided with a process.   The method for manufacturing a component built-in wiring board according to claim 1, further comprising a pressing step of pressing the protruding conductor to adjust a shape of the protruding conductor.   A wiring board with a built-in component obtained by the method for manufacturing a wiring board with a built-in component according to any one of claims 1 to 10.

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