JP4945974B2 - Component built-in wiring board - Google Patents

Description

The present invention relates to a component built-in wiring board having a chip component embedded in an insulating plate, and more particularly to a component built-in wiring board suitable for preventing the reliability of the wiring board from being lowered due to the built-in component.

  As a prior art of a component built-in wiring board, there is one disclosed in Patent Document 1 below. According to the structure shown in FIG. 1 of the same document, solder (or conductive adhesive) is used for electrical connection of the electrical component to the wiring layer. In the manufacturing method, electrical components are electrically and mechanically connected to a wiring board serving as a core in advance using solder (or conductive adhesive). In addition, a hole is formed in another insulating resin layer, and the hole is filled with a conductive composition, aligned and arranged with the core plate on which the component has been previously mounted, and laminated and integrated.

  In the component built-in wiring board, when another component is externally mounted on this wiring board or when the component built-in wiring board itself is mounted on another wiring board (both referred to as secondary mounting), It is important that the connection reliability is not impaired. Specifically, for example, when solder is used as a connection material for a built-in component, it is necessary to prevent connection failure or short circuit due to remelting of the solder.

This document describes the use of high-temperature solder having a high melting point in order to prevent such remelting (paragraph 0034 of the document). However, the specific components of solder are not clear. In general, Sn—Pb-based Pb-rich materials are known as high-temperature solders, including Pb-5Sn (melting point: 314 ° C. to 310 ° C.) and Pb-10 Sn (melting point: 302 ° C. to 275 ° C.). However, a high temperature of 300 ° C. or higher is required as the soldering temperature. At such a high temperature, a general epoxy resin as an insulating plate material for a wiring board is insufficient in heat resistance and is difficult to apply.
JP 2003-197849 A

The present invention provides in the wiring board having buried the chip component in an insulating plate, a solder re-melted to be no component built-in wiring board reliability is reduced as a wiring board for built-in components connected The purpose is to do.

In order to solve the above-described problems, a component built-in wiring board according to the present invention includes a first insulating layer of an epoxy resin and a second insulating resin layer positioned on the first insulating layer. Between the first insulating layer and the second insulating layer, and the chip component embedded in the second insulating layer , the electrodes being terminals at both ends, and the first insulating layer and the second insulating layer. and a wiring pattern including a mounting lands of the chip component, the connection with the chip component terminal and the mounting land of the wiring pattern, and the compound than Suzuto tin consisting of a refractory metal comprising a connection part made of solder containing particles of the metal surface is covered, and the like there is no occurrence of voids around the chip component, the chip component, embedded in the second insulating layer And the terminal of the chip component , Characterized in that it is connected to the mounting land of the wiring pattern via the connection portion.

That is, the connecting portion for connecting the built-in chip component to the wiring pattern is made of solder containing a certain kind of metal grain. The metal particles are particles of a metal whose surface is covered with a compound composed of tin and a metal having a melting point higher than that of tin. The solder of the connection portion having such a configuration is, for example, when cream particles (with solder particles dispersed in the flux) are dispersed with metal particles having a melting point higher than tin and reflowed. Obtained by chemical reaction.

  Since the solder of this connecting portion is covered with a compound composed of metal having a melting point higher than that of tin and tin, tin in the solder is taken into this compound and is not a compound of tin. It is decreasing as a percentage. In addition, this compound itself has a considerably higher melting point than that of tin. Therefore, remelting itself is difficult to occur, and even if remelted, the ratio of the tin portion is reduced, so the volume change is small and the influence on the surroundings is suppressed. Therefore, the reliability as a wiring board is not easily lowered.

According to the present invention, in a component built-in wiring board having a chip component embedded in an insulating plate, the component built-in wiring board does not deteriorate reliability as a wiring board due to re-melting of the solder for connecting the built-in component Can be provided.

  As an embodiment of the present invention, the metal particles may be copper particles. This is an example of a metal having a melting point higher than that of tin, but in addition, grains such as silver, gold, aluminum, and copper-tin alloy can be used. In such other examples, a reaction compound with tin is formed on the surface of the metal grains, and the same effect is obtained.

  Here, for example, the solder of the connection portion may be an alloy containing tin, silver, and copper except for the copper grain portion. Further, for example, the solder of the connection portion may be 5 wt% to 50 wt% as a ratio of the copper grain portion. Further, for example, the solder of the connection part may be 3 μm to 40 μm in diameter as the copper grain. It is a specific example of a part except a copper grain, and a copper grain part.

  As an embodiment, the solder of the connecting portion can be lead-free. Substances that are considered harmful are actively excluded.

As an embodiment of the present invention, the second insulating layer is a laminate of at least two insulating layers, and a second wiring pattern provided between the at least two insulating layers, and the second An axis that penetrates part of the insulating layer in the stacking direction and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, and is made of a conductive composition and coincides with the stacking direction. And an interlayer connection body having a shape whose diameter changes in the direction of the axis. This interlayer connection body is an example of an interlayer connection body that penetrates a part in the stacking direction of the second insulating layer in which the chip component is embedded. For example, the interlayer connection body is derived from conductive bumps formed by screen printing of a conductive composition. It is an interlayer connection body.

As an embodiment, the second insulating layer is a laminate of at least two insulating layers, and a second wiring pattern provided between the at least two insulating layers, and the second wiring layer An axis which penetrates a part of the insulating layer in the stacking direction and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern and which is made of metal and coincides with the stacking direction. And an interlayer connection body having a shape whose diameter changes in the direction of. This interlayer connection body is another example of an interlayer connection body that penetrates a part in the stacking direction of the second insulating layer in which the chip component is embedded. For example, the interlayer connection body is derived from a conductor bump formed by etching a metal plate. It is an interlayer connection body.

As an embodiment, a surface of the wiring pattern penetrating through the first insulating layer, a second wiring pattern provided on the opposite side of the first insulating layer from the side on which the wiring pattern is located, and Between the first wiring pattern and the surface of the second wiring pattern, and is made of a conductive composition and has an axis that coincides with the laminating direction and has a shape whose diameter changes in the direction of the axis It may be further provided with a connection body. This interlayer connection body is an example of an interlayer connection body that penetrates a first insulating layer different from the second insulating layer in which the chip component is embedded. For example, the interlayer connection body is formed by screen printing of a conductive composition. This is an inter-layer connection body derived from a conductive bump.

As an embodiment, a surface of the wiring pattern penetrating through the first insulating layer, a second wiring pattern provided on the opposite side of the first insulating layer from the side on which the wiring pattern is located, and And an interlayer connection body that is sandwiched between the surface of the second wiring pattern and is made of metal and has an axis that coincides with the lamination direction and has a diameter that changes in the direction of the axis; It is good also as comprising. This interlayer connection body is another example of the interlayer connection body that penetrates the first insulating layer different from the second insulating layer in which the chip component is embedded, and is formed by etching a metal plate, for example. It is an interlayer connection body derived from a conductor bump.

As an embodiment, a surface of the wiring pattern penetrating through the first insulating layer, a second wiring pattern provided on the opposite side of the first insulating layer from the side on which the wiring pattern is located, and Between the first wiring pattern and the surface of the second wiring pattern, and is made of a conductive composition and has an axis that coincides with the lamination direction and has a shape in which the diameter does not change in the direction of the axis It may be further provided with a connection body. This interlayer connection body is still another example of the interlayer connection body that passes through the first insulating layer different from the second insulating layer in which the chip component is embedded, for example, a hole that passes through the first insulating layer. It is an interlayer connection body formed by filling a conductive composition.

As an embodiment, a surface of the wiring pattern penetrating through the first insulating layer, a second wiring pattern provided on the opposite side of the first insulating layer from the side on which the wiring pattern is located, and An interlayer connection body that is sandwiched between the surface of the second wiring pattern and is made of metal and has an axis that coincides with the stacking direction and has a diameter that does not change in the direction of the axis; It is good also as comprising. This interlayer connection body is still another example of the interlayer connection body that penetrates the first insulating layer different from the second insulating layer in which the chip component is embedded. For example, a conductor bump formed by metal plating is used. It is an interlayer connection body derived from.

Further, as an aspect, wherein the side of the chip component the chip component by the connection portion is connected to the wiring pattern the chip components on the surface of the opposite side of, may be, are exposed. As a component built-in wiring board, the thickness is suppressed as much as possible.

Further, as an aspect, wherein the side of the chip component the chip component by the connection portion is connected to the wiring pattern surface of the chip component on the opposite side, is hidden by the second insulating layer It can also be said. As a component built-in wiring board, the built-in components are completely enclosed inside.

  Based on the above, embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to an embodiment of the present invention. As shown in FIG. 1, this component built-in wiring board includes insulating layers 11 (first insulating layers), 12, 12, 13 (second insulating layers at 12, 13, 14), 15, Wiring layer 21 (second wiring pattern), 22 (wiring pattern), 23 (another second wiring pattern), 24, 25, 26 (= 6 layers in total), interlayer connector 31 , 32, 34, and 35, through-hole conductor 33, chip component 41 (electric / electronic component), and connection portion 51 (solder portion).

  Here, the chip component 41 is, for example, a chip capacitor, and its planar size is, for example, 0.6 mm × 0.3 mm. Terminals (electrodes) are provided at both ends, and the lower side thereof is opposed to a land for mounting a built-in component by the wiring layer 22. The terminals of the chip component 41 and the mounting lands are electrically and mechanically connected by the connecting portion 51.

  Here, the fine structure of the connecting portion 51 that connects the terminal of the chip component 41 and the mounting land of the wiring layer 22 will be described with reference to FIG. FIG. 2 is an enlarged view schematically showing the configuration of the connection portion 51 and the formation process thereof in the component built-in wiring board shown in FIG. As shown on the right side of FIG. 2, the connecting portion 51 is composed of a solder portion 501 </ b> A mainly composed of tin and copper grains 502 </ b> A whose surface is covered with a copper-tin compound as a fine structure. The formation process of the connection part 51 is related to such a fine structure.

That is, the connecting portion 51 is formed by reflow of the cream solder 51A. As shown in the left side of FIG. 2, the cream solder 51A includes solder (components such as Sn-3Ag-0.5Cu lead-free) grains 501. It originally has a configuration in which copper particles 502 are dispersed in a flux 503. When such cream solder 51A is reflowed by heating (for example, 230 ° C. to 250 ° C.), the solder particles 501 are melted at, for example, 217 ° C. to 221 ° C. to cover the surfaces of the copper particles 502. At this time, the tin component of the solder covering the surface of the copper particles 502 forms a compound Cu ₆ Sn ₅ with copper. As a result, the tin component of the solder portion 501A is reduced. The copper grains 502 </ b> A whose surfaces are covered with a copper-tin compound may be partially connected to each other by the compound Cu ₆ Sn ₅ .

According to such a connection part 51, when this component built-in wiring board is used for secondary mounting, it is possible to effectively prevent reliability deterioration due to remelting. That is, the compound Cu ₆ Sn ₅ has a high melting point of 600 ° C. or higher and does not melt during secondary mounting. Further, the tin component of the solder portion 501A is reduced as compared with that of the original solder grain 501, and even if remelted, the volume change is small and the influence on the surroundings is suppressed. Therefore, reliability as a component built-in wiring board is unlikely to decrease.

  The copper particles 502 in the cream solder 51A may be metal particles such as other metals such as silver, gold, aluminum, and copper-tin alloy. Further, the solder particles 501 whose component is, for example, Sn-3Ag-0.5Cu can be used having a particle size of, for example, 10 μm to 20 μm. Furthermore, the particle diameter of the copper particles 502A whose surfaces are covered with the copper-tin compound in the connection portion 51 can be set to 3 μm to 40 μm, for example. Further, the proportion of the copper particles 502A in the connection portion 51 can be set to 5 wt% to 50 wt%, for example.

  The other structure as the component built-in wiring board will be described. The wiring layers 22, 23, 24, and 25 different from the outer wiring layers 21 and 26 are the inner wiring layers, respectively. 22, the insulating layer 11 between the wiring layer 22 and the wiring layer 23, the insulating layer 12 between the wiring layer 23 and the wiring layer 24, and the insulating layer 13 between the wiring layer 24 and the wiring layer 25. The insulating layer 14 is located between the wiring layer 25 and the wiring layer 26, and the wiring layers 21 to 26 are separated from each other. Each of the wiring layers 21 to 26 is made of, for example, a metal (copper) foil having a thickness of 18 μm.

  The inner wiring layers 22 to 25 are positioned so as to sink into the insulating layer 12 or the insulating layer 14 side, and there is no sinking of the wiring layer into the insulating layers 11, 13, and 15. This is based on the manufacturing process, and the wiring layers 22 and 25 may be in different subsidence positions due to differences in the manufacturing process (described later).

  Each of the insulating layers 11 to 15 is a rigid material made of, for example, a glass epoxy resin, each having a thickness of 100 μm, for example, only the insulating layer 13 has a thickness of, for example, 300 μm, excluding the insulating layer 13. In particular, the insulating layer 13 has an opening at a position corresponding to the built-in chip component 41, and provides a space for incorporating the chip component 41. The insulating layers 12 and 14 are deformed so as to fill the opening of the insulating layer 13 for the built-in chip component 41 and the space inside the through-hole conductor 33 of the insulating layer 13 and become voids inside. There is no space.

  The wiring layer 21 and the wiring layer 22 can be conducted by an interlayer connector 31 that is sandwiched between the surfaces of the patterns and penetrates the insulating layer 11. Similarly, the wiring layer 22 and the wiring layer 23 can be conducted by an interlayer connector 32 that is sandwiched between the surfaces of the patterns and penetrates the insulating layer 12. The wiring layer 23 and the wiring layer 24 can be conducted by a through-hole conductor 33 provided through the insulating layer 13. The wiring layer 24 and the wiring layer 25 can be conducted by an interlayer insulator 34 that is sandwiched between the surfaces of these patterns and penetrates the insulating layer 14. The wiring layer 25 and the wiring layer 26 can be conducted by an interlayer connector 25 that is sandwiched between the surfaces of these patterns and penetrates the insulating layer 15.

  The interlayer connectors 31, 32, 34, and 35 are derived from conductive bumps formed by screen printing of a conductive composition, respectively, and depend on the manufacturing process in the axial direction (shown in FIG. 1). The diameter changes in the upper and lower stacking directions). The diameter is, for example, 200 μm on the thick side.

  As described above, in the component built-in wiring board according to this embodiment, even when the connection portion 51 may be remelted during the secondary mounting, the volume expansion is suppressed to a slight amount, and the insulating layers 11, 12, It is possible to effectively prevent cracks and delamination from occurring in the wiring layer 22 and the like. If the cracks and delamination are excessive, the wiring patterns and the connection between the wiring patterns and the components may be defective or short-circuited, which affects the reliability and product yield. Therefore, this embodiment can improve reliability and yield.

  Further, there is an advantage that the connecting portion 51 can be made of solder and does not require an expensive material such as a conductive adhesive. Furthermore, the cream solder 51A for connecting the chip component 41 does not require high-temperature solder, and therefore does not require a high temperature exceeding 300 ° C., so that an epoxy resin is used as the material for the insulating layer 11 or the like. Suitable for component built-in wiring boards.

  Next, the manufacturing process of the component built-in wiring board shown in FIG. 1 will be described with reference to FIGS. 3 to 5 are process diagrams schematically showing a part of the manufacturing process of the component built-in wiring board shown in FIG. In these figures, the same or equivalent components as those shown in FIG.

  It demonstrates from FIG. FIG. 3 shows a manufacturing process of a portion centering on the insulating layer 11 in each configuration shown in FIG. First, as shown in FIG. 3 (a), a paste-like conductive composition to be an interlayer connection 31 is formed on a metal foil (electrolytic copper foil) 22A having a thickness of, for example, 18 μm by, for example, screen printing. It is formed in a bump shape (bottom diameter, eg, 200 μm, height, eg, 160 μm). This conductive composition is obtained by dispersing fine metal particles such as silver, gold and copper or fine carbon particles in a paste-like resin. For convenience of explanation, printing is performed on the lower surface of the metal foil 22A, but it may be printed on the upper surface (the following drawings are also the same). After the interlayer connector 31 is printed, it is dried and cured.

  Next, as shown in FIG. 3B, an FR-4 prepreg 11A having a thickness of, for example, 100 μm is laminated on the metal foil 22A to penetrate the interlayer connector 31 so that the head is exposed. To do. At the time of exposure or afterwards, the tip thereof may be crushed by plastic deformation (in any case, the shape of the interlayer connection body 31 is a shape having an axis coinciding with the stacking direction and the diameter changing in the axial direction). Subsequently, as shown in FIG. 3C, a metal foil (electrolytic copper foil) 21A is laminated on the prepreg 31A, and the whole is integrated by pressing and heating. At this time, the metal foil 21A is in electrical continuity with the interlayer connector 31, and the prepreg 11A is completely cured to become the insulating layer 11.

  Next, as shown in FIG. 3D, patterning by, for example, well-known photolithography is performed on the metal foil 22A on one side, and this is processed into a wiring pattern 22 including mounting lands. Then, as shown in FIG. 3E, the cream solder 51A described above is printed on the mounting land obtained by processing, for example, by screen printing. The cream solder 51A can be easily printed in a predetermined pattern by using screen printing. A dispenser can be used instead of screen printing.

  Next, the chip component 41 is placed on the mounting land through the cream solder 51A, for example, with a mounter, and then the cream solder 51A is reflowed in, for example, a reflow furnace. Thereby, as shown in FIG. 3F, the wiring board material 1 in a state where the chip component 41 is connected to the mounting land of the wiring layer 22 through the connection portion 51 is obtained. The subsequent steps using this wiring board material 1 will be described later with reference to FIG.

  Next, a description will be given with reference to FIG. FIG. 4 shows a manufacturing process of a part centering on the insulating layer 13 and the same 12 in each configuration shown in FIG. First, as shown in FIG. 4A, for example, an FR-4 insulating layer 13 having a thickness of, for example, 300 μm in which metal foils (electrolytic copper foils) 23A and 24A having a thickness of 18 μm are laminated on both surfaces is prepared. A through-hole 62 for forming a through-hole conductor is formed at a predetermined position, and an opening 61 is formed in a portion corresponding to the chip component 41 to be incorporated.

  Next, electroless plating and electrolytic plating are performed to form a through-hole conductor 33 on the inner wall of the through-hole 62 as shown in FIG. At this time, a conductor is also formed on the inner wall of the opening 61. Further, as shown in FIG. 4C, the metal foils 23A and 24A are patterned in a predetermined manner using well-known photolithography to form wiring layers 23 and 24. By patterning the wiring layers 23 and 24, the conductor formed on the inner wall of the opening 61 is also removed.

  Next, as shown in FIG. 4 (d), conductive bumps (bottom diameter: 200 μm, height: 160 μm, for example) that will become the interlayer connector 32 are formed at predetermined positions on the wiring layer 23 of the paste-like conductive composition. It is formed by screen printing. Subsequently, as shown in FIG. 4E, an FR-4 prepreg 12A (nominal thickness, for example, 100 μm) to be the insulating layer 12 is laminated on the wiring layer 23 side using a press. The prepreg 12 </ b> A is previously provided with an opening corresponding to the built-in chip component 41, similar to the insulating layer 13.

  In this lamination process, the head of the interlayer connector 32 is passed through the prepreg 12A. In addition, the broken line of the head part of the interlayer connection body 32 in FIG. 10 (e) indicates that there are both cases where the head part is plastically deformed and crushed at this stage, and when it is not plastically deformed. By this step, the wiring layer 23 is located by sinking to the prepreg 12A side. The wiring board material obtained as described above is referred to as a wiring board material 2.

  Note that the steps shown in FIG. 4 may be performed as follows. In the stage of FIG. 4A, only the through hole 62 is formed and the subsequent steps from FIG. 4B to FIG. 4D are performed without forming the opening 61 for the built-in component. Next, as a process corresponding to FIG. 4E, prepreg 12A (without opening) is stacked. And it is the process of forming simultaneously the opening part for components incorporation in the insulating layer 13 and the prepreg 12A.

  Next, a description will be given with reference to FIG. FIG. 5 is a diagram showing an arrangement relationship in which the wiring board materials 1 and 2 obtained as described above are stacked. Here, the upper wiring board material 3 applies the same process as the lower wiring board material 1, and thereafter, the interlayer connector 34 and the prepreg 14 </ b> A are connected to the interlayer connector 32 in the intermediate wiring board material 2. And it was obtained in the same manner as the prepreg 12A. However, there is no component (chip component 41) and no part (mounting land) for connecting it, and the prepreg 14A is not provided with an opening for the chip component 41. Other than that, the metal foil (electrolytic copper foil) 26A, the insulating layer 15, the interlayer connection body 35, the wiring layer 25, the prepreg 14A, and the interlayer connection body 34 are the metal foil 21A of the wiring board material 1, the insulating layer 11, and the interlayer connection, respectively. The same as the body 31, the wiring layer 22, the prepreg 12 </ b> A of the wiring board material 2, and the interlayer connection body 32.

  The respective wiring board materials 1, 2, and 3 are laminated and arranged in the arrangement as shown in FIG. Thereby, the prepregs 12A and 14A are completely cured, and the whole is laminated and integrated. At this time, due to the fluidity of the prepregs 12 </ b> A and 14 </ b> A obtained by heating, the prepregs 12 </ b> A and 14 </ b> A are deformed into the space around the chip component 41 and the space inside the through-hole conductor 33, and no gap is generated. The wiring layers 22 and 24 are electrically connected to the interlayer connectors 32 and 34, respectively. After this laminating step, the metal foils 26A and 21A on the upper and lower surfaces can be patterned in a predetermined manner using well-known photolithography to obtain a component built-in wiring board as shown in FIG.

  As a modification, the through-hole conductor 33 provided in the intermediate insulating layer 13 can naturally have a configuration similar to the interlayer connector 31 or 32. In addition, the outer wiring layers 21 and 26 are formed at the stage of each wiring board material 1 and 3 (for example, at the stage of FIG. 3D) other than patterning after the last lamination step. May be.

  Further, in the laminating process shown in FIG. 5, for the wiring board materials 1 and 2, the prepreg 12 </ b> A and the interlayer connector 32 are provided not on the wiring board material 2 side but on the wiring board material 1 side. May be. That is, the formation of the interlayer connector 32 and the lamination of the prepreg 12A are performed in advance on the wiring layer 22 (on the insulating layer 11) of the wiring board material 1. In this case, the mounted chip component 41 seems to be an interference factor when the interlayer connection body 32 is formed by screen printing at first glance. However, when the chip component 41 is a sufficiently thin component, what is actually an interference factor? Don't be. In the step of laminating the prepreg 12A, the prepreg 12A can be laminated uniformly in the in-plane direction by pressing and heating with a cushioning material capable of absorbing the thickness of the chip component 41 interposed therebetween.

  Next, a component built-in wiring board according to another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to another embodiment of the present invention. Components identical or equivalent to those shown in the already described drawings are denoted by the same reference numerals. Is attached. The description of the part is omitted unless there is an additional matter.

  In this embodiment, it has the interlayer connection bodies 72 and 74 formed by metal plate etching instead of the interlayer connection bodies 32 and 34 by printing of the conductive composition. As shown in the drawing, an etching stopper layer remains on the wiring layer 22 side or the wiring layer 25 side of these interlayer connectors 72 and 74. Further, the boundary between the insulating layer 11 (15) and the insulating layer 12 (14) is moved deeper by the thickness of the wiring layer 22 (25) as compared with the embodiment shown in FIG. Hereinafter, the manufacturing process will be described including the reason for such a configuration.

  FIG. 7 is a process diagram schematically showing a part of the manufacturing process of the component built-in wiring board shown in FIG. 6 in an insulating layer 11, wiring layers 21 and 22 (including mounting lands) in FIG. The manufacturing process of the part of the interlayer connection bodies 31 and 72 is shown. The manufacturing process of the insulating layer 15, wiring layers 25 and 26, and interlayer connectors 35 and 74 in FIG. 6 is substantially the same. In addition, the same code | symbol is attached | subjected to the same or equivalent thing as the component shown in FIG.

  First, for example, a laminated film in which a layer (etching stopper layer ES) made of, for example, a nickel alloy having a very thin thickness, for example, 2 μm, is prepared on a metal foil (electrolytic copper foil) 22A having a thickness of 18 μm is prepared, and this etching stopper layer ES is prepared. A metal plate (copper plate) 72A having a thickness of, for example, 120 μm is laminated and integrated on the side to obtain a clad material having a three-layer structure as shown in FIG.

  Next, as shown in FIG. 7B, the metal foil 22A is patterned in a predetermined pattern with an etchant that can etch only copper using well-known photolithography. Thereby, the wiring layer 22 is formed. Further, as shown in FIG. 7C, an interlayer connection 31 is formed at a predetermined position on the wiring layer 22 by screen printing of a paste-like conductive composition. Subsequently, as shown in FIG. 7D, the prepreg 11A to be the insulating layer 11 is laminated on the wiring layer 22 side using a press machine. At this time, the head of the interlayer connector 31 is made to penetrate the prepreg 11A. By this lamination process, the wiring layer 22 sinks to the prepreg 11A side and is positioned. Note that the broken line at the head of the interlayer connector 31 in FIG. 7D indicates that there are both cases where the head of the interlayer connector 31 is plastically deformed and crushed at this stage and when it is not plastically deformed. .

  Next, a metal foil (electrolytic copper foil) 21A having a thickness of 18 μm, for example, is arranged on the laminated prepreg 11A, and is pressed and heated in the laminating direction by a press. Thereby, as shown in FIG.7 (e), the prepreg 11A is hardened | cured completely and becomes the insulating layer 11, and is laminated | stacked and integrated. At this time, the metal foil 21A is electrically connected to the interlayer connector 31.

  Next, an etching resist at a predetermined position is formed on the metal plate 72A. This etching resist is left where the interlayer connector 72 is to be formed by etching. Then, etching is performed using an etchant that can etch only copper, and an interlayer connector 72 is formed by etching a metal plate, as shown in FIG. The shape varies depending on the shape and size of the etching resist and the etching processing time. Generally, the shape has an axis that coincides with the stacking direction, and the diameter changes in the direction of the axis.

  Then, the wiring board material having a form as shown in FIG. 7G can be obtained by etching away the etching stopper layer ES using the formed interlayer connector 72 as a mask. The following steps include mounting of the chip components shown in FIG. 3E and subsequent steps, and stacking of the prepreg 12A shown in FIG. 4E (however, the prepreg 12A is on the wiring layer 22 side in FIG. 7G). To be laminated). The obtained wiring board material can be used in place of the lower wiring board material 1 in the laminating process shown in FIG. As the intermediate wiring board material 2, the one without the formation of the interlayer connector 32 and the lamination of the prepreg 12 </ b> A is used. Thus, the component built-in wiring board shown in FIG. 6 can be obtained.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to still another embodiment of the present invention. Components that are the same as or equivalent to the components shown in the drawings already described are denoted by the same reference numerals. The description of the part is omitted unless there is an additional matter. In this embodiment, instead of the interlayer connection bodies 31 and 35 of the component built-in wiring board shown in FIG. 1, the interlayer connection is made of metal and has an axis that coincides with the stacking direction and has a shape whose diameter changes in the axial direction. The bodies 81 and 85 are used.

  Hereinafter, the manufacturing process of the component built-in wiring board shown in FIG. 8 will be described with reference to FIG. FIG. 9 is a process diagram schematically showing a partial manufacturing process of the component built-in wiring board shown in FIG. 8, in which the wiring layer 22 (more precisely, the metal foil 22A processed into the wiring layer 22) and the interlayer The manufacturing process of the part which consists of the connection body 81 is shown.

  First, for example, a laminated film in which a layer (etching stopper layer ES) made of, for example, a nickel alloy having a very thin thickness, for example, 2 μm, is prepared on a metal foil (electrolytic copper foil) 22A having a thickness of 18 μm is prepared, and this etching stopper layer ES is prepared. A metal plate (copper plate) 81A is laminated and integrated on the side to obtain a clad material having a three-layer structure as shown in FIG. Then, an etching mask 89 is formed at a predetermined position on the metal plate 81A.

  Next, the three-layer clad metal plate 81A on which the etching mask 89 is formed is etched with an etchant that can etch only copper. As a result, as shown in FIG. 9B, an interlayer connector 81 can be obtained. Then, the etching stopper layer ES is removed by etching using the formed interlayer connector 81 as a mask. As a result, the material shown in FIG. 9C is obtained. In the following steps, the material shown in FIG. 9C may be replaced with the material shown in FIG. 3A, and the steps shown in FIG. The above description is the same for the portion composed of the wiring layer 25 and the interlayer connector 85.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 10 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to still another embodiment of the present invention. In FIG. 10, the same or equivalent parts as those already described are denoted by the same reference numerals, and the description thereof is omitted. In this embodiment, instead of the interlayer connection bodies 31 and 35 of the component built-in wiring board shown in FIG. 1, a shape made of a conductive composition and having an axis that coincides with the laminating direction and whose diameter does not change in the axial direction. The interlayer connection bodies 91 and 95 are used.

  Hereinafter, the manufacturing process of the component built-in wiring board shown in FIG. 10 will be described with reference to FIG. FIG. 11 is a process diagram schematically showing a partial manufacturing process of the component built-in wiring board shown in FIG. 10, in which the insulating layer 11, the wiring layers 21 and 22 on both sides thereof, and the layers penetrating the insulating layer 11. The manufacturing process of the part of the connection body 91 is shown.

  First, as shown in FIG. 11A, for example, a predetermined position of a prepreg 11 </ b> A having a nominal thickness of 100 μm is formed, and the inside of the hole is filled with a conductive composition to form an interlayer connector 91. Next, as shown in FIG. 11B, metal foils (electrolytic copper foils) 21A, 22A having a thickness of, for example, 18 μm are laminated on both surfaces of the prepreg 11A, and are integrated by pressing and heating. By this lamination and integration, the respective metal foils 21A and 22A establish electrical continuity with the interlayer connector 91, and the prepreg 11A is completely cured to become the insulating layer 11.

  Next, as shown in FIG. 11C, the metal foil 22A on one side is subjected to patterning by, for example, well-known photolithography, and processed into a wiring layer 22 (including mounting lands). The material shown in FIG. 11C is used instead of the material shown in FIG. 3D, and the subsequent steps are the same as those described in FIG. The above description is the same for the insulating layer 15, the wiring layers 25 and 26 on both sides thereof, and the portion of the interlayer connector 95 that penetrates the insulating layer 15.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 12 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to still another embodiment of the present invention. In FIG. 12, parts that are the same as or equivalent to those already described are given the same reference numerals, and descriptions thereof are omitted. In this embodiment, instead of the interlayer connection bodies 31 and 35 of the component built-in wiring board shown in FIG. 1, the interlayer connection is made of metal and has a shape that has an axis that coincides with the stacking direction and does not change its diameter in the axial direction. The bodies 101 and 105 are used.

  Hereinafter, the manufacturing process of the component built-in wiring board shown in FIG. 12 will be described with reference to FIG. FIG. 13 is a process diagram schematically showing a partial manufacturing process of the component built-in wiring board shown in FIG. 12. In the above description, the wiring layer 22 (more precisely, the metal processed into the wiring layer 22) is shown. The manufacturing process of the part which consists of foil 22A) and the interlayer connection body 101 is shown.

  First, as shown in FIG. 13A, a plating prevention mask 109 having a mask removal portion 109A at a predetermined position is formed on a metal foil (electrolytic copper foil) 22A having a thickness of 18 μm, for example. The shape of the mask removal unit 109A is, for example, a substantially cylindrical shape. Next, an electrolytic plating process is performed on the plating prevention mask 109 side using the metal foil 22A as an electric supply path, and as shown in FIG. 13B, for example, a copper plating layer is grown in the mask removal portion 109A. This grown plating layer becomes the interlayer connection body 101. After the plating layer is grown, the plating block mask 109 is removed to obtain a material as shown in FIG. In the following steps, the material shown in FIG. 13C may be replaced with the material shown in FIG. 3A, and the steps shown in FIG. The above description is the same for the portion composed of the wiring layer 25 and the interlayer connector 104.

  8 to 13, the double-sided wiring board portion including the insulating layer 11 and the wiring layers 21 and 22 on both sides thereof, and the double-sided wiring board portion including the insulating layer 15 and the wiring layers 25 and 26 on both sides thereof. The examples are shown from the viewpoint of the structure of the interlayer connector. Of course, a double-sided wiring board having an interlayer connection other than those described above may be used. For example, the interlayer connection body may be a well-known through-hole inner wall conductor formed by a drilling and plating process. Furthermore, a double-sided wiring board having various other configurations of the interlayer connector can be used.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 14 is a cross-sectional view schematically showing a configuration of a component built-in wiring board according to still another embodiment of the present invention. In FIG. 14, parts that are the same as or equivalent to those already described are given the same reference numerals, and descriptions thereof are omitted. In this embodiment, the component built-in wiring board shown in FIG. 1 has a configuration in which there is no portion above the insulating layer 14 (interlayer connector 34, wiring layer 25, insulating layer 15, interlayer connector 35, wiring layer 26). Thus, the side opposite to the mounting side of the chip component 41 is exposed. As a component built-in wiring board, the thickness is suppressed as much as possible.

  FIG. 15 is a process diagram schematically showing a part of the manufacturing process of the component built-in wiring board shown in FIG. Components that are the same as or equivalent to the components shown in the drawings already shown are denoted by the same reference numerals. FIG. 15 shows a lamination process corresponding to FIG. 5, and as shown, the same wiring board materials 1 and 2 as those described with reference to FIGS. 1 to 5 can be used.

  In this lamination step, a release sheet 141 is used on the upper side of the lamination. As a result, a slight protrusion such as the wiring layer 24 is absorbed on the upper side surface so that the release sheet 141 adheres. The prepreg 12 </ b> A obtains fluidity by heating at the time of lamination, and the prepreg 12 </ b> A deforms and enters the space around the chip component 41 and the space inside the through-hole conductor 33. After the lamination process, the release sheet is removed. The height of the chip component 41 is adjusted to the upper side of the insulating layer 13, and thereby the surface of the chip component 41 is exposed.

Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on one Embodiment of this invention. The enlarged view which shows typically the structure of the connection part 51 in the component built-in wiring board shown in FIG. 1, and its formation process. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. Process drawing which shows another part of manufacturing process of the component built-in wiring board shown in FIG. FIG. 9 is a process diagram schematically showing still another part of the manufacturing process of the component built-in wiring board shown in FIG. 1. Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on another embodiment of this invention. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on another embodiment of this invention. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on another embodiment of this invention. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on another embodiment of this invention. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. Sectional drawing which shows typically the structure of the component built-in wiring board which concerns on another embodiment of this invention. Process drawing which shows a part of manufacturing process of the component built-in wiring board shown in FIG. 14 with a typical cross section.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wiring board material, 2 ... Wiring board material, 3 ... Wiring board material, 11 ... Insulating layer, 11A ... Prepreg, 12 ... Insulating layer, 12A ... Prepreg, 13 ... Insulating layer, 14 ... Insulating layer, 14A ... Prepreg, DESCRIPTION OF SYMBOLS 15 ... Insulating layer, 21 ... Wiring layer (metal wiring pattern), 21A ... Metal foil (copper foil), 22 ... Wiring layer (metal wiring pattern), 22A ... Metal foil (copper foil), 23 ... Wiring layer (metal wiring) Pattern), 23A ... metal foil (copper foil), 24 ... wiring layer (metal wiring pattern), 24A ... metal foil (copper foil), 25 ... wiring layer (metal wiring pattern), 26 ... wiring layer (metal wiring pattern) , 31 ... interlayer connection (conductive bump by conductive composition printing), 32 ... interlayer connection (conductive bump by conductive composition printing), 33 ... through-hole conductor, 34 ... interlayer connection (conductive) Conductive van by composition printing ), 35... Interlayer connection body (conductive bump by conductive composition printing), 41... Chip component (electric / electronic component), 51... Connection (solder), 51 A. Cream solder, 61. ... through holes, 72, 74 ... interlayer connection (metal bump formed by metal plate etching), 72A ... metal plate (copper plate), 81,85 ... interlayer connection (metal bump formed by metal plate etching), 81A ... metal plate (copper plate), 89 ... etching mask, 91,95 ... interlayer connector (filled with conductive composition), 101,105 ... interlayer connector (conductor bump formed by plating), 109 ... plating prevention mask 109A ... mask removal part, 141 ... release sheet, ES ... etching stopper, 501 ... solder grain, 502 ... copper grain, 503 ... flux, 501A ... tin Field portion, 502A ... surface copper - copper particles covered with tin compounds.

Claims (14)

A first insulating layer of epoxy resin;
A second insulating layer of an epoxy-based resin located in a laminated form with respect to the first insulating layer;
A chip component embedded in the second insulating layer, provided with electrodes as terminals at both ends ;
A wiring pattern including a land for mounting the chip component provided between the first insulating layer and the second insulating layer;
Connected between the chip component terminal and the mounting land of the wiring pattern , and made of solder containing particles of the metal whose surface is covered with a compound consisting of a metal having a higher melting point than tin and tin. comprising a connecting portion, the,
The chip component is embedded in the second insulating layer so that no void is generated around the chip component, and the terminal of the chip component is connected to the wiring pattern via the connection portion. the wiring board, characterized in that it is connected to the mounting land.   2. The component built-in wiring board according to claim 1, wherein the metal grains are copper grains.   The component built-in wiring board according to claim 1, wherein the solder of the connection portion is lead-free.   3. The component built-in wiring board according to claim 2, wherein the solder of the connecting portion is an alloy containing tin, silver, and copper except for the copper grain portion.   3. The component built-in wiring board according to claim 2, wherein the solder of the connection portion is 5 wt% to 50 wt% as a ratio of the copper grain portion.   3. The component built-in wiring board according to claim 2, wherein the solder of the connection portion has a diameter of 3 to 40 μm as the diameter of the copper particles. The second insulating layer is a stack of at least two insulating layers;
A second wiring pattern provided between the at least two insulating layers;
The second insulating layer penetrates a part in the stacking direction and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, and is made of a conductive composition and coincides with the stacking direction. 2. The component built-in wiring board according to claim 1, further comprising: an interlayer connection body having a shaft that has a shape that changes in diameter in a direction of the shaft. The second insulating layer is a stack of at least two insulating layers;
A second wiring pattern provided between the at least two insulating layers;
An axis that penetrates a part of the second insulating layer in the stacking direction and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, is made of metal, and coincides with the stacking direction. The component built-in wiring board according to claim 1, further comprising: an interlayer connection body having a shape that has a diameter that changes in a direction of the axis. A second wiring pattern provided on the side of the first insulating layer opposite to the side on which the wiring pattern is located;
An axis that penetrates the first insulating layer and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, is made of a conductive composition, and coincides with the stacking direction. 2. The component built-in wiring board according to claim 1, further comprising an interlayer connection body having a shape whose diameter changes in a direction of the axis. A second wiring pattern provided on the side of the first insulating layer opposite to the side on which the wiring pattern is located;
An axis that penetrates the first insulating layer and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, is made of metal, and has an axis that coincides with the stacking direction. The component built-in wiring board according to claim 1, further comprising an interlayer connection body having a shape whose diameter changes in the direction. A second wiring pattern provided on the side of the first insulating layer opposite to the side on which the wiring pattern is located;
An axis that penetrates the first insulating layer and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, is made of a conductive composition, and coincides with the stacking direction. 2. The component built-in wiring board according to claim 1, further comprising an interlayer connection body having a shape whose diameter does not change in the direction of the axis. A second wiring pattern provided on the side of the first insulating layer opposite to the side on which the wiring pattern is located;
An axis that penetrates the first insulating layer and is sandwiched between the surface of the wiring pattern and the surface of the second wiring pattern, is made of metal, and has an axis that coincides with the stacking direction. The component built-in wiring board according to claim 1, further comprising an interlayer connection body having a shape whose diameter does not change in the direction. Wherein the chip component of the surface of the connecting portion by the chip component side opposite to the side of the chip component connected to the wiring pattern, exposed and wherein the has claim 1, wherein the component-incorporated wiring Board. Claims wherein the side of the chip component the chip component by the connection portion is connected to the wiring pattern the chip components on the surface of the opposite side, characterized in that they are hidden by the second insulating layer Item 1. The component built-in wiring board according to Item 1.

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