JP2008135483A - Substrate incorporating electronic component and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate incorporating electronic component that can reduce the complication in a manufacturing step and improve the degree of freedom in the position of electrical connection between wiring patterns of facing wiring boards, and to provide its manufacturing method. <P>SOLUTION: In the substrate incorporating electronic component, wiring boards 1 and 2 with wiring patterns 10 and 20 formed on one surface in the direction of thickness are opposed each other in the direction of thickness so that the joint parts 10a and 20a of the respective wiring patterns 10 and 20 may be overlapped each other, and an active element 50 and a passive element 51 to be incorporated between the wiring boards 1 and 2 are mounted on a second wiring board 2 and a to a first wiring board 1, respectively. An insulation part 6 made of insulative resin is interposed between the wiring boards 1 and 2 to cover both active element 50 and passive element 51, and a metal ball 7 is also interposed between the wiring boards 1 and 2 so as to keep a distance between the wiring boards 1 and 2 at a regulated distance that is set larger than a mounting dimension for both active element 50 and passive element 51, as well as to electrically connect the joint parts 10a and 20a with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic component built-in substrate having an electronic component built therein and a method of manufacturing the same.

  In recent years, there has been an increasing demand for downsizing and thinning of electronic devices, and higher functions and higher frequencies (higher operating speed) of electronic devices have been promoted. In order to respond to such trends in electronic devices, various electronic component (circuit component) mounting structures and substrate structures have been proposed that realize miniaturization and high frequency compatibility. Among them, the electronic component built-in substrate having a structure in which the electronic component is embedded in the substrate has the advantage that it can be miniaturized by the three-dimensional component arrangement and can further reduce the wiring distance between the electronic components. Is one of the technologies.

  As this type of electronic component-embedded substrate, for example, as shown in FIG. 5, a first wiring board 110 on which electronic components 101 and 102 are mounted on one surface side (upper surface side in FIG. 5), and a first wiring The second wiring board 120 disposed opposite to the one surface of the board 110 and the opening 131 for arranging the electronic components 101 and 102 are interposed between the first wiring board 110 and the second wiring board 120. There has been proposed one including an inner layer wiring board 130 and an insulating portion 140 made of an insulating resin filled in a space between the first wiring board 110 and the second wiring board 120 ( For example, Patent Document 1).

  Here, a first wiring pattern 111 is formed on the one surface of the first wiring board 110, and a first external electrode 112 is formed on the other surface (the lower surface in FIG. 5). The first external electrode 112 is electrically connected to the first wiring board 110 by a first via 113 penetrating in the thickness direction (vertical direction in FIG. 5).

  A second external electrode 121 is formed on one surface (upper surface in FIG. 5) of the second wiring board 120, and a second wiring pattern 122 is formed on the other surface (lower surface in FIG. 5). 122 and the second external electrode 121 are electrically connected to the second wiring board 120 by a second via 123 penetrating in the thickness direction.

  A third wiring pattern 132 is formed on one surface (upper surface in FIG. 5) of the inner layer wiring board 130, and a fourth wiring pattern 133 is formed on the other surface (lower surface in FIG. 5). The fourth wiring pattern 133 is electrically connected to the inner wiring board 130 by a third via 134 penetrating in the thickness direction.

  In the electronic component built-in substrate having the configuration shown in FIG. 5 described above, the electronic components 101 and 102, the second wiring pattern 122 of the second wiring board 120, the first wiring pattern 111, and the fourth wiring The pattern 133, the via 134, and the third wiring pattern 132 are electrically connected.

On the other hand, as the electronic component built-in substrate, instead of using the inner layer wiring board 130 having the opening 131 for arranging the electronic components 101 and 102, the first and second wiring boards 110 and 120 are for accommodating electronic components. The thing using the multilayer wiring board (multilayer printed wiring board) in which the component accommodating part was formed is proposed (for example, patent document 2). Here, in the multilayer wiring board, a wiring pattern is formed on both sides in the thickness direction so that an electronic component is mounted, and a wiring pattern for connection with at least one other multilayer wiring board is formed on one surface in the thickness direction. The other surface in the thickness direction has an inner wiring board joined to the outer wiring board. The inner wiring board has an opening for forming a concave component housing portion for housing an electronic component mounted on the outer wiring board in the thickness direction, and the wiring pattern of the inner wiring board and the outer wiring board. Vias for electrically connecting the electronic components mounted on the through holes are provided in the thickness direction.
JP-A-2005-191156 (refer mainly to paragraph numbers [0016] to [0021] and FIG. 1) JP 11-103147 A (refer mainly to paragraph numbers [0015] to [0018] and FIG. 2)

  By the way, in the electronic component built-in substrate as shown in FIG. 5, the inner wiring board 130 electrically connects the first wiring pattern 111 of the first wiring board 110 and the second wiring pattern 122 of the second wiring board 120. And a space for incorporating the electronic components 101 and 102 is formed between the first wiring board 110 and the second wiring board 120.

  Therefore, it is necessary to provide the above-described opening 131 and the via hole for forming the via 134 in the inner wiring board 130, and a lot of drilling processes must be performed, which makes the manufacturing process complicated. There was a problem.

  Furthermore, when forming the via 134, if the via 134 is formed at the opening edge of the opening 131, the inner wiring board 130 may be damaged when the via 134 is formed. Since the position where the via 134 is provided is restricted because it is necessary to provide the device at a certain distance from the 131, the degree of freedom in the position of electrical connection between the wiring patterns 111 and 122 of the opposing wiring boards 110 and 120 is consequently limited. Decreases. Moreover, since the distance between the via 134 and the electronic components 101 and 102 is long under such a restriction, when the electronic components 101 and 102 and the via 134 are to be electrically connected, the inner layer The electric path between the electronic components 101 and 102 and the via 134 in the third and fourth wiring patterns 131 and 132 of the wiring board 130 becomes long.

  Further, when the number of electronic components increases, for example, it is necessary to increase the size of the opening 131 so that all the electronic components can be arranged inside, so that the manufacturing process is further complicated. Further, if the size is the same, the area for forming the third and fourth wiring patterns 131 and 132 and the via 134 is reduced, and the position where the via 134 is formed is further restricted.

  On the other hand, even in the electronic component built-in substrate as disclosed in Patent Document 2 described above, it is necessary to provide an opening or via for the component housing portion for housing the electronic component in the inner wiring board. As in the case of the electronic component built-in substrate disclosed in FIG. 1, the manufacturing process is complicated because it is necessary to drill holes such as openings and vias, and the positions where vias are provided are limited. There is a problem that the degree of freedom in the position of electrical connection between the wiring patterns of the multilayer wiring board is low. After all, the problem of the electronic component built-in substrate as shown in FIG. 5 has not been solved even in the electronic component built-in substrate as disclosed in Patent Document 2.

  The present invention has been made in view of the above points, and an object of the present invention is to reduce the complexity of the manufacturing process and to improve the degree of freedom of the electrical connection position between the wiring patterns of the opposing wiring boards. An object is to provide a built-in substrate and a manufacturing method thereof.

  In order to solve the above-described problem, in the invention of claim 1, at least a part of the wiring patterns of the wiring boards facing each other in the thickness direction is a plurality of wiring boards having wiring patterns formed on at least one surface in the thickness direction. An electronic part that is arranged in a form that overlaps and is built in between at least one wiring board is mounted on at least one wiring board, and an insulating part that is made of an insulating resin and covers the electronic part between the opposing wiring boards In the electronic component built-in board, wherein the distance between the wiring boards is kept at a specified distance set larger than the mounting height dimension of the electronic parts, and the opposing wirings are interposed between the opposing wiring boards. A metal ball for electrically connecting the portions of the wiring pattern of the plate is interposed.

  According to the first aspect of the present invention, the distance between the wiring boards facing each other by the metal balls is maintained at a specified distance set larger than the mounting height dimension of the electronic component, and the wiring patterns of the wiring boards facing each other are electrically connected. As a result, there is no need to form openings for placing electronic components inside and vias for electrically connecting the wiring patterns of opposing wiring boards as in the prior art. This eliminates the need for drilling holes, so that it is possible to reduce the complexity of the manufacturing process. In addition, unlike vias that require drilling, the metal balls have a high degree of freedom in the positions to be provided. There is an effect that the degree of freedom of the electrical connection position of the wiring pattern can be improved. In addition, since the distance between the facing wiring boards is determined by a metal ball whose diameter does not vary during pressurization, the prescribed distance can be set to a desired length.

  According to a second aspect of the invention, in the first aspect of the invention, the metal ball is fixed and electrically connected to the wiring pattern by solder.

  According to the second aspect of the present invention, the bonding reliability between the metal ball and the wiring pattern can be improved, and further the bonding reliability can be improved by bonding the solder and the wiring pattern. There is an effect that the reliability of the electrical connection with the pattern can be improved.

  The invention of claim 3 is characterized in that, in the invention of claim 2, each wiring board is formed of Au at a portion of the wiring pattern in contact with the metal ball.

  According to the invention of claim 3, it is possible to improve the bonding reliability between the solder and the wiring pattern and to further improve the reliability of the electrical connection between the metal ball and the wiring pattern.

  The invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the insulating resin is an epoxy resin filled with a filler.

  According to the invention of claim 4, since the epoxy resin is an insulating resin having good fluidity, for example, an insulating resin sheet serving as a base of the insulating portion is disposed between the facing wiring boards, and the insulating resin When the insulating portion is interposed between the wiring boards by pressurizing the sheet in a softened state, it is possible to prevent the occurrence of voids in the insulating portion, and the hardness of the insulating portion can be improved by the filler. There is an effect that the hardness of the entire electronic component built-in substrate can be improved.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the electronic component has at least an active element, and the active element is flip-chip mounted on one of the opposing wiring boards. It is characterized by that.

  According to the invention of claim 5, since the active element is flip-chip mounted, the mounting area can be reduced and the mounting height dimension of the active element can be reduced as compared with the case of mounting using a bonding wire. There is an effect that the size can be reduced.

  In invention of Claim 6, in any one of Claims 1-5, each wiring board is formed using a glass epoxy board | substrate, and insulating resin is the epoxy resin with which the filler was filled. It is characterized by being.

  According to the invention of claim 6, since both the wiring board and the insulating part are formed of a material mainly made of epoxy resin, the difference in linear expansion coefficient between the wiring board and the insulating part can be reduced. This has the effect of reducing the warpage. In addition, since the epoxy resin is an insulating resin with good fluidity, for example, an insulating resin sheet that is the basis of the insulating portion is disposed between opposing wiring boards, and the insulating resin sheet is softened. When the insulating part is interposed between the wiring boards by pressurizing, the effect of preventing the generation of voids in the insulating part can be obtained, and the hardness of the insulating part can be improved by the filler. There is an effect that the hardness of the can be improved.

  The invention according to claim 7 is the method for manufacturing an electronic component built-in substrate according to any one of claims 1 to 6, wherein the electronic component to be built in between the facing wiring boards is mounted on at least one wiring board. And a mounting step of mounting the metal ball on the part of any wiring pattern of the wiring board facing the wiring board, and the wiring board mounting the electronic component and the metal ball mounted by the mounting step. A laminating step of placing the facing wiring boards facing each other with the insulating resin sheet serving as the foundation of the insulating portion interposed between the laminating step and the facing wiring board so that at least some of the wiring patterns overlap with each other The insulating resin sheet disposed in the space between the facing wiring boards is pressurized through the wiring board in a heated state, and the opposing resin is interposed through the insulating portion. Characterized in that it has a unifying step of electrically connecting the portion between the wiring board wiring pattern for the face by the metal balls with integrating the wiring board that.

  According to the invention of claim 7, when the insulating resin sheet is pressed, the electronic component can be embedded between the opposing wiring boards and the electrical connection between the wiring patterns by the metal balls can be performed at the same time, thereby shortening the manufacturing process. There is an effect that can be made.

  According to an eighth aspect of the present invention, in the seventh aspect of the invention, an active element and a passive element are provided as electronic components built in between the facing wiring boards, and the wiring board to be opposed is provided in the mounting step. An active element is mounted on one of the two, and a passive element is mounted on the other of the facing wiring boards.

  According to the eighth aspect of the present invention, when an active element and a passive element are provided as electronic components incorporated between opposing wiring boards, the wiring board for mounting the active element and the wiring board for mounting the passive element are provided. Because it is a separate wiring board, compared to the case where active elements and passive elements are mixed in one wiring board, it has the effect that the specifications of the wiring board can be simplified, and the process of mounting electronic components on the wiring board There is an effect that can be simplified.

  The present invention keeps the distance between the wiring boards facing each other by the metal balls at a specified distance set larger than the mounting height dimension of the electronic component, and electrically connects the wiring patterns of the facing wiring boards. In addition to the effect that the complexity of the manufacturing process can be reduced, the effect that the degree of freedom of the electrical connection position of the wiring pattern can be improved, and the effect that the specified distance can be set to a desired length is achieved. .

(Embodiment 1)
As shown in FIG. 1 (d), the electronic component built-in substrate according to the present embodiment has a plurality of electronic components between two wiring boards 1 and 2 that are opposed to each other in the thickness direction (vertical direction in FIG. 1 (d)). Components 50 and 51 are incorporated, and a wiring pattern 10 formed on one surface of one wiring board 1 and a wiring pattern 20 formed on one surface of the other wiring board 2 are electrically connected by a metal ball 7. Has been. The distance between the wiring boards 1 and 2 is maintained by the metal ball 7 at a specified distance set larger than the mounting height dimension of the electronic components 50 and 51. Further, an insulating portion 6 is interposed between the wiring boards 1 and 2 so as to cover the electronic components 50 and 51.

  An electronic component 51 mounted on one wiring board (hereinafter referred to as “first wiring board”) 1 is an active element such as an IC, and uses, for example, a bare chip to reduce the thickness. . As the bare chip, a wafer that is processed to a thickness of about 500 μm to 100 μm by polishing the wafer is used. An electronic component 50 mounted on the other wiring board (hereinafter referred to as “second wiring board”) 2 is an active element such as a resistor, a capacitor, or an inductor, and is, for example, 0603 parts (chip size is 0.6 mm). X0.3mm) and other surface mount chip components are used.

  As shown in FIG. 1A, the first wiring board 1 and the second wiring board 2 are each a glass epoxy having a thickness of about 0.1 mm to 1.0 mm in which a copper foil is formed on both surfaces in the thickness direction. The wiring patterns 10, 11, 20, and 21 are formed by appropriately patterning the copper foil, which is formed using the substrates 1a and 2a.

  A wiring pattern (hereinafter referred to as “first wiring pattern”) 10 formed on one surface in the thickness direction of the first wiring board 1 (upper surface in FIG. 1A) is referred to as the second wiring board 2. A connecting portion (hereinafter, referred to as “metal ball 7”) for electrical connection with a wiring pattern (hereinafter referred to as “third wiring pattern”) 20 on one surface in the thickness direction (the upper surface in FIG. 1 (a)). A plurality (four in the illustrated example) 10a (referred to as "first connection portions") are provided. The first wiring pattern 10 and a wiring pattern (hereinafter referred to as “second wiring pattern”) 11 formed on the other surface in the thickness direction of the first wiring board 1 (the lower surface in FIG. 1A). Is electrically connected to the first wiring board 1 by a through-hole wiring (hereinafter referred to as “first through-hole wiring”) 12 penetrating in the thickness direction.

  The third wiring pattern 20 formed on one surface in the thickness direction of the second wiring board 2 (the upper surface in FIG. 1A) is connected to the metal balls 7 mounted on each first connection portion 10a. A plurality of connecting portions (hereinafter, “second connecting portions”) 20a are provided (four in the illustrated example). The third wiring pattern 20 and a wiring pattern (hereinafter referred to as “fourth wiring pattern”) 21 formed on the other surface in the thickness direction of the second wiring board 2 (the lower surface in FIG. 1A). Is electrically connected to the second wiring board 2 by a through-hole wiring (hereinafter referred to as “second through-hole wiring”) 22 penetrating in the thickness direction.

  Incidentally, a Ni layer (not shown) and an Au layer (not shown) are formed on the surfaces of the wiring patterns 10 and 20 by plating with the Au layer as the outermost surface side. The Ni layer and the Au layer are not necessarily provided on the entire surface of the wiring patterns 10 and 20, but are provided on the surfaces of the connection portions 10a and 20a that are at least contact portions with the metal balls 7 in the wiring patterns 10 and 20. It only has to be done.

  The insulating portion 6 is formed using an insulating resin formed by filling an epoxy resin with a filler (for example, an inorganic filler such as alumina or silica). Such an insulating resin can adjust a linear expansion coefficient by the filling amount of the filler, and the linear expansion coefficient is the glass epoxy substrate 1a which is the basis of the first wiring board 1 and the second wiring board 2. , 2a is preferably set to such a value that the difference from the linear expansion coefficient becomes small. By the way, in interposing the insulating part 6 between the first wiring board 1 and the second wiring board 2, as shown in FIG. 1C, an insulating resin sheet ( Organic sheet) 60 is used. Here, the insulating resin sheet 60 is formed to have a thickness of about 100 μm and the same size as the first wiring board 1 and the second wiring board 2.

  The metal ball 7 is, for example, a metal material (preferably Cu) that does not melt at a temperature during heat treatment (for example, heat treatment in a mounting process or an integration process described later) performed in the manufacturing process of the electronic component built-in substrate of the present embodiment. , Au, etc.), and the diameter thereof is larger than both the mounting height dimensions of the electronic components 50 and 51 (in the illustrated example, the mounting height dimensions of the electronic components 50 and 51 are substantially equal). (In this embodiment, the length is set to be equal to the set specified distance). However, the diameter of the metal ball 7 is not required to be strictly equal to the specified dimension. The metal balls 7 are not limited to those formed entirely of a metal material. For example, the entire surface of the sphere surface of a core ball formed into a sphere using a material that does not have conductivity. It may be formed by forming a metal layer having a predetermined thickness. In this case, as the material for the core ball and the material for the metal layer, those that do not melt at the temperature at the time of heat treatment performed in the manufacturing process of the electronic component built-in substrate of this embodiment are used.

  Incidentally, a solder layer 82 having a thickness of about 20 μm to 200 μm (preferably 25 μm to 30 μm) is provided on the spherical surface of the metal ball 7 in order to improve the reliability of electrical connection with the wiring patterns 10 and 20. It is formed so as to cover the entire surface of the sphere. The solder layer 82 is formed using, for example, Sn—Au or Sn—Zn solder.

  Next, the manufacturing method of the electronic component built-in substrate of this embodiment will be described with reference to FIG. In the manufacturing method of the electronic component built-in substrate according to the present embodiment, first, the electronic component 50 to be incorporated between the facing wiring boards 1 and 2 is the second wiring board 2, and the electronic component 51 is the first wiring board 1. An electronic component mounting process for mounting and a metal ball mounting process for mounting the metal ball 7 on the first wiring pattern 10 of the first wiring board 1 are performed. In the present embodiment, the mounting process is composed of an electronic component mounting process and a metal ball mounting process. Note that either the electronic component mounting process or the metal ball mounting process may be performed first or in parallel.

  In the electronic component mounting process, as shown in FIG. 1B, the electronic component 51 is mounted on the first wiring board 1 by fixing and electrically connecting the electronic component 51 to the first wiring pattern 10 by reflow soldering or the like. Have a process to do. In the electronic component mounting process, the second wiring board is formed by fixing and electrically connecting the electronic component 50 to the third wiring pattern 20 by a bump (for example, Au bump) 80 made of a stud bump or a plating bump. 2 has a process of flip chip mounting. Further, when the electronic component 50 is flip-chip mounted, in order to improve the bonding reliability of the bump 80 (relaxation of stress generated in the electronic component 50 and prevention of the electronic component 50 from falling off), the electronic component 50 and the second component 50 are connected. An underfill layer 81 is interposed between the wiring board 2 and an underfill material (for example, epoxy resin).

  In the metal ball mounting process, as shown in FIG. 1B, the metal ball 7 is fixed to each of the first connection portions 10a of the first wiring pattern 10 by using the same solder as the solder layer 82. Is a process of mounting on the first wiring board 1 by connecting to (in the illustrated example, the solder used for mounting the metal balls 7 is integrated with the solder layer 82). In the present embodiment, since the outermost layer of the first wiring pattern 10 is made of an Au layer, Sn contained in the solder layer 82 diffuses into the Au layer (metal bonding is performed), whereby the solder layer 82 and the first layer are connected. The reliability of bonding with the wiring pattern 10 is improved.

  Thereafter, as shown in FIG. 1C, the electronic component 50 mounted on the second wiring board 2 by the mounting process, the electronic component 51 mounted on the first wiring board 1, and the first The metal ball 7 mounted on the wiring board 1 is positioned in the space between the wiring boards 1 and 2, and the connection portions 10 a and 20 a are overlapped with each other in the thickness direction so that the first wiring board 1 and the second wiring board 1 are connected. A laminating process is performed in which the wiring board 2 and the insulating resin sheet 60 are disposed opposite to each other. Here, the insulating resin sheet 60 is disposed in a space between the first wiring board 1 and the second wiring board 2 so as to overlap the electronic components 50 and 51 and the metal balls 7 in the thickness direction. By the way, the insulating resin sheet 60 is arranged in a space between the first wiring board 1 and the second wiring board 2 in a state where a plurality (5 in the illustrated example) are stacked in the thickness direction. At this time, the total thickness dimension of the insulating resin sheet 60 is set to a value larger than the diameter dimension of the metal ball 7, so that the space between the first wiring board 1 and the second wiring board 2 is excessive. It can be filled without any shortage.

  Subsequently, by pressurizing the insulating resin sheet 60 through the first wiring board 1 in a state where the insulating resin sheet 60 arranged in the space between the wiring boards 1 and 2 opposed by the laminating process is heated, In addition to integrating the wiring boards 1 and 2 with the insulating portion 6, an integration step of electrically connecting the connection portions 10 a and 20 a of the wiring patterns 10 and 20 of the wiring boards 1 and 20 with the metal ball 7 is performed. More specifically, in the integration step, the wiring boards 1 and 2 and the insulating resin sheet 60 laminated in the lamination step are about 100 to 150 ° C. in the vacuum atmosphere (insulating properties constituting the insulating resin sheet 60). The insulating resin sheet 60 is softened (melted) by heating to a temperature at which the resin softens. After this, while maintaining the heated state (while maintaining the softened state of the insulating resin sheet 60), the insulating resin softened by secondly pressing the first wiring board 1 toward the wiring board 2 The sheet 60 is pressurized. The pressing of the first wiring board 1 to the second wiring board 2 side pushes the insulating resin sheet 60 softened by the metal balls 7 so that each metal ball 7 is connected to each second connection of the third wiring pattern 20. The process is performed until the respective parts 20a are contacted.

  Here, when the metal ball 7 comes into contact with the second connecting portion 20a, the solder layer 82 covering the surface of the metal ball 7 breaks the oxide film on the surface and exposes new solder to the surface. Since the metal ball 7 is crushed between the second connecting portion 20a and spreads on the surface of the second connecting portion 20a, the contact area between the solder layer 82 and the second connecting portion 20a increases. This improves the bonding reliability. Therefore, the thicker the solder layer 82 is, the more solder is crushed between the metal ball 7 and the second connecting portion 20a, so that the contact area is increased and the bonding reliability can be improved. However, if the thickness of the solder layer 82 is too thick, the solder of the solder layer 82 may protrude from the second connection portion 20a and may short-circuit between the wiring patterns 20 on the same plane. It is necessary to set the thickness of the solder layer 82 so as not to short-circuit between the wiring patterns 20 on the same plane by the solder of the solder layer 82.

  Further, since the outermost layer of the second connection portion 20a of the third wiring pattern 20 is composed of an Au layer, Sn contained in the solder of the solder layer 82 diffuses into the Au layer (metal bonding is performed), thereby Bonding reliability is further improved. Moreover, in this integration process, in order to soften the insulating resin sheet 60, the plurality of insulating resin sheets 60 are fused and integrated.

  As described above, after the first wiring board 1 is pressed toward the second wiring board 2 and the respective metal balls 7 are brought into contact with the respective second connection portions 20a of the third wiring pattern 20, While maintaining the contact state, at least the insulating resin sheet 60 is heated and cured to about 150 ° C. to 200 ° C. (temperature at which the insulating resin constituting the insulating resin sheet 60 is cured). As described above, the insulating resin sheet 60 is cured to form the insulating portion 6, and the wiring boards 1 and 2 are integrated via the insulating portion 6. As a result, an electronic component built-in substrate as shown in FIG. When the insulating resin sheet 60 is cured, the metal bond (metal bond between Sn and Au contained in the solder) is strengthened by thermal diffusion between the solder layer 82 and the second connection portion 20a, and the bonding reliability is further increased. Improves. In the integration process, a temperature history for melting the solder such as reflow is added as necessary to promote diffusion of Sn contained in the solder of the solder layer 82 into the Au layer of the second connection portion 20a. Further, it is possible to improve the bonding reliability.

  In the electronic component built-in substrate of the present embodiment obtained by the process described above, as shown in FIG. 1D, the two wiring boards 1 and 2 are connected to the connecting portions 10a and 10a of the wiring patterns 10 and 20, respectively. 20a are arranged opposite to each other, and between the wiring boards 1 and 2 facing each other, the distance between the wiring boards 1 and 2 is set to a specified distance set larger than the mounting height dimension of the electronic components 50 and 51. A metal ball 7 is interposed to electrically connect the connecting portions 10a and 20a of the wiring patterns 10 and 20 of the wiring boards 1 and 2 facing each other.

  Therefore, according to the electronic component built-in substrate of the present embodiment, the distance between the wiring boards 1 and 2 facing each other by the metal ball 7 is set larger than the mounting height dimension of the electronic components (active element 50 and passive element 51). Since the distance between the wiring patterns 10 and 20 of the opposing wiring boards 1 and 2 is electrically connected, the openings for arranging the electronic components on the inner side as in the conventional case and the opposing wiring boards Since there is no need to form vias for electrically connecting the wiring patterns and there is no need to perform drilling for these openings and vias, the complexity of the manufacturing process can be reduced, and in addition Unlike the vias that require opening processing, the metal balls 7 have a high degree of freedom in the positions where they are provided, so that the degree of freedom in the electrical connection positions of the wiring patterns 10 and 20 can be improved. In addition, since the distance between the facing wiring boards 1 and 2 is determined by the metal ball 7 whose diameter does not change during pressurization, the distance between the facing wiring boards 1 and 2 is set to a desired distance. it can.

  The metal ball 7 is in contact with each of the connection portions 10a and 20a, and is fixed and electrically connected to the connection portions 10a and 20a by a solder layer 82 made of solder. In addition to improving the bonding reliability between the metal ball 7 and the wiring patterns 10 and 20, the bonding reliability between the solder balls 82 and the wiring patterns 10 and 20 can be further improved. The reliability of electrical connection can be improved. In addition, each wiring board 1, 2 is made of Au at the portion of the wiring patterns 10, 20 that contacts the metal ball 7, so that the bonding reliability between the solder layer 82 and the wiring patterns 10, 20 is improved. Thus, the reliability of electrical connection between the metal ball 7 and the wiring patterns 10 and 20 can be further improved.

  In addition, each of the wiring boards 1 and 2 is formed using glass epoxy substrates 1a and 2a, respectively, and the insulating resin constituting the insulating portion 6 is an epoxy resin filled with a filler. 2 and the insulating portion 6 are both formed of a material mainly composed of epoxy resin, so that the difference in linear expansion coefficient between the wiring boards 1 and 2 and the insulating portion 6 can be reduced, so that the warpage of the electronic component built-in substrate can be reduced. .

  In addition, since the epoxy resin is an insulating resin having good fluidity, an insulating resin sheet 60 serving as the basis of the insulating portion 6 is disposed between the facing wiring boards 1 and 2 in the integration process, thereby insulating the epoxy resin. When the insulating part 6 is interposed between the wiring boards 1 and 2 by pressurizing the resin sheet 60 in a softened state, it is possible to prevent voids from being generated in the insulating part 6, and the hardness of the insulating part 6 by the filler. Therefore, the hardness of the entire electronic component built-in substrate can be improved.

  In addition, since the electronic component 50 is flip-chip mounted on one of the opposing wiring boards (the second wiring board 2 in this embodiment), the mounting area is larger than when mounting using bonding wires. Can be reduced and the mounting height dimension of the active element can be reduced, so that the size can be reduced.

  On the other hand, according to the manufacturing method of the electronic component built-in substrate of the present embodiment, the electronic components 50 and 51 are embedded between the wiring boards 1 and 2 and the wiring pattern 10 by the metal ball 7 is applied during pressurization in the integration process. Since the electrical connection between 20 can be performed simultaneously, the manufacturing process can be shortened. In addition, the electronic component 50 made of an active element is mounted on the second wiring board 2, and the electronic component 51 made of a passive element is mounted on the first wiring board 1, whereby the electronic component 50 and the electronic component 51 are combined. Since they are mounted on different wiring boards 1 and 2, for example, the specifications of the first wiring board 1 as in the case where the electronic component 50 and the electronic component 51 having different mounting methods are mounted on the first wiring board 1 are used. Therefore, the configuration of each of the wiring boards 1 and 2 can be simplified, and when both the electronic parts 50 and 51 are mounted on one wiring board. In comparison, the process of mounting electronic components can be simplified.

(Embodiment 2)
In the electronic component built-in substrate of this embodiment, the first wiring board 1 and the second wiring board 2 are multilayer printed wiring boards (multilayer printed wiring boards) formed by laminating a plurality of substrates in the thickness direction. This is different from the first embodiment. In addition, about the same thing as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The wiring boards 1 and 2 in the present embodiment are, for example, three glass epoxy substrates 1a to 1c and 2a to 2c each having a thickness of about 0.1 mm to 1.0 mm in which a copper foil is formed on both surfaces in the thickness direction. The wiring patterns 10, 11, 13, 20, 21, and 23 are formed by laminating in the thickness direction and appropriately patterning the copper foil.

  A glass epoxy substrate 1a serving as a first outer layer plate is joined to one surface (the lower surface in FIG. 2A) of the glass epoxy substrate 1b serving as an inner layer plate of the first wiring board 1, and the glass epoxy substrate 1b. A glass epoxy substrate 1c serving as a second outer layer plate is bonded to the other surface in the thickness direction (the upper surface in FIG. 2A). A first wiring pattern 10 is formed on one surface in the thickness direction of the glass epoxy substrate 1a, and a second wiring pattern 11 is formed on the other surface in the thickness direction of the glass epoxy substrate 1c. Furthermore, an inner layer wiring pattern 13 is formed on each other surface in the thickness direction of the glass epoxy substrate 1a, both surfaces in the thickness direction of the glass epoxy substrate 1b, and one surface in the thickness direction of the glass epoxy substrate 1c. In addition, the glass epoxy substrates 1a to 1c are each provided with a first through-hole wiring 12, and the first wiring pattern 10 is inserted through the first through-hole wiring 12 and the inner layer wiring pattern 13. And the second wiring pattern 11 are electrically connected.

  A glass epoxy substrate 2a serving as a first outer layer plate is bonded to one surface (upper surface in FIG. 2A) of the glass epoxy substrate 2b serving as an inner layer plate of the second wiring board 2, and the glass epoxy substrate 2b. A glass epoxy substrate 2c serving as a second outer layer plate is bonded to the other surface in the thickness direction (the lower surface in FIG. 2A). A third wiring pattern 20 is formed on one surface in the thickness direction of the glass epoxy substrate 2a, and a fourth wiring pattern 21 is formed on the other surface in the thickness direction of the glass epoxy substrate 2c. Further, an inner layer wiring pattern 23 is formed on each other surface in the thickness direction of the glass epoxy substrate 2a, both surfaces in the thickness direction of the glass epoxy substrate 2b, and one surface in the thickness direction of the glass epoxy substrate 2c. In addition, a second through-hole wiring 22 is provided in each of the glass epoxy substrates 2 a to 2 c, and the third wiring pattern 20 is provided via the second through-hole wiring 22 and the inner layer wiring pattern 23. And the fourth wiring pattern 21 are electrically connected.

  Then, by using the first wiring board 1 and the second wiring board 2 as shown in FIG. 2A, the same mounting process, laminating process, and integrating process as those in the first embodiment are performed, and FIG. The electronic component built-in substrate of the present embodiment as shown in FIG.

  In the electronic component built-in substrate of the present embodiment obtained by the process described above, as shown in FIG. 2B, the two wiring boards 1 and 2 are connected to the connecting portions 10a and 10a of the respective wiring patterns 10 and 20, respectively. The distance between the wiring boards 1 and 2 is set larger than the mounting height of both the active element 50 and the passive element 51 between the wiring boards 1 and 2 facing each other. A metal ball 7 is interposed between the connection patterns 10a and 20a of the wiring patterns 10 and 20 of the wiring boards 1 and 2 facing each other while keeping the specified distance.

  Therefore, according to the electronic component built-in substrate of the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, since the first wiring board 1 and the second wiring board 2 are made of multilayer printed wiring boards, the density of the electronic component built-in substrate can be increased.

  In the present embodiment, the wiring boards 1 and 2 are formed by laminating three glass epoxy substrates 1a to 1c and 2a to 2c, but the number of laminated glass epoxy substrates is three. The number is not limited to two, but may be two, four or more, or only one of the wiring boards 1 and 2 may be a multilayer printed wiring board. Further, the inner layer wiring patterns 13 and 23 may include a resistance pattern or the like.

(Embodiment 3)
As shown in FIGS. 3A and 3B, the electronic component built-in substrate according to the present embodiment includes the third wiring board 3 and the fourth wiring board in addition to the first wiring board 1 and the second wiring board 2. This embodiment is different from the first embodiment in that the wiring board 4 is provided. In addition, about the same thing as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 3A, the wiring boards 3 and 4 are made of glass having a thickness of about 0.1 mm to 1.0 mm in which copper foils are formed on both surfaces in the thickness direction, respectively, like the wiring boards 1 and 2. The wiring patterns 30, 31, 40, 41 are formed by appropriately patterning the copper foil. The wiring patterns 30, 31, 40, 41 are formed by using the epoxy substrates 3a, 4a.

  A wiring pattern (hereinafter referred to as “fifth wiring pattern”) 30 formed on one surface (the lower surface in FIG. 3A) in the thickness direction of the third wiring board 3 includes the first wiring board 1. A plurality of (two in the illustrated example) 30a connecting portions (hereinafter referred to as "fifth connecting portions") on which the metal balls 7 for electrical connection with the third wiring pattern 11 are mounted are provided. . The fifth wiring pattern 30 and the outer wiring pattern 31 formed on the other surface (upper surface in FIG. 3A) in the thickness direction of the third wiring board 3 are formed on the third wiring board 3 with the thickness. They are electrically connected by through-hole wiring 32 penetrating in the direction. The sixth wiring pattern 40 formed on one surface in the thickness direction of the fourth wiring board 4 (upper surface in FIG. 3A) is electrically connected to the fourth wiring pattern 21 of the second wiring board 2. A plurality (four in the illustrated example) of connecting portions (hereinafter referred to as “sixth connecting portions”) 40a on which the metal balls 7 for connection are mounted are provided. The sixth wiring pattern 40 and the outer wiring pattern 41 formed on the other surface in the thickness direction of the fourth wiring board 4 (the lower surface in FIG. 3A) have a thickness on the fourth wiring board 4. They are electrically connected by through-hole wiring 42 penetrating in the direction.

  On the fifth wiring pattern 30 of the third wiring board 3 described above, the electronic component 52 built in between the opposing wiring boards 1 and 3 is mounted, and the sixth wiring pattern of the fourth wiring board 4 is mounted. 40 is mounted with an electronic component 53 incorporated between the wiring boards 2 and 4 facing each other. The electronic component 52 is a passive element similar to the electronic component 51, and the electronic component 53 is an active element similar to the electronic component 50.

  In the present embodiment, the first wiring board 1 is connected to the second wiring pattern 11 with the metal ball 7 mounted on each of the fifth connection portions 30a (hereinafter, “third connection portion”). This embodiment is different from the first embodiment in that a plurality (two in the illustrated example) 11a are provided.

  On the other hand, the second wiring board 2 in the present embodiment is connected to the fourth wiring pattern 21 with the metal ball 7 mounted on each of the sixth connection portions 40a (hereinafter referred to as “fourth connection”). The second embodiment is different from the first embodiment in that a plurality (four in the illustrated example) 21a are provided.

  In the present embodiment, the Ni layer and the Au layer are formed on the surfaces of the wiring patterns 11, 21, 30, 40 in the same manner as the first wiring pattern 10.

  Next, the manufacturing method of the electronic component built-in substrate according to the present embodiment will be described with reference to FIG. The manufacturing method of the electronic component built-in substrate according to the present embodiment includes a mounting process, a stacking process, and an integration process.

  In the mounting process, the electronic component 51 is provided on the first wiring board 1, the electronic component 50 is provided on the second wiring board 2, the electronic component 52 is provided on the third wiring board 3, and the electronic component 53 is provided on the fourth wiring board 53. The electronic component mounting process and the metal ball mounting process for mounting the metal ball 7 on each of the wiring boards 1, 3, 4. Note that either the electronic component mounting process or the metal ball mounting process may be performed first or in parallel.

  The electronic component mounting process includes a process of mounting each electronic component 51, 52 on each wiring board 1, 3 by fixing and electrically connecting each electronic component 51, 52 to each wiring pattern 10, 30 by reflow soldering or the like. Yes. In the electronic component mounting process, each electronic component 50, 53 is fixed and electrically connected to each wiring pattern 20, 40 by a bump (for example, Au bump) 80 made of a stud bump or a plating bump. It has a process of flip-chip mounting on the wiring boards 2 and 4. When flip-chip mounting the electronic components 50 and 53, the underfill layer 81 is provided between the electronic component 50 and the second wiring board 2 and between the electronic component 53 and the fourth wiring board 4, respectively. Intervene.

  In the metal ball mounting process, each of the wiring boards 1, 3, 4 is respectively fixed by electrically connecting the metal balls 7 to the respective connection portions 10 a, 30 a, 40 a using the same solder as the solder layer 82. (The example shown in the drawing shows a state in which the solder used for mounting the metal ball 7 is integrated with the solder layer 82). At this time, since the outermost layer of each wiring pattern 10, 30, 40 is composed of an Au layer, Sn contained in the solder layer 82 diffuses into the Au layer (metal bonding is performed), and thereby the solder layer 82 and each wiring Bonding reliability with the patterns 10, 30, and 40 is improved.

  In the laminating process, as shown in FIG. 3A, four wiring boards 1 to 4 are laminated, and one set of four wiring boards 1, 2, 1, 3, 2, 4 each In this step, the insulating resin sheet 60 is interposed.

  Below, it demonstrates still in detail about a lamination process. In the stacking process, the electronic component 50 mounted on the second wiring board 2 by the mounting process, the electronic component 51 mounted on the first wiring board 1, and the metal ball 7 mounted on the first wiring board 1. Is placed in the space between the wiring boards 1 and 2, and the first wiring board 1 and the second wiring board 2 are connected to each other in such a manner that the connecting portions 10a and 20a overlap each other in the thickness direction. 60 are arranged opposite to each other. Further, the electronic component 52 and the metal ball 7 mounted on the third wiring board 3 by the mounting process are positioned in the space between the wiring boards 1 and 3, and the connection portions 11a and 30a are overlapped in the thickness direction. Thus, the third wiring board 3 and the first wiring board 1 are arranged to face each other with the insulating resin sheet 60 interposed therebetween. In addition, the electronic component 53 and the metal ball 7 mounted on the fourth wiring board 4 by the mounting process are positioned in the space between the wiring boards 2 and 4, and the connection portions 21a and 40a are overlapped in the thickness direction. In this way, the fourth wiring board 4 and the second wiring board 2 are arranged to face each other with the insulating resin sheet 60 interposed therebetween. Insulating resin sheets 60 are interposed between opposing wiring boards 1, 2, 1, 3, 2, 4 in a state where a plurality (4 in the illustrated example) are stacked in the thickness direction. At this time, the total value of the thickness dimensions of the insulating resin sheet 60 is set to a value larger than the diameter dimension of the metal ball 7, thereby allowing a space between the facing wiring boards 1, 2, 1, 3, 2, 4 to be exceeded. It can be filled without any shortage.

  In the integration step, the insulating resin sheet 60 disposed in each of the spaces between the wiring boards 1, 2, 1, 3, 2, and 4 opposed by the lamination step is heated via the third wiring board 3 in a heated state. In this step, the wiring boards 1 to 4 are integrated by the insulating portions 6 by applying pressure, and the connecting portions 10a, 20a, 11a, 30a, 21a, and 40a are electrically connected to each other by the metal balls 7, respectively. More specifically, in the integration process, the wiring boards 1 to 4 and the respective insulating resin sheets 60 stacked in the stacking process are heated to about 100 to 150 ° C. in a vacuum atmosphere so that the insulating resin sheet 60 is heated. Soften. After that, while maintaining the heated state, the insulating resin sheet 60 softened by pressing the third wiring board 3 to the fourth wiring board 4 side is pressed. The third wiring board 3 is pressed to the fourth wiring board 4 side by pushing the insulating resin sheet 60 softened by the metal balls 7 and moving the metal balls 7 mounted on the first wiring board 1 to the third wiring board 3. The metal ball 7 mounted on the third wiring board 3 contacts the second connection section 20a, and the metal ball 7 mounted on the fourth wiring board 4 contacts the fourth connection section 21a. Do until you do.

  When each metal ball 7 comes into contact with each of the connecting portions 11a, 20a, and 21a, the solder layer 82 covering the surface of each metal ball 7 breaks off the oxide film on the surface and exposes new solder to the surface. It will be crushed between the metal ball 7 and each connection part 11a, 20a, 21a, and will spread on the surface of each connection part 11a, 20a, 21a. At this time, since the outermost layer of each of the connecting portions 11a, 20a, and 24a is made of an Au layer, Sn contained in the solder of the solder layer 82 diffuses into the Au plating and metal bonding is performed, thereby further improving the bonding reliability. Moreover, in this integration process, in order to soften the insulating resin sheet 60, the four insulating resin sheets 60 stacked in the thickness direction are melted and integrated.

  After the third wiring board 3 is pressed toward the fourth wiring board 4 and each metal ball 7 comes into contact with each of the connecting portions 11a, 20a, and 21a, at least insulation is maintained while maintaining this contact state. The conductive resin sheet 60 is heated to about 150 ° C. to 200 ° C. and cured. As described above, the insulating resin sheet 60 is cured to form the insulating portion 6, and the wiring boards 1 to 4 are integrated via the insulating portion 6. As a result, an electronic component built-in substrate as shown in FIG.

  In the electronic component built-in substrate of the present embodiment obtained by the process described above, as shown in FIG. 3B, the four wiring boards 1 to 4 are arranged such that the wiring boards 1 and 2 are opposed to each other in the thickness direction. 1, 3, 2, and 4, each of the connecting portions 10 a, 20 a, 11 a, 30 a, 21 a, and 40 a is arranged so as to overlap each other. Keeps the distance between the opposing wiring boards 1, 2, 1, 3, 2, 4 at a specified distance set larger than the mounting height dimension of the built-in electronic components 50, 51, 52, 53, and opposes Metal balls 7 for electrically connecting the connecting portions 10a, 20a, 11a, 30a, 21a, 40a of the wiring boards 1, 2, 1, 3, 2, 4 are interposed.

  Therefore, according to the electronic component built-in substrate of the present embodiment, the same effects as those of the first embodiment can be obtained. Also, an electronic component built-in substrate (multilayered electronic component built-in substrate) in which electronic components 50, 51, 52, and 53 are mounted between the facing wiring boards 1, 2, 1, 3, 1, and 4 can be obtained. Therefore, electronic components can be built in with high density.

  On the other hand, in the manufacturing method of the electronic component built-in substrate according to the present embodiment, the opposing wiring boards 1, 2, 1, 3, 2, 4 are integrated, and the wiring patterns 10, 20, 11, 30, 21, 40 are connected. Since the work of electrically connecting with the metal balls 7 is performed in a lump, the manufacturing process can be simplified.

(Embodiment 4)
As shown in FIGS. 4A to 4D, the electronic component built-in substrate of the present embodiment is described in the first wiring board 1 and the third wiring board 3 described in the third embodiment and in the first embodiment. The second wiring board 2 is provided, and its manufacturing method is different from that of the first embodiment. In addition, about the structure similar to Embodiment 1 or 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Below, the manufacturing method of the electronic component built-in board | substrate of this embodiment is demonstrated. The manufacturing method of the electronic component built-in substrate according to the present embodiment includes a mounting step, a first stacking step performed after the mounting step, a first integration step performed after the first stacking step, It has the 2nd lamination process performed after an integration process, and the 2nd integration process performed after a 2nd lamination process.

  The mounting process includes an electronic component mounting process in which the electronic component 51 is mounted on the first wiring board 1, the electronic component 50 is mounted on the second wiring board 2, and the electronic component 52 is mounted on the third wiring board 3. 10a, 30a each has a metal ball mounting process for mounting the metal ball 7. Here, the electronic component mounting process is the same as the electronic component mounting process of the third embodiment except for the operation of mounting the electronic component 53 on the fourth wiring board 4, and thus the description thereof is omitted. The metal ball mounting process is the same as the metal ball mounting process of the third embodiment except for the work of mounting the metal ball 7 on the fourth wiring board 4, and thus the description thereof is omitted. Note that either the electronic component mounting process or the metal ball mounting process may be performed first or in parallel.

  Since the first stacking step is the same as the stacking step of the first embodiment, description thereof is omitted. As shown in FIG. 4A, the first wiring board 1, the second wiring board 2, and the insulating resin sheet 60 are obtained by this first lamination process.

  Since the first integration process is the same as the integration process of the first embodiment, description thereof is omitted. In this first integration step, the wiring boards 1 and 2 are integrated via the insulating portion 6 as shown in FIG.

  In the second lamination step, the third wiring board 3 and the insulating resin sheet 60 are laminated on the first wiring board 1 electrically connected to the second wiring board 2 in the first integration step. 4C, the electronic component 52 and the metal ball 7 mounted on the third wiring board 3 by the mounting process are positioned in the space between the wiring boards 1 and 3, and the first In this step, the first wiring board 1 and the third wiring board 3 are disposed opposite to each other so that the two connection portions 11a and the fifth connection portion 30a overlap each other in the thickness direction. Also in this embodiment, the total thickness dimension of the insulating resin sheet 60 is set to a value that is larger than the diameter dimension of the metal ball 7.

  In the second integration step, the insulating resin sheet 60 disposed in the space between the wiring boards 1 and 3 opposed in the second lamination step is heated and the insulating resin is passed through the third wiring board 3. By pressurizing the sheet 60, the wiring boards 1 and 3 are integrated by the insulating part 6, and the connection parts 11 a and 30 a of the wiring patterns 11 and 30 of the wiring boards 1 and 3 facing each other by the metal ball 7 are electrically connected. It is the process of connecting to. More specifically, in the second integration step, the wiring boards 1 and 3 and the insulating resin sheet 60 stacked in the stacking step are heated to about 100 to 150 ° C. in a vacuum atmosphere, thereby insulating resin sheets. 60 is softened. After that, while maintaining the heated state, the insulating resin sheet 60 softened by first pressing the third wiring board 3 toward the wiring board 1 is pressed. The pressing of the third wiring board 3 toward the first wiring board 1 side pushes the insulating resin sheet 60 softened by the metal balls 7 so that each metal ball 7 is connected to each second connection of the second wiring pattern 11. The process is performed until each part 11a comes into contact. And after pressing the 3rd wiring board 3 to the 1st wiring board 1 side and making each metal ball 7 contact each 2nd connection part 11a, this contact state is maintained, At least the insulating resin sheet 60 is heated to about 150 ° C. to 200 ° C. to be cured. As described above, the insulating portion 6 is formed by curing the insulating resin sheet 60, and the wiring boards 1 and 3 are integrated via the insulating portion 6. As a result, an electronic component built-in substrate as shown in FIG. In the first and second integration steps, a temperature history for melting the solder such as reflow is added to the Au layer of the Sn connection portions 11a and 20a included in the solder of the solder layer 82 as necessary. May be promoted to improve the bonding reliability.

  In the electronic component built-in substrate of the present embodiment obtained by the process described above, as shown in FIG. 4D, the three wiring boards 1 to 3 are the wiring boards 1, 2, The connection portions 10a, 20a, 11a, 30a of the first and third wiring patterns 10, 20, 11, 30 are arranged so as to overlap each other, and between the wiring boards 1, 2, 1, 3 facing each other, respectively. In addition, the distance between the wiring boards 1, 2, 1, 3 is maintained at a specified distance set larger than the mounting height dimension of the electronic components 50, 51, 52, and the connection of the opposing wiring boards 1, 2, 1, 3 is maintained. Metal balls 7 that electrically connect the portions 10a, 20a, 11a, and 30a are interposed.

  Therefore, according to the electronic component built-in substrate of the present embodiment, the same effects as those of the first embodiment can be obtained. Further, since an electronic component built-in substrate (multilayered electronic component built-in substrate) in which electronic components 50, 51, 52 are mounted between the opposing wiring boards 1, 2, 1, 3 can be obtained, Can be built into the density.

  Furthermore, in the manufacturing method of the electronic component built-in substrate according to the present embodiment, the operation of incorporating the electronic components 50 and 51 between the facing wiring boards 1 and 2 and the electronic component between the wiring boards 1 and 3 facing the electronic component 52 are performed. Since the operation of incorporating the circuit 52 is performed separately, the wiring boards 1, 2, 3 are not biased when the insulating resin sheet 60 is pressed, as compared with the case where these operations are performed collectively. Therefore, it is possible to reduce the flatness of each of the wiring boards 1, 2, 3 by reducing the warping of the wiring boards 1, 2, 3 that occurs when the wiring boards 1, 2, 3 are integrated. As a result, it is possible to reduce the stress applied to the electronic components 50, 51, 52 incorporated between the wiring boards 1, 2, 3.

  In addition, although the electronic component built-in board of this embodiment is provided with the three wiring boards 1-3, it may be provided with the four wiring boards 1-4 like Embodiment 3. FIG. Further, more wiring boards may be used. In short, at least a plurality of wiring boards having wiring patterns formed on one surface in the thickness direction are at least of the wiring patterns of the wiring boards facing each other in the thickness direction. What is necessary is just to be arrange | positioned in the form where parts overlap. This also applies to the third embodiment.

FIG. 6 is a process diagram of the electronic component built-in substrate according to the first embodiment. FIG. 10 is a process diagram of the electronic component built-in substrate according to the second embodiment. FIG. 11 is a process diagram of the electronic component built-in substrate according to the third embodiment. FIG. 10 is a process diagram of the electronic component built-in substrate according to the fourth embodiment. It is a schematic explanatory drawing of the conventional electronic component built-in board | substrate.

Explanation of symbols

1, 2, 3, 4 Wiring board 1a, 2a, 3a, 4a Glass epoxy board 6 Insulating part 7 Metal ball 10, 11, 20, 21, 30, 40 Wiring pattern 10a, 11a, 20a, 21a, 30a, 40a Connection (Part of wiring pattern)
50, 51 Electronic component 60 Insulating resin sheet 82 Solder layer

Claims (8)

  A plurality of wiring boards having wiring patterns formed on at least one surface in the thickness direction are arranged in such a manner that at least a part of the wiring patterns of the wiring boards facing each other in the thickness direction overlap each other, and are built in between the wiring boards facing each other The electronic component is mounted on at least one of the wiring boards, and an electronic component-embedded substrate made of an insulating resin between the opposing wiring boards and having an insulating portion covering the electronic component interposed therebetween, Between the wiring boards, the distance between the wiring boards is maintained at a specified distance set larger than the mounting height dimension of the electronic component, and the part of the wiring patterns of the opposing wiring boards is electrically connected to each other An electronic component-embedded substrate characterized by interposing balls.   2. The electronic component built-in substrate according to claim 1, wherein the metal ball is fixed and electrically connected to the wiring pattern by solder.   3. The electronic component built-in board according to claim 2, wherein each wiring board is made of Au at a portion of the wiring pattern that contacts the metal ball.   4. The electronic component built-in substrate according to claim 1, wherein the insulating resin is an epoxy resin filled with a filler.   5. The electronic component built-in substrate according to claim 1, wherein the electronic component has at least an active element, and the active element is flip-chip mounted on one of the facing wiring boards. .   6. The electronic component built-in according to claim 1, wherein each wiring board is formed using a glass epoxy substrate, and the insulating resin is an epoxy resin filled with a filler. substrate.   It is a manufacturing method of the electronic component built-in board | substrate of any one of Claims 1-6, Comprising: While mounting the electronic component built in between the said wiring boards made to oppose at least one wiring board, the said metal ball | bowl is mounted | worn. A mounting step of mounting on one of the wiring patterns of the facing wiring board, and the electronic component and the metal ball mounted by the mounting step are positioned in a space between the facing wiring boards A laminating step in which at least a part of the wiring patterns overlap each other and the facing wiring boards are disposed opposite to each other with an insulating resin sheet serving as a basis of the insulating portion interposed therebetween, and between the facing wiring boards by the laminating step The insulating resin sheet placed in the space is heated and pressed through the wiring board, and the opposing wiring boards are integrated through the insulating portion. The counter electronic component-embedded board fabrication method characterized in that it has a integration step of the portion between the wiring pattern of the wiring board are electrically connected to by the metal balls with.   An active element and a passive element are provided as electronic components built in between the facing wiring boards, and in the mounting step, the active element is mounted on one of the facing wiring boards, and the facing wiring board A method for manufacturing a substrate with built-in electronic components according to claim 7, wherein a passive element is mounted on the other of the two.

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