JP4622449B2 - Electronic component built-in substrate and manufacturing method thereof - Google Patents

Description

The present invention relates to an electronic component an electronic component-embedded substrate that is embedded and its manufacturing how.

  Conventionally, this type of electronic component built-in substrate has a configuration as shown in FIGS.

  6 and 7 show a conventional method for manufacturing an electronic component built-in substrate.

  First, as shown in FIG. 6A, an anisotropic or isotropic semiconductor element adhesive 19 in which conductive particles are blended is applied to the adhesion region on the lower wiring substrate 11, and then FIG. 6B. As shown in FIG. 2, the electrode terminal 17 of the bare semiconductor element 16 is connected to the connection portion 12 on the wiring pattern p of the lower wiring substrate 11, and the semiconductor element 16 is mounted by heating and pressing. Then, as shown in FIG. 6C, the lower wiring board 11 is overlaid with the lower wiring board 11 on which the prepreg 13 is applied on the lower surface of the intermediate wiring board 21 in which the portion corresponding to the semiconductor element 16 is hollowed out. A prepreg 13 applied to the lower surface is superposed on the upper surface of the intermediate wiring board 21.

  Next, as shown in FIG. 7 (a), under a reduced pressure atmosphere, by heating and pressurizing a laminate of the lower wiring board 11, the intermediate wiring board 21, and the upper wiring board 31 to collectively cure the prepreg, As shown in FIG. 7B, a multilayer wiring board 100 with a built-in semiconductor element 16 is formed.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2002-270712 A

  However, in the configuration of the semiconductor-embedded substrate as described above, the lower layer wiring substrate, the intermediate wiring substrate, and the upper layer wiring substrate are stacked and stacked, but at the time of stacking, the lower surface side of the lower layer wiring substrate and the upper surface side of the upper layer wiring substrate are stacked. To be heated and pressurized by a flat plate press. For this reason, since the central portion of the intermediate wiring board is cut out, the pressure applied at the time of stacking does not apply to the area where the semiconductor is mounted, and only the remaining area of the intermediate wiring board is pressed. At that time, since the shape of the wiring pattern formed on the outermost layer of the lower layer wiring board and the upper layer wiring board within the area of the remaining intermediate wiring board is small, the pressure during pressing is concentrated on the wiring pattern part. become. Therefore, if heating and pressurization are performed in this state, the lower layer wiring substrate and the upper layer wiring substrate are deformed and eventually cause a connection failure of the inner via hole.

  In addition, a semiconductor device is built in a structure in which a lower wiring board, an intermediate wiring board, and an upper wiring board are used and an uncured prepreg is sandwiched between the boards, but the amount of resin derived from the prepreg Therefore, two or more elements cannot be built in one cut-out portion of the intermediate wiring board. This is because when two or more semiconductor elements or chip components are built in one cut-out portion of the intermediate wiring board, there is a space formed by the elements, and the volume to which the resin is to be supplied increases. . Therefore, a space not filled with resin will remain around the element after heating and pressurization, and there is a problem that outgas from the wiring board and resin tends to accumulate in this space, and condensation tends to occur in the space. Long-term use may cause defects.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide an electronic component built-in substrate excellent in connection reliability and mass productivity.

In order to solve the above-mentioned problems, the present invention is mounted on a multilayer wiring board having in advance an electrode as a wiring pattern, a support pattern formed so as to surround the outer periphery of the electrode, and a via, and the board. At least one or more electronic components, and a first insulating layer made of a woven or non-woven fabric and a thermosetting resin that is laminated on the upper surface of the substrate and has a space larger than the outer dimensions of the electronic components; A second insulating layer stacked on an upper surface of the first insulating layer; and a wiring layer stacked on an upper surface of the second insulating layer, the substrate, the first insulating layer, and the second An electronic component-embedded substrate in which the insulating layer and the wiring layer are integrated by thermocompression bonding, the position being opposite to the portion where the woven or non-woven fabric of the first insulating layer is formed across the substrate the support pattern is formed on said support path The first insulating layer overlapping the over emissions, which was always electronic component-embedded substrate in which the woven fabric or the nonwoven fabric is provided, when a built-in electronic component in the substrate by thermocompression bonding by a press In addition, since the pressure can be received by the support pattern, it is possible to prevent the deformation of the substrate due to the pressure, so that the yield at the time of stacking can be stabilized.

  As described above, according to the present invention, it is possible to easily produce an electronic component built-in substrate and an electronic component built-in module using a prepreg by providing a support pattern on the wiring board in advance, and is excellent in mass productivity. Thus, it is possible to manufacture an electronic component built-in substrate and an electronic component built-in module that can be reduced in cost.

(Embodiment 1)
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a manufacturing process of an electronic component built-in substrate according to Embodiment 1 of the present invention.

  In FIG. 1A, the wiring substrate 101 is supported so as to surround the electrode 102 on the front surface, the inner layer wiring pattern 104, the inner via hole 103, the electrode 105 that is the wiring pattern on the back surface, and the outer periphery of the electrode 105. This is a multilayer wiring board on which a pattern 107 is formed.

  The electrodes 102 and 105 and the wiring pattern 104 are made of a material having electrical conductivity, for example, a Cu foil or a conductive resin composition. In the present invention, Cu foil is used. The support pattern 107 is also formed of the same material as the electrode 105, and the height of the support pattern 107 is the same as that of the electrode 105 in order to prevent the substrate from being denatured due to the pressure during lamination. .

  In the present invention, Cu foil is also used for the support pattern 107, and the electrode 105 and the support pattern 107 are simultaneously formed by photolithography.

  The inner via hole 103 is made of a thermosetting conductive material such as a conductive resin composition in which metal particles and a thermosetting resin are mixed. As the metal particles, Au, Ag, Cu, or the like can be used. Au, Ag, or Cu is preferable because of its high conductivity, and Cu is particularly preferable because of its high conductivity, low migration, and low cost. As the thermosetting resin, for example, an epoxy resin, a phenol resin, or a cyanate resin can be used. Epoxy resins are particularly preferred because of their high heat resistance.

  Next, as shown in FIG. 1B, electronic components 108 a and 108 b are mounted using solder 109 at predetermined positions on the wiring board 101. The electronic components 108a and 108b include, for example, active components that are semiconductor elements such as transistors, ICs, and LSIs, and passive components that are surface-mounted components such as resistors, capacitors, inductors, vibrators, and filters.

  Pb—Sn eutectic solder or Pb-free solder (for example, Sn—Ag—Cu, Au—Sn, or Sn—Zn) can be used as the solder 109, but in any case, the melting point is 230 ° C. Since it is the following, even a non-heat-resistant component can be used.

  Also, the solder 109 for mounting the electronic components 108a and 108b and the solder for mounting the electronic component built-in substrate 130 on the mother substrate (not shown) may be the same material or different materials. . However, in consideration of recent environmental problems, it is preferable to use Pb-free solder. Note that flux cleaning after mounting the electronic components 108 a and 108 b is one of the most important items in satisfying the reliability of the electronic component built-in substrate 130.

  Next, as shown in FIG. 1C, the first insulating layer 120 and the second insulation are formed on the surface of the wiring board 101 on which the electronic components 108a and 108b have been mounted. The layer 122 and the wiring layer 123 are overlaid at desired positions. Here, in order to enable lamination with a uniform pressure, the area of the wiring layer 123 has an area equal to or larger than the same shape of the support pattern 107.

  The 1st insulating layer 120 and the 2nd insulating layer 122 are comprised with the prepreg which impregnated the thermosetting resin of the uncured state to the woven fabric or the nonwoven fabric. As the prepreg, a glass epoxy prepreg in which a glass cloth is impregnated with a thermosetting epoxy resin, a BT resin prepreg in which a glass cloth is impregnated with a thermosetting bismaleidotriamide resin, and a thermosetting epoxy resin in an aramid nonwoven fabric It is possible to use an aramid prepreg impregnated with, but various materials can be used as long as the structure is obtained by impregnating a thermosetting resin into a woven fabric or a non-woven fabric. Note that the first insulating layer 120 and the second insulating layer 122 are preferably made of materials having the same composition in order to prevent warping or deformation of the substrate.

  A space 121 is formed in the first insulating layer 120 so as not to contact the electronic components 108a and 108b. Even when a plurality of electronic components 108a and 108b as shown in FIG. 1C are mounted, the space 121 is a single space surrounding the entire mounting area. By doing so, the processing of the space 121 can be simplified, so that the manufacturing process can be simplified.

  In addition, the first insulating layer 120 is formed to be thicker than the electronic components 108a and 108b so that the electronic components 108a and 108b are not pressurized when the second insulating layer 122 contacts the electronic components 108a and 108b. There is a need.

  On the other hand, it is difficult to avoid an increase in cost because it is a custom-made product to make the first insulating layer 120 thick, and it is not suitable for mass production. Therefore, a desired thickness is ensured for the first insulating layer 120 by using a plurality of prepregs having a general thickness (for example, 100 μm) that are normally used when manufacturing a wiring board.

  The prepreg is a mixed sheet of woven fabric or non-woven fabric and an uncured thermosetting resin. When this prepreg is heated and pressurized, the softened thermosetting resin flows out of the prepreg, and heating and pressurization are completed. Later, it is always thinner than the initial thickness. For this reason, if the thickness reduction is taken into consideration in advance and the design is made based on the total thickness of the woven fabric or nonwoven fabric in the prepreg used in plural, the second insulating layer 122 can be made into an electronic component even after lamination. It is possible to prevent contact with 108a and 108b. Further, by using a plurality of prepregs, a sufficient amount of the thermosetting resin 124 that flows out from the prepreg during heating and pressurization can be secured, and thus there are a plurality of electronic components 108a and 108b. It is possible to fill the gaps in the space 121 that can be formed with the thermosetting resin 124.

  Next, as shown in FIG. 1D, the space 121 is filled with the thermosetting resin 124 by heating and pressurizing by hot pressing, and the electronic components 108a and 108b are built in the substrate. Since the space 121 is formed in the first insulating layer 120 at the time of lamination, the pressure at the time of lamination corresponds to the shape of the remaining prepreg of the first insulating layer, and the wiring substrate 101 and the second insulation are used. The layer 122 and the wiring pattern 123 are applied.

  In the present invention, since the support pattern 107 is present on the wiring substrate 101, it is possible to receive the pressure at the time of stacking with the support pattern 107, so that the stacking process can be performed without deforming the wiring substrate 101. It is. At this time, it is important that the support pattern 107 has a shape of 50% or more with respect to the width of the woven or non-woven fabric in which the first insulating layer 120 leaving the space 121 remains.

  If the width of the support pattern 107 is less than 50% of the width of the woven or non-woven fabric, even if the support pattern 107 is present, it is insufficient to receive the pressure in a plane. 101 may be deformed.

  Further, as shown in FIG. 2, the support pattern 107 may be an aggregate of independent patterns. By forming the support pattern 107 as an aggregate of independent patterns, the difference in the remaining copper ratio on the front and back surfaces of the wiring board 101 is reduced, thereby preventing warping of the wiring board 101 and effective as the support pattern 107. It becomes possible. In addition, if the distance between the independent patterns of the support pattern 107 is too wide, the effect as the support pattern 107 cannot be exhibited. Therefore, it is important to set the pattern distance to 200 μm or less.

  Then, after completion of the lamination, as shown in FIG.

  As described above, according to the first embodiment, the pressure can be received by the support pattern when the electronic component is built into the substrate by thermocompression bonding with a press, so that the deformation of the substrate due to the pressure is prevented. Therefore, it is possible to stably manufacture a substrate with built-in electronic components that is excellent in mass productivity.

(Embodiment 2)
The second embodiment of the present invention will be described below with reference to the drawings.

  FIG. 4 is a sectional view of a manufacturing process of an electronic component built-in module according to the second embodiment of the present invention, and FIG. 5 is a sectional view of the electronic component built-in module according to the second embodiment of the present invention. In addition, about the same structure as Embodiment 1, the same number is provided and description is abbreviate | omitted.

  As in the first embodiment, as shown in FIGS. 1A to 1C, the first insulating layer 120 and the second insulating layer 120 each having a space 121 formed on the wiring board 101 on which the electronic components 108a and 108b are mounted. The insulating layer 122 and the wiring layer 123 are overlapped at a desired position and integrated by heating and pressing. At this time, the wiring substrate 101 can be integrally formed without deformation due to the presence of the support pattern 107.

  Next, as shown in FIG. 4A, a through hole 125 is formed so as to penetrate the upper and lower surfaces.

  Next, as shown in FIG. 4B, the upper and lower surfaces are electrically connected through the through holes 125 by plating 126, and the wiring layer 123 is processed into a desired wiring pattern. At this time, the support pattern 107 may or may not be used as a part of the wiring pattern. In the first place, the purpose of the support pattern 107 is to receive the pressure applied to the wiring substrate 101 at the time of stacking. However, even if the support pattern 107 is used as a wiring pattern thereafter for the substrate after stacking. It doesn't cause any problems.

  Next, as shown in FIG. 4C, electronic components 128 a and 128 b are mounted on the back electrode 105 of the wiring substrate 101. The mounting positions of the electronic components 128a and 128b may be on the back electrode 105 of the wiring board 101 or on a wiring pattern newly formed from the wiring layer 123. The upper and lower surfaces are made conductive through the through hole 125 so that they can be mounted on either surface.

  Also, the solder 129 used for mounting is a Pb—Sn based eutectic solder or Pb free solder (for example, Sn—Ag—Cu based, Au—Sn based, or Sn—), similar to the built-in electronic components 108a and 108b. (Zn-based) can be used, but in any case, since the melting point is 230 ° C. or less, even non-heat-resistant parts can be used. However, in consideration of recent environmental problems, it is preferable to use Pb-free solder.

  Then, as shown in FIG. 5, the electronic component built-in module 131 is formed by cutting after completion of the mounting.

  As described above, according to the present embodiment, when the electronic component is built in the substrate by thermocompression bonding using a press, not only the pressure is received by the support pattern but also the deformation of the substrate due to the pressure is prevented. Since the support pattern can be used as a wiring pattern and through-hole connection can be performed, it is possible to mount components on the front and back surfaces of the electronic component-embedded substrate or to be mounted on another substrate.

  INDUSTRIAL APPLICABILITY The present invention is useful for an electronic component built-in substrate in which an electronic component is embedded, a manufacturing method thereof, and an electronic component built-in module using the electronic component built-in substrate, which are less susceptible to thermal stress and mechanical stress and can be reduced in cost. It is.

Manufacturing process sectional drawing of the electronic component built-in substrate in Embodiment 1 of this invention Sectional drawing of the electronic component built-in substrate in Embodiment 1 of this invention Sectional drawing of the electronic component built-in substrate in Embodiment 1 of this invention Manufacturing process sectional drawing of the electronic component built-in substrate in Embodiment 2 of this invention Sectional drawing of the electronic component built-in module in Embodiment 2 of this invention Cross-sectional view of the manufacturing process of a conventional substrate with built-in electronic components Cross-sectional view of the manufacturing process of a conventional substrate with built-in electronic components

DESCRIPTION OF SYMBOLS 101 Wiring board 102 Electrode 103 Inner via hole 104 Inner layer wiring pattern 105 Electrode 107 Support pattern 108a Electronic component 108b Electronic component 109 Solder 120 First insulating layer 121 Space 122 Second insulating layer 123 Wiring layer 124 Thermosetting resin 125 Through hole 126 Plating 128a Electronic component 128b Electronic component 129 Solder

Claims (13)

A multilayer wiring board having in advance an electrode which is a wiring pattern, a support pattern formed so as to surround the outer periphery of the electrode, and a via, at least one electronic component mounted on the board, and A first insulating layer made of a woven or non-woven fabric and a thermosetting resin, which is laminated on the upper surface of the substrate and has a space larger than the outer dimensions of the electronic component, and laminated on the upper surface of the first insulating layer. A second insulating layer and a wiring layer laminated on the upper surface of the second insulating layer, and the substrate, the first insulating layer, the second insulating layer, and the wiring layer are thermocompression bonded. Integrated electronic component built-in board,
The support pattern is formed at a position opposite to the portion where the woven or non-woven fabric of the first insulating layer is formed across the substrate,
The electronic component built-in substrate in which the woven fabric or the non-woven fabric is necessarily provided on the first insulating layer overlapping the support pattern. The electronic component built-in substrate according to claim 1, wherein the support pattern and the wiring layer are electrically connected through a through hole. The electronic component built-in substrate according to claim 1, wherein the support pattern is formed of the same material as the wiring pattern of the substrate. The electronic component built-in substrate according to claim 1, wherein the support pattern has the same height as the wiring pattern of the substrate. The electronic component built-in substrate according to claim 1, wherein the width of the support pattern has 50% or more of the width of the woven or non-woven fabric of the first insulating layer corresponding to the position of the support pattern. 3. The electronic component built-in substrate according to claim 1, wherein the woven fabric or the non-woven fabric of the first insulating layer provided at a position overlapping the support pattern is individually cut after completion of the lamination. The electronic component built-in substrate according to claim 1, wherein the support pattern is an assembly of a plurality of independent patterns. The electronic component built-in substrate according to claim 7, wherein the interval between the support patterns is 200 μm or less. The electronic component built-in substrate according to claim 1, wherein the second insulating layer is made of a material having the same composition as that of the first insulating layer. The electronic component built-in substrate according to claim 1, wherein the first insulating layer includes a plurality of sheet-like insulating layers. The electronic component built-in substrate according to claim 1, wherein a total thickness of the woven fabric or the nonwoven fabric in the first insulating layer is equal to or greater than a height of the electronic component. The wiring layer has an area equal to or larger than that of the support pattern when the substrate, the first insulating layer, the second insulating layer, and the wiring layer are integrated by thermocompression bonding. 2. The electronic component built-in substrate according to 2. A multilayer wiring board, at least one or more electronic components mounted on the substrate, a woven or non-woven fabric laminated on the upper surface of the substrate and formed with a space larger than the outer dimensions of the electronic components, and thermosetting A first insulating layer made of a conductive resin, a second insulating layer stacked on the top surface of the first insulating layer, and a wiring layer stacked on the top surface of the second insulating layer, And a method of manufacturing an electronic component-embedded substrate in which the first insulating layer, the second insulating layer, and the wiring layer are integrated by thermocompression bonding,
Preparing a multilayer wiring board having in advance an electrode that is a wiring pattern, a support pattern formed so as to surround the outer periphery of the electrode, and a via;
A support pattern forming step of forming a support pattern at a position opposite to the portion of the substrate on which the woven or nonwoven fabric of the first insulating layer is formed across the substrate;
After this support pattern forming step, by applying heat and pressure, the thermosetting resin is extruded from the woven or non-woven fabric of the first insulating layer, and the electronic component is completely covered with the thermosetting resin, and the first all the space of the insulating layer is filled with the thermosetting resin, wherein the first insulating layer overlying the support pattern and the thermosetting resin filling process that is provided is always the woven or the nonwoven fabric,
A method of manufacturing an electronic component built-in substrate having

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