JP4227482B2 - Manufacturing method of module with built-in components - Google Patents

Description

  The present invention relates to an electronic component built-in module in which an electronic component is disposed inside an electrical insulating layer, and a manufacturing method thereof.

In recent years, with the trend toward higher performance and miniaturization of electronic devices, there is a growing demand for higher density of component mounting technology and circuit board formation technology. For increasing the density of circuit boards, techniques such as multilayer circuit boards, miniaturization of wiring patterns, and formation of conductive vias have been actively developed. Further, as proposed in Patent Document 1 below, development of a component built-in module in which electronic components are embedded in a substrate has been promoted as a technology aiming at higher density.
Japanese Patent Laid-Open No. 11-220262

  When the electronic component is built in the substrate, it is preferable from the viewpoint of electrical characteristics and reliability that the built-in electronic component is completely covered with an electrical insulating material and that no gap is left inside the substrate as much as possible. In particular, gaps are likely to remain under the component (electrical connection surface side of the electronic component), and there are cases where the short circuit between the electrodes of the electronic component and the connection reliability are reduced.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide a component built-in module having high density, high functionality, and high reliability, and a method for manufacturing the same.

  In order to achieve the above object, a first component built-in module according to the present invention includes a core layer made of an electrically insulating material of a mixture containing at least an inorganic filler and a thermosetting resin, and a plurality of core layers formed inside the core layer. A plurality of wiring patterns formed in the core layer, and at least one of the wiring patterns electrically connected to the wiring pattern via a connecting material and embedded in the core layer A component built-in module having the above-described electronic component, wherein a distance between the electrical connection surface of the electronic component and the lower surface of the wiring pattern is larger than an average particle size of the inorganic filler.

  A second component built-in module according to the present invention includes a core layer made of an electrically insulating material of a mixture containing at least an inorganic filler and a thermosetting resin, and a plurality of conductive vias formed in the core layer. A component having a plurality of wiring patterns formed in the core layer and at least one electronic component electrically connected to the wiring pattern via a connecting material and embedded in the core layer It is a built-in module, The thickness of the said wiring pattern is larger than the average particle diameter of the said inorganic filler, It is characterized by the above-mentioned.

  A third component built-in module according to the present invention includes a core layer made of an electrically insulating material of a mixture containing at least an inorganic filler and a thermosetting resin, and a plurality of conductive vias formed in the core layer. A component having a plurality of wiring patterns formed in the core layer and at least one electronic component electrically connected to the wiring pattern via a connecting material and embedded in the core layer It is a built-in module, The thickness of the said connection material is larger than the average particle diameter of the said inorganic filler, It is characterized by the above-mentioned.

  Next, a method for manufacturing a component built-in module according to the present invention is a method for manufacturing any one of the component built-in modules, the step of applying a connecting material to a desired position of a wiring pattern formed on a carrier, A step of mounting an electronic component on a connecting material, a step of incorporating the electronic component in a core layer made of an electric insulating material of a mixture containing an inorganic filler and a thermosetting resin, and a step of peeling the carrier.

  Another method for manufacturing a component built-in module according to the present invention is a method for manufacturing any one of the component built-in modules described above, and a step of applying a connecting material to a desired position of a wiring pattern formed on a wiring board; A step of mounting an electronic component on the connection material, and a step of incorporating the electronic component in a core layer made of an electrically insulating material of a mixture containing an inorganic filler and a thermosetting resin.

  According to another aspect of the present invention, there is provided a third component built-in module manufacturing method, the step of applying a connection material on a metal plate, and mounting the electronic component on the connection material. A process, a process of incorporating the electronic component in a core layer made of an electrical insulating material of a mixture containing an inorganic filler and a thermosetting resin, and a process of processing the metal plate to form a wiring pattern.

  As described above, in the component built-in module according to the present invention, since the electrical insulating material can easily flow on the electrical connection surface side (under the component) of the electronic component, the gap under the component can be filled small or completely. . As a result, a component built-in module having excellent connection reliability can be obtained.

  In the present invention, the distance between the electrical connection surface of the electronic component and the lower surface of the wiring pattern is made larger than the average particle diameter of the inorganic filler used for the core layer, so that the electrical insulating material is placed under the component (the electrical connection surface side of the electronic component). It is easy to flow in and the gap under the part can be made small or completely filled. Moreover, the same effect is acquired by making wiring pattern thickness or connection material thickness larger than the average particle diameter of the inorganic filler used for a core layer. With these improvements, it is possible to provide a component built-in module with high connection reliability without causing the connection material to short-circuit under the component (electrical connection surface side of the electronic component).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a component built-in module according to Embodiment 1 of the present invention. The component built-in module according to the present embodiment includes a core layer 8 including an electrical insulating material 5 that is a mixture including an inorganic filler and a thermosetting resin, and via holes are formed inside the core layer 8 and filled with a conductive resin. A plurality of conductive vias 7, a plurality of wiring patterns 4 formed on the surface of the core layer 8, and an electronic component 1 built in the core layer 8. 2 and the wiring pattern 4 are electrically connected via a connecting material. Further, the distance 11 between the electrical connection surface 9 and the wiring pattern lower surface 10 of the electronic component 1 is larger than the average particle diameter of the inorganic filler 6. With this configuration, the electrical insulating material 5 can easily flow under the electronic component 1 and the gap under the electronic component 1 can be made small or completely filled. Shortening between the component electrodes can be prevented by eliminating or completely filling the gap. In addition, in terms of reliability such as moisture resistance and reflow resistance, moisture does not accumulate in the voids, and a decrease in reliability can be prevented. In addition, since the gap is reduced, the adhesive strength between the electronic component and the wiring pattern is increased, and the connection reliability such as thermal shock is improved.

  In order for the distance 11 between the electrical connection surface 9 of the electronic component 1 and the wiring pattern lower surface 10 to be larger than the average particle diameter of the inorganic filler 6, the sum of the thickness of the wiring pattern 4 and the thickness of the connection material 3 is It is preferable to make it larger than the average particle diameter. The thickness control of the wiring pattern can be freely designed by changing the thickness of the metal foil such as the copper foil to be used, and is simple.

  The core layer 8 is made of a mixture electric insulating material containing the inorganic filler 6 and a thermosetting resin. There may also be reinforcing agents such as glass cloth. By selecting an inorganic filler and an insulating resin as the electrical insulating material, the linear expansion coefficient, thermal conductivity, dielectric constant, and the like can be easily controlled. A solvent or the like may be added to adjust the viscosity.

  As the inorganic filler, alumina, magnesia, boron nitride, aluminum nitride, silicon nitride, polytetrafluoroethylene, silica and the like can be used. By using alumina, boron nitride, or aluminum nitride, a substrate having higher thermal conductivity than that of a conventional glass-epoxy substrate can be manufactured, and the heat generated by the built-in electronic component can be effectively radiated. Alumina also has the advantage of low cost. When silica is used, an electrical insulating material having a low dielectric constant can be obtained and the specific gravity is light. Even if silicon nitride or polytetrafluoroethylene is used, an electrical insulating material having a low dielectric constant can be formed. Moreover, the linear expansion coefficient can be reduced by using boron nitride. The average particle diameter of the inorganic filler is preferably in the range of 0.1 to 100 μm.

  As the thermosetting resin, an epoxy resin, a phenol resin or an isocyanate resin having high heat resistance is preferable. Epoxy resins are particularly preferred because of their particularly high heat resistance. A thermoplastic resin may be mixed with these thermosetting resins. The mixing ratio of the resin and the inorganic filler is preferably in the range of 70 to 95% by weight of the inorganic filler and 5 to 30% by weight of the resin when the entire resin and inorganic filler are 100% by weight.

  Further, the mixture may contain a dispersant, a colorant, a coupling agent or a release agent. The inorganic filler can be uniformly dispersed in the resin by the dispersant. Since the electrical insulating material can be colored by the colorant, the automatic recognition device can be easily used. Since the bonding agent can increase the adhesive strength between the resin and the inorganic filler, the insulating property of the electrical insulating material can be improved. Since the mold release agent can improve the mold release property between the mold and the mixture, the productivity can be improved.

  The wiring pattern is made of a material having electrical conductivity, and a metal foil, a conductive paste, a lead frame processed from a metal plate, or the like can be used. When using a copper foil as the wiring pattern, for example, a copper foil having a thickness of about 18 μm to 35 μm manufactured by electrolytic plating can be used. The wiring pattern desirably has a roughened surface in contact with the electrical insulating material in order to improve adhesion with the electrical insulating material. In addition, a wiring pattern whose surface is subjected to a coupling treatment or a surface plated with tin, zinc, nickel, gold, or the like may be used for improving adhesion and oxidation resistance. The wiring pattern can be formed by a simple manufacturing method such as fine patterning by etching or punching.

  In addition, in the metal foil, a wiring pattern can be formed by transfer using a release film. In particular, copper foil is preferable because of its low price and high electrical conductivity. Moreover, a wiring pattern becomes easy to handle by forming a wiring pattern on a release film. Further, by using the conductive paste, it is possible to produce a wiring pattern by screen printing or the like. By using a lead frame, it is possible to use a metal having a low electric resistance and a large thickness.

  Electronic components include active components and passive components. A semiconductor element such as a transistor, IC, or LSI is used as the active component. The semiconductor element may be a semiconductor bare chip. As passive components, chip-shaped components such as resistors, capacitors, and inductors, diodes, thermistors, switches, connectors, and the like can be used.

  The external electrode of the electronic component is not particularly limited in shape and type as long as it is generally used, such as metals and alloys such as gold, silver, copper, nickel, palladium, and tin, carbon, and a mixture thereof.

  The conductive via has a function of connecting between the wiring patterns or between the wiring pattern and the connection material, and is made of, for example, a conductive substance. By having the conductive vias, it is possible to connect the wiring patterns of a plurality of layers, and high-density mounting is possible.

  As the conductive substance, for example, a conductive paste in which a conductive filler and a thermosetting resin are mixed can be used. As the conductive filler, metals and alloys such as gold, silver, copper, nickel, palladium, and tin, carbon, and a mixture thereof can be used. Gold, silver, copper, or nickel is preferable because of its high electrical conductivity, and copper is particularly preferable because of its high electrical conductivity and low migration. Even if a metal filler in which copper is coated with silver is used, it is possible to satisfy both the characteristics of low migration and high electrical conductivity. The conductive via can also be formed by plating the side wall after forming the hole of the conductive via.

  The connection material has a function of electrically connecting the external electrode of the electronic component and the wiring pattern or the conductive via, and solder, conductive adhesive, or the like can be used. As the solder, SnPb (lead tin) eutectic solder, high-temperature solder with increased lead content, lead-free solder such as tin silver copper, and the like can be used. Environmental impact can be reduced by using lead-free solder and conductive adhesive. Further, when a high-temperature solder or a conductive adhesive is used as the connection material, remelting of the connection material can be prevented even when the component built-in module passes through the reflow process again. In addition, the conductive adhesive can be preferably used because it has a small amount of deformation at the time of curing and can easily control the thickness. Methods for controlling the thickness of the conductive adhesive include control of the amount of conductive adhesive applied, viscosity (viscosity, thixotropy) control, pressure control during component mounting, and control of the amount of cure shrinkage when the conductive adhesive is cured. Available. When solder is used as the connection material, it is desirable to control the thickness by providing a method for controlling the amount of solder applied or by providing a solder resist or the like at a desired position.

  The conductive adhesive as the connecting material is made of a mixture of a resin and a conductive filler. As the resin, a thermosetting resin such as an epoxy resin, an acrylic resin, a phenol resin, a silicon resin, a polyimide resin, or a urethane resin, a thermoplastic resin, or a mixture thereof can be used. Epoxy resins can be preferably used because of their low cure shrinkage and excellent adhesion.

  As the conductive filler of the conductive adhesive, metals and alloys such as gold, silver, copper, nickel, palladium, and tin, carbon, and a mixture thereof can be used. Silver and copper are more preferable because they have good electrical conductivity and are inexpensive. The average particle diameter of the conductive filler of the conductive adhesive can be 0.1 μm to 150 μm. The conductive filler content is preferably 65% to 95% by weight, and the resin content is preferably 5% to 35% by weight. If the amount of the conductive filler is small, the connection resistance is increased. Conversely, if the amount of the conductive filler is large, the adhesion strength is lowered and the connection resistance is also increased.

  The connection material, the conductive paste for forming the wiring pattern, and the conductive substance for forming the conductive via can be made of the same material. Further, when the wiring pattern is formed of a conductive paste, it is also possible to electrically connect external electrodes of components directly to the wiring pattern.

  In the component built-in module shown in FIG. 1, the wiring pattern is embedded in the core layer. However, the wiring pattern may not be embedded in the core layer.

  In the component built-in module shown in FIG. 1, the electronic component is not mounted on the surface layer of the core layer. However, the electronic component may be mounted on the surface layer of the core layer. Further, in the component built-in module shown in FIG. 1, the electronic component is mounted and built only on the lower surface of the core layer, but the direction in which the electronic component is built in the core layer is not particularly limited. Further, in the component built-in module shown in FIG. 1, the case where the core layer is one layer has been shown. However, it is also possible to form a component built-in module by stacking the core layers in multiple layers. Further, it is possible to manufacture a module with a higher density by providing a single-sided, double-sided or multi-layer wiring board on the surface layer or inside of the core layer. Also, these can be realized independently, and may be mixed, and by combining them, high-density mounting can be realized (see FIG. 11). In FIG. 11, 18 is an electronic component such as a passive component, 19 is a wiring board, and 20 is an electronic component such as an active component.

(Embodiment 2)
FIG. 2 is a cross-sectional view of the component built-in module according to Embodiment 2 of the present invention. The same numbers as those in the first embodiment are indicated. The materials used in this embodiment are the same as those in Embodiment 1 described above unless otherwise specified.

  In the present embodiment, the thickness of the wiring pattern is larger than the average particle diameter of the inorganic filler. With this structure, the electrical insulating material easily flows under the component, and the gap under the component can be made small or completely filled. Therefore, the same effect as in the first embodiment can be obtained.

  The thickness control of the wiring pattern can be freely designed by changing the thickness of the metal foil such as the copper foil to be used, and is simple.

  If solder is used as the connection material and the wiring pattern material and solder form an alloy layer and the connection interface cannot be clearly distinguished, the composition ratio (element ratio) of the original wiring pattern material The particle size is measured by setting the portion where 50% or more is the interface. The same applies to the thickness of the connecting material when solder is used as the connecting material.

(Embodiment 3)
FIG. 3 is a cross-sectional view of the component built-in module according to Embodiment 3 of the present invention. The same numbers as those in the first and second embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 and 2 described above unless otherwise specified.

  This embodiment is characterized in that the thickness of the connecting material is larger than the average particle diameter of the inorganic filler. With this structure, the electrical insulating material easily flows under the component, and the gap under the component can be made small or completely filled. Therefore, the same effect as in the first and second embodiments can be obtained.

  The thickness of the connection material indicates the shortest straight distance between the external electrode of the electronic component and the wiring pattern in the connection material portion. That is, the fillet portion formed when solder is used is not included in the thickness of the connection material.

(Embodiment 4)
FIG. 4 is a cross-sectional view of a component built-in module according to Embodiment 4 of the present invention. The same numbers as those in the first to third embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 3 described above unless otherwise specified. When using a conductive adhesive as the connecting material, the average particle diameter of the conductive filler 12 in the connecting material portion is made larger than the average particle diameter of the inorganic filler 6 included in the core layer, so that the average particle diameter of the inorganic filler 6 is increased. The thickness of the connection material 3 can be reliably increased. Since this embodiment can be achieved by kneading the conductive filler 12 larger than the average particle diameter of the inorganic filler 6 in the conductive adhesive in advance, it is easy and yield is good. That is, in the case of this form, the conductive filler in the conductive adhesive is responsible for both electrical connection and thickness control of the connecting material. When one conductive filler is in contact with both the wiring pattern and the external electrode, the effect of further improving the electrical characteristics and connection reliability can be obtained.

(Embodiment 5)
FIG. 5 is a cross-sectional view of a component built-in module according to Embodiment 5 of the present invention. The same numbers as those in the first to fourth embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 4 described above unless otherwise specified. When a conductive adhesive is used as the connecting material, the average of the inorganic filler contained in the core layer includes the non-conductive filler 13 in addition to the resin and conductive filler in the connecting material portion, and the average particle size of the non-conductive filler By making it larger than the particle size, the thickness of the connecting material can be surely made larger than the average particle size of the inorganic filler.

  As the non-conductive filler, organic fillers such as the inorganic fillers, rubber particles, polyamideimide resin, urethane resin, and epoxy resin mentioned in the first embodiment can be used. Further, in the case of organic fillers, filler-shaped ones may be kneaded in the conductive adhesive in advance, or may be kneaded in the conductive adhesive in a liquid or uncured state. .

(Embodiment 6)
FIG. 6 is a cross-sectional view of a component built-in module according to Embodiment 6 of the present invention. The same numbers as those in the first to fifth embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 5 described above unless otherwise specified. When solder is used as the connecting material, the connecting material portion includes the second filler (non-conductive filler) 14 and the average particle size of the second filler 14 is larger than the average particle size of the inorganic filler contained in the core layer. By doing so, the thickness of the connection material can be surely made larger than the average particle diameter of the inorganic filler.

  As a 2nd filler, the metal filler which has electroconductivity, the inorganic filler quoted in Embodiment 1, the organic filler quoted in Embodiment 5, etc. can be utilized. In the case of a metal filler, since it is difficult to control the thickness if the solubility in solder is high, copper, nickel, palladium, aluminum, iron, chromium, alloys and mixtures thereof having low solubility in solder, etc. It can be preferably used. In the case of these metal fillers, an alloy with solder is formed on the filler surface, but since the rough shape can be maintained, the thickness of the connecting material portion can be controlled. If the material of the second filler and the solder form an alloy layer and the connection interface cannot be clearly distinguished, the portion where the material composition ratio (element ratio) of the second filler is 50% or more is used as the interface. The particle size of the second filler is measured.

  In the case of an organic filler, a filler that has been in the form of a filler in advance may be kneaded in the solder, or may be kneaded in the solder in a liquid or uncured state. Alternatively, in order to improve the adhesiveness with the solder, a part of the surface of the inorganic filler or the organic filler or the entire surface coated with a metal that forms an alloy with solder can be preferably used.

(Embodiment 7)
FIG. 7 shows a method for manufacturing a component built-in module according to Embodiment 7 of the present invention. 7A to 7F are cross-sectional views showing the manufacturing process of the component built-in module. The same numbers as those in the first to sixth embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 6 described above unless otherwise specified. In the manufacturing method of the present embodiment, a connection material is applied to a desired position of the wiring pattern (FIG. 7A) formed on the carrier 15 (FIG. 7B), and an electronic component is mounted at the desired position. (FIG. 7C). This is aligned with an uncured electrical insulating material formed with conductive vias (FIG. 7D). By pressurizing this, the electronic component is built in the electrical insulating material (FIG. 7E). Finally, the carrier can be peeled off to produce a component built-in module (FIG. 7F).

  The wiring pattern on the carrier can be formed using a method such as etching or printing. Particularly in etching, a fine wiring pattern forming method such as a photolithography method can be used.

  As the carrier, a resin film such as PET (polyethylene terephthalate) or PPS (polyphenylene sulfite), or a metal foil such as copper foil or aluminum foil can be used. By using the carrier, the wiring pattern can be easily handled. In addition, a release layer may be provided between the wiring pattern and the carrier to facilitate peeling of the wiring pattern.

  Metal plate printing, screen printing, dispenser, dip method, ink jet method and the like can be used as a method for applying the connecting material. When the connecting material is solder, a method using solder balls can be used. Metal plate printing or a method using a dispenser can be preferably used from the viewpoint that a sufficient coating thickness of the connecting material can be secured.

  As the electrical insulating material, a material obtained by kneading an insulating resin containing a thermosetting resin and an inorganic filler and adding a solvent or the like as necessary to form a paste can be preferably used. As a method for forming into a sheet shape, for example, an electrical insulating material can be formed on the film by using a doctor blade method or the like. The electrical insulating material can be reduced in adhesiveness by being dried at a curing temperature or lower. This heat treatment loses the adhesiveness of the electrical insulating material, so that peeling from the film becomes easy. Moreover, handling becomes easy by making an electrically insulating material into an unhardened state (B stage).

  The hole formation of the conductive via can be produced by laser processing, drilling, punching, or the like. Laser processing is desirable because vias can be formed at a fine pitch and no shavings are generated. In the case of laser processing, a carbon dioxide laser, YAG laser, excimer laser, or the like can be used. Further, in the case of drilling or punching, it is easy to form conductive vias with existing versatile equipment. Moreover, it becomes easy to process by using an electrical insulating material in a B-stage state.

  For the conductive via, a method of filling a conductive paste using a method such as a printing method or an injection method, a method of forming by plating, or the like can be preferably used. In the case of the printing method, it is possible to simultaneously form a wiring pattern and a connection material.

  A chip mounter can be preferably used as a method for mounting the electronic component at a predetermined position.

  Before the wiring board is built in the electrical insulating material, a gap of the built-in electronic component may be formed in the electrical insulating material. By providing the gap, the conductive via can be prevented from being deformed.

  In order to electrically connect the electronic component and the wiring pattern, in the case of solder, it is necessary to raise the temperature to the solder melting temperature or more once. In this case, a reflow furnace can be preferably used. Further, when the connecting material is a conductive adhesive and contains a thermosetting resin, it is necessary to raise the curing temperature. When a thermoplastic resin is included, it is necessary to remove the solvent and the like. It is also possible to cure the resin by light such as ultraviolet rays using a light curable resin. These processes can be performed after mounting the components, simultaneously with the pressurizing process for incorporating the wiring board, or after the wiring board is built in the electrical insulating material.

  Even when a conductive paste is used for forming conductive vias, the electrical connection step is performed after filling the conductive vias, simultaneously with the pressurizing step for incorporating the wiring board, or the wiring board is electrically connected. It can be performed after being incorporated in the insulating material.

  The step of curing the electrical insulating material can be performed simultaneously with the pressurizing step for incorporating the wiring board, or can be performed after the wiring board is built in the electrical insulating material. By simultaneously performing the process of heating the electrical insulating material and the process of pressurizing the wiring board, the electrical insulating material can easily flow into the part under the component, and the gap can be minimized.

  Further, without using a sheet-shaped electrical insulating material, it can be melted and flowed into a mold after being processed into a powder or pellet form. Moreover, it can also be melt-molded after pouring in powder form. As a method for injecting the insulating resin, transfer molding or injection molding can be used.

  In the present embodiment, a chip-like component is shown as an electronic component, but the same applies to other passive components and active components. As a method of mounting a semiconductor on a wiring pattern, a wire bonding method, a method using solder or a conductive adhesive, SBB (stud bump bonding), ACF (anisotropic conductive film), NCF (non-conductive particle film), etc. A method using a construction method, a method using a CSP (chip size package), or the like can be used.

(Embodiment 8)
FIG. 8 shows a method for manufacturing a component built-in module according to Embodiment 8 of the present invention. 8A to 8E are cross-sectional views showing the manufacturing process of the component built-in module. The same numbers as those in the first to seventh embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 7 described above unless otherwise specified. The elements having the same names as those of the seventh embodiment have the same configuration as those of the seventh embodiment, are manufactured by the same manufacturing method, and have the same functions unless otherwise specified.

  The manufacturing method of the component built-in module in the present embodiment is a manufacturing method using the wiring board 16 instead of the carrier in the manufacturing method of the seventh embodiment.

  In the manufacturing method of the present embodiment, the wiring pattern 4 is formed on the wiring board 16 (FIG. 8A), the connection material is applied to the desired position (FIG. 8B), and then the electronic component is placed at the desired position. (FIG. 8C).

  This is aligned with an uncured electrical insulating material formed with conductive vias (FIG. 8D). This is a manufacturing method in which an electronic component is built into an electrical insulating material by pressurizing this to produce a component built-in module (FIG. 8E).

  The wiring board is a general wiring board such as a glass epoxy board, a ceramic board, a build-up board, a multilayer board with conductive via connection, and the like, and is composed of an electrically insulating layer, a wiring pattern, and a conductive via. The electrical insulating layer may contain a reinforcing agent such as an insulating resin, a mixture of a filler and an insulating resin, ceramic, glass cloth, and the like. Moreover, the same material as the electrical insulating material may be used. The same applies to wiring patterns and conductive vias. The wiring pattern of the wiring board may be single-sided, double-sided or multilayer.

(Embodiment 9)
FIG. 9 shows a method for manufacturing a component built-in module according to Embodiment 9 of the present invention. 9A to 9E are cross-sectional views showing the manufacturing process of the component built-in module. The same numbers as those in the first to eighth embodiments are indicated. The materials used in this embodiment are the same as those in Embodiments 1 to 8 described above unless otherwise specified. The elements having the same names as those of the seventh embodiment have the same configuration as those of the seventh embodiment, are manufactured by the same manufacturing method, and have the same functions unless otherwise specified.

  The manufacturing method of the component built-in module in the present embodiment uses the metal plate 17 instead of the carrier in the seventh embodiment and the wiring board in the manufacturing method in the eighth embodiment, and processes the metal plate in the final process, This is a manufacturing method for forming a wiring pattern.

  In the manufacturing method of the present embodiment, a connection material is applied to a desired position of the metal plate 17 (FIG. 9A), and an electronic component is mounted at a desired position (FIG. 9B). This is built in by positioning and pressing an uncured electrical insulating material provided with conductive vias (FIGS. 9C to 9D). The metal plate 17 on the surface layer of the core layer is processed by a method such as etching to form a wiring pattern.

  In the seventh to ninth embodiments, a carrier, a wiring board, and a metal plate are used, and a wiring pattern is formed on the surface layer of the core layer. However, these means can be implemented individually and mixed. . In other words, it is possible to manufacture the core layer in different forms on the upper and lower surfaces (carrier, wiring board, metal plate, and electronic components mounted on each), and a more complex and high-functional component built-in module It can be produced (see FIG. 11).

  In the manufacturing methods of Embodiments 7 to 9, it is possible to use a method in which a conductive filler having an average particle size larger than the average particle size of the inorganic filler is previously kneaded in a conductive adhesive and used as a connection material.

  Moreover, the method of knead | mixing the nonelectroconductive filler which has an average particle diameter larger than the average particle diameter of an inorganic filler previously in a conductive adhesive, and using it as a connection material can be utilized.

  Moreover, the 2nd filler which has an average particle diameter larger than the average particle diameter of an inorganic filler can knead | mix beforehand in solder | pewter, and the method of using it as a connection material can be utilized.

  These methods of adding a filler having a desired average particle diameter to the connection material in advance are preferable in terms of simplification of the component built-in module process and maintaining the quality of the connection portion. In addition, after applying the second filler to a desired position, solder is applied as a connecting material to the second filler, and the solder is melted to electrically connect the electronic component and the wiring pattern. Is available. In this case, the thickness of the solder connecting material portion can be controlled by the second filler, and general-purpose solder can be used. A dispenser or the like can be used regardless of the particle size of the second filler.

  In order not to cause positional deviation after the second filler is applied to a desired position, a method of applying a viscous material such as solder flux to the desired position can also be used. Moreover, when the average particle diameter of this 2nd filler is larger than the average particle diameter of an inorganic filler, since the thickness of a connection material part becomes larger reliably than the average particle diameter of an inorganic filler, it can utilize more preferable.

  Examples of the present invention will be described below.

  In this example, copper foils having different thicknesses were used in order to change the wiring pattern thickness. Moreover, the influence of the thickness of the connection material was examined using solder and a conductive adhesive as the connection material. In this example, the component built-in module shown in FIG. 10 was manufactured according to the manufacturing method shown in FIG.

  Moreover, the moisture absorption reflow test and the thermal shock test were done as reliability evaluation regarding the component built-in module produced in each Example. The moisture absorption reflow test was carried out by passing the component built-in module held for 168 hours under conditions of a temperature of 85 ° C. and a humidity of 85% once through a belt-type reflow furnace at a maximum temperature of 250 ° C. for 15 seconds. Further, in the thermal shock test, the resistance value of the connecting material portion was measured after 1000 cycles of holding at a temperature of 125 ° C. on the high temperature side and −40 ° C. on the low temperature side for 30 minutes each.

  At the same time, the component built-in module produced in each example was subjected to cross-sectional polishing in the vicinity of the dashed line in FIG. 10, and the presence or absence of voids in the lower part of the chip resistor was confirmed by an optical microscope.

Example 1
As the electrical insulating material, alumina powder (90% wt, average particle size 33 μm) is used as the inorganic filler, and thermosetting epoxy resin (10% wt) is used as the resin, and these are mixed by a stirring mixer to adjust the viscosity. Solvent was added. This was applied in a sheet form on a polyethylene terephthalate film coated with a release agent. By performing heat treatment at 120 ° C. for 15 minutes, an electric insulating material in a B stage state having a thickness of 500 μm was obtained.

  This was cut into a predetermined size, and a through hole having a diameter of 0.15 mm was formed using a carbon dioxide gas laser. This through hole was filled with a conductive paste for filling conductive vias by a printing method. A conductive paste for filling conductive vias is a kneaded mixture of 85% by mass of spherical copper powder having an average particle size of 2 μm, 12% by mass of epoxy resin and 3% by mass of amine adduct curing agent as a resin in a three roll. It was used.

  On the other hand, PPS (polyphenylene sulfide) having a thickness of 150 μm was used as a carrier, and copper having a thickness shown in Table 1 was formed on the carrier. This was chemically etched by a photolithography method to form a wiring pattern. Two of these were prepared, and component mounting was performed on one of them. As a method, solder (SnPb eutectic cream solder) as a connection material was printed using a metal plate only at a desired position on the wiring pattern. Next, a 1005 size chip resistor (10 ohms, external electrode tin plating) is mounted on the soldered portion using a chip mounter, the solder is melted using a reflow furnace, and the chip resistor and the wiring pattern are electrically connected. Connected.

  The sheet-like electrical insulating material is aligned and sandwiched between the component mounting body thus produced and another PPS on which a wiring pattern is formed, and heated for 60 minutes at a press temperature of 170 ° C. and a pressure of 1 MPa using a hot press. Pressurized.

  At the beginning of this process, the thermosetting resin in the electrical insulating material is melted and softened by heating, so that the chip resistor and the wiring pattern are buried in the electrical insulating material and try to penetrate into the voids under the parts. . Thereafter, the epoxy resin curing reaction proceeds, the epoxy resin in the electrical insulating material and the epoxy resin in the conductive paste are cured, and the chip resistor, the wiring pattern, and the conductive via are mechanically firmly bonded and conductive. The conductive paste is electrically connected to the wiring pattern. Finally, the PPS carrier was peeled off to produce the component built-in module shown in FIG.

  In this example, component built-in modules each having a connection material thickness shown in Table 1 were produced. The solder thickness control as the connecting material was performed by adjusting the area of the wiring pattern and the solder coating (printing plate thickness). However, when only solder was used, it was difficult to make the connecting material thickness 15 μm or more. A sample in which solder is used and the connection material thickness is increased will be described in Example 3.

(Example 2)
In this example, two types of conductive adhesives were used as the connection material. As a conductive adhesive, silver filler (85% wt) and epoxy resin (15% wt) are kneaded as a conductive filler, and a solvent (butyl carbitol acetate, 1% wt or less) is added to adjust the viscosity. What was done was used. As the conductive adhesive A, an average particle diameter of silver filler was 3 μm, and as the conductive adhesive B, an average particle diameter of silver filler was 35 μm.

  The method for manufacturing the component built-in module is the same as in the first embodiment. However, the part for mounting the chip resistor in Example 1 was changed as follows. A conductive adhesive is printed by a printing method, a chip resistor is mounted at a desired position using a chip mounter, and the epoxy resin in the conductive adhesive is cured by placing it in a batch furnace at 150 ° C. for 30 minutes. At the same time, the chip resistor and the wiring pattern were electrically connected. The following steps are the same as in Example 1.

  In this example, each of the component built-in modules having the connection material thickness shown in Table 2 was produced. Regarding the thickness control of the conductive adhesive as the connecting material, it was performed by adjusting the coating amount (printing plate thickness) of the conductive adhesive.

(Example 3)
In this example, Ni ball (10 μm, 45 μm) previously kneaded in solder (SnPb eutectic cream solder) was used as the connecting material. The wiring pattern thickness was examined with respect to 9 μm (Table 3). The manufacturing method of the component built-in module is the same as that of the first embodiment.

(Example 4)
In this example, a conductive ball obtained by previously kneading resin balls (silicone resin balls, powdered, 10 μm, 50 μm) in the conductive adhesive A was used as the connecting material. The wiring pattern thickness was examined with respect to 9 μm (Table 3). The manufacturing method of the component built-in module is the same as that of the second embodiment.

表１に示すように、配線パターン厚みと接続材料の厚みの合計が電気絶縁材中の無機質フィラーの平均粒径より小さい場合、チップ抵抗体の電気接続面側（部品下）に空隙が観測された（×印は空隙面積大、△印は空隙面積小）。また、吸湿リフロー試験において、チップ抵抗体の電気接続面側でハンダのショートが確認された。また、部品下が埋まっていないためチップ抵抗体の接着強度が弱く、熱衝撃試験後に抵抗値が大きく上昇した。配線パターン厚みと接続材料の厚みの合計が電気絶縁材中の無機質フィラーの平均粒径より大きい場合には、このような現象は見られず、熱衝撃試験においても良好であった。

As shown in Table 1, when the sum of the wiring pattern thickness and the thickness of the connection material is smaller than the average particle size of the inorganic filler in the electrical insulating material, voids are observed on the electrical connection surface side (under the component) of the chip resistor. (× indicates a large void area, Δ indicates a small void area). Moreover, in the moisture absorption reflow test, a short circuit of the solder was confirmed on the electrical connection surface side of the chip resistor. Also, since the bottom of the component was not buried, the adhesive strength of the chip resistor was weak, and the resistance value increased greatly after the thermal shock test. When the sum of the thickness of the wiring pattern and the thickness of the connection material is larger than the average particle size of the inorganic filler in the electrical insulating material, such a phenomenon was not observed and it was good in the thermal shock test.

  As shown in Table 2, even when a conductive adhesive is used as the connection material, if the sum of the wiring pattern thickness and the thickness of the connection material is smaller than the average particle size of the inorganic filler in the electrical insulating material, the chip resistor Gaps were observed on the electrical connection surface side (below the parts) of the above (× mark indicates a large gap area and Δ mark indicates a small gap area). In the moisture absorption reflow test, no short-circuit was observed, but the moisture absorbed was accumulated in the voids, causing a steam explosion that explodes during reflow, peeling off the connected parts, and opening the resistance value (Table 2, moisture absorption reflow). X of test item). Also, the resistance value greatly increased after the thermal shock test. When the sum of the thickness of the wiring pattern and the thickness of the connection material is larger than the average particle size of the inorganic filler in the electrical insulating material, such a phenomenon was not observed and it was good in the thermal shock test. Further, when the conductive adhesive B is used, since the average particle size of the conductive filler is larger than the average particle size of the inorganic filler, the thickness of the connecting material is always larger than the average particle size of the inorganic filler. As a result, good results were obtained in each test.

  As shown in Table 3, in Example 3, when a 10 μm Ni ball was added to the solder cream, the connection material thickness could not be obtained, and each test result was poor (moisture absorption reflow test: short, thermal shock test: resistance However, when a 45 μm Ni ball was added, no void was confirmed, and each test was good.

  Similarly, in Example 4, when a 10 μm resin ball was added to the conductive adhesive A, the connection material thickness could not be obtained, and each test result was poor (moisture absorption reflow test: resistance value open due to steam explosion, thermal shock However, when a 50 μm resin ball was added, voids were not confirmed and each test was good.

Sectional drawing of the component built-in module in Embodiment 1 of this invention. Sectional drawing of the component built-in module in Embodiment 2 of this invention. Sectional drawing of the component built-in module in Embodiment 3 of this invention. Sectional drawing of the component built-in module in Embodiment 4 of this invention. Sectional drawing of the component built-in module in Embodiment 5 of this invention. Sectional drawing of the component built-in module in Embodiment 6 of this invention. (A)-(f) is process sectional drawing which shows the manufacturing method of the component built-in module in Embodiment 7 of this invention. (A)-(e) is process sectional drawing which shows the manufacturing method of the component built-in module in Embodiment 8 of this invention. (A)-(e) is process sectional drawing which shows the manufacturing method of the component built-in module in Embodiment 9 of this invention. Sectional drawing of the component built-in module in Example 1 to 4 of this invention. An example sectional view of a component built-in module of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component 2 External electrode 3 Connection material 4 Wiring pattern 5 Electronic insulation material 6 Inorganic filler 7 Conductive via 8 Core layer 9 Electrical connection surface 10 of electronic component Wiring pattern lower surface 11 Distance between electric connection surface of electronic component and lower surface of wiring pattern 12 conductive filler 13 nonconductive filler 14 second filler 15 carrier 16 wiring board 17 metal plate

Claims (1)

Including a core layer made of an electrical insulating material of a mixture containing at least an inorganic filler and a thermosetting resin, and a plurality of conductive vias formed inside the core layer;
A method of manufacturing a component built-in module having a plurality of wiring patterns formed in the core layer and at least one electronic component electrically connected to the wiring pattern and embedded in the core layer There,
Applying a connection material containing a non-conductive filler having a resin, a conductive filler, and an average particle size larger than the average particle size of the inorganic filler to a desired position on the metal plate;
Mounting electronic components on the connection material;
The electronic component is embedded in the core layer made of the electric insulating material, and the electric insulating material is filled between an electric connection surface of the electronic component and a surface of the metal plate in contact with the core layer. Filling the bottom gap small or completely;
Processing the metal plate to form a wiring pattern,
A method for manufacturing a module with a built-in component, wherein an interval between the electrical connection surface of the electronic component and the metal plate is larger than an average particle size of the inorganic filler contained in the electrical insulating material.

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