JPWO2015029783A1 - Manufacturing method of component-integrated sheet, manufacturing method of resin multilayer substrate incorporating electronic component, and resin multilayer substrate - Google Patents

Abstract

A method of manufacturing a component-integrated sheet capable of suppressing deterioration of characteristics while sufficiently preventing misalignment of an electronic component in a resin multilayer substrate incorporating an electronic component, and a resin multilayer substrate incorporating an electronic component Apply the manufacturing method. The present invention is a method for producing a component-integrated sheet in which an electronic component and a thermoplastic resin sheet containing a thermoplastic resin are integrated, and at least a part of one main surface of the electronic component, or A paste applying step of applying a paste containing the same thermoplastic resin as the thermoplastic resin contained in the resin sheet to at least a part of a portion to be bonded to the electronic component on one main surface of the resin sheet; It is a manufacturing method of a component-integrated sheet including a mounting step of mounting a component on the resin sheet via the paste, and a drying step of drying the paste.

Description

  The present invention relates to a method for manufacturing a component-integrated sheet, a method for manufacturing a resin multilayer substrate incorporating an electronic component, and a resin multilayer substrate.

  As a method of manufacturing a resin multilayer substrate incorporating an electronic component, one or more resin sheets having through holes for accommodating electronic components are stacked, and vacuum suction or the like is performed in a cavity formed by the through holes. A method of laminating a resin sheet so as to cover an exposed portion of an electronic component arranged in a cavity after arranging the electronic components individually held by the known technique is known.

  Here, when the size of the cavity (through hole) when viewed in plan is the same as the size of the electronic component, the electronic component does not enter the cavity even if the position of the electronic component is slightly shifted. Therefore, in order to avoid such a situation, the size of the cavity (through hole) is made larger than the size of the electronic component so as to allow the deviation of the maximum deviation width. Therefore, in a state where the electronic component is disposed in the cavity, a gap is generated between the outer peripheral side surface of the electronic component and the inner peripheral side surface of the cavity.

  When such a gap is generated, a region filled with the flow of the resin becomes large at the time of thermocompression bonding for integrating a plurality of resin sheets as a resin multilayer substrate. There has been a problem that the electronic components are likely to be displaced due to the resin flow. In some cases, the circuit pattern around the electronic component (for example, a flat conductor made of metal foil or a via-hole conductor derived from a conductive paste) changes its shape and changes its electrical characteristics, or a short circuit occurs. In some cases, problems such as things happened.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-73763) discloses a method of providing a plurality of protrusions on the inner wall of a through hole of a resin sheet in manufacturing a resin multilayer substrate incorporating such an electronic component. In this method, when the chip component is placed in the cavity, the electronic component is press-fitted while crushing the tips of these protrusions. In this way, since the chip component is fixed from the side by the protrusion, the chip component is moved from a predetermined position by vibration when the chip component is inserted into the surrounding concave portion (cavity), vibration generated when the chip component is conveyed to the next process, or the like. It is described that it is possible to suppress problems such as deviation.

JP 2006-73763 A

  As described above, the gap between the outer peripheral side surface of the electronic component and the inner peripheral side surface of the cavity needs to be large. If this gap is large, the electronic component generated by the flow of resin during thermocompression bonding This is a problem. Even when the through hole is provided with a protrusion as in Patent Document 2, the gap must be secured to a certain extent, and even if the electronic component is prevented from being displaced due to vibration in the manufacturing process, the thermocompression bonding is possible. It was difficult to sufficiently prevent displacement of electronic components due to resin flow. In addition, when the electronic component is placed in the cavity, the protrusion may flip the electronic component, which may cause a problem in the placement of the electronic component.

  Accordingly, the present invention provides a method for producing a component-integrated sheet, which can suppress deterioration of characteristics while sufficiently preventing displacement of the electronic component in a resin multilayer substrate incorporating the electronic component, and an electronic component. An object of the present invention is to provide a method for producing a built-in resin multilayer substrate.

The present invention is a method for producing a component-integrated sheet in which an electronic component and a thermoplastic resin sheet containing a thermoplastic resin are integrated,
The same heat as the thermoplastic resin contained in the resin sheet is applied to at least a part of one main surface of the electronic component or at least a part of a portion bonded to the electronic component on one main surface of the resin sheet. A paste application step of applying a paste containing a plastic resin;
A mounting step of mounting the electronic component on the resin sheet via the paste;
And a drying step of drying the paste.

  The paste preferably includes a fibrillated powder made of the same thermoplastic resin as the thermoplastic resin contained in the resin sheet. The thermoplastic resin contained in the resin sheet preferably contains a liquid crystal polymer as a main component.

Further, the present invention is a method for manufacturing a resin multilayer substrate incorporating an electronic component,
A component-integrated sheet manufactured by the above-described manufacturing method and one or more thermoplastic resin sheets having through holes for accommodating the electronic components are placed in a cavity in which the electronic components are formed by the through holes. A laminating step of laminating so as to be arranged;
The present invention also relates to a manufacturing method including a thermocompression bonding step of thermocompressing the laminated component-integrated sheet and the one or more thermoplastic resin sheets.

Further, the present invention is a resin multilayer substrate including a thermoplastic resin layer containing a thermoplastic resin and a built-in electronic component,
The present invention also relates to a resin multilayer substrate including an adhesive layer made of the same thermoplastic resin as the thermoplastic resin included in the resin layer in at least a part on one main surface of the electronic component.

  In the present invention, by producing a component-integrated sheet in which electronic components are fixed on the surface of the resin sheet in advance, the same misalignment as that of the resin sheet can be achieved while sufficiently preventing displacement of the electronic components in the resin multilayer substrate incorporating the electronic components. By fixing the electronic component to the resin sheet using the material, it is possible to suppress the characteristic deterioration of the resin multilayer substrate.

FIG. 5 is a schematic cross-sectional view for explaining a manufacturing process (paste application process) of the component-integrated sheet according to the first embodiment. FIG. 5 is a schematic cross-sectional view for explaining a manufacturing process (mounting process) of the component-integrated sheet according to the first embodiment. It is a cross-sectional schematic diagram for demonstrating the manufacturing process (lamination process) of the resin multilayer substrate of Embodiment 1. FIG. It is a cross-sectional schematic diagram for demonstrating the manufacturing process (thermocompression bonding process) of the resin multilayer substrate of Embodiment 1. It is a cross-sectional schematic diagram for demonstrating the manufacturing process (paste application | coating process) of the components integrated sheet of Embodiment 2. FIG.

<Manufacture of component-integrated sheets>
In the present invention, the “component-integrated sheet” refers to an electronic component integrated with a thermoplastic resin sheet containing a thermoplastic resin.

  The component-integrated sheet manufacturing method of the present invention includes at least a paste application step, an electronic component mounting step, and a paste drying step.

(Paste application process)
In the paste application step, a paste containing the same thermoplastic resin as the thermoplastic resin contained in the resin sheet is used. Examples of the thermoplastic resin include liquid crystal polymer (LCP), polyethylene (PE), thermoplastic polyimide (PI), polyether ether ketone (PEEK), polyether imide (PEI), and poniphenylene sulfide (PPS). It is done.

  Usually, the thermoplastic resin is dispersed in the paste in the form of a powder, and the paste contains a dispersion medium for dispersing the powder of the thermoplastic resin. The dispersion medium is preferably a liquid that can be removed at a temperature at which the thermoplastic resin does not melt or decompose. As such a dispersion medium, for example, ethanol, terpineol, butyl lactone, isopropyl alcohol, or the like can be used.

  The thermoplastic resin powder contained in the paste is not particularly limited, and may be a powder made of spherical particles or the like, but may be fibrillated (made of the same thermoplastic resin as the thermoplastic resin contained in the resin sheet). Preferably, it is a “fibrillated powder” containing the prepared particles. “Fibrilized powder” (hereinafter sometimes abbreviated as “fibrillated powder”) is composed of particles having a large number of fibrils (for example, fibrillar fibrous branches, fibrillar network structure). A powder that is substantially fibrillated throughout.

  Since the thermoplastic resin constituting the fibrillated powder is the same resin as the thermoplastic resin contained in the resin sheet to which the electronic component is fixed, the thermoplastic resin used in the present invention is a resin that can be fibrillated. It is preferable that Examples of the thermoplastic resin that can be fibrillated include liquid crystal polymer, polyethylene, and polyimide. Among these, a more preferable thermoplastic resin is a liquid crystal polymer.

  Since the fibrillated powder has a large number of fibrils, the fibrillated powder has a large number of voids near the surface and has a low bulk density. The bulk density of the entire fibrillated powder in the dry state is preferably 0.01 to 0.2, more preferably 0.03 to 0.08. For this reason, it is suppressed that a thickness increases too much in the application part of the paste containing a thermoplastic resin because a fibrillated powder is crushed by compression at the time of thermocompression bonding of a laminated body. Thereby, the resin multilayer substrate is easily flattened.

  In order to further improve the adhesion between the particles constituting the fibrillated powder and the adhesion between the fibrillated powder and the resin sheet, at least part of the fibrillated powder is irradiated with ultraviolet (UV) or plasma. Processing may be performed. Note that the surface treatment with ultraviolet rays is more preferable than the surface treatment with plasma because the effect of improving the bonding property is greater.

  The fibrillated powder can be produced, for example, by a method in which a biaxially oriented thermoplastic resin film is pulverized using a freeze pulverization method or the like and further crushed with a wet high-pressure crusher. The wet high-pressure crushing device is a device that passes a dispersion of raw material particles through a high-pressure narrow nozzle (chamber) and crushes the raw material particles by a shearing force generated at that time. In addition, the apparatus which makes a dispersion liquid pass through a narrow nozzle and makes a dispersion liquid collide with a certain target at high pressure may be sufficient.

  As a wet high-pressure crushing apparatus, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-10663 and Japanese Patent Application Laid-Open No. 2001-29776, the raw material supplied to the raw material supply port is pressurized and sent to the apparatus main body. The apparatus which can atomize and take out the substance in a raw material can be used. Here, the substance in the pressurized fluid is atomized to have a desired particle size (determined by the particle size distribution) by merging collision in a through hole, a groove, or the like, or diversion expansion. In addition, a fluid collision device as disclosed in Japanese Patent Application Laid-Open No. 2000-448 can be used for making a substance encased in a fluid into a fine particle by colliding a high-pressure fluid with a hard body. Examples of commercially available wet high-pressure crushing apparatuses include “wet cavitation mill” manufactured by Advanced Nano Technology Co., Ltd.

  In the methods other than using the wet high pressure crusher, only the powder is deformed, and the fibrillated powder is hardly generated. For example, Japanese Patent Laid-Open No. 2002-348487 discloses an LCP composed of a plate-shaped trunk and branches by pulverizing a biaxially stretched film composed of a mixture of a copolymer having reactivity with a liquid crystal polymer (LCP) and LCP. A method for obtaining a filler is described. Japanese Patent Application Laid-Open No. 2004-043624 describes a method for flaking an LCP film by a method such as cutting, crushing, and tapping. However, in any of these methods, a film-like material is used as a starting material, but only a flat plate-like material and a flake-like material are obtained, and a fibrillated powder having a large number of fibrils cannot be obtained.

  The pressure when the LCP powder dispersion passes through the nozzle of the wet high-pressure crushing apparatus is preferably 20 MPa or more, more preferably 50 MPa or more. In order for the pressure when the LCP powder dispersion liquid passes through the nozzle to be in such a desired range, the diameter of the nozzle and the pressure applied at the raw material supply port may be appropriately adjusted.

  Since the fibrillated powder includes particles having a large number of fibrils (fibrillated), the fibrillated powder improves the bondability between the fibrillated particles after the drying step, and improves the bondability between the resin sheet and the electronic component via the paste. Can be improved.

  In addition, the paste containing the fibrillated powder has a higher viscosity than the paste containing the non-fibrillated thermoplastic resin powder, and the dispersion medium and the powder are less likely to be separated. There is no need to add other binder resin components or the like that cause deterioration of electrical characteristics. Further, there is no possibility of problems such as characteristic changes due to moisture absorption and occurrence of popcorn phenomenon due to moisture absorption when used as a circuit board material.

  Such a paste is applied to (1) at least a part on one main surface of the electronic component, or (2) at least a part of a portion to be bonded to the electronic component on one main surface of the resin sheet. In the case of (1), it is preferable that one main surface of the electronic component is a main surface (top surface) opposite to the surface on which the external electrodes of the electronic component are formed.

(Installation process)
In the mounting process, the electronic component is mounted at a predetermined position of the resin sheet via the paste. The electronic component can be mounted using, for example, a general-purpose component mounting machine.

(Drying process)
In the drying step, the paste is dried. As long as the electronic component is fixed (temporarily fixed) to the resin sheet, the drying can be performed by various known methods, and heating may be performed, but heating is not necessarily performed. In addition, it is preferable that the temperature in the case of performing heating is a temperature at which the thermoplastic resin does not melt or decompose. The temperature in a specific drying process is 100-200 degreeC, for example, Preferably it is 130-180 degreeC.

  Heating can be performed using, for example, an oven or a hot plate. Further, when the stage on which the resin sheet and the electronic component are placed in the mounting process has a heating mechanism, the drying process can be performed simultaneously with the mounting process.

<Manufacturing of resin multilayer substrate with built-in electronic components>
The method for producing a resin multilayer substrate incorporating an electronic component according to the present invention includes at least a lamination step of laminating a component-integrated sheet and another thermoplastic resin sheet, and thermocompression bonding of the laminate obtained by the lamination step. Process.

(Lamination process)
In the laminating step, at least the component-integrated sheet manufactured as described above and one or more thermoplastic resin sheets having through holes for accommodating electronic components are laminated. At this time, the electronic components are stacked so as to be disposed in the cavity formed by the through holes.

  In the lamination step, a thermoplastic resin sheet may be further laminated so as to cover the exposed part of the electronic component housed in the cavity. In this case, in the thermocompression bonding process, this thermoplastic resin sheet is also thermocompression bonded.

  Such a lamination process is preferably carried out continuously or simultaneously by a series of operations from the viewpoint of production efficiency and production cost.

  In general, a conductor wiring layer is formed on at least one main surface of the resin sheet constituting the resin multilayer substrate. As a constituent material of the conductor wiring layer, various known materials used for the wiring board can be used, but a metal is preferable. Examples of the metal include copper, silver, aluminum, SUS, nickel, gold, and alloys thereof, and copper or copper alloy is preferable.

(Thermo-compression process)
In the thermocompression bonding step, at least one component-integrated sheet laminated and one or more thermoplastic resin sheets having through holes are heated and pressed by a temperature equal to or higher than the softening start temperature of the thermoplastic resin sheet. Crimp. A thermoplastic resin sheet or the like for covering the exposed part of the electronic component housed in the cavity may be thermocompression bonded at the same time.

  Since the thermoplastic resin sheet easily flows through heat treatment, it is desirable that the heating temperature in the thermocompression bonding process be relatively low.

  In the method for manufacturing a resin multilayer substrate in which the resin sheets thus laminated are collectively thermocompression bonded, productivity and stacking accuracy are greatly improved as compared with a conventional build-up method.

  Hereinafter, an embodiment of a method for producing a component-integrated sheet and a method for producing a resin multilayer substrate incorporating an electronic component will be described with reference to the drawings. In the drawings, the same reference numerals represent the same or corresponding parts. In addition, dimensional relationships such as length, width, thickness, and depth are changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

[Embodiment 1]
(Manufacture of component-integrated sheets)
Referring to FIG. 1, first, a mounter nozzle 6 of a component mounting machine is adsorbed on the surface of the electronic component 4 on the side of the external electrode 41, and in this state, a paste in which a fibrillated thermoplastic resin is dispersed in an organic solvent is used. Applying to the top surface of the electronic component (application process). As this paste, for example, a fibrillated liquid crystal polymer powder of 5 to 20% by weight and the balance made of an organic solvent can be used. Examples of paste application methods include printing, dispensing, and transfer. Note that the paste does not necessarily have to be applied to the entire surface of the electronic component 4 as shown in FIG. 1, and may be applied to at least a part of the portion in contact with the resin sheet 1.

  Next, referring to FIG. 2, a resin sheet 1 is prepared which includes a metal foil 2 mainly composed of copper on one side and a liquid crystal polymer having via-hole conductors 3 as a main component. The via-hole conductor 3 is provided by providing a hole in the resin sheet 1 with a laser or the like and applying a conductive paste containing the hole or the like, for example, silver, copper, nickel, tin. This conductive paste is metallized by heat in a subsequent thermocompression bonding process. Next, the electronic component 4 is positioned at a predetermined position of the resin sheet 1 and the electronic component 4 is mounted on the resin sheet 1 via the paste 5 (mounting process). Note that before the electronic component 4 is mounted, the metal foil 2 may be patterned by etching or the like so as to form a circuit pattern in advance. Further, the metal foil 2 and the via-hole conductor 3 are not necessarily provided.

  Next, the resin sheet 1 on which the electronic component 4 is mounted is held at a temperature of 180 ° C. or higher to dry the paste 5 (drying process). As a result, the organic solvent in the paste 5 is volatilized, and the remaining fibrillated thermoplastic resin develops adhesiveness, whereby the electronic component 4 can be fixed to the resin sheet 1 through the dried product of the paste 5. I can do it. Thus, the resin sheet 1 (component integrated sheet) to which the positioned electronic component 4 is fixed is produced.

(Manufacture of resin multilayer substrates with built-in electronic components)
Referring to FIG. 3, the component-integrated sheet manufactured as described above, the thermoplastic resin sheet 11 having an opening (through hole) for housing electronic component 4, and external electrode 41 of electronic component 4 The thermoplastic resin sheet 12 having the land via 31 electrically connected to the thermoplastic resin sheet 12 and the thermoplastic resin sheet 13 are arranged in the cavity 110 in which the electronic component 4 is formed by the through hole of the resin sheet 11. Are stacked in a predetermined order. Circuit patterns and via-hole conductors 3 made of the metal foil 2 in the plurality of resin sheets 11, 12, and 13 are also provided in the same process as the resin sheet 1. The number of resin sheets is not limited to this embodiment.

  Next, the plurality of laminated resin sheets (resin layers) 1, 11, 12, and 13 are subjected to thermocompression bonding (heating and vacuum pressing) (thermocompression step). 4, the gap between the outer peripheral side surface of the electronic component 4 and the inner peripheral side surface of the cavity 110 is filled by the flow of the thermoplastic resin constituting the resin sheet by the thermocompression bonding process. It has become.

  Furthermore, by cooling the thermocompression-bonded resin multilayer substrate, a resin multilayer substrate having the electronic component 4 built therein is produced. In addition, after this, you may implement the plating of a surface electrode (not shown), loading of other electronic components (mounting components), etc. as needed.

  When the adhesive component for fixing the electronic component to the resin sheet is different from that of the resin sheet, for example, assuming that the resin sheet and the electronic component are bonded with a known adhesive, the laminated resin sheet is heat-treated. At this time, gas may be generated from the adhesive component or the adhesive component may be expanded to cause deterioration of characteristics. However, in the present invention, the adhesive component is the same component (thermoplastic resin) as the resin sheet. Such characteristic deterioration is suppressed. Moreover, since the material different from a resin sheet is not included, the characteristic of a resin multilayer substrate does not change easily. Therefore, circuit design and the like on the substrate can be facilitated. From the above, it is most preferable to use as the paste 5 a paste using a powder obtained by pulverizing the same resin sheet as the resin sheet constituting the resin multilayer substrate.

  In the present invention, since the electronic component is fixed to the resin sheet in advance, it is possible to prevent displacement of the electronic component without requiring a fixing structure in the cavity. In addition, since the resin sheet constituting the component-integrated sheet is used as a surface to hold the electronic component toward the cavity, the electronic component is repelled compared to the case where only the electronic component is conveyed by a conveying device and placed in the cavity. It is suppressed. Therefore, the electronic component can be stably disposed in the cavity even if the cavity is narrowed. Thus, the electronic component can be stably held in the cavity without providing a member such as a protrusion. In addition, since the cavity can be narrowed, it is possible to suppress the positional deviation of the electronic component and the change in the shape of the circuit pattern around the electronic component.

  If the component-integrated sheet is not prepared in advance, a plurality of resin sheets having through holes are first laminated to form a cavity for accommodating the electronic component, and then the electronic component is accommodated in the cavity. Then, a complicated laminating process such as laminating a resin sheet for further coating an electronic component is required. However, by preparing a component-integrated sheet in advance as in the present invention, this component-integrated sheet Can be laminated in the same manner as other resin sheets, which is advantageous in terms of production efficiency and production cost.

[Embodiment 2]
In the present embodiment, in the production of the component-integrated sheet, the paste 5 is applied to the part to be bonded to the electronic component 4 on one main surface of the resin sheet 1 in the paste application process as shown in FIG. This is different from the first embodiment.

  In other respects, the component-integrated sheet is manufactured in the same manner as in the first embodiment, and the resin multilayer substrate incorporating the electronic component is manufactured. In the present embodiment, the same effect as that of the first embodiment is obtained.

  In any of the embodiments, when a paste containing the same thermoplastic resin as the thermoplastic resin contained in the resin sheet is used in the paste application step, at least a part of one main surface of the electronic component has a resin sheet (resin A resin multilayer substrate including an adhesive layer made of the same thermoplastic resin as the thermoplastic resin contained in the layer) is obtained. Such an adhesive layer is made of the same material as the resin sheet. For example, it can be confirmed that the adhesive layer is included by confirming the cross section of the multilayer resin substrate.

  In each embodiment, the electronic component disposed in the cavity is different from an active component such as an IC chip, a passive component such as a chip capacitor, a chip inductor, and a chip resistor, or a resin multilayer substrate such as a ferrite substrate. It is a concept that includes all different types of substrates made of materials.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 11, 12, 13 Resin sheet (resin layer), 110 cavity, 2 conductor wiring layer (conductor foil), 3 via hole conductor, 31 land via, 4 electronic component, 41 external electrode, 5 paste, 6 mounter nozzle.

Claims (5)

A method for producing a component-integrated sheet in which an electronic component and a thermoplastic resin sheet containing a thermoplastic resin are integrated,
The same heat as the thermoplastic resin contained in the resin sheet is applied to at least a part of one main surface of the electronic component or at least a part of a portion bonded to the electronic component on one main surface of the resin sheet. A paste application step of applying a paste containing a plastic resin;
A mounting step of mounting the electronic component on the resin sheet via the paste;
A method for producing a component-integrated sheet, comprising a drying step of drying the paste.   The manufacturing method according to claim 1, wherein the paste includes fibrillated powder made of the same thermoplastic resin as the thermoplastic resin included in the resin sheet.   The manufacturing method according to claim 1, wherein the thermoplastic resin contained in the resin sheet contains a liquid crystal polymer as a main component. A method for producing a resin multilayer substrate incorporating electronic components,
A component-integrated sheet manufactured by the manufacturing method according to claim 1 and at least one thermoplastic resin sheet having a through-hole for accommodating the electronic component, wherein the electronic component is formed by the through-hole. A laminating process for laminating so as to be disposed in the cavity;
And a thermocompression bonding step of thermocompression bonding the laminated component-integrated sheet and the one or more thermoplastic resin sheets. A resin multi-layer substrate including a thermoplastic resin layer containing a thermoplastic resin and a built-in electronic component,
A resin multilayer substrate comprising an adhesive layer made of the same thermoplastic resin as the thermoplastic resin contained in the resin layer, at least in a part on one main surface of the electronic component.

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