JP2004311987A - Multilayered substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize and lower electronic parts by a simple process, to raise a capacity of a capacitor built in a multilayered substrate, and to improve reliability. <P>SOLUTION: In a laminated substrate holding both sides of a thermoplastic resin film 11 with a substrate 13 whose main component is a thermosetting resin, there are provided one or more functional element layers having a capacitor function by forming an electrode 12 on the both sides of the thermoplastic resin film 11. The thermoplastic resin film 11 preferably has a depth of 30μm or less, and a melting point at 200°C or more. Dielectric ceramic powder is dispersed so that the thermoplastic resin film 11 may have a higher dielectric constant than the substrate whose main component is the thermosetting resin, and thereby the thermoplastic resin film 11 functions as a dielectric layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer substrate, and more particularly to a multilayer circuit component structure formed by laminating substrates, sheets, and films based on organic materials.

  In recent years, as electronic devices such as mobile phones and notebook personal computers have become smaller, lighter and thinner, there is a strong demand for electronic components and mounting boards used in these devices to be smaller, denser, and thinner. . As a substrate to be used, an organic multilayer substrate is often used especially as a high-speed element mounting substrate due to a material characteristic having a low dielectric constant. Such an organic multilayer substrate is generally formed by laminating a substrate impregnated with glass cloth.

  On the other hand, those which do not include a glass cloth include substrate structures described in JP-A-8-186376 and JP-A-10-193520. Further, a multilayer substrate on which a thermoplastic film is disposed is disclosed in Japanese Patent Publication No. 7-50831.

JP-A-8-186376 JP-A-10-193520 Japanese Patent Publication No. 7-50831

  By the way, when using a substrate impregnated with glass cloth, there is a limit to thinning due to the presence of glass cloth, and even if an attempt is made to make the substrate thinner, the limit is at most about 40 to 60 μm. Is difficult. Therefore, there is a problem that it is difficult to increase the capacity particularly when a capacitor is formed. Further, in the conventional substrate structure using a glass cloth, the interface between the glass cloth and the resin may be deteriorated by moisture absorption, and thus the reliability may be reduced.

  On the other hand, the structures described in Patent Document 1 (Japanese Patent Application Laid-Open No. 8-186376) and Patent Document 2 (Japanese Patent Application Laid-Open No. 10-193520) do not include a glass cloth, but the former requires sequential lamination. For this reason, it is difficult to lengthen the process, and in the latter case, there is a problem that sufficient heat resistance cannot be obtained because the film is entirely formed of a thermoplastic film. In addition, since thermoplastic films have flexibility, it is easy to make a structure around which the film is wound like a film capacitor, but there are problems with mechanical strength and heat resistance to the soldering temperature during component mounting. Therefore, it is difficult to form a substrate using only a thermoplastic film.

  On the other hand, Patent Document 3 (Japanese Patent Publication No. 7-50831) discloses that a thermoplastic film is used for a multilayer substrate. However, according to the present invention, as is apparent from the necessity of a considerable film thickness (50 to 150 μm), the use of the cushioning property of the thermoplastic film makes it possible to prevent the axial deviation of the drill at the time of forming a through hole. It prevents smearing and does not intend to use a thermoplastic film as a functional element layer.

  Therefore, an object of the present invention is to reduce the size and height of an electronic component by a simple process, and to further increase the capacitance of a capacitor incorporated in a multilayer substrate and improve reliability.

  In order to achieve the object and solve the problem, a multilayer substrate according to the present invention is a laminated substrate in which both surfaces of a thermoplastic resin film are held by a substrate mainly composed of a thermosetting resin, It is characterized in that one or more functional element layers having a capacitor function by forming electrodes on both surfaces of a resin film are provided.

  Further, the method for producing a multilayer substrate according to the present invention includes one or more functional element layers having a capacitor function formed by arranging electrodes on both surfaces of a thermoplastic resin film, and the thermoplastic resin film A method for manufacturing a multilayer substrate having both surfaces held by a substrate mainly composed of a thermosetting resin, wherein the electrodes are arranged on the thermoplastic resin film or the substrate mainly composed of the thermosetting resin. A forming step and a pressing step of heating and integrating the thermoplastic resin film and the substrate containing the thermosetting resin as a main component.

  In the multilayer substrate and the method for manufacturing a multilayer substrate according to the present invention, since the capacitor layer can be thinned by using a thermoplastic film for forming the capacitor, the capacity of the capacitor can be increased. Further, it is possible to reduce the thickness and height of a substrate having a built-in functional element and an electronic component / functional module formed using the substrate. In addition, according to the thermoplastic thin film, good handling characteristics can be obtained without using a glass cloth, so that it is possible to avoid the moisture absorption deterioration conventionally caused at the interface between the glass cloth and the resin. In addition, the reliability of electronic components can be improved. Further, as can be seen from the fact that the thermoplastic resin is used for the dielectric layer of the film capacitor, the thermoplastic resin exhibits flexible physical properties, so that there are few problems such as cracks and cracks, and it is easy to form a thin film. is there. For this reason, even if a thin film substrate of 30 μm or less, which cannot be obtained by using a thermosetting resin such as a glass epoxy (glass cloth-epoxy) substrate which is usually used as a resin substrate material, it can be easily formed by using the thermoplastic resin. Thus, the capacitance of the capacitor element formed inside the substrate can be increased.

  In addition, by holding both surfaces of the thermoplastic resin film on a substrate mainly composed of a thermosetting resin, the low heat resistance of the thermoplastic resin is compensated for, and the substrate deformation due to heat during a multilayering process or solder reflow is prevented. Can be prevented.

  The thermoplastic resin film may have a thickness of 30 μm or less. Further, a film having a melting point of 200 ° C. or more may be used as the thermoplastic resin film. Further, a dielectric ceramic powder is dispersed in the thermoplastic resin film so as to have a higher dielectric constant than a substrate containing the thermosetting resin as a main component, and the thermoplastic resin film functions as a dielectric layer. It may be.

  The electrode may be embedded in a substrate containing the thermosetting resin as a main component.

  According to such a configuration, the thickness of the dielectric layer (thermoplastic resin film) sandwiched between the two electrodes even after the laminating step of holding both surfaces of the thermoplastic resin film with the substrate containing a thermosetting resin as a main component. Therefore, a capacitor having a thinner (large capacity) and more accurate capacitance value can be formed.

  In order to embed the electrode on the substrate side mainly composed of a thermosetting resin, for example, a thermoplastic resin film on which the electrode is formed is formed by two uncured or semi-cured thermosetting resin prepregs. What is necessary is just to carry out by pinching, heating and pressurizing and integrating.

  Further, another method of manufacturing a multilayer substrate according to the present invention includes at least one functional element layer having a capacitor function formed by arranging electrodes on both surfaces of a thermoplastic resin film, and the thermoplastic resin A method for producing a multilayer substrate in which both surfaces of a film are held by a substrate containing a thermosetting resin as a main component, an electrode forming step of arranging the electrodes on the thermoplastic resin film, and the thermoplastic resin film And a pressing step of heating and integrating the substrate mainly composed of the thermosetting resin at a temperature lower than the melting point of the thermoplastic resin film.

  When the thermoplastic resin film softens and flows when the thermoplastic resin film is sandwiched between substrates composed mainly of thermosetting resin and press-formed, the thickness of the dielectric layer forming the capacitor changes. As a result, inconveniences such as a failure to obtain predetermined characteristics occur.

  In the method for producing a multilayer substrate according to the present invention, in the pressing step, the thermoplastic resin film and the substrate containing a thermosetting resin as main components are integrated by heating at a temperature lower than the melting point of the thermoplastic resin film. This inconvenience can be avoided. In this case, if the temperature at the time of heating and integrating is lower than the melting point of the thermoplastic resin film by 50 ° C. or more, the deformation of the thermoplastic resin film can be more reliably prevented. According to such a manufacturing method, particularly, there is an advantage that a capacitor layer (functional element layer having a capacitor function) can be formed thinly and accurately.

  Other objects, features, and advantages of the present invention will become apparent from the following description of embodiments and examples of the present invention.

  ADVANTAGE OF THE INVENTION According to the multilayer board | substrate which concerns on this invention, a small-sized and low profile of an electronic component can be aimed at by a simple process, Furthermore, it becomes possible to increase the capacity | capacitance of the capacitor built in a multilayer board, and to improve the reliability. .

  Other objects, features, and advantages of the present invention will become apparent from the following description of embodiments and examples of the present invention.

  Hereinafter, embodiments of the present invention (hereinafter, referred to as the present embodiment) will be described with reference to the accompanying drawings. 1 to 5 show a multilayer substrate according to the present embodiment. As shown in these figures, this multilayer board is one in which a thermoplastic resin film 11 and a thermosetting resin board 13 (or prepreg material) are each used in one or more layers to form a multilayer circuit board.

  As shown in FIG. 1, a predetermined pattern of electrodes 12 is provided on both surfaces of the thermoplastic resin film 11 by a conductor pattern forming method, thereby forming a dielectric layer (capacitor). The type of the thermoplastic resin film 11 to be used is not particularly limited as long as it satisfies intended dielectric properties and heat resistance and has low moisture absorption (preferably 0.5% or less). However, from the viewpoint of heat resistance, it is desirable to use a material having a melting point of 200 ° C. or higher (for example, 200 to 400 ° C.). Specifically, for example, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polyimide, polytetrafluoroethylene (PTFE) and polyallyl ether nitrile (PEN), polyethylene terephthalate (PET) and the like can be used. The resin materials usable in the present invention and their properties are shown in Table 1 below.

  When used as an electronic component, it is heated to a temperature of about 260 ° C. to 300 ° C. during mounting. As is clear from Table 1, when the melting point of the resin film for a capacitor is less than 200 ° C., Deformation is remarkable, and the capacitance value of the capacitor greatly decreases due to contraction and elongation (see the rightmost column in Table 1). For this reason, the heat-resistant temperature needs to have a melting point of 200 ° C. or higher, preferably 260 ° C. or higher. In addition, the reason for this has been that eutectic solder has been required to have a heat resistance of about 230 to 260 ° C. at the time of mounting by reflow, but mounting with Pb-free solder has been required from the viewpoint of environmental considerations in recent years. There is a growing need for heat-resistant electronic component materials capable of withstanding a reflow temperature of 260 to 350 ° C. Further, the thermoplastic resin film has a drawback that the shape retention property against heat is poor, but if both sides are reinforced with a thermosetting resin as in the present invention, the reflow is higher by 50 to 60 ° C. than the melting point of the thermoplastic resin film. Can withstand temperature.

  Furthermore, referring to the same table, regarding the water absorption, it is desirable that the water absorption is small in the capacitor. When water is absorbed, Q is reduced, leading to a reduction in characteristics. Also, in terms of reliability, it is anticipated that the presence of moisture will cause a decrease in insulation properties and cause a failure. In addition, there is a possibility that the metal used for an electrode or the like may cause migration of the metal, so that a resin portion forming an insulating material is desired to have low water absorption. For example, when an epoxy resin is used as a capacitor by forming electrodes on both sides of a dielectric film, and when the capacitor is left in a high-temperature and humidity-proof test chamber at a temperature of 85 ° C. and a humidity of 85% for 500 hours, the Q value is measured. , 35% to 45% lower than before the humidity resistance test. This is considered to be because the water absorption of the epoxy resin increased to 2 to 3% in the moisture resistance test. In the present invention, as shown in Table 1, a thermoplastic resin having a water absorption of 0.5% or less is used. Therefore, even when a high-temperature humidity resistance test is performed under the same conditions, the Q value hardly fluctuates. Absent.

  The thickness of the thermoplastic resin film 11 is desirably 30 μm or less (for example, 4 to 30 μm), and more preferably 10 μm or less (for example, 4 to 10 μm) in order to increase the capacity of the formed capacitor. I do. The film can be formed by a method such as extrusion or casting.

  The metal film to be the electrode 12 can be formed on the thermoplastic resin film 11 by sticking or plating a metal foil. However, a dry method such as sputtering, vapor deposition, or CVD that can form a smoother metal film can be used. Preferably, According to these dry film forming methods, unevenness such as an electrolytic metal foil does not occur, so that it is possible to prevent local electric field concentration when used as a counter electrode of a capacitor. The reliability of the module can be improved.

  As a material of the metal film (capacitor electrode 12), copper or nickel is preferable. However, other materials can be used as long as they have conductivity, and the material is not limited to these. It is also possible to add a metal having a strong oxygen affinity, such as Ti or Cr, whereby the adhesion to the film can be increased. A predetermined pattern is formed on the formed metal film by a photolithographic etching process.

  In forming the capacitor layer, in addition to the method of forming the electrodes 12 on the thermoplastic film 11 in advance as shown in FIG. 1, the electrodes are formed on the surfaces of two thermosetting substrates 13 as shown in FIG. 12 (FIG. 2A), the two thermosetting substrates 13 may be integrated with the thermoplastic resin film 11 interposed therebetween. In this case, the formation of the conductor (electrode 12) on the thermosetting resin substrate 13 can be performed by attaching a copper foil in addition to the metal film forming method as described above.

  Then, the thermoplastic film and the thermosetting resin base material are alternately laminated, for example, to form a multilayer substrate as shown in FIGS. In each layer to be laminated, a functional element such as a coil 15 and a resistor can be formed in addition to the capacitor 12, and a chip component 21 such as an IC, a transistor, or a diode can be mounted on the surface of the multilayer substrate. .

It is also possible to add an inorganic filler to the thermoplastic resin film 11 as appropriate. For example, in order to increase the capacitance of the _{capacitor, BaO-TiO 2 -Nd 2 O} 3 based, BaO-TiO ₂ -SnO _{2 based, BaO-TiO 2 -Sm 2 O} 3 _{based, PbO-BaO-Nd 2 O} 3 -TiO ₂ system, BaTiO ₃ system, PbTiO ₃ system, SrTiO ₃ system, CaTiO ₃ system, (Ba, Sr) TiO ₃ system, Ba (Ti, Zr) O ₃ system, BaTiO ₃ —SiO ₂ system, SrZrO ₃ system, BiTiO _{4 system, (Bi 2 O 3, PbO} ) -BaO-TiO 2 based, La ₂ Ti ₂ O ₇ based, Nd ₂ TiO ₇ system, (Li, Sm) TiO ₃ system, MgTiO ₃ system, Mg ₂ O ₄ system , Al ₂ O ₃ system, TiO ₂ system, BaO-SiO ₂ system, PbO-CaO based, BaWO ₄ system, CaWO ₄ based, Ba (Mg, Nb) O 3 based, Ba (Mg, Ta) O 3 based, BA (Co, Mg, Nb) O ₃ system, Ba (Co, Mg, Ta) O ₃ system, Sr (Mg, Nb) O ₃ system, Ba (Zn, Ta) O ₃ system, Ba (Zn, Nb) O ₃ system, Sr (Zn, Nb) O ₃ system, Ba (Mg, W) O ₄ system, Ba (Ga, Ta) O ₃ -based, ZnTiO ₃ -based, ZrTiO ₄ -based, (Zr, Sn) TiO ₄ -based dielectric materials are added. These may be added alone or as a mixture of two or more kinds, and may be appropriately selected depending on characteristics desired from these materials.

It is also possible to add a magnetic material. For example, Mn-Zn ferrite, Ni-Zn ferrite, Mn-Mg-Zn ferrite, Ni-Cu-Zn ferrite and oxides of Ba ferrite or the like, _{Fe 2 O 3, Fe 3 O} 4 , etc. It is iron oxide.

  Note that these inorganic fillers may be treated with a surface treatment agent such as a silane coupling agent.

  On the other hand, as the thermosetting resin substrate 13, for example, an epoxy resin, a phenol resin, an unsaturated polyester resin, a vinyl ester resin, a polyimide resin, a cyanate resin, a polybutadiene resin, a polyvinyl benzyl ether resin, or the like can be used. It is also possible to use a prepreg obtained by dissolving these resin materials in a solution, impregnating a support such as glass cloth, glass nonwoven fabric, or aramid nonwoven fabric and drying. However, it is not always necessary to impregnate the various supports such as the glass cloth and the like, and the support may be omitted if desired strength is obtained.

  The advantages of the present invention by using a thermoplastic resin film are as follows.

  The thermoplastic resin is easy to form a thin layer and has flexibility even when thinned, so that it is hard to be broken and hardly causes a problem such as a crack. Further, since it can be handled as a film, it is possible to easily form an electrode made of copper or the like having high adhesion on both surfaces by sputtering or the like. Another advantage is that a material having a small dielectric loss tangent (tan δ) can be selected. Therefore, by using a thermoplastic resin as a functional element layer in a multilayer substrate, a high-capacity capacitor layer can be formed in a substrate by a simple process (the acquisition capacity of a capacitor that can be formed in one layer is improved). As a result, it is possible to reduce the number of stacked substrates, and to achieve a reduction in the size and thickness of electronic components / modules. Furthermore, according to the thermoplastic thin film, good handling characteristics can be obtained without using a glass cloth, and a low-hygroscopic material can be used as a material for the dielectric layer. Thus, it is possible to prevent moisture absorption deterioration at the interface between the glass cloth and the resin, which is a problem in the substrate structure, and to improve the reliability of the product.

  Furthermore, when a thermosetting resin is used as in the present invention, the heat resistance of the thermoplastic resin can be covered, and the heat resistance during solder reflow can be ensured. When a thermosetting resin substrate is not used and the substrate is entirely made of a thermoplastic resin, (1) the thermoplastic resin often has a melting point of about 200 to 350 ° C. In addition, there is a problem that (2) in the case of multi-layering, the temperature is raised to near the melting point and each layer is adhered, so that the substrate may be deformed and wiring in the substrate may be displaced. According to the present invention, such a problem can be avoided by disposing a thermosetting resin.

  The present invention can be applied to, for example, an electronic component having a built-in capacitor, or a circuit component obtained by integrating this electronic component with a coil component such as a transformer or a choke coil. And, it is possible to contribute to the miniaturization, reduction in height and reliability of these circuit components, and increase in the capacity of the capacitor.

  Further, in the present invention, as shown in FIG. 6, the electrode 12 forming the capacitor may be configured to be embedded in the substrate 13 mainly composed of a thermosetting resin.

  For example, as shown in FIG. 7, a thermoplastic resin film 11 having electrodes 12 formed on both sides thereof is sandwiched between two uncured or semi-cured thermosetting resin prepregs 13 as shown in FIG. Can be formed.

  According to such a configuration, the functional element layer (thermoplastic resin film) 11 having a capacitor function and the substrate 13 mainly composed of a thermosetting resin are integrated to form the capacitor layer with the thermosetting resin. Since the thickness of the dielectric layer (thermoplastic resin film) 11 does not change even after the step of holding the substrate, a capacitor having a more accurate capacitance value can be formed. This configuration is particularly suitable for forming a capacitor having a thin dielectric layer, a large capacity, and an accurate capacitance value.

A first embodiment of the present invention will be described.
Electrodes are formed on both surfaces of a polyimide sheet (melting point: 380 ° C.) by sputtering. At this time, titanium is laminated with a thickness of 0.005 μm on the surface in contact with the resin, and copper is further laminated thereon with a thickness of 2 μm to form an electrode. Thereafter, electrodes on both sides were completed through a photoresist process so as to have a predetermined capacitor pattern. Next, this was cut into a 10 cm square, arranged in a layered structure so as to form a predetermined circuit, and then heated and pressed (forming temperature: 180 ° C.) to obtain a multilayer substrate structure. At this time, the layers other than the polyimide were epoxy substrates in which glass cloth was embedded. The epoxy substrate used was in a semi-cured state before heating and pressing. Thereafter, through holes were formed to obtain a product. According to this substrate structure, the obtained capacitance per unit area (1.15 pF / mm ² ) per unit area in the capacitor layer could be obtained. In this embodiment, the structure of the electrode between the thermoplastic film and the thermosetting resin substrate is the structure shown in FIG. 6 (embedded on the thermosetting resin substrate side).

A second embodiment of the present invention will be described.
Patterning is performed by a photolithography process so that electrodes are formed on both sides of a liquid crystal polymer film (manufactured by Japan Gore-Tex Corporation) having a copper foil on both sides (melting point: 335 ° C.). Then, lamination is performed by applying heat and pressure (molding temperature: 195 ° C.) so that the vinylbenzyl resin is sandwiched between the prepreg materials coated on the copper foil on both surfaces. Thereafter, patterning is performed on the upper and lower outer copper foils so as to form a coil pattern. Further, after a through hole is formed at the center by a laser, the through hole is made conductive by plating. Also in this embodiment, the structure of the electrode between the thermoplastic film and the thermosetting resin substrate is the structure shown in FIG. 6 (embedded on the thermosetting resin substrate side).

  Further, an external terminal is formed on one of the capacitor electrodes to serve as a ground electrode, and the other electrode is connected so as to be arranged in series between the upper and lower coil patterns. As a result, a T-type LC filter can be configured. This equivalent circuit is shown in FIG. Finally, a protective resist is formed by printing in order to prevent a short circuit with the pattern of the substrate mounted on the upper and lower coils.

A third embodiment of the present invention will be described.
First, an LCP (liquid crystal polymer) (melting point: 320 ° C.) prepared so as to have an addition amount of barium titanate of 60% by weight is formed to have a thickness of 10 μm. This sheet was formed on a copper foil in consideration of the handleability of the film. Next, a copper thin film having a thickness of 0.15 μm is directly formed on the resin surface by sputtering. After that, the sheet is inverted, and the copper foil used as the base material at the time of forming the sheet is removed by etching. Further, on the resin surface from which the copper foil was removed, a copper thin film was formed by sputtering in the same manner as described above so as to have a thickness of 0.15 μm to prepare a thin film as a base of the capacitor.

  Thereafter, in the same manner as in the first embodiment, both sides are completed through a photoresist process so as to have a predetermined capacitor pattern, which is cut into 10 cm squares, and a layer in which a predetermined circuit is formed. It is arranged in a configuration, and a multi-layer substrate structure is formed by a heating and pressing press (forming temperature: 180 ° C.). At this time, the layers other than the thin film were epoxy substrates in which glass cloth was embedded. The epoxy substrate used was in a semi-cured state before heating and pressing. Then, a through hole is formed to obtain a product.

The obtained capacity per unit area in the capacitor layer at this time is shown in Table 3 below. As is clear from this table, the addition of the dielectric material (barium titanate) made it possible to achieve a larger acquisition capacity. When the dielectric film of this embodiment is used, a capacitor with a built-in substrate having a Q value of 100 or more (measured at 1 GHz) and a capacitance per unit area of 1 pF / mm ² or more can be easily formed. Also in this embodiment, the structure of the electrode between the thermoplastic film and the thermosetting resin substrate is the structure shown in FIG. 6 (embedded on the thermosetting resin substrate side).

  In Table 3, epoxy (FR-4) is listed as a comparison. However, since thermosetting resin does not have flexibility in physical properties, there is a problem in strength when used as a substrate for electronic components. Occurs. For this reason, glass cloth is used as a reinforcing material for improving strength. Even if the thickness of the glass cloth is thin, the limit is at most 30 to 40 μm, and the base material impregnated with epoxy is about 60 μm. If the thickness is less than that, it is difficult to mold the sheet thickness of the laminated substrate. Further, the relative permittivity of the epoxy resin differs between Table 1 and Table 3, which is based on the presence or absence of glass cloth. That is, in Table 3, the glass cloth is used as a reinforcing material for the substrate, and the relative dielectric constant is higher due to the higher relative dielectric constant.

A fourth embodiment of the present invention will be described.
First, patterning is performed so that one side of a double-sided copper-clad substrate having a thickness of 100 μm becomes a capacitor electrode. The double-sided copper-clad substrate is in a cured state before heating and pressing. Next, a pattern is formed on the double-sided copper-clad substrate having a thickness of 100 μm so as to face the capacitor electrode. A liquid crystal polymer film (melting point: 290 ° C.) having a thickness of 25 μm is sandwiched between the obtained two substrates, and these substrates are bonded by a vacuum press machine heated to 300 ° C. at a pressure of 2N to form a capacitor layer. Further, the upper and lower coils were formed in the same manner as in the second embodiment to form a T-type filter. In this embodiment, the structure of the electrode between the thermoplastic film and the thermosetting resin substrate is the structure shown in FIG. 2B (embedded on the thermoplastic film side).

A fifth embodiment of the present invention will be described.
As in the second embodiment, patterning is performed by a photolithography process so that electrodes are formed on both surfaces of a liquid crystal polymer film (manufactured by Japan Gore-Tex Corporation) having a copper foil on both surfaces (melting point: 335 ° C.). Then, lamination is performed by heating and pressurizing (molding temperature: 180 ° C.) such that the vinylbenzyl resin is sandwiched between the prepreg materials coated on the copper foil on both sides. Therefore, in this embodiment, the structure of the electrode between the thermoplastic film and the thermosetting resin substrate is the structure shown in FIG. 6 (embedded on the thermosetting resin substrate side). Thereafter, via holes are formed in the upper and lower outer copper foils so as to be above the capacitor portion. At this time, only the vinylbenzyl resin is removed so that the electrode portion of the capacitor is not processed. Thereafter, the via hole is electrolessly plated with copper, and then electrolytically plated to form a capacitor lead. Then, the same process is performed on the other capacitor electrode to form a multilayer substrate as in the first embodiment.

  Although the embodiments and examples of the present invention have been described above, the present invention is not limited to these, and it will be obvious to those skilled in the art that various changes can be made within the scope described in the claims. it is obvious.

  As a preferred embodiment, a form in which a thermoplastic thin film and a thermosetting resin base material are alternately laminated as described above can be considered, but the form is particularly limited as long as there is no problem in terms of heat resistance. Not something. A glass cloth may be put in a thermosetting resin substrate in a layer portion where a capacitor is not formed.

  In addition, as described above, an inorganic filler may be added to the thermoplastic resin film to improve the dielectric constant or to add magnetism, but the thermoplastic resin film or the thermosetting resin substrate In order to improve the reliability of the substrate, it is also possible to add an inorganic filler such as ceramic. If such an inorganic filler is mixed, the coefficient of thermal expansion is reduced, and the coefficient of linear expansion can be made closer to the metal film.Therefore, delamination or disconnection of wiring arranged in the substrate can be prevented, and more. It is possible to provide a high-quality board / component module with high reliability.

FIG. 3 is a cross-sectional view illustrating a capacitor layer of the multilayer substrate according to the embodiment of the present invention. (A)-(b) is sectional drawing which shows the manufacturing process of the multilayer substrate which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view illustrating an example of a multilayer substrate according to the present invention. It is a perspective see-through view showing an example of a multilayer board concerning the present invention. FIG. 3 is a diagram showing an equivalent circuit in the multilayer substrate according to one embodiment of the present invention. It is sectional drawing which shows another example of a structure of the capacitor layer part in the multilayer substrate of this invention. FIG. 7 is a cross-sectional view illustrating a manufacturing process of the capacitor layer portion illustrated in FIG. 6.

Explanation of reference numerals

11 Thermoplastic resin film 12 Capacitor electrode 13 Thermosetting resin substrate

Claims (7)

A laminated substrate in which both surfaces of the thermoplastic resin film are held by a substrate mainly composed of a thermosetting resin,
A multilayer substrate comprising at least one functional element layer having a capacitor function by forming electrodes on both surfaces of the thermoplastic resin film.   The multilayer substrate according to claim 1, wherein the thermoplastic resin film has a thickness of 30 μm or less.   The multilayer substrate according to claim 1, wherein the thermoplastic resin film has a melting point of 200 ° C. or more. 4. The thermoplastic resin film, wherein a dielectric ceramic powder is dispersed so as to have a higher dielectric constant than a substrate containing the thermosetting resin as a main component, and functions as a dielectric layer. Item 13. The multilayer substrate according to Item 1. The multilayer substrate according to any one of claims 1 to 4, wherein the electrode is embedded in a substrate containing the thermosetting resin as a main component. The thermoplastic resin film includes at least one functional element layer having a capacitor function formed by arranging electrodes on both surfaces of the thermoplastic resin film, and both surfaces of the thermoplastic resin film are formed of a substrate having a thermosetting resin as a main component. A method of manufacturing a held multilayer substrate, comprising:
An electrode forming step of arranging the electrodes on a substrate containing the thermoplastic resin film or the thermosetting resin as a main component,
A pressing step of heating and integrating the thermoplastic resin film and the substrate containing the thermosetting resin as a main component,
A method for manufacturing a multilayer substrate, comprising: The thermoplastic resin film includes at least one functional element layer having a capacitor function formed by arranging electrodes on both surfaces of the thermoplastic resin film, and both surfaces of the thermoplastic resin film are formed of a substrate having a thermosetting resin as a main component. A method of manufacturing a held multilayer substrate, comprising:
An electrode forming step of arranging the electrodes on the thermoplastic resin film,
A pressing step of integrating the thermoplastic resin film and the substrate mainly composed of the thermosetting resin by heating at a temperature lower than the melting point of the thermoplastic resin film,
A method for manufacturing a multilayer substrate, comprising:

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