JP2010129604A - Circuit board and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board and its manufacturing method using a common wiring material which have different thicknesses, and a simple transfer technology, in particular, which is most suitable for preparing conductor layers on the same substrate which are most suited for a signal and power. <P>SOLUTION: The circuit board has an insulating resinous substrate 1 having a first main surface 1a and a second main surface 1b, and first and second conductor layers 2 and 3 that are buried in the first main surface side 1a of the insulating resinous substrate 1 and have different thicknesses wherein the first and second conductor layers 2 and 3 are patterned so that they are juxtaposed in a direction along the first main surface 1a, and buried so that respective outer surfaces located in the first main surface side 1a may be on the same plane. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit wiring board and a manufacturing method thereof, and more particularly to a circuit wiring board having a signal circuit wiring layer and a power circuit wiring layer provided on the same substrate, and a manufacturing method thereof.

  In recent years, as the demands for miniaturization, thinning, and multi-functionality of various electronic devices have increased, not only miniaturization / thinness / multifunctionality of circuit wiring boards incorporated in such devices, but also high-density wiring There is an increasing demand for higher current capacity for increasing the speed of signal transmission and energizing power elements such as power semiconductor elements.

  In order to meet such a requirement, a technique of a wiring board having a structure in which a thin conductor wiring as a signal wiring and a thick conductor wiring as a power wiring is conventionally disclosed in Patent Document 1.

  As shown in FIGS. 1 and 2, the technique of the wiring board disclosed in Patent Document 1 is a method of plating a patterned metal film 2 on the surface of a roughened stainless steel transfer substrate 1. The metal piece 3 having a pattern shape matching a part of the pattern of the metal film 2 is overlapped on the surface of the metal film 2 and bonded. In the pattern, a portion of the metal film 2 where the metal piece 3 is not laminated is a thin conductor wiring (signal wiring) 7 by the metal film 2 itself, and the metal piece 3 is formed on the metal film 2. The parts that are laminated and joined are used as the thick conductor wiring (power system wiring) 6 and the electronic component mounting portion 8.

  In such a conventional technique, when the metal film 3 is deposited on the surface of the transfer substrate 1 by plating, the roughening treatment of the surface of the stainless steel transfer substrate 1 is moderately performed between them. In order to obtain the peel strength, it is necessary to adjust the roughness with high accuracy, and the setting of the plating treatment conditions for the metal film 3 on the transfer substrate 1 is complicated.

Further, the metal piece 3 is formed by a multilayer material in which a plurality of metal materials are laminated (copper, various invar alloys, copper are laminated in this order in order to obtain reliable bonding to the surface of the metal film 2 and the like. The clad material obtained in this manner is complicated in its production and causes an increase in material costs. Further, in order to join the metal piece 3 to the surface of the metal film 2, special joining means such as soldering, metal-to-metal joining or ultrasonic joining is required. Furthermore, it is necessary to obtain a high overlay position accuracy of the pattern of the metal piece 3 and the metal film 2, and if the overlay shift occurs, various problems such as the electrical characteristics such as the current capacity of the wiring deviate from the design value. There is a point.
Japanese Patent Application Laid-Open No. 2005-312102

  The present invention solves the above-described problems. In particular, a common wiring material or a simple transfer technique is used to provide conductor layers having different thicknesses suitable for signals and power on the same substrate. It is an object of the present invention to provide a suitable circuit wiring board and a manufacturing method thereof.

  A circuit wiring board according to a first aspect of the present invention includes an insulating resin substrate having a first main surface and a second main surface, and first insulating layers that are embedded on the first main surface side of the insulating resin substrate and have different thicknesses. And the second conductor layer, wherein the first and second conductor layers are respectively patterned in a relationship of being juxtaposed with each other in a direction along the first main surface, and are arranged on the first main surface side. The surface is embedded so that it may mutually become the same surface.

  According to a second aspect of the present invention, in the circuit wiring board according to the first aspect, the first and second conductor layers are formed as a signal circuit wiring layer and a power circuit wiring layer, respectively, and the first conductor The thickness of the layer is thin enough for fine patterning, whereas the thickness of the second conductor layer is thick enough for high current capacity.

  According to a third aspect of the present invention, in the circuit wiring board according to the second aspect, an electronic component is mounted on a part of the inner surface of the first conductor layer, and the electronic component is embedded in the insulating resin substrate. It is characterized by being.

  According to a fourth aspect of the present invention, in the circuit wiring board according to the second or third aspect, the second conductive layer having a thickness thicker than the first conductive layer is configured to dissipate heat in which circuit elements are mounted. It is a body.

  According to a fifth aspect of the present invention, in the circuit wiring board according to any one of the first to fourth aspects, the third conductive layer having a thickness different from that of the first and second conductive layers is The third conductor layer is embedded along the first main surface of the insulating resin substrate so that the outer surface thereof is flush with the outer surfaces of the first and second conductor layers. It is characterized by that.

  A sixth aspect of the present invention is the circuit wiring board according to any one of the first to fifth aspects, comprising a flexible circuit wiring board using a flexible material as the insulating resin substrate. Features.

  The method for producing a circuit wiring board of the present invention according to claim 7 includes: (A) a first conductor layer base material is detachably bonded to a film-like first transfer base material, and the first conductor layer base material is attached to the first conductor layer base material. Forming a patterned first conductor layer as a signal circuit wiring layer by patterning; and (B) forming a thick patterned second conductor layer thicker than the first conductor layer. (C) the first and second conductor layers are juxtaposed with each other along the first main surface of the flat insulating resin substrate having the first and second main surfaces; Embedded in one main surface side, and (D) peeling the transfer substrate to expose the outer surfaces located on the first main surface side of the first and second conductor layers. It is characterized by.

  According to an eighth aspect of the present invention, in the method for manufacturing a circuit wiring board according to the seventh aspect, in the step (B), (B-1) the second conductor layer base material is formed into a film-like second transfer group. A step of forming a second conductor layer by patterning the second conductor layer base material by etching, and the step (C) includes (C-1) the first and first steps. (2) performing the alignment of the transfer base material and the insulating resin substrate, and embedding the patterned first and second conductor layers on the first main surface side of the insulating resin substrate. To do.

  According to a ninth aspect of the present invention, in the method for manufacturing a circuit wiring board according to the seventh aspect, the step (B) comprises (B-2) a second conductor plate or foil-shaped single conductor material. A step of forming a patterned second conductor layer by punching a conductor layer substrate, and the step (C) includes (C-2) the first conductor of the first transfer substrate. After the second conductor layer is juxtaposed with the first conductor layer in a peelable manner on the surface to which the layer is bonded, the first and second conductor layers are attached to the first main surface side of the insulating resin substrate. It has the process of burying in.

  According to a tenth aspect of the present invention, in the method for manufacturing a circuit wiring board according to any one of the seventh to ninth aspects, a resin adhesive film is used as the transfer base material.

  The present invention according to claim 11 is the method for manufacturing a circuit wiring board according to claim 10, wherein the adhesive material constituting the surface of the resin adhesive film is a slightly adhesive resin, a UV curable resin, a UV extinction resin, and a heat A material selected from the group of foamed resins.

  In the circuit wiring board and the manufacturing method thereof of the present invention, the first and second conductor layers 2 and 3 having different thicknesses constituting the signal circuit wiring layer, the power circuit wiring layer, and the circuit element mounting, It can be provided on the same substrate using a general wiring material or a simple transfer technique.

  Further, the first and second conductor layers individually patterned and juxtaposed to each other and embedded on the first main surface side of the insulating resin substrate are formed by the metal piece 3 and the metal film 2 as in Patent Document 1. Since it is not necessary to use a special piece of metal 3 made of a superposition bonding or a multilayer material, both can be formed of a single kind of metal material, so that a circuit wiring board with a low material cost and a low manufacturing cost can be obtained.

  Further, the alignment of the first and second conductor layers juxtaposed with each other can be easily performed without requiring the same accuracy as in the case of the superposition of the metal piece 3 and the metal film 2 in Patent Document 1. The manufacturing process of the wiring board is simplified.

  The first and second conductor layers are both designed to have electrical characteristics such as a predetermined current capacity, but the metal piece 3 and the metal film 2 are overlapped as in Patent Document 1. Since there is no problem such as misalignment, the circuit wiring board of the present invention has various effects such as easily obtaining electrical characteristics according to the circuit pattern design values of the first and second conductor layers. Can do.

  Hereinafter, Embodiments 1 to 4 according to a circuit wiring board and a manufacturing method thereof according to the present invention will be sequentially described with reference to FIGS. In addition, about the same or similar part through FIGS. 1-4, the same referential mark may be attached | subjected and the detailed description may be abbreviate | omitted.

[Embodiment 1]
FIG. 1A to FIG. 1H are cross-sectional views showing a method of manufacturing a circuit wiring board according to the first embodiment of the present invention, and FIG. 1H shows the circuit wiring board of the first embodiment. It is sectional drawing which shows the structure of the main-body part which is a main part.

  First, the structure of the circuit wiring board according to the first embodiment will be described with reference to FIG. 1 (h). The flat insulating resin substrate 1 has a first main surface 1a (upper surface in the drawing) and both surfaces thereof, respectively. It has the 2nd main surface 1b (lower surface in a figure), for example, is formed using the material suitably selected from the prepreg, the thermosetting resin, and the thermoplastic resin. Further, in order to cope with a case where a circuit wiring board is mounted on a bending operation site of an electronic device, the insulating resin substrate 1 is made flexible such as polyimide resin (PI) or liquid crystal polymer resin (LCP). It is preferable to use an abundant flexible film and provide an adhesive layer on the surface to constitute an insulating resin substrate.

  On the first main surface 1a side of the insulating resin substrate 1, a first conductor layer 2 and a second conductor layer 3 having different thicknesses are embedded in a relationship juxtaposed in the direction along the first main surface 1a. ing. The first and second conductor layers 2 and 3 in the juxtaposed relationship have shapes patterned on the basis of the respective pattern designs, and are exposed to the respective outer surfaces (see FIG. The middle and upper surfaces are embedded so that they are flush with each other.

  Accordingly, the patterns of the first and second conductor layers 2 and 3 do not overlap each other in the thickness direction, and are arranged in a complementary relationship within the plane of the first main surface 1a. . Strictly speaking, the outer surfaces do not necessarily have to be flush with each other on the basis of the first main surface 1a, but here they are embedded so as to be flush with each other. ing.

  Here, the first conductor layer 2 is formed as a signal circuit wiring layer. In order to increase the wiring density, the first conductor layer 2 is finely formed by, for example, a subtractive method so as to reduce the wiring pitch and the wiring width as much as possible. The pattern is formed into a fine pattern. Therefore, the first conductor layer 2 is formed by using a base material made of a copper foil having a thin thickness of, for example, 12 μm or less, for circuit patterning mainly for the miniaturization.

  On the other hand, the second conductor layer 3 is formed as a power circuit wiring layer or a mounting member or a radiator for mounting a semiconductor element (circuit element) such as a transistor or an IC. Further, the second conductor layer 3 does not require much miniaturization as compared with the signal circuit wiring layer, and in order to obtain as large a cross-sectional area as possible mainly for the purpose of increasing current capacity and high heat dissipation efficiency. The substrate is formed by patterning a copper foil or copper plate that is thicker than the first conductor layer 2 and has a thickness of, for example, 18 μm to 210 μm. This pattern shape is not limited to the complicated meandering shape of the power circuit wiring, but also includes a simple shape such as a mounting member or a rectangular shape for the radiator.

  By the way, the circuit wiring board according to the first embodiment has the main body as described above, which is the main part, and is not shown, but on the surface of the first main surface 1a of the insulating resin substrate 1, An insulating coating such as a cover lay film or a coat covering the outer surface of the first and second conductor layers 2 and 3 is applied, a circuit element is mounted on a part of the second conductor layer 2, and the first and second The conductor layers 2 and 3 can be provided with external lead lands to provide external terminals, and can be configured to include members according to user requirements.

  Next, the manufacturing method of the circuit wiring board will be described. As shown in FIG. 1A, the first conductor layer for forming the first conductor layer 2 is formed on the entire surface of one side of the film-like first transfer substrate 4. The base material 2a is detachably bonded to form a copper clad laminate. A thin copper foil having a thickness of 12 μm or less is used for the first conductor layer base material 2a for fine patterning of the first conductor layer 2 as a signal circuit wiring layer.

  As the first transfer substrate 4, a resin adhesive film is used. The main body of the resin adhesive film is a material that is stable against heating in a chemical solution such as a subtractive etching solution in a subsequent patterning step, or in a surface mounting step, a laminating step of each conductor layer, or the like. And a flexible insulating film base material such as polyimide resin (PI), liquid crystal polymer resin (LCP), or polyethylene terephthalate (PET) can be used.

  Moreover, the adhesive material which comprises the surface of the said resin adhesive film (1st transfer base material 4) is adhere | attached on the one-side surface of the said insulating film base material, As a necessary condition, it is stable against heat and can be reliably peeled off with an appropriate peel strength that does not exert excessive tensile or peeling stress on other members in the subsequent peeling process of the transfer substrate. Yes.

  The pressure-sensitive adhesive material suitable for this condition is preferably a material selected from the group of a light-adhesive resin, a UV curable resin, a UV extinguishing resin, and a thermally foamed resin. As such an adhesive material, for example, one sold by Somar Co., Ltd. can be used. Moreover, if the conditions of the said adhesive material are prepared, the main body of the 1st transfer base material 4 can be replaced with the said insulating film base material, and can also be used as a metal film base material. The above-mentioned moderate peel strength is the material and weight (thickness) of the member (conductor layer for circuit wiring) to be adhered to the transfer substrate and the material of the insulating resin substrate for the circuit wiring board as the transfer destination. It can be easily obtained by adjusting the type and composition of the material of the adhesive material according to the type and the like.

  Next, in the step of FIG. 1B, a general subtractive method is applied, and a photosensitive film is deposited on the surface of the first conductor layer base 2a made of a thin copper foil, and is subjected to photolithography. Then, an etching mask having a pattern corresponding to the signal circuit wiring layer is formed. Then, by performing chemical etching with an etching solution (chemical solution), unnecessary copper foil portions are removed by etching to form the first conductor layer 2 having a circuit pattern as a signal circuit wiring layer. At this time, the first conductor layer 2 is formed to have a small cross-sectional area equivalent to a design value capable of receiving a small signal current.

  On the other hand, in the process of FIG. 1C, the second conductor layer base material 3a for forming the second conductor layer 3 is detachably bonded to the entire surface of one side of the film-like second transfer base material 5 so as to be a copper clad laminate. Form. The second conductor layer base material 3a has a thickness of 18 μm in order to increase the current capacity or increase the heat dissipation of the second conductor layer 3 as a power circuit wiring layer or a circuit element mounting portion or a radiator. A thick copper foil having a thickness of ˜210 μm or less is used.

  In the step of FIG. 1D, as in the case of the patterning of the first conductor layer 2, a subtractive method is applied to the second conductor layer substrate 3a made of a thick copper foil, which is unnecessary. The copper foil portion is removed by etching to form a second conductor layer 3 having a circuit pattern as a power circuit wiring layer or a pattern as a circuit element mounting portion or a radiator.

  At this time, the second conductor layer 3 is formed to have a large cross-sectional area equivalent to a design value capable of receiving a large current for power as compared with the first conductor layer 2.

  The pattern of the second conductor layer 3 is spaced from the inner periphery of the planar space S (see FIG. 1B) provided in advance in the pattern of the first conductor layer 2 to the side. The conductor layer 2 does not overlap with each other and is shaped so as to be juxtaposed in a complementary relationship within the plane of the first main surface 1a.

  Incidentally, the second transfer substrate 5 can be made of the same or similar material as the first transfer substrate 4. Further, since the second conductor layer 3 has a thickness and weight larger than those of the first conductor layer 2, the thickness of the insulating film constituting the resin adhesive film for the second transfer substrate 5 and the adhesive material on the surface thereof. The peel strength can be a material adjusted to be larger than that of the first transfer substrate 4 as required. Note that the etching is not limited to chemical etching, and it is also possible to apply a plasma etching method with a small amount of side etching compared to chemical etching.

  Thus, since the second conductor layer 3 is supported by being adhered to the second transfer substrate 5, the second conductor layer 3 can be obtained without using a metal multilayer material such as the metal piece 3 of Patent Document 1. Since it can be composed of a single kind of material such as a copper foil as in the case of the one conductor layer 2, the material cost can be reduced.

  In the step of FIG. 1E, an insulating resin substrate 1 having a planar outer shape equivalent to the film outer shape of each of the transfer base materials 4 and 5 is prepared. The insulating resin substrate 1 has a first main surface 1a and a second main surface 1b on both sides thereof, and a material appropriately selected from, for example, a prepreg, a thermosetting resin, and a thermoplastic resin is used.

  Then, the first conductor layer 2 of the first transfer substrate 4 formed in the step of FIG. 1B is aligned and superposed on the first main surface 1a of the insulating resin substrate 1, and the heating and pressing conditions are set. Laminate below. The first conductor layer 2 is embedded and bonded to the surface layer on the first main surface 1a side of the insulating resin substrate 1 by the lamination, but the outer surface thereof is the same as the surface of the first main surface 1a. It is buried so as to be flush with the height.

  In addition, in order to perform the alignment accurately and reliably, alignment marks (not shown) for mutual alignment are respectively formed in advance on the insulating resin substrate 1 and the first transfer base 4. The alignment marks are formed on the first transfer substrate 4 at the same time during the patterning process for forming the first conductor layer 2 shown in the step of FIG. 1B. It is desirable to perform patterning so that a part remains as an alignment mark.

  In the step of FIG. 1F, the first conductor layer 2 for the signal circuit wiring layer is removed by peeling and removing the first transfer base material 4 from the first main surface 1a of the insulating resin substrate 1. With the outer surface (upper surface side in the figure) exposed, the step of transferring to the surface layer on the first main surface 1a side of the insulating resin substrate 1 (first transfer step) is completed.

  Next, in the step of FIG. 1G, the second conductor layer 3 of the second transfer substrate 5 formed in the step of FIG. 1D is positioned on the first main surface 1a of the insulating resin substrate 1. Laminate together and laminate under heat and pressure conditions. The second conductor layer 3 is embedded and bonded to the surface layer on the first main surface 1a side of the insulating resin substrate 1 by the lamination, and the outer surface thereof is the surface of the first main surface 1a and the second main layer 1a. 1 conductor layer 2 is embedded so as to be flush with the outer surface of the conductor layer 2.

  When embedding the second conductor layer 3, the insulating resin substrate 1 prepared in the step of FIG. 1E is provided with a through hole or a bottomed concave hole corresponding to the pattern shape of the second conductor layer 3 (see FIG. (Not shown) may be formed in advance, and the second conductor layer 3 may be inserted or fitted into the through hole or the recessed hole so that it can be easily embedded with a relatively small pressure. In this case, the resin contained in the insulating resin substrate 1 can be flown by heat and embedded between the peripheral wall of the second conductor layer 3 and the through hole or the recessed hole.

  In the alignment, the second conductor layer 3 is disposed in the plane space S of the pattern of the first conductor layer 2, and the pattern outer periphery of the second conductor layer 3 is the plane space of the pattern of the first conductor layer 2. S is laterally separated from the inner periphery of S, and does not overlap with the first conductor layer 2 but is juxtaposed in a complementary relationship in the plane of the first main surface 1a.

  Thus, since the second conductor layer 3 is not overlapped with the first conductor layer 2 in the thickness direction, the metal piece 3 of Patent Document 1 is specially bonded to the metal film 2 by soldering or the like. The manufacturing cost can be reduced. Further, when compared with the problem of deviation from the design value of the electrical characteristics due to the overlap deviation between the metal piece 3 and the metal film 2 in Patent Document 1, the first and second conductor layers 2 in the present embodiment are described. 3 are not overlapped with each other, and can maintain current capacity values as designed.

  Incidentally, an alignment mark (not shown) for mutual alignment is also formed in advance on the second transfer base 5 in the same manner as the insulating resin substrate 1 and the first transfer base 4. The alignment marks are formed on the second transfer substrate 5 at the same time as one of the second conductor layer substrates 3a during the patterning process of forming the second conductor layer 3 shown in the step of FIG. It is desirable to perform patterning so that the portion remains as an alignment mark.

  In the step of FIG. 1 (h), the second transfer base 4 is peeled and removed from the first main surface 1a of the insulating resin substrate 1 so as to be used for a power circuit wiring layer (or a circuit element mounting portion or a radiator). The second conductor layer 3 is transferred to the surface layer on the first main surface 1a side of the insulating resin substrate 1 with the outer surface (upper surface side in the drawing) exposed (second transfer step). Is completed.

  The main body portion, which is the main part of the circuit wiring board manufactured through the above-described steps in Embodiment 1, may be referred to as a circuit wiring board. Although not shown, the surface of the first main surface 1a of the insulating resin substrate 1 is provided with an insulating coating such as a coverlay film or a coat that covers the outer surfaces of the first and second conductor layers 2 and 3. A circuit element is mounted on a part of the second conductor layer 2 and an electronic component is mounted thereon, or an external terminal is provided on the first and second conductor layers 2 and 3 with external terminals. A thing etc. can also be handled as a circuit wiring board.

  According to the structure and manufacturing method of the circuit wiring board of the first embodiment, the first and second conductor layers 2, 3 having different thicknesses constituting the signal circuit wiring layer, the power circuit wiring layer, and the circuit element mounting. Can be provided on the same substrate using a general wiring material or a simple transfer technique.

  Further, the first and second conductor layers individually patterned and juxtaposed to each other and embedded on the first main surface side of the insulating resin substrate are formed by the metal piece 3 and the metal film 2 as in Patent Document 1. Since it is not necessary to use a special piece of metal 3 made of a superposition bonding or a multilayer material, both can be formed of a single kind of metal material, so that a circuit wiring board with a low material cost and a low manufacturing cost can be obtained.

  Further, the alignment of the first and second conductor layers juxtaposed with each other can be easily performed without requiring the same accuracy as in the case of the superposition of the metal piece 3 and the metal film 2 in Patent Document 1. The manufacturing process of the wiring board is simplified.

  The first and second conductor layers are both designed to have electrical characteristics such as a predetermined current capacity, but the metal piece 3 and the metal film 2 are overlapped as in Patent Document 1. Since there is no problem such as misalignment, the circuit wiring board of the present invention has various effects such as easily obtaining electrical characteristics according to the circuit pattern design values of the first and second conductor layers.

  Then, during the transfer substrate peeling step shown in FIGS. 1 (f) and (h), which will be described later, a decrease in the adhesive strength of the first and second conductor layers 2 and 3 to the insulating resin substrate 1 and peeling. In order to maintain a stable adhesive state with the transfer base materials 4 and 5 until the peeling step, the material selection and composition of the adhesive material are required in order to obtain the peel strength necessary for the maintenance. You just have to make adjustments. The material selection and composition adjustment of this pressure-sensitive adhesive material are performed by adjusting the roughness of the surface of the transfer substrate 1 of the metal film 3 and the metal film on the transfer substrate 1 in Patent Document 1 without the concept of using such a pressure-sensitive adhesive material. Compared with the plating process of No. 3, it is much easier and simpler.

[Embodiment 2]
2 (a) to 2 (h) are cross-sectional views showing the manufacturing method of the circuit wiring board according to the second embodiment of the present invention, and FIG. 2 (h) is a circuit element mounting type according to the second embodiment. It is sectional drawing which shows the structure of this circuit wiring board.

  2A and 2B, the first transfer substrate 4 is thinned by the same method as the process shown in FIGS. 1A and 1B according to the first embodiment. The first conductor layer 2 for the signal circuit wiring layer is formed by patterning the first conductor layer substrate 2a using a copper clad laminate on which the first conductor layer substrate 2a made of copper foil is bonded. At this time, alignment marks for alignment in subsequent processes are patterned.

  In the step of FIG. 2 (c), a second second conductor layer 3 for forming a thick second conductor layer 3 made of a single conductor material of copper foil or copper plate having a planar outer shape equivalent to the film outer shape of the first transfer substrate 4 is used. A conductor layer substrate 3a is prepared. The second conductor layer base material 3a is a thick material thicker than the first conductor layer 2 so as to cope with its large current capacity and high heat dissipation when the mounted circuit element is a high power element. Is used.

  In the step of FIG. 2D, the second conductor layer 3 for power patterned by punching the thick second conductor layer base material 3a is formed. When chemical etching by a subtractive method is applied in patterning, there is a risk that the cross-sectional area may be reduced by side etching as the second conductor layer 3 becomes thicker. Therefore, the punching process is more suitable for the second conductor layer 3. There is an advantage that a large cross-sectional area equivalent to a design value capable of receiving a large current for power can be secured.

  By the way, when the second conductor layer base material 3a is punched, a plurality of parts constituting the pattern of the second conductor layer 3 are separated, and the positional relationship (overall pattern) between the parts cannot be maintained. Need to prevent. For this purpose, punching is performed so that a thin bridge (not shown) for temporary support remains between the adjacent portions. Alternatively, punching is performed so as to leave a temporary support frame pattern (not shown) around the pattern of the second conductor layer 3 and a thin bridge (not shown) between the frame pattern and each of the adjacent parts. Process and temporarily fix the positional relationship between the parts.

  In the step shown in FIG. 2E, the first conductor layer 2 is aligned with the alignment mark provided on the first transfer substrate 4 and the first conductor layer 2 is positioned at the plane space S of the pattern of the first conductor layer 2. Thus, the second conductor layer 3 is adhered to the surface of the first transfer substrate 4 and laminated (may be called a temporary laminate). After the lamination, by removing the bridge, each of the plurality of portions of the pattern of the second conductor layer 3 is made independent of the original shape, and the positional relationship between the portions is determined by the first transfer substrate 4. Maintain as designed.

  In the step of FIG. 2F, an insulating resin substrate 1 similar to that in the step of FIG. Then, the first and second conductor layers 2 patterned on the first main surface 1a of the insulating resin substrate 1 by aligning the insulating resin substrate 1 and the first transfer substrate 4 with each alignment mark, 3 are laminated at the same time and laminated by thermocompression bonding.

  By the laminating, the first and second conductor layers 2 and 3 are embedded and bonded to the surface layer on the first main surface 1a side of the insulating resin substrate 1, and each outer surface thereof is bonded to the first surface. It is embedded so as to be flush with the surface of the main surface 1a. This state is the same as in the case of the process of FIG. As in the case of the first embodiment, the insulating resin substrate 1 may be previously formed with a through hole or a bottomed recessed hole for inserting or fitting the second conductor layer 3.

  In the step of FIG. 2G, the first and second conductor layers 2 for signal and power are removed by peeling and removing the first transfer base material 4 from the first main surface 1a of the insulating resin substrate 1. 3 is transferred to the surface layer on the first main surface 1a side of the insulating resin substrate 1 with each outer surface (upper surface side in the figure) exposed.

  2H, a part of the second conductor layer 3 is used as a mounting part, a circuit element E such as a semiconductor chip is mounted on the mounting part, and a part of the first conductor layer 2 is mounted. The provided land portion or pad portion and the electrode of the circuit element are electrically connected by bonding with a wire W to provide a circuit wiring board mounted with a circuit element. The mounting portion can also function as a heat radiator for the circuit element E.

  Such a circuit wiring board and manufacturing method according to the second embodiment have the same effects as those of the first embodiment, and the second conductor layer 3 can be formed by adopting a punching process as the thickness of the second conductor layer 3 increases. The cross-sectional area of the layer 3 can be increased to the same size as the design value. Further, the number of transfer substrates may be less than that in the first embodiment.

[Embodiment 3]
As shown in FIG. 3, the circuit wiring board according to the third embodiment has a middle-thickness third conductor layer having an intermediate thickness between the first and second conductor layers 2 and 3 according to the first and second embodiments. This is an example in which 6 is added. In this case, the first conductor layer 2 is the thinnest and is provided as a signal circuit wiring layer, and the second conductor layer 3 is the thickest and is provided as a mounting portion or a radiator of the power circuit element E, and the intermediate thickness of the first conductor layer 2 is provided. The third conductor layer 6 is provided as a power circuit wiring layer.

  The pattern formation of the third conductor layer 6 is performed in the same manner as the steps of FIGS. 1A to 1D in the first embodiment and the steps of FIGS. 2A to 1D in the second embodiment. Can be adopted.

  In order to embed the patterned third conductor layer 6 on the first main surface 1a side of the insulating resin substrate 1 in parallel with other conductor layers, the manufacturing steps of Embodiments 1 and 2 are both performed. Can be adopted. That is, when conforming to the first embodiment, the third conductor layer 6 adhered to the third transfer substrate may be prepared in advance and transferred to the first main surface 1 a of the insulating resin substrate 1. When conforming to the manufacturing process of the second embodiment, the third conductor layer 6 patterned by punching is juxtaposed with another conductor layer as shown in FIG. In addition, the first main surface 1a of the insulating resin substrate 1 may be transferred.

  Here, an example of a circuit board mounted with a power circuit element is shown, and the land portion of the third conductor layer 6 and the electrode of the circuit element E are bonded and connected by a wire W. This embodiment is intended to allow multiple types of conductor layers with different thicknesses such as circuit wiring layers for small current, medium current, or large current to be provided on the same circuit wiring board. In this embodiment, the same effects as those in the first and second embodiments can be obtained.

[Embodiment 4]
4 (a) to 4 (i) are cross-sectional views showing the method of manufacturing a circuit wiring board according to the fourth embodiment of the present invention, and FIG. 4 (i) is an electronic component built-in type according to the fourth embodiment. It is sectional drawing which shows the structure of this circuit wiring board.

  The formation of the patterned first conductor layer 2 on the surface of the first transfer substrate 4 in the steps of FIGS. 4A and 4B is different from the first embodiment in the pattern shape of the first conductor layer. Are different in the same manner as in the steps of FIGS. 1 (a) and 1 (b).

  In the step of FIG. 4C, an electronic component P such as a resistor chip or a chip capacitor is mounted by soldering on a land portion provided on a part of the thin first conductor layer 2 by, for example, a surface mounting method.

  On the other hand, the formation of the patterned thick second conductor layer 3 on the surface of the second transfer substrate 5 in the steps of FIGS. 4D and 4E is performed as shown in FIG. ) And the process shown in FIG. 1 (d).

  In the step of FIG. 4F, the first conductor layer 2 and the electronic component P on the first transfer base 4 formed in the step of FIG. 4C are formed on the first main surface 1a of the insulating resin substrate 1. Align and overlap and laminate under heat and pressure conditions. By this lamination, the first conductor layer 2 is embedded and bonded to the surface layer on the first main surface 1a side of the insulating resin substrate 1, but the outer surface thereof is the same height as the surface of the first main surface 1a side. Buried to be flush with each other. The electronic component P is built in a deep position inside the insulating resin substrate 1.

  In the step of FIG. 4G, the first transfer base 4 is peeled by the same method as in the step of FIG. 1F according to the first embodiment, and the first conductor layer 2 is transferred to the insulating resin substrate 1. (First transfer).

  In the step of FIG. 4 (h), the patterned second conductor layer 3 on the second transfer base 5 formed in the step of FIG. 4 (e) is formed on the first main surface 1a of the insulating resin substrate 1. In the same manner as the method described in the step of FIG. 1 (g) according to the first embodiment, the alignment is performed, and the layers are laminated under heating and pressing conditions. By this lamination, the second conductor layer 3 is embedded and bonded to the surface layer of the insulating resin substrate 1 on the first main surface 1a side, but its outer surface is the same height as the surface of the first main surface 1a side. Buried to be flush with each other.

  In addition, if a through hole or a bottomed recessed hole is formed in advance in a portion corresponding to the second conductor layer 3 and the electronic component P in the insulating resin substrate 1 prepared in the step of FIG. It is easy to embed the second conductor layer 3 and the electronic component P.

  In the step of FIG. 4I, the second transfer base material 5 is peeled by the same method as in the step of FIG. 1H according to the first embodiment, and the second conductor layer 3 is transferred to the insulating resin substrate 1. (Second transfer).

  As described above, a circuit wiring board with a built-in electronic component is manufactured. In this embodiment, the circuit elements shown in Embodiments 2 and 3 may be mounted on the second conductor layer 3.

  According to this embodiment, the electronic component P can be easily mounted by a transfer technique and a general surface mounting technique (SMT) and can be built in the circuit wiring board, and the same effects as those of the above embodiments can be obtained. Can do.

It is sectional drawing according to process for showing and explaining the circuit wiring board which concerns on Embodiment 1 of this invention, and its manufacturing method to (a)-(h). It is sectional drawing according to process for showing and explaining the circuit wiring board which concerns on Embodiment 2 of this invention, and its manufacturing method to (a)-(h). It is sectional drawing of the circuit wiring board which concerns on Embodiment 3 of this invention. It is sectional drawing according to process for showing and explaining the circuit wiring board which concerns on Embodiment 4 of this invention, and its manufacturing method to (a)-(i).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation resin board | substrate 1a, 1b The 1st, 2nd main surface 2 of an insulation resin board | substrate 1st conductor layer 2a 1st conductor layer base material 3 2nd conductor layer 3a 2nd conductor layer base material 4 1st transfer base material 5 1st 2 Transfer base material 6 Third conductor layer E Circuit element S Plane space P of first conductor layer pattern Electronic component W Wire

Claims (11)

  An insulating resin substrate having a first main surface and a second main surface; and first and second conductor layers embedded in the first main surface side of the insulating resin substrate and having different thicknesses. The two conductor layers are patterned so as to be juxtaposed with each other in the direction along the first main surface, and are embedded so that the outer surfaces located on the first main surface side are flush with each other. A circuit wiring board characterized by that.   The first and second conductor layers are formed as a signal circuit wiring layer and a power circuit wiring layer, respectively, and the thickness of the first conductor layer is thin enough for fine patterning. 2. The circuit wiring board according to claim 1, wherein the thickness of the two conductor layers is a thickness suitable for increasing the current capacity.   The circuit wiring board according to claim 2, wherein an electronic component is mounted on a part of an inner surface of the first conductor layer, and the electronic component is embedded in the insulating resin substrate.   4. The circuit wiring board according to claim 2, wherein the second conductive layer having a thickness greater than that of the first conductor layer is a heat radiating body on which circuit elements are mounted. 5.   A third conductor layer having a thickness different from that of the first and second conductive layers is embedded in parallel along the first main surface of the insulating resin substrate, and the outer surface of the third conductor layer is the first conductor layer. The circuit wiring board according to claim 1, wherein the circuit wiring board is embedded so as to be flush with the outer surface of the first and second conductor layers.   The circuit wiring board according to claim 1, comprising a flexible circuit wiring board using a flexible material as the insulating resin substrate. (A) The first conductor layer base material is releasably adhered to the film-like first transfer base material, and the first conductor layer base material is patterned to form a patterned first circuit wiring layer. Forming a conductor layer;
(B) forming a thick patterned second conductor layer thicker than the first conductor layer;
(C) The first main surface of the insulating resin substrate in which the first and second conductor layers are juxtaposed with each other along the first main surface of the flat insulating resin substrate having the first and second main surfaces. Embedding on the side,
(D) peeling the transfer substrate to expose each outer surface located on the first main surface side of the first and second conductor layers;
A method of manufacturing a circuit wiring board, comprising: The step (B)
(B-1) A step of bonding the second conductor layer substrate to the film-like second transfer substrate so as to be peelable and patterning the second conductor layer substrate by etching to form a second conductor layer. And
The step (C)
(C-1) The first and second transfer base materials and the insulating resin substrate are respectively aligned, and the patterned first and second conductor layers are arranged on the first main surface side of the insulating resin substrate. The method of manufacturing a circuit wiring board according to claim 7, further comprising a step of embedding in the circuit board. The step (B)
(B-2) having a step of forming a patterned second conductor layer by patterning a second conductor layer base material made of a plate-like or foil-like single conductor material by punching,
The step (C)
(C-2) After the second conductor layer is juxtaposed with the first conductor layer on the surface of the first transfer substrate to which the first conductor layer is adhered, the first conductor layer is peeled and adhered. The method of manufacturing a circuit wiring board according to claim 7, further comprising a step of embedding the second conductor layer on the first main surface side of the insulating resin substrate.   The method for manufacturing a circuit wiring board according to claim 7, wherein a resin adhesive film is used as the transfer base material.   11. The circuit wiring according to claim 10, wherein the adhesive material constituting the surface of the resin adhesive film is a material selected from the group consisting of a slightly adhesive resin, a UV curable resin, a UV extinguishing resin, and a thermally foamed resin. A method for manufacturing a substrate.

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