JP4824972B2 - Circuit wiring board and manufacturing method thereof - Google Patents

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 multilayer wiring structure and a manufacturing method thereof.

  In recent years, with the demand for downsizing of electronic devices, there are increasing demands for downsizing, thinning, weight reduction and cost reduction of printed wiring boards (circuit wiring boards) used as electronic components. Conventionally, electronic devices have difficulty in meeting the above requirements due to restrictions in design and manufacturing of various electronic components to be mounted and printed wiring boards themselves. Double-sided multilayer printed wiring boards capable of mounting electronic components and the like have been used.

  This double-sided multilayer printed wiring board requires an interlayer conductive path for electrical connection between the wiring layers on both sides of the board. As a technique for forming the interlayer conductive path, for example, a through-hole method or an interstitial is used. There is a via hole (IVH: Interstitial Via Hole) method. In the former method, through-holes become deeper as the number of multilayered layers increases, and the plating layer thickness on both surfaces of the substrate is thicker than the base in order to form a reliable interlayer conductive path. There is a problem that it becomes thick as desired and there is a problem that it is difficult to mount components at the through-hole position, and the mounting density tends to decrease. On the other hand, the latter IVH method has the advantage that high-density mounting is possible because a good interlayer conductive path is reliably formed for each layer of the multilayered layer and the entire surface of the substrate has a continuous plane. Yes.

  A conventional double-sided multilayer printed wiring board using the IVH system is generally a single-sided copper-clad laminate (hereinafter, single-sided) in which copper foil is laminated on one side of an insulating substrate made of polyimide resin, for example, and the opposite side is exposed. Using CCL (Copper Clad Lamination) as a starting material, a plurality of CCLs are overlapped.

That is, in the conventional double-sided multilayer printed wiring board, for example, a thermoplastic or thermosetting polyimide resin adhesive layer is bonded to the opposite surface (exposed surface) of each insulating substrate of the first and second single-sided CCLs. Means, a means for forming a wiring layer of a desired pattern on the copper foil of each CCL, a means for forming each via hole penetrating each insulating substrate and adhesive layer at a predetermined position of the interlayer conductive path of each CCL, and each via hole A conductive paste made of a conductive resin composition is filled, and means for connecting each end of the conductive paste to the predetermined position of each wiring layer, and an insulating substrate of the second single-sided CCL on the adhesive layer of the first single-sided CCL Overlaying the surface on the wiring layer side and superimposing another copper foil (upper outermost layer) on the adhesive layer of the second single-sided CCL, and necessary alignment such as the planned position of the interlayer conductive path of each CCL It is formed using means for laminating and integrating the overlapping members together by hot pressing and means for forming a wiring layer of a desired pattern on the other copper foil of the uppermost outermost layer (an example) (See FIG. 7 of Patent Document 1 below).
Japanese Patent Laid-Open No. 2003-318546

  However, in the double-sided multilayer printed wiring board of the conventional example, the outermost layer insulating material on one side is constituted by the adhesive layer on the second single-sided CCL side, and the outermost layer insulating material on the opposite side is the first. Since the outermost adhesive layer and the insulating substrate are made of different materials, the multilayer wiring board structure is asymmetric in the thickness direction due to the material arrangement.

  Therefore, the double-sided multilayer printed wiring board bonded by the hot press generates a compressive stress in the substrate due to the shrinkage phenomenon of the adhesive layer, and warps. Furthermore, there is a problem in that the chemical melting of the adhesive layer material progresses due to the solder melting temperature at the time of component mounting on the wiring board, and the compressive stress and the warping of the wiring board increase. In particular, if the wiring board is warped during component mounting, the wiring board may crack or rupture in the electronic component such as a thin film or thick film element, leading to a decrease in the reliability of the component and the constituent circuit. easy.

  The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a circuit wiring board suitable for a multilayer wiring structure and a manufacturing method thereof.

According to a first aspect of the present invention, there is provided the circuit wiring board according to the first aspect of the invention, wherein the first and second insulating substrates are symmetrically overlapped on both surfaces of the film-like first adhesive layer, and the first and second insulating substrates are the same. First and second wiring layers provided on the respective surfaces opposite to the first adhesive layer, and first and second contact portions provided on respective opposing portions of the first and second wiring layers, respectively. A through hole provided through the first and second insulating substrates and the first adhesive layer between the first and second contact parts, and the contact parts provided in the through hole. comprising: a first interlayer conductive member interconnecting the said through-hole penetrates the first first hole penetrating an insulating substrate, a second hole penetrating the first adhesive layer, and a second insulating substrate first has a third hole, the third hole has a larger pore size than said second hole, said Contact area between the second contact portions of the first interlayer conductive member is characterized in that greater than the contact area between the first contact portion.
According to a second aspect of the present invention, in the circuit wiring board according to the first aspect, the first hole and the second hole are formed with the same hole diameter, and the first interlayer conductive member is formed of a conductive resin composition. And a crushing portion that is crushed by being pressed against the second contact portion and bulged into the third hole.

According to a third aspect of the present invention, there is provided the circuit wiring board according to the first or second aspect , wherein the circuit wiring board is interposed between at least one of the first and second contact portions and the first interlayer conductive member. A contact layer having a conductivity higher than that of the one-layer conductive member is provided.

According to a fourth aspect of the present invention, there is provided the circuit wiring board according to any one of the first to third aspects, wherein the third and second surfaces provided on the partial surfaces of the first and second wiring layers, respectively. 4 contact portions, second and third adhesive layers superimposed on the first wiring layer side and second wiring layer side, respectively, and a third superimposed on each surface of the second and third adhesive layers, respectively. And the fourth insulating substrate, the third and fourth wiring layers provided on the surfaces of the third and fourth insulating substrates opposite to the adhesive layers, respectively, and the third and fourth contact portions, respectively. Oppositely, a fifth and a sixth contact part respectively provided in each part of the third and fourth wiring layers, and a third insulating substrate and a second adhesive layer are penetrated between the third and fifth contact parts. A second interlayer conductive member provided in the form of a fourth conductor and a fourth conductor A third interlayer conductive member provided through the fourth insulating substrate and the third adhesive layer between the defect part each other and characterized in that it comprises a.

According to a fifth aspect of the present invention, there is provided a circuit wiring board manufacturing method according to the first aspect of the present invention, wherein the first insulating substrate is provided with a conductive layer for a first wiring layer having a first contact portion on one surface. Overlaying the adhesive layer, providing a first hole penetrating the first insulating substrate and a second hole penetrating the first adhesive layer and communicating with the first hole at a position facing the first contact portion, Forming a first wiring substrate material by filling the first and second holes with a conductive paste and providing a first interlayer conductive member having one end connected to the first contact portion; A conductive layer for a second wiring layer having a second contact portion opposed to the first contact portion is provided on the other surface of the second insulating substrate disposed facing the first adhesive layer, and the second contact portion is provided with the second contact portion. said second insulating substrate penetrates into opposing positions, than the second hole Forming a second wiring board material by providing a third bore formed in Kina pore size, the first to the other end of the first interlayer conductive member is in contact with the second contact portion and a second wiring board material superposed on each other, bonding the first and second insulating substrate to said first adhesive layer both sides symmetrically, the first interlayer conductive member thus the first and second a step of connecting the contact portions cross, is characterized in that it comprises a.

According to a sixth aspect of the present invention, in the method for manufacturing a circuit wiring board according to the fifth aspect , in the step of forming the first wiring board material, the first hole and the second hole have the same hole diameter. The conductive paste is a conductive resin composition, and the first interlayer conductive member causes the other end of the first interlayer conductive member to protrude from the first adhesive layer, and the first interlayer conductive member And the step of connecting the first and second contact portions to each other includes the step of connecting the first and second wiring substrate materials to each other. hot pressed superimposed on each other, the other end of the first interlayer conductive member, the second crushed by being pressed against the contact portion, to form a pinch that bulges into the third bore Rukoto It is characterized by.

  According to the circuit wiring board of the present invention, in the circuit wiring board, in the thickness direction, the adhesive layer is located in the center, and each insulating substrate on which the wiring layers are laminated is symmetrically on both sides of the adhesive layer. Since the layers are symmetrically arranged at the outermost layer positions on both sides, even if the shrinkage phenomenon of the adhesive layer occurs, the stress distribution in the circuit wiring board is equalized, so the occurrence of warpage is remarkably suppressed. The Further, since the third hole has a larger diameter than the second hole, the second contact portion of the second wiring layer and the first interlayer conductive member have a large contact area and are electrically and physically Can be securely connected.

According to the method of manufacturing a circuit wiring board of the present invention, the other end of the first interlayer conductive member is aligned so as to contact the second contact portion, and the first and second wiring board materials are mutually connected. superimposed, said by bonding the first and second insulating substrate on both surfaces first adhesive layer, while connected to the first interlayer conductive member thus said first and second contact portions mutually, the symmetrical structure Therefore, it is possible to easily produce a circuit wiring board having no warp by a simple process.

  Hereinafter, an embodiment of a circuit wiring board of the present invention will be described with reference to FIG. FIG. 1A is an exploded sectional view showing a state immediately before completion of the circuit wiring board, and FIG. 1B is a sectional view showing the circuit wiring board after completion.

  The first wiring board material 1 includes a flat first or film-like flexible first insulating substrate 2, a first wiring layer 3 that is laminated on one side of the first wiring layer 3 and has a first contact portion c 1 at a predetermined position of an interlayer conductive path. A flat or film-like first adhesive layer 4 entirely bonded to the opposite surface of the insulating substrate 2, and one end electrically and physically connected to the first contact portion c1, and the insulating substrate 2 and And a first interlayer conductive member 5 provided through the adhesive layer 4.

  A first hole h1 and a second hole h2 that are coaxial with the first interlayer conductive member 5 and have the same hole diameter are formed in the penetrating portions of the first insulating substrate 2 and the first adhesive layer 4, respectively. Yes. In addition, the first interlayer conductive member 5 is formed in a substantially columnar shape by filling the first and second holes h1 and h2 with a conductive paste described later, and most of the first interlayer conductive member 5 including the root portion is the hole. It is located in h1 and h2, and has a shape in which its tip protrudes from the exposed surface of the first adhesive layer 4 to a desired height.

  The second wiring substrate material 11 disposed opposite to the first adhesive substrate 4 side of the first wiring substrate material 1 is a flat or film-like flexible material using the same material as the first insulating substrate 2. Second insulating substrate 12, and a second contact portion c2 which is laminated on one side (opposite side to the first adhesive layer 4) and has a second contact portion c2 at a predetermined position of an interlayer conductive path corresponding to the first contact portion c1. The wiring layer 13 is provided with a third hole h3 provided through the second insulating substrate 12 at the planned position of the interlayer conductive path.

  The first to third holes h1 to h3 are in communication with each other in a coaxial arrangement, and the third hole h3 has a larger diameter than the second hole portion h2. Further, the protruding height of the front end portion of the first interlayer conductive member 5 is formed to be a height dimension larger than the thickness dimension of the second insulating substrate 12.

  Then, as shown in FIG. 1A, the projecting end portions of the first interlayer conductive member 5 are opposed to each other with the second contact portions c2 being coaxially opposed to and in contact with each other. A circuit wiring board having a double-sided (multi-layer) wiring structure as shown in FIG. 1B is formed by heat-pressing the first and second wiring board materials 1 and 11 together so as to be sandwiched from above and below. Is done.

  In the circuit wiring board integrated in this way, the first to third holes h1 to h3 are formed between the first contact portion c1 and the second contact portion c2 in the first and second insulating substrates. And a through hole penetrating the first adhesive layer.

  The protruding end portion of the first interlayer conductive member 5 has a shape having a crushed portion D5 that is crushed by pressing against the second contact portion c2, and the crushed portion D5 is formed by the second hole portion h2. The third hole h3 has a larger diameter than the third hole h3, and is firmly crimped to the second contact portion c2 with a large contact area (low electrical contact resistance) over a wide range. A physically excellent connection structure is obtained. In addition, when the crushing portion D5 fills the third hole h3, the contact area further increases. Even when the first adhesive layer 1 is not filled, a part of the first adhesive layer 1 can be filled with the hot press to increase the adhesive strength between the members.

  According to the circuit wiring board of the present invention of the above-described embodiment, the first and second insulating substrates 2 that can be composed of the same material with the adhesive layer 4 positioned at the center in the thickness direction of the circuit wiring board. , 12 are symmetrically superimposed on both sides of the adhesive layer 1 and have a symmetrical structure arranged at the outermost layer positions on both sides. Therefore, even if the adhesive layer 1 is contracted or cross-linked, the circuit wiring Since the stress distribution in the substrate is equalized, the occurrence of warpage is remarkably suppressed.

  Accordingly, warping of the wiring board during component mounting is suppressed, and there is no possibility that cracks or tears occur in electronic components such as a wiring board, thin film, or thick film element, and high reliability of the components and constituent circuits can be obtained.

  Further, since the third hole h3 has a larger diameter than the second hole h2, the second contact part c2 of the second wiring layer 13 and the first interlayer conductive member 5 have a large contact area. Securely connected electrically and physically.

  As a base material for each of the insulating substrates and the wiring layers, for example, a commercially available single-sided CCL obtained by laminating, for example, a copper foil (conductive material for wiring layers) on one side of a polyimide resin film (insulating substrate material) is used. In addition, the second insulating substrates 2 and 12 can easily obtain uniform material characteristics as the same material.

  In addition, the conductive paste (conductive resin composition) for the first interlayer conductive member 5 includes a viscous medium containing a solvent, for example, a metal filler (metal powder) as a conductive material mixed in a binder made of phenol resin. They are mixed to form a paste.

  A general conductive paste has conductivity by contact between metal fillers, but here, as the metal filler, when the conductive layer material for the wiring layer is a copper foil like CCL, for example, tin, Of silver, copper, indium, bismuth, and zinc, a combination of particles of at least two elements that are easily fused with the copper foil is preferable.

  Examples of the particle combination include a combination of tin and silver or tin and bismuth. In this case, the first interlayer conductive member 5 has the metal filler as the first and second wiring layers 3, Therefore, electrical connection with a small contact resistance can be obtained because the wiring layers 3 and 13 are physically connected and firmly connected.

  In addition, the adhesion prevents the adhesion layer 1 from entering the contact interface between the first interlayer conductive member 5 and the wiring layers 3 and 13, and the contact contact resistance hardly increases. There are advantages such that deterioration with time in a wet environment is prevented and an improvement in heat and moisture resistance is obtained.

  Next, an example of the manufacturing method according to the circuit wiring board of the embodiment will be described with reference to the process diagrams of FIGS. In FIG. 2, the same parts as those shown in FIG.

  First, in the step of FIG. 2A, a conductive layer for a wiring layer is formed on one surface (upper surface) of a flexible insulating substrate material 21 made of, for example, a polyimide or polyester resin in a flat or film shape. A single-sided CCL laminated with the copper foil 31 is prepared.

  In the step of FIG. 2B, a circuit wiring pattern mask (not shown) is formed on the copper foil 31 by, for example, photolithography, and the copper foil 31 is selectively etched, for example, to perform wiring patterning. The first wiring layer 3 having a desired pattern shape is formed.

  In the step of FIG. 2C, a first adhesive layer using an adhesive resin film mainly composed of, for example, a thermosetting epoxy resin or a thermoplastic polyimide resin, on the other surface (lower surface) of the insulating substrate material 21. The base material 41 is overlaid. Then, the first adhesive layer base material 41 is temporarily attached to the insulating substrate material 21 by heating (about 80 to 120 ° C.) for a short time (about 1 to 10 minutes).

  In the step of FIG. 2D, a masking film 61 made of, for example, polyimide resin or PET (polyethylene terephthalate) is temporarily attached to the entire surface (lower surface) opposite to the first wiring layer 3 of the adhesive layer base material 41. The

  In the step of FIG. 2 (e), a first through hole penetrating the overlapped body of the insulating substrate material 21, the adhesive layer base material 41, and the masking film 61 at a position corresponding to the planned position of the interlayer conductive path. (Via hole) A first hole h1 and a second hole h2 constituting a part of H1 are formed, and the first contact portion c1 of the first wiring layer 3 is exposed. By forming the via hole, the first insulating substrate 2 and the first adhesive layer 4 are formed.

  Here, the via hole H1 is formed by a laser beam processing technique more suitable for fine processing than drilling, and has high dimensional accuracy using, for example, a carbon dioxide (CO2) laser, a UV-YAG laser, or an excimer laser as a laser processing machine. Is opened. In this processing, undesired smears or residues are generated in the via hole. For example, a desmear process using plasma is performed for cleaning.

  Next, in the step of FIG. 2F, the conductive paste in which the metal filler is mixed into the resin binder as described above is filled in the via hole H1 to the exposed surface position of the masking film 61 by, for example, squeezing printing. The first interlayer conductive member 5 is formed.

  Thereafter, the masking film 61 is peeled off from the first adhesive layer 4, one end of the first interlayer conductive member 5 is connected to the first contact part c1, and the other end is an exposed surface (lower surface) of the first adhesive layer 4. The first wiring board material 1 described above is completed.

  The height dimension of the protruding end of the first interlayer conductive member 5 corresponds to the thickness dimension of the masking film 61, and the desired protruding height can be adjusted by selecting the thickness of the masking film 61. In this step (f), if the protrusion height is adjusted to be more than 1 times and twice the thickness dimension of the second insulating substrate 12 described above, the first interlayer conductive member 5 is heated during hot pressing. The bulging crushing part D5 as shown in FIG. 1B is reliably formed at the projecting end, and a good electrical and physical connection state with the second contact part c2 is obtained.

  In the step of FIG. 2 (g), a single-sided CCL as shown in FIG. 2 (a) is prepared as another starting material, and a circuit is formed on a copper foil by, for example, a photolithography technique as in the step of FIG. 2 (b). A wiring pattern mask (not shown) is formed, and the copper foil is selectively subjected to, for example, chemical etching and wiring patterning to form a second wiring layer 13 having a desired pattern shape.

A third hole h3 (via hole) that penetrates the second insulating substrate 12 at the position of the second contact portion c2 of the second wiring layer 13 is formed by the laser beam processing technique as described above. The second wiring board material 11 is completed.

  Therefore, as shown in FIG. 1, the first and second opposing first and second conductive members 5 are positioned so that the protruding end portions of the first interlayer conductive member 5 are coaxially opposed to and in contact with the second contact portion c2. A circuit wiring board having an integrated double-sided (multilayer) wiring structure can be obtained by hot-pressing the second wiring board materials 1 and 11 in a lump so as to be sandwiched from above and below.

  The alignment between the first interlayer conductive member 5 and the second contact portion c2 is performed using, for example, an image processing technique.

  In addition, the batch heat press applies a pressure of about 1 to 5 MPa under a heating temperature of about 150 to 250 ° C. using a vacuum press or a curing press, for example, for about 30 minutes to 2 hours. This is done to hold the press.

  According to one embodiment of the manufacturing method, the symmetrical structure as described above is obtained with a high processing accuracy by a series of processes such as patterning of each wiring layer by photolithography technology, via hole formation by laser processing and collective heat pressing. The circuit wiring board can be easily manufactured.

  Further, since the third hole h3 (via hole) is formed to have a diameter larger than that of the second hole h2, even if the via hole is misaligned, the second insulating substrate 12 is not disturbed. The protruding end portion of the first interlayer conductive member 5 is securely connected to the second contact portion c2, and a crushing portion D5 bulged by hot pressing is formed on the protruding end portion, thereby increasing the contact area. The

  The patterning of the conductive layer for the first and second wiring layers 3 and 13 may be performed after the batch hot pressing step.

  Next, another embodiment of the circuit wiring board of the present invention will be described with reference to FIG. This embodiment provides a circuit wiring board having a via-on-via multilayer wiring structure in which six wiring layers are laminated in the thickness direction, and FIG. (B) is the completed sectional view.

  This multi-layer circuit wiring board uses a circuit wiring board having a two-layer wiring structure made of the first and second wiring board materials 1 and 11 shown in FIG. 1 as a core board CB, as shown in FIG. In addition, two wiring layers are additionally laminated on both surfaces of the core substrate CB.

  This additional laminated portion is constituted by the third to sixth wiring substrate materials 1A to 1D, and each of the wiring substrate materials 1A to 1D is the same by the same manufacturing method as that of the first wiring substrate material 1. It is formed with various constituent members.

  First, the first wiring layer 3 of the first wiring substrate material 1 has a third contact portion c3 provided on a part of the upper surface thereof, and the second wiring layer 13 of the second wiring substrate material 11 is provided. Has a fourth contact portion c4 provided on a partial surface thereof.

  Therefore, the third wiring substrate material 1A is arranged so that the second adhesive layer 4a is superposed and bonded to the upper surface of the first wiring substrate material 1, and the second interlayer conductive member 5a is The third insulating substrate 2a overlapped with the second adhesive layer 4a and the upper surface of the adhesive layer 4a is provided. The second interlayer conductive member 5a has fifth contact portions c5 on the lower surface (inner surface) of the third wiring layer 3a provided on the upper surface of the third insulating substrate 2a. The three contact portions c3 are formed so as to be connected to each other.

  The fourth wiring board material 1B is arranged so that the third adhesive layer 4b is superposed and bonded to the lower surface of the second wiring board material 11, and the third interlayer conductive member 5b. Is provided penetrating through the third adhesive layer 4b and the fourth insulating substrate 2b superimposed on the lower surface of the adhesive layer 4b. The third interlayer conductive member 5b has sixth contact portions c6 at both ends thereof on the upper surface (inner surface) of the fourth wiring layer 3b provided on the lower surface of the fourth insulating substrate 2b. The four contact portions c4 are formed so as to be connected to each other.

  Further, the fifth and sixth wiring substrate materials 1C and 1D are not shown with reference numerals, but all have the same adhesive layer, insulating substrate, wiring layer, and interlayer conductivity as the third wiring substrate material 1A. Each of the adhesive layers is disposed so as to face each other so as to overlap and adhere to the third and fourth wiring substrate materials 1A and 1B.

  By the way, the pattern shapes of the wiring layers of the third to sixth wiring substrate materials 1A to 1D are different from the wiring layers of the first and second wiring substrate materials 1 and 11, respectively. The predetermined positions of the 1D interlayer conductive paths are not limited to the via-on-via type, but may take various different positions according to circuit design requirements such as a chip-on-via type. Also good.

  Each of the wiring board materials 1, 1A to 1D and 11 is integrally pressed as shown in FIG. 3B by hot-pressing in a lump from above and below in the overlapping arrangement state. A double-sided multilayer circuit wiring board having a wiring structure is obtained.

  Each of the second and third interlayer conductive members 5a, 5b and the like is formed so that each one end protrudes from the surface of each adhesive layer as shown in FIG. 3 (a). Both ends of each interlayer conductive member are firmly crimped and connected to the opposing contact portions.

  However, since the protruding ends of the interlayer conductive members 5a and 5b are in contact with the respective contact portions on the back surface of the wiring layers on the surfaces of the insulating substrates, the protruding heights corresponding to the thicknesses of the wiring layers. May be smaller than the first interlayer conductive member 5 by the thickness of each wiring layer. Of course, considering that each adhesive layer is compressed and deformed by the hot press, the height of the interlayer conductive members 5a and 5b itself in the state shown in FIG. It may be approximately the same as the thickness dimension (the state in which there is no protrusion of the interlayer conductive members 5a and 5b).

  According to the other embodiment, the circuit wiring board having the six-layer wiring structure includes an insulating substrate and an adhesive layer disposed on both sides of the core circuit wiring board CB located at the center in the thickness direction. Each of the plurality of sets of insulating substrates of the superposed body is configured to be symmetrically arranged with respect to both surfaces of the core circuit wiring board CB, and the occurrence of warping of the circuit wiring board is remarkably suppressed. In addition, since the outermost layers on both sides of the six-layer wiring structure are formed of an insulating substrate with a wiring layer, double-sided mounting is also possible in this case.

  Further, the third to sixth wiring board materials 1A to 1D having the same configuration as the first wiring board material 1 are sequentially stacked on both surfaces of the core circuit wiring board CB, and then batch hot press is performed. By doing so, it is laminated at once and the process is simplified.

  The patterning of each wiring layer of each of the wiring substrate materials 1, 1A to 1D and 11 can be performed collectively in one patterning operation, and each interlayer conductive member of each of the wiring substrate materials 1, 1A to 1D and each The alignment with the contact portion can be performed in one centralized operation. Accordingly, it is possible to improve the accuracy of each of these operations by intensively controlling the pattern jig and the alignment.

  FIG. 4 shows an improvement of each of the contact portions. For example, the surface of the second contact portion c2 of the second wiring layer 13 and the inner surface of the third hole h3 of the second insulating substrate 12 are more than the interlayer conductive member. If the contact layer Cx having high conductivity is formed by, for example, pre-plating copper, the resistance of the interlayer conductive path is reduced and conduction is improved. The contact layer Cx is not limited to the above example, and may be formed in all contact parts such as the first contact part c1 and the third to sixth contact parts c3 to c6. Can be further improved.

  Next, still another embodiment of the present invention will be described with reference to FIG. Here, the same parts as those constituting the circuit wiring board in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof is omitted.

  The circuit wiring board in this embodiment has a six-layer wiring layer structure as in the example of FIG. 3, but is roughly composed of a cable part Y and two wiring board parts X1 and X2 respectively connected to both sides thereof. ing.

  Each of the wiring board portions X1 and X2 is basically configured by arranging third to sixth wiring board materials 1A to 1D on both surfaces of the core circuit wiring board CB, as in the embodiment of FIG. ing.

  The portions corresponding to the cable portion Y of the fifth wiring board material 1C and the sixth wiring board material 1D are removed, and the third insulating substrate 2a and the fourth wiring board material 1A of the third wiring board material 1A are removed. The fourth insulating substrate 2b of the wiring board material 1B is exposed.

  A portion corresponding to the cable portion Y of the first adhesive layer 4 of the core circuit wiring board CB is removed, and a space AG is formed between the first insulating substrate 2 and the second insulating substrate 12. ing. Accordingly, the cable portion Y is composed of first and second cable regions y1 and y2 that are spaced apart from and parallel to the space portion AG. The first cable region y1 has a laminated structure of a first insulating substrate 2, a second adhesive layer 4a, and a third insulating substrate 2a, and a part of the first wiring layer 3 is disposed therein. The second cable region y2 has a laminated structure of the second insulating substrate 12, the third adhesive layer 4b, and the fourth insulating substrate 2b, and a part of the second wiring layer 13 is disposed therein.

  In addition, regarding the installation of the interlayer conductive member, in the embodiment of FIG. 3, all are shown in the form of via-on-via, but as can be seen from the illustration of the wiring board portions X1 and X2, the interlayer conductive member There is a portion of the wiring layer in which is not provided. That is, the number and positions of the interlayer conductive members are appropriately selected according to the circuit design for each product, and are not limited to the illustration.

  According to such an embodiment, in addition to the effects of the invention in each of the embodiments, the regions y1 and y2 of the cable portion Y can be freely bent, bent, or bent due to the presence of the space AG. Therefore, the circuit wiring board can be accommodated in the electronic device casing in a volumetric efficiency, and the density of component mounting is further improved. Moreover, the space AG is formed by removing the first adhesive layer 4 of the core circuit wiring board CB, and the flexibility of the cable portion Y can be obtained by a simple process.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the circuit wiring board based on one Embodiment of this invention, (a) is an exploded sectional view of a wiring board, (b) is the completion sectional drawing. It is sectional drawing according to process which shows one Example of the manufacturing method of the circuit wiring board of one Embodiment of this invention. It is sectional drawing which shows the circuit wiring board which concerns on other embodiment of this invention, (a) is an exploded sectional view of a wiring board, (b) is the completion sectional drawing. It is sectional drawing for demonstrating the improvement example of the contact part of the circuit wiring board of this invention. It is sectional drawing which shows the circuit wiring board which concerns on other embodiment of this invention.

Explanation of symbols

1, 11 First and second wiring substrate materials 1A to 1D Third to sixth wiring substrate materials 2, 12, 2a, 2b First, second, third, and fourth insulating substrates 3, 13, 3a, 3b First, second, third, fourth wiring layers 4, 4a, 4b First, second, third adhesive layers 5, 5a, 5b First, second, third interlayer conductive member 21 Insulating substrate material 31 Conductive layer (copper foil) for wiring layer
41 1st adhesion layer base material 61 Masking film c1 thru | or c6 1st thru | or 6th contact part CB Core circuit wiring board CX Contact layer D5 Crushing part H1 1st through-hole (via hole)
h1 to h3 first to third holes X1 and X2 wiring board portion Y cable portion

Claims (6)

First and second insulating substrates that are symmetrically superimposed on both sides of the film-like first adhesive layer,
First and second wiring layers respectively provided on opposite surfaces of the first and second insulating substrates from the first adhesive layer;
First and second contact portions respectively provided in opposite portions of the first and second wiring layers;
A through hole provided through the first and second insulating substrates and the first adhesive layer between the first and second contact portions;
A first interlayer conductive member provided in the through hole and interconnecting the contact portions ;
With
The through hole has a first hole that penetrates the first insulating substrate, a second hole that penetrates the first adhesive layer, and a third hole that penetrates the second insulating substrate, and the third hole is the first hole. Having a hole diameter larger than 2 holes ,
The circuit wiring board, wherein a contact area of the first interlayer conductive member with the second contact portion is larger than a contact area with the first contact portion . The circuit wiring board according to claim 1,
The first hole and the second hole are formed with the same hole diameter,
The first interlayer conductive member is formed of a conductive resin composition, and has a crushing portion that is crushed by being pressed against the second contact portion and bulged into the third hole. Circuit wiring board. In the circuit wiring board according to claim 1 or 2 ,
A circuit wiring comprising a contact layer interposed between at least one of the first and second contact portions and the first interlayer conductive member and having a conductivity higher than that of the first interlayer conductive member. substrate. In the circuit wiring board according to any one of claims 1 to 3 ,
Third and fourth contact portions respectively provided on partial surfaces of the first and second wiring layers;
A second adhesive layer and a third adhesive layer respectively superimposed on the first wiring layer side and the second wiring layer side;
Third and fourth insulating substrates respectively superimposed on the surfaces of the second and third adhesive layers;
Third and fourth wiring layers provided on the surfaces of the third and fourth insulating substrates opposite to the adhesive layers, respectively.
Fifth and sixth contact portions respectively provided in respective portions of the third and fourth wiring layers so as to face the third and fourth contact portions, respectively.
A second interlayer conductive member provided through the third insulating substrate and the second adhesive layer between the third and fifth contact portions;
A third interlayer conductive member provided through the fourth insulating substrate and the third adhesive layer between the fourth and sixth contact portions ;
A circuit wiring board comprising: A conductive layer for the first wiring layer having the first contact portion is overlaid on the other surface of the first insulating substrate provided on one surface, and the first adhesive layer is overlaid on the surface facing the first contact portion. A first hole penetrating the first insulating substrate and a second hole penetrating the first adhesive layer and communicating with the first hole are provided, the first and second holes are filled with a conductive paste, and one end is Forming a first wiring substrate material by providing a first interlayer conductive member connected to the first contact portion;
A conductive layer for a second wiring layer having a second contact portion facing the first contact portion is provided on the other surface of the second insulating substrate, one surface of which is disposed facing the first adhesive layer, 2 through the second insulating substrate at a position opposite to the contact portion, and forming a second wiring board material by providing a third hole formed in the larger pore diameter than the second hole,
The first and second wiring substrate materials are overlapped with each other so that the other end of the first interlayer conductive member is in contact with the second contact portion, and the first and second layers are disposed on both surfaces of the first adhesive layer. bonding the insulating substrate symmetrically, a step of connecting to the first interlayer conductive member thus said first and second contact portions mutually,
A method for manufacturing a circuit wiring board, comprising: In the manufacturing method of the circuit wiring board according to claim 5,
In the step of forming the first wiring substrate material, the first hole and the second hole are formed with the same hole diameter, the conductive paste is a conductive resin composition, and the first interlayer conductive member is The other end of the first interlayer conductive member is protruded from the first adhesive layer, and the protruding height of the first interlayer conductive member is formed with a height dimension larger than the thickness dimension of the second insulating substrate,
The step of connecting the first and second contact portions to each other includes heat-pressing the first and second wiring substrate materials on top of each other, and connecting the second contact to the other end of the first interlayer conductive member. A method of manufacturing a circuit wiring board, comprising: forming a crushing portion that is crushed by being pressed against a portion and bulged in the third hole.

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