JP2004072125A - Manufacturing method of printed wiring board, and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed wiring board with high yield ratio by using a simple process, which can realize higher interconnection and packaging and high reliability, and a printed wiring board manufactured thereby. <P>SOLUTION: The method comprises: a step for laminating and arranging a piece of synthetic resin based sheet without holes, of which principal plane is mutually brought into contact with a first conductive metal layer on which a group of conductive bumps is formed at a predetermined position using curable conductive paste, and a piece of synthetic resin based sheet of which second principal plane is mutually brought into contact with a second conductive metal layer; and a step for forming a multi-layer interconnection board which is electrically connected to the first and second conductive metal layers through the group of bumps by heating and pressurizing the laminate to insert the group of conductive bumps of the first conductive metal layer into the thickness direction of the synthetic resin based sheet so that the group of bumps is brought into contact with the second conductive metal layer to be plastically deformed. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a highly reliable printed wiring having a conductor wiring portion for connecting wiring pattern layers and a through hole for inserting component pins, and capable of high-density wiring and mounting. The present invention relates to a method for manufacturing a plate with good yield while reducing the number of steps.

(4) Multi-layer wiring patterns are being used for the purpose of enhancing the functionality and reducing the size of wiring circuits. In this type of multilayer printed wiring board, electrical connection between the inner wiring pattern layers and between the inner wiring pattern layer and the surface wiring pattern layer is inevitably required. To go. For example, after patterning a copper foil stretched on both sides of a substrate, an electrical connection between both sides is formed if necessary, and then an insulating sheet (for example, a prepreg) is formed on the patterning surface. The copper foils are laminated and arranged via a vial, and integrated by heating and pressing. The electrical connection between the two surfaces, referred to as the IVH, is made by forming a hole in a predetermined position of the substrate and forming a conductive layer on the inner wall surface of the hole by plating. After pressurizing, as in the case of the double-sided type described above, by drilling and plating, electrical through-hole connections between wiring pattern layers and solderable through-holes for inserting component pins are made. By forming and patterning the surface copper foil, a multilayer printed wiring board having a required wiring pattern interlayer connection portion and through holes for inserting component pins is obtained. In the case of a multilayer printed wiring board having more wiring pattern layers, it can be manufactured by a method of increasing the number of double-sided boards to be interposed.

In the method of manufacturing a printed wiring board, as a method of performing an electrical connection between wiring pattern layers without depending on a plating method, a method of forming a hole in a predetermined position on a double-sided copper foil-clad board and printing a conductive paste in the hole is used. For example, a method is also used in which the conductive paste is poured into the holes and the resin of the conductive paste is hardened to electrically connect the wiring layers.

As described above, in a method for manufacturing a printed wiring board using a plating method for electrical connection between wiring pattern layers, a hole is formed on a substrate for electrical connection between wiring pattern layers. A plating process including the inner wall surface of the hole is required, so that the manufacturing process of the printed wiring board is redundant and the process management is complicated. On the other hand, a method of embedding a conductive paste in a hole for electrical connection between the wiring pattern layers by printing or the like also requires a drilling step as in the case of the plating method. In addition, it is difficult to uniformly (uniformly) pour and embed the conductive paste into the formed hole, and there is a problem in reliability of electrical connection. In any case, in view of the tendency that the number of connection portions between wiring pattern layers increases with the enhancement of functions and the like, the necessity of the perforation step (increased number of perforated portions) and the like necessitate the cost of the printed wiring board and the like. There is a drawback that it is not possible to respond to demands for cost reduction, etc., reflecting on the yield and the like.

Further, in the case of the electrical connection configuration between the wiring pattern layers, since a conductor hole for wiring pattern layer connection is provided on the front and back surfaces of the printed wiring board, wiring is formed in the region of the conductor hole. -Cannot be placed. Furthermore, since it is not possible to mount electronic components, there is a problem that the improvement of the wiring density is restricted and the improvement of the mounting density of the electronic components is hindered. In other words, the printed wiring board obtained by the conventional manufacturing method cannot sufficiently meet the demands for downsizing of the circuit device by high-density wiring and high-density mounting, and furthermore, downsizing of the electronic devices, and the cost cannot be reduced. There is a need for a practically more effective method of manufacturing a printed wiring board, including a surface.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method capable of manufacturing a highly reliable printed wiring board with a high yield in a simple process, with higher density wiring and mounting. .

The first method of manufacturing a printed wiring board according to the present invention is directed to a method of manufacturing a printed wiring board, comprising forming a conductive bump group at a predetermined position on a first main surface of a non-perforated synthetic resin sheet using a curable conductive paste. Contacting a conductive metal layer, placing a second conductive metal layer on the second main surface of the synthetic resin-based sheet in a stacked manner, and heating and pressing the stacked body to form the first conductive metal layer. The first and second conductive metal layers are formed by penetrating a conductive bump group of the conductive metal layer in the thickness direction of the synthetic resin-based sheet to abut against the second conductive metal layer and plastically deforming the conductive bump group. Forming a multi-layer wiring board electrically connected by the bump group; forming a through hole between both surfaces at a predetermined position of the multi-layer wiring board; Depositing and forming a metal layer by the method described above.
A second method for manufacturing a printed wiring board according to the present invention includes a step of forming a conductive bump at a predetermined position on a main surface of a conductive metal layer by using a curable conductive paste; A step of forming a laminate composed of a plurality of layers including a wiring pattern in an inner layer with the principal surfaces of the synthetic resin sheet having no holes facing each other, a step of heating the laminate, and heating and heating the synthetic resin sheet. Pressing, connecting the conductive bump to the wiring pattern in the conductive metal layer to form a multilayer wiring board, and forming a through hole for penetrating a predetermined position of the multilayer wiring board and receiving a lead terminal. And a step of forming a metal layer on the inner wall of the through hole by plating.
A third method for manufacturing a printed wiring board according to the present invention is characterized in that, in the first or second method for manufacturing a printed wiring board, the synthetic resin-based sheet is a fiber-reinforced thermosetting resin.
The printed wiring board according to the present invention is a printed wiring board provided with two or more conductive metal layers arranged via a synthetic resin sheet, wherein the composite of the conductive metal layer penetrates the synthetic resin sheet. A first interlayer connection portion made of a cured conductive paste connected to the conductive metal layer surface on the same surface as the surface in contact with the resin-based sheet, and a through-hole having a hole passing through the synthetic resin-based sheet and the conductive metal layer; And a second interlayer connection part of a mold type.

In the present invention, examples of the conductive metal layer forming the conductor bump group include a conductive sheet (foil) such as an electrolytic copper foil, and the conductive metal layer may be a single sheet. It may be patterned and its shape is not particularly limited. Further, the conductor bump group may be formed not only on one main surface but also on both main surfaces.

Here, the conductive bumps are made of, for example, conductive powders such as silver, gold, copper, and solder powders, alloy powders or composite (mixed) metal powders thereof, and polycarbonate resins, polysulfone resins, polyester resins, phenoxy resins, and phenol resins. , A conductive composition prepared by mixing with a binder component such as polyimide resin, or a conductive metal. When the bump group is formed of a conductive composition, for example, a bump having a high aspect ratio can be formed by a printing method using a relatively thick metal mask. Preferably, the height is about 100 to 400 μm, and the height of the bump group may be a height that can penetrate one layer of the synthetic resin sheet and a height that can penetrate a plurality of layers of the synthetic resin sheet. . In the formation of the conductor bump, if the conductor bump is provided at a plurality of locations on the inner wall surface of the through hole to be drilled at a position where the through hole (through hole) is to be drilled, plating may be performed. Makes it easier to form a metal layer. On the other hand, as means for forming a bump group with a conductive metal, (a) a fine metal soul having a certain shape or size is sprayed on a conductive metal layer surface on which an adhesive layer is provided in advance, and selectively. (B) A plating resist is printed and patterned on the surface of the electrolytic copper foil, and selectively plated with copper, tin, gold, silver, solder or the like. Formation of minute metal pillars (bumps), (c) Application and patterning of solder resist on conductive metal layer surface, immersion in solder bath and selective formation of minute metal pillars (bumps) Can be Here, the minute metal pillar without the minute metal soul corresponding to the bump may have a multilayer structure or a multilayer shell structure formed by combining different metals. For example, copper may be used as a core and the surface may be coated with a layer of gold or silver to provide oxidation resistance, or copper may be used as a core and the surface may be coated with a solder layer to provide solder bonding properties. In the present invention, when the bump group is formed of the conductive composition, the steps and the like can be further simplified as compared with the case where the bump group is formed by means such as a plating method, which is effective in terms of cost reduction.

In the present invention, examples of the synthetic resin-based sheet into which the conductor bump group is inserted to form a through-type conductor wiring portion include a thermoplastic resin film (sheet), and the thickness thereof is about 50 to 800 μm. Is preferred. Here, examples of the thermoplastic resin sheet include sheets such as a polycarbonate resin, a polysulfone resin, a thermoplastic polyimide resin, a polyethylene tetrafluoride resin, a hexafluoropropylene resin, and a polyether ether ketone resin. The thermosetting resin sheet held in a pre-cured state includes epoxy resin, bismaleimide triazine resin, polyimide resin, phenol resin, polyester resin, melamine resin, butadiene rubber, butyl rubber, natural rubber, neoprene rubber, silicone Examples include sheets of raw rubber such as rubber. These synthetic resins may be used alone or may contain an insulating inorganic or organic filler, and may be a sheet made of glass cloth or mat, organic synthetic fiber cloth or mat, or a reinforcing material such as spots. There may be.

Further, in the present invention, a laminate formed by stacking and laminating a plurality of layers having a configuration in which the synthetic resin-based sheet main surface is in contact with the main surface of the conductive metal layer forming the bump group is heated and pressed. At this time, a base (backing plate) on which the synthetic resin sheet is placed is a metal plate or a heat-resistant resin plate having small dimensions and deformation, such as a stainless steel plate, a brass plate, a polyimide resin plate (sheet), and polytetrafluoroethylene. A resin plate (sheet) is used.

The drilling of the through hole may be a conventional means in the manufacture of a printed wiring board such as a drill, and the plating on the inner wall surface of the drilled through hole may be performed by chemical plating (electroless plating) or chemical plating. It can be achieved by using electroplating in combination. The drilling step and the plating step are much less than the number of electrical connections between wiring pattern layers, such as so-called through-hole connections in the prior art, so that the process complexity is hardly a problem.

According to the method of manufacturing a printed wiring board according to the present invention, the conductor wiring portions between the layers electrically connecting the wiring pattern layers are combined to form an interlayer insulating layer by heating and pressing in a so-called lamination and integration process. Due to the plastic state of the resin-based sheet or a state similar thereto, and the press-fitting of the conductive bump group on the conductive metal layer surface, highly reliable electrical connection between the wiring pattern layers is reliably achieved. In other words, highly accurate and highly reliable electrical connection can be formed at any position (location) between the fine wiring pattern layers while simplifying the process. That is, it is possible to manufacture a printed wiring board having a high wiring density at low cost, and it is not necessary to form connection holes in the electrical connection between the wiring pattern layers. It is possible to obtain a printed wiring board that can be mounted at a high density and that can reliably mount a pin insertion component with high reliability.

According to the present invention, a process of forming conductive bumps for connecting pattern layers, a process of laminating synthetic resin-based sheets and hot pressing, and a process of outer layer patterning are simplified, in other words, a manufacturing process. It is possible to easily manufacture a double-sided printed wiring board or a multilayer printed wiring board while reducing the number to significantly fewer steps as compared with the conventional manufacturing method. Particularly, in the production of a multilayer printed wiring board in which steps are frequently repeated, the number of steps is greatly reduced, which is effective in improving productivity or mass productivity. In addition, since the drilling step and the plating step, which are indispensable in the manufacturing process of the conventional multilayer printed wiring board and the like, are no longer required, defects generated in the manufacturing process are significantly suppressed, and the yield is improved. In addition, a highly reliable printed wiring board can be obtained. Further, since the printed wiring board to be manufactured has no holes for interlayer connection on the surface, the wiring density can be remarkably improved, and the mounting area of the electronic component can be set regardless of the position of the hole. As a result, the mounting density is remarkably improved, and the distance between the mounted electronic components can be shortened, so that the performance of the circuit can be improved. That is, it can be said that the present invention not only contributes to cost reduction of the printed wiring board, but also greatly contributes to downsizing and high performance of the mounted circuit device.

1 (a) to 1 (c), 2 (a) and 2 (b), 3 (a) and 3 (b), 4A (a) to 4 (d), and 5 (a) to 5 (c). An embodiment of the present invention will be described with reference to FIGS.

[Example 1]
FIGS. 1A to 1C, FIGS. 2A and 2B, and FIGS. 3A and 3B schematically show an embodiment of the present embodiment. First, a 35 μm-thick electrolytic copper foil was used as the conductive metal layer 1 as a polymer type silver-based conductive paste (trade name, thermosetting conductive paste MS-7, Toshiba Chemical KK). A metal mask having a hole of 0.35 mm in diameter at a predetermined position on a 300 μm stainless steel plate was prepared. Then, the metal mask is positioned and arranged on one surface of the electrolytic copper foil, and a conductive paste is printed. After the printed conductive paste is dried, it is printed again at the same position using the same mask. The printing was repeated once to form (form) a mountain-shaped conductor bump 2 having a height of 20 to 300 μm.

On the other hand, a glass epoxy-based prepreg (synthetic resin-based sheet) 3 having a thickness of 160 μm and an electrolytic copper foil 1 ′ having a thickness of 35 μm were prepared, and as shown in cross section in FIG. Then, the formed conductive bumps 2 were opposed to each other, and an electrolytic copper foil 1 ′ was positioned and arranged on the back side of the synthetic resin-based sheet 3 to form a laminate. Thereafter, it is disposed between hot plates of a hot press maintained at 100 ° C. (not shown). When the synthetic resin sheet 3 is in a thermoplastic state, the resin is pressed at 1 MPa as a resin pressure, cooled and taken out. As shown in cross section in b), a double-sided copper-clad laminate was obtained in which the conductive bumps 2 constituted the conductive connecting portions 2a and were electrically connected to both electrolytic copper foils 1 and 1 '. As shown in FIG. 1 (b), the laminated board is pressed into the synthetic resin sheet 3 with the conductive bump 2 as it is, and the tip is crushed by contacting the electrolytic copper foil 1 'surface. It takes a form that has been shaped.

積 層 The laminate having the structure shown in FIG. 1B can be manufactured as follows. That is, a synthetic resin sheet 3, an aluminum foil and a rubber sheet are laminated and arranged on the conductive bump 2 forming surface side of the electrolytic copper foil 1 on which the conductive bumps 2 are formed, and hot-pressed to form the conductive bumps. 2 is made by inserting a synthetic resin sheet 3 at the tip thereof, taken out after cooling, the aluminum foil and the rubber sheet are peeled off, and an electrolytic copper foil is After laminating and arranging 1 ', for example, it is arranged between hot plates of a hot press kept at 170 ° C., and when synthetic resin sheet 3 is in a thermoplastic state, it is pressed at 1 MPa as a resin pressure for about 1 hour. Can also be manufactured.

A normal etching resist ink (trade name, PSR-4000H, sun ink KK) is screen-printed on the electrolytic copper foils 1, 1 'on both sides of the surface copper-clad laminate to mask the conductor pattern portion, After performing an etching process using 2 copper as an etching solution, the resist mask was peeled off to obtain a double-sided printed wiring board 4 shown in cross section in FIG.

Next, on both sides of the double-sided printed circuit board, a copper-clad laminate (2 sheets) 5 and a glass epoxy prepreg (synthetic resin sheet) 3 having one side wiring-patterned are prepared, and FIG. As shown in a cross section in a), each was positioned and arranged to form a laminate. Then, it is placed between the hot roots of a hot press maintained at 170 ° C., and when the synthetic resin sheet 3 is in a thermoplastic state, the resin pressure is applied at 1 MPa as a resin pressure, cooled and taken out to obtain a multilayer laminate. Was. A through hole 6 is drilled at a predetermined position of the multilayer laminate by drilling, and the inner wall surface of the through hole 6 is selectively subjected to chemical copper plating for about 3 hours, and the inner wall surface of the through hole 6 has a thickness of about 3 hours. A 7 μ wide copper layer 7 was deposited. Thereafter, a normal etching resist ink (trade name, PSR-4000H, sun ink KK) is screen-printed on the electrolytic copper foil 1 'on both sides of the multilayer laminate, and the conductor pattern portion is masked. After etching using copper as an etchant, the resist mask was peeled off to obtain a multilayer printed wiring board 8.

電 気 An electrical check was conducted on the multilayer printed wiring board 8 manufactured as described above, and no problems were found in all the connections, such as the reliability of the connection without defects. In addition, in order to evaluate the reliability of connection between the wiring patterns, the hot oil test was performed 500 times in a hot oil test (a cycle of immersion in oil at 260 ° C. for 10 seconds and immersion in oil at 20 ° C. for 20 seconds). However, no defect was observed, and there was no problem in connection reliability between the conductive (wiring) pattern layers as compared with the case of the conventional copper plating method.

[Example 2]
In this embodiment, in the case of the first embodiment, the conductive bumps 2 form the conductive connection portions 2a on each of the two wiring pattern layers on both sides (outside) so that both the electrolytic copper foil 1 and the wiring pattern are formed. A double-sided wiring base plate 5 having a connected configuration is used, and a double-sided wiring base plate 4 'having no through-hole connection is used for the inner layer, and stacked and arranged as shown in cross section in FIG. And placed between hot plates of a hot press maintained at 170 ° C., and when the synthetic resin sheet 3 was in a thermoplastic state, the resin pressure was applied at 1 MPa, cooled and taken out to obtain a multilayer laminate. A through hole 6 is drilled at a predetermined position of the multilayer laminate by drilling, and the inner wall surface of the through hole 6 is selectively subjected to chemical copper plating for about 3 hours, and the inner wall surface of the through hole 6 has a thickness of about 3 hours. A 7 μm copper layer 7 was deposited. Then, a normal etching resist ink (trade name, PSR-4000H, sun ink KK) is screen-printed on the electrolytic copper foil 1 'on both sides of the multilayer laminate to mask the conductor pattern portion, After etching using copper as an etchant, the resist mask was peeled off to obtain a multilayer printed wiring board 8.

電 気 An electrical check was conducted on the multilayer printed wiring board 8 manufactured as described above. As a result, no problems such as defects or reliability were found in all the connections. In addition, in order to evaluate the reliability of connection between the wiring patterns, the hot oil test was performed 500 times in a hot oil test (a cycle of immersion in 260 ° C. oil for 10 seconds and immersion in 20 ° C. oil for 20 seconds was one cycle). No defect was observed, and there was no problem in the connection reliability between the conductive (wiring) pattern layers as compared with the conventional copper plating method.

[Example 3]
As in the case of the first embodiment, a polymer-type silver-based conductive paste (trade name, heat-treated) is generally used as a conductive metal layer with a 35 μm-thick electrolytic copper foil used for manufacturing a printed wiring board. Curable conductive paste MS-7, Toshiba Chemical KK) was used as a conductive paste, and a metal mask having a hole of 0.35 mm diameter formed in a predetermined position on a stainless steel plate having a thickness of 300 μm was prepared. Then, the metal mask is positioned and arranged on the electrolytic copper foil, and the conductive paste is printed. After the printed conductive paste is dried, the printing is repeated twice by using the same mask and printing again at the same position. A mountain-shaped conductor bump having a height of 200 to 300 μm was formed (formed).

Next, as shown in cross section in FIG. 4 (a), a resin sheet 3, an aluminum foil, and a rubber sheet having a thickness of about 160 μm are formed on the electrolytic copper foil 1 on which the conductor bump groups 2 are formed by printing at the predetermined positions. Are stacked and arranged (not shown), and positioned and arranged between hot plates of a heat brace held at 100 ° C., at a temperature equal to or higher than the glass point transfer, preferably at a temperature at which the resin component of the synthetic resin-based sheet 3 is in a plastic state. After cooling, the aluminum foil and the rubber sheet were peeled off, and the ends of the conductor bumps 2 penetrated the synthetic resin-based sheet 3 that was in contact, and were inserted and exposed. Next, an electrolytic copper foil 1 'is laminated and arranged on the side of the laminated body of the electrolytic copper foil 1 and the synthetic resin sheet 3 where the tip of the conductor bump 2 is inserted and exposed, and pressed at 1 MPa at 170 ° C. for 1 hour. Then, the tip of the conductor bump 2 is joined to the electrolytic copper foil 1 ′, the synthetic resin sheet 3 is hardened, and the double-sided electrolytic copper foil 1, 1 ′ has a conductor wiring portion 2 a having a penetrating connection. A copper clad plate was obtained (FIG. 4 (b)).

A normal etching resist is stuck on both sides of this double-sided copper-clad board with a laminator, a negative film is aligned, exposed and developed, and then the copper foil 1.1 'is etched. Finally, the etching resist is peeled off with an alkaline aqueous solution. Then, a conductor pattern was formed, and a double-sided wiring base plate 4 was formed (see FIG. 4C). With respect to the double-sided wiring base plate 4, a continuity test was performed on each conductor wiring portion 2a from the front and back with a tester.

Electrodeposited copper foil 1 on which conductive bumps 2 are printed, synthetic resin sheet 3 having a thickness of about 160 μm, aluminum foil and rubber sheet are stacked and arranged (not shown) at predetermined positions formed according to the above. After holding at 100 ° C. for 7 minutes, pressurizing at 1 MPa for 3 minutes, the aluminum foil and the rubber sheet were peeled off to obtain a member formed by inserting the synthetic resin sheet 3 with which the tip of the conductor bump 2 was in contact. This member and the double-sided wiring base plate 4 are positioned, laminated and arranged as shown in cross section in FIG. 4 (c), pressed at 170 ° C. for 30 minutes at 1 MPa, and the ends of the conductive bumps 2 come into contact with each other. By bonding to the wiring pattern surface of the double-sided wiring base 4, a double-sided copper clad board as shown in cross section in FIG.

In the structure of the double-sided copper-clad board, for example, when a through hole 6 for inserting a pin is formed around a position where a discrete component pin is to be inserted and mounted, one conductor bump 2 is formed on the inner wall surface of the through hole 6. Four through-type conductor wiring portions 2b are formed so that the portions are exposed. In other words, as shown in a plan view in FIG. 5B, four through-type conductor wiring portions 2b (see FIG. 4D) are particularly formed in a region where the through holes 6 for inserting component pins are formed. It is set up.

Next, a through hole 6 for inserting a discrete component pin is formed at a substantially center of the through-type conductor wiring portion 2b of the double-sided copper clad board by drilling, and a chemical copper plating process is performed on the inner wall surface of the through hole 6. For 3 hours to deposit a copper layer 7 having a thickness of about 7 μm. Next, a normal etching resist was stuck on the double-sided copper foils 1 and 1 of the double-sided copper-clad board with a laminator, the negative film was aligned, and, as in the above case, an etching treatment was performed. As shown in FIG. 5C in a sectional view and in a plan view in FIG. 5D, a component mounting through hole 6 made of a high-quality copper layer 7 and a pad connected to the through-type conductive wiring portion 2b are provided. A four-layer thin multilayer wiring board 8 having a thickness of about 550 μm was prepared.

When a pin of a discrete component was inserted into the through hole 6 of the four-layer thin multilayer wiring board 8 and soldered to form a mounting circuit device, highly reliable connection and mounting of the discrete component were achieved.

[Example 4]
In Example 3, a four-layer thin multilayer wiring board 8 was prepared under the same conditions except that a copper paste was used instead of forming the conductor bumps 2 with a silver paste. In the case of this embodiment, when a through-hole 6 for a discrete component pin is formed in the center of the four through-type conductive wiring portions 2b, the conductor containing copper is exposed on the inner wall surface of the through-hole, so that the solder corrosion is prevented. With no worries, I was able to insert the discrete component pins and solder them.

In the case of mounting a discrete component in the multilayer wiring board, chemical copper plating on the inner wall surface of the through-hole (through hole) is indispensable. No need for chemical copper plating or the like, and the reliability of electrical connection between the surface wiring pattern layer and the inner wiring pattern is secured by the plurality of through-type conductive wiring portions 2b. Can be established.

1A schematically shows the basics of a first embodiment of the present invention. FIG. 1A shows a state in which a conductive metal layer provided with a conductive bump, a synthetic resin sheet, and a conductive metal layer are positioned and laminated. , (B) is a cross-sectional view of a state in which the laminated body is pressed and integrated by a hot press, and (c) is a cross-sectional view of a double-sided wiring plate obtained by patterning both conductive metal layers. 1A is a schematic view of a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view of a double-sided wiring base plate on both sides of a synthetic resin sheet and a single-side patterned copper-clad laminated base plate in a stacked and arranged state. (B) is a cross-sectional view showing the structural state of the finally formed multilayer wiring board. FIG. 4A schematically shows a second embodiment of the present invention, in which (a) shows a double-sided wiring base plate having no through conductive connecting portions, a synthetic resin sheet on both sides, and a plate with a through conductive connecting portion patterned on one side. Sectional drawing of the lamination and arrangement | positioning state of a copper-clad laminated base plate, (b) is sectional drawing which shows the structural state of the multilayer wiring board finally formed. FIG. 4A schematically shows a second embodiment of the present invention, in which (a) is a cross-section of a state in which a conductive metal layer provided with a conductive bump, a synthetic resin sheet, and a conductive metal layer are positioned and laminated. FIG. 2B is a cross-sectional view of a double-sided wiring base plate obtained by patterning both conductive metal layers after pressure-integrating the laminate by a hot press, and FIG. Sectional view with positioning and lamination of conductive bumps formed on conductive metal layers with synthetic resin sheets inserted through them. (D) is a double-sided copper-clad laminate obtained by press-integrating the laminate by hot pressing FIG. FIGS. 4A and 4B further schematically illustrate a second embodiment of the present invention, in which FIG. 4A is a cross-sectional view of a double-sided copper-clad laminate (FIG. 4D) in which both sides are patterned, and FIG. A plan view of a patterned state, (c) is a cross-sectional view of a state where a hole for inserting a component pin is formed, and a copper plating layer is formed on the inner wall, and (d) is a state where a copper plating layer is formed on the inner wall surface. FIG.

Explanation of reference numerals

1, 1 ': conductive metal layer, 2: conductor bump, 2a: conductor connection portion, 2b: penetrating conductor connection portion, 3: synthetic resin sheet, 4: double-sided wiring base plate, 4': conductor connection portion No double-sided wiring blank, 5: Single-sided patterned copper-clad laminate, 6: Through hole, 7: Copper plating layer, 8: Multi-layer printed wiring board, 9: Pad

Claims (4)

A first conductive metal layer in which a conductive bump group is formed with a curable conductive paste at a predetermined position on the first main surface of the non-hole synthetic resin sheet is brought into contact with the first main surface of the synthetic resin sheet. A step of laminating and placing a second conductive metal layer in contact with the main surface of No. 2;
The laminate is heated and pressed, and the conductive bumps of the first conductive metal layer are penetrated in the thickness direction of the synthetic resin-based sheet to abut on the second conductive metal layer, resulting in plastic deformation. Forming a multilayer wiring board in which the first and second conductive metal layers are electrically connected by the bump group;
A step of forming a through-hole penetrating between both surfaces at a predetermined position of the multilayer wiring board; and a step of forming a metal layer on the inner wall surface of the through-hole by a plating method. Manufacturing method of printed wiring board. A step of forming a conductive bump at a predetermined position on the main surface of the conductive metal layer with a curable conductive paste,
A step of forming a laminate composed of a plurality of layers including a wiring pattern in an inner layer, with the main surface of the conductive metal layer facing the non-hole synthetic resin-based sheet main surface,
Heating the laminate, heating and pressurizing the synthetic resin sheet, connecting the conductive bumps to a wiring pattern in the conductive metal layer, and forming a multilayer wiring board;
Forming a through hole for penetrating a predetermined position of the multilayer wiring board and receiving a lead terminal; and forming a metal layer on an inner wall of the through hole by plating. Manufacturing method of a printed wiring board. The method according to claim 1, wherein the synthetic resin sheet is a fiber-reinforced thermosetting resin. In a printed wiring board having two or more conductive metal layers disposed via a synthetic resin-based sheet,
A first interlayer connection portion made of a cured conductive paste which penetrates the synthetic resin sheet and is connected to the conductive metal layer surface on the same surface as the surface of the conductive metal layer in contact with the synthetic resin sheet; A printed wiring board comprising: a resin-based sheet; and a penetrating second interlayer connection portion having a hole penetrating the conductive metal layer.

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