JPH09307235A - Manufacturing single-side wiring board and multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the interconnection wiring with the least distance by using an insulation resin board having specified conductor pattern having through-holes for vias at specified positions on one surface and adhesive resin layer on the other entire surface; through-holes extending from the conductor surface to the resin layer at the back surface. SOLUTION: A resin board 2 has a conductor pattern 3 on one surface and epoxy resin prepreg pasted to the opposite surface to form an adhesive resin layer 4. Through-holes 5 are formed at desired positions and conductive paste is filled in the holes 5 and half hardened to form a wiring board with the resin layer 4. Similarly three wiring boards 1, 1', 1" are formed. A double-side wiping board 8 having wiring patterns 6 and vias 7 at desired positions is formed. The boards 1, 1', 1" are positioned with the resin layers 4 between, laminated on the wiring board 8 and pressed to integrate the wiring boards with prepregs and interconnect the conductor patterns of the upper and lower wiring boards through the vias, thus forming an interconnection wiring with the least distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-sided wiring board and a method for producing a resin-based multilayer wiring board using the same. More specifically, the present invention relates to a method for manufacturing a multilayer wiring board having via holes for electrically connecting conductor patterns inside the substrate and a single-sided wiring board used for the method. More specifically, the present invention relates to a single-sided wiring board and an inner layer conductor in which the wiring board is laminated. The present invention relates to a method for producing a resin-based multilayer printed wiring board capable of forming a via hole at an arbitrary position of a pattern, and a suitable single-sided wiring board used for the method.

[0002]

2. Description of the Related Art A standard manufacturing process for a conventional resin-based multilayer wiring board is shown in FIGS. For example, in the example of the four-layer board of FIG. 5, the core board 9 in which the copper foil of the double-sided copper clad laminate is etched to form the wiring conductor pattern 3 is prepared in advance (FIG. 5A). As shown in FIG. 5B, the epoxy resin prepreg 11 and the copper foil 10 are superposed on both surfaces of the sheet 9 and press laminated by applying appropriate heat and pressure (FIG. 5).
(C)). Thereafter, as shown in FIG. 5D, a through hole 12 is formed in a necessary portion, and a conductive metal layer 13 is formed on the entire surface of the substrate including the inner wall of the through hole 12 by electroless plating and / or electrolytic plating. , Via holes 14 for electrically connecting the conductor patterns on the front and back surfaces and the inner layer are formed (FIG. 5).
(C)). Further, the conductive metal layers on the front and back surfaces are etched to form the wiring conductor pattern 15, and the basic four-layer wiring board is completed (FIG. 5 (f)). In such a method of manufacturing a multilayer wiring board, it is difficult to form a via hole at an arbitrary position of the inner layer conductor pattern 16, so that it is difficult to connect the wiring in the shortest distance, the number of wirings is increased and the number of layers is increased, and a high speed circuit is used. When applied to, it may cause signal delay and noise generation.

Therefore, as shown in FIG. 6, a double-sided wiring board 18 in which a via hole 17 is previously formed at a required location,
A required number of 18 'are prepared (FIG. 6 (a)), the double-sided wiring boards 18, 18' and the copper foil 10 are laminated with the prepreg 11 sandwiched therebetween as shown in FIG. 6 (b), and thermocompression bonded. Fig. 6 (c)
After that, the through hole 12 is similarly formed (FIG. 6D), plating is performed (FIG. 6E), and then etching is performed to form the external wiring pattern 19.
There is also a method of manufacturing a multilayer wiring board (FIG. 6 (f)) in which the inner layer conductor pattern 16 and the outer wiring pattern 19 are connected to each other.
However, even with this method, it is difficult to completely form a via hole at an arbitrary position, and since the through hole 12 is formed, it is necessary to avoid the position and dispose the inner layer pattern. There is a problem that it becomes large.

Therefore, a build-up multilayer wiring structure as shown in FIG. 7 has been developed as a method of forming a via hole at an arbitrary position and performing the shortest distance wiring without requiring a through via hole. This method is shown, for example, in FIG.
The insulating resin layer 20 is formed on this double-sided wiring board 18 as a base substrate (FIG. 7 (b)), and holes 21 are formed in the insulating resin layer 20 at necessary locations by photolithography (FIG. 7).
(C)), a via-hole conductor 23 is formed in the hole 21, a wiring pattern 22 is formed on the insulating resin layer 20 by a plating method (FIG. 7D), and an insulating resin layer 20 'is further formed thereon. (FIG. 7 (e)), holes 21 ′ are formed at required locations to form via-hole conductors 23 ′ and wiring patterns 22 ′, and thereafter, this process is repeated to form a multilayer (FIG. 7).
(F) (g)).

This method is characterized in that a via hole can be formed at an arbitrary position and a fine pattern can be formed because a conductor pattern is formed by plating. However, since the insulating layer and the wiring pattern are sequentially formed, it is necessary to perform coating, curing treatment, drilling, plating, and the like of the insulating layer each time, which complicates the manufacturing process. Furthermore, since the unevenness is generated on the surface of the insulating layer when sequentially stacked in this manner, the number of stacked layers is limited to 4 to 5 layers.

[0006]

As described above, in the conventional method for manufacturing a multilayer wiring board, the more the number of layers, the more complicated the connection and routing of the conductor pattern and the more complicated the process, which is not only the performance but also the cost. There was also a problem in terms of disadvantage.
From this point of view, the present invention provides a high-density multi-layer wiring board using a resin-based insulating substrate, in which a via hole can be arranged in any position of the inner layer pattern in a simple process and a high multi-layer can be formed. The purpose is to do.

[0007]

According to the present invention, an insulating resin substrate has a predetermined conductor pattern on one surface and an adhesive resin layer on the entire other surface, and a conductor surface to a back surface are provided at predetermined positions of the conductor pattern. The single-sided wiring board having an adhesive resin layer, which has a through hole for a via hole penetrating up to the adhesive resin layer and is filled with a conductive paste in the through hole.

Further, according to the present invention, the n single-sided wiring boards (where n is an integer of 1 or more) and the insulating resin substrate have predetermined conductor patterns on both sides, and the conductor patterns on both sides are electrically connected. One double-sided wiring board having a via hole to be connected is prepared, and a single-sided wiring board having the adhesive resin layer on one side or both sides of the double-sided wiring board is aligned through the adhesive resin layer to obtain a total of n. The gist of the invention is a method for producing a multilayer wiring board, which is characterized by stacking a plurality of sheets and laminating them by applying predetermined heat and pressure. Furthermore, the present invention provides a plurality of single-sided wiring boards,
A method for producing a multilayer wiring board is characterized in that both surfaces of the obtained multilayer wiring board are aligned and aligned so that both surfaces have conductor patterns, and the layers are stacked by applying predetermined heat and pressure. It is a summary.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, as shown in FIG. 1 (c), a conductive pattern is provided at a predetermined position on one side of an insulating resin substrate, and an adhesive resin layer is provided on the other side of the insulating resin substrate. A wiring board having an adhesive resin layer, in which a through hole for a via hole opened at the position is filled with a conductive paste, is prepared as follows.

The conductor pattern of this wiring board is formed by, for example, a method of etching a copper foil of a single-sided copper clad laminate, a method of additively plating a metal on a resin substrate, or a method of plating a metal on the entire surface of a resin substrate and then etching it into a predetermined shape. Various conventional pattern forming methods such as a method of performing the above, or a method of printing a conductive paste made of a conductive powder and a resin on a resin substrate and then curing the conductive paste. Copper, silver,
A commonly used conductive metal such as gold or nickel is used.

The adhesive resin layer is made of a prepreg (a reinforcing material such as glass cloth impregnated with a thermosetting resin and semi-cured into a B stage), a B stage thermosetting resin sheet or a thermoplastic resin. Formed by a method of sticking a sheet, a method of applying a thermosetting resin solution on the entire surface of a substrate to form a B-stage film, a method of applying a thermoplastic resin solution in the same manner, and drying and solidifying to form a film. To do. The adhesive resin layer may contain a filler such as glass powder or ceramic powder for adjusting the thermal expansion coefficient and the like.

Since the conductive paste filled in the through-holes makes electrical connection between the wiring boards, the through-holes are preferably laminated at appropriate positions, preferably with the adhesive resin layer sandwiched therebetween. Are formed at positions where they can be connected at the shortest distance. The through holes may be formed before or after forming the conductor pattern.

The filling of the conductive paste is carried out by a conventional method such as screen printing or a filling method using a dispenser. In order to improve the electrical contact with the conductor pattern, as shown in FIG. It is desirable that they be slightly projected on the front and back surfaces. As the conductive paste, one containing conductive powder and a thermosetting resin or a thermoplastic resin as main components is used. As the conductive powder, those commonly used such as copper powder, nickel powder, silver powder and gold powder are used. As a processing procedure for producing a wiring board having an adhesive resin layer, it is desirable to basically take one of the following methods.

(1) When a prepreg or B-stage thermosetting resin is used for the adhesive resin layer, a predetermined conductor pattern is formed in advance on one surface of the insulating substrate, and then the adhesive resin layer is entirely formed on the multiple surfaces of the insulating substrate. Then, a via hole is formed, and then a thermosetting resin-based conductive paste is filled into the via hole and dried to be semi-cured in a B-stage shape, or a thermoplastic resin-based conductive paste is filled. Dry and solidify.

(2) When a thermoplastic resin is used for the adhesive resin layer, the thermoplastic resin solution is applied over the entire surface of the single-sided copper-clad laminate substrate having no copper foil, and a film is formed to form the adhesive resin layer. After forming a through hole for a via hole, a predetermined conductor pattern is formed by etching or the like, and then (a)
Similarly to the above, the through holes are filled with a thermosetting resin-based or thermoplastic resin-based conductive paste.

A double-sided wiring board having a via hole is formed by a method similar to the conventional method. That is, in order to form the conductor pattern on the front and back surfaces, for example, a method of etching a copper foil of a double-sided copper-clad laminate, a method of additively plating a metal on a resin substrate, or a method of plating a metal on the entire surface of a resin substrate and then forming a predetermined shape Various conventional pattern forming methods such as an etching method or a method of printing a conductive paste made of a conductive powder and a resin on a resin substrate and then curing the conductive paste can be applied. Via holes for connecting the conductor patterns on the front and back surfaces are provided with through holes at predetermined positions on the double-sided wiring board, and the inner walls of the holes are plated with a conductive metal such as copper, or a conductive paste is filled into the holes, Various conventional via hole forming methods such as curing can be applied.

Next, a method of manufacturing the multilayer wiring board will be described. First,
In order to manufacture a multilayer wiring board by combining and stacking the above-mentioned single-sided wiring board and double-sided wiring board having a via hole, the double-sided wiring board and the wiring board having the adhesive resin layer are aligned, and then stacked, heated, and heated. Press and stack. The heating and pressurizing conditions at this time are mechanical adhesion of the upper and lower substrates by the adhesive resin layer,
The type is appropriately selected depending on the type of the adhesive resin layer and the type of the conductive paste filled in the through holes so that the electrical connection of the conductive patterns between the upper and lower substrates can be completely obtained by the conductive paste.

For example, when a B-stage thermosetting resin is used for the adhesive resin layer and the conductive paste, the resin is completely cured to bond and integrate the laminated substrates, and between the conductor patterns of the upper and lower wiring boards. It is necessary to apply the temperature, pressure and time for which the electrical connection is completely obtained. On the other hand, in the case of a thermoplastic resin, the temperature of the adhesive resin layer and the resin in the filled conductive paste is raised to the re-melting temperature and then returned to room temperature, whereby the stacked substrates are bonded and integrated, and the upper and lower wiring boards are integrated. Of the conductor patterns are electrically connected.

By appropriately selecting the laminating conditions, the conductor pattern of the inner layer enters the resin of the adhesive resin layer and is flattened during heating and pressurization, and a multilayer wiring structure having no unevenness can be obtained. Regardless of the number, a high multilayer wiring board can be manufactured in a single laminating process. After this, as in the case of manufacturing a normal printed wiring board, if necessary, formation of solder resist and component marks, pre-flux to the exposed conductor pattern portion, pre-soldering treatment, etc. are performed to form a multilayer wiring board. Complete.

Next, in order to manufacture a multilayer wiring board by laminating a plurality of the above-mentioned single-sided wiring boards, it is necessary that both surfaces of the manufactured multilayer wiring board have the conductor patterns, that is, only one. Is manufactured by adhering adhesive resin layers to each other and stacking them. The same multilayer wiring board can be obtained in the same manufacturing method and subsequent steps as in the manufacturing method of a multilayer wiring board in which the single-sided wiring board and the double-sided wiring board having via holes are combined and laminated.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A manufacturing example of a multilayer wiring board having five conductor layers will be specifically described with reference to the drawings. As shown in FIG. 1A, the copper foil of a single-sided copper-clad laminate obtained by laminating a copper foil on one surface of a resin substrate 2 is etched to form a wiring conductor pattern 3, and an epoxy resin prepreg is attached to the opposite surface. To form an adhesive resin layer 4. Then, as shown in FIG. 1B, the through hole 5 is formed at a desired position. The through hole is filled with a conductive paste 6 containing copper powder and a thermosetting resin as main components, dried and semi-cured in a B-stage shape to obtain a wiring board 1 having an adhesive resin layer (see FIG. 1 ( c)). Similarly, a total of three wiring boards 1 , 1 ′, 1 ″ having an adhesive resin layer, which have through holes for via holes filled with a wiring pattern and conductive paste at desired positions, are manufactured.

Separately from this, according to the conventional method, as shown in FIG.
One double-sided wiring board 8 having the wiring pattern 6 and the via hole 7 at a desired position as shown in FIG. The wiring pattern 6 is formed by etching the copper foil of the double-sided copper-clad laminate,
The via hole 7 is formed by copper plating. Subsequently, as shown in FIG. 1E, wiring boards 1 , 1 ′ and 1 ″ having an adhesive resin layer are aligned and stacked on the double-sided wiring board so that the adhesive resin layer 4 is sandwiched, and then,
The wiring boards and the prepreg are integrated by completely curing the prepreg and the conductive paste 6 in the through-holes by stacking the stacked substrates by heating and pressing, and the via holes 7 electrically connect between the conductor patterns of the upper and lower wiring boards. Connection to obtain a multilayer wiring board (FIG. 1 (f)).

Example 2 Similar to Example 1, a single-sided wiring having an adhesive resin layer having a wiring pattern and a via hole through hole filled with a conductive paste at a desired position as shown in FIG. 3C. Boards 1 , 1 ′ and 1 ″ are manufactured. Further, in the same manner as in Example 1, a double-sided wiring board 8 having a wiring pattern and a via hole at a desired position as shown in FIG.
Make one sheet. In the future, stacking in the order of single-sided wiring board-single-sided wiring board-double-sided wiring board-single-sided wiring board as shown in FIG. 3 (c),
Similarly, the layers are laminated to form a multilayer wiring board as shown in FIG.

Example 3 As in Example 1, one side having an adhesive resin layer having through holes for via holes filled with a wiring pattern and a conductive paste at desired positions as shown in FIG. 4C. Wiring boards 1 , 1 ′ and 1 ″ are produced. These three single-sided wiring boards are stacked side by side so that both surfaces of the multilayer wiring board obtained as shown in FIG. Were laminated in the same manner to prepare a multilayer wiring board as shown in FIG.

[0026]

According to the method of the present invention, since the via hole can be arranged at an arbitrary position of the inner layer conductor pattern, the interconnection wiring can be made in the shortest distance, and the high density which cannot be obtained by the conventional press lamination method. In addition to the provision of the multilayer wiring board, there is an advantage that the manufacturing process of the laminated multilayer wiring board, which requires a complicated laminating process and a perforating process, is simplified. Further, the present invention does not take a continuous stacking step of stacking after forming an insulating layer, a via hole, and a wiring pattern for each layer such as a build-up multilayer wiring board, and the via hole and the wiring pattern at a single board level. This is a simple manufacturing process in which the multilayer wiring board is processed and then laminated once to obtain a multilayer wiring board regardless of the number of laminated layers. Therefore, the time required for manufacturing is shortened,
A low-cost multilayer wiring board can be provided. Furthermore, as the total number increases like a build-up multilayer wiring board, unevenness does not occur on the surface, so that a higher number of layers can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a method for manufacturing a multilayer wiring board according to the present invention.

FIG. 2 is a partial explanatory view of a wiring board having an adhesive resin layer on one surface laminated according to the present invention.

FIG. 3 is an explanatory view showing an example of a method for manufacturing a multilayer wiring board according to the present invention.

FIG. 4 is an explanatory view showing an example of a method for manufacturing a multilayer wiring board according to the present invention.

FIG. 5 is an explanatory diagram illustrating a conventional method for manufacturing a multilayer wiring board.

FIG. 6 is an explanatory diagram illustrating a conventional method for manufacturing a multilayer wiring board.

FIG. 7 is an explanatory diagram illustrating a conventional method for manufacturing a multilayer wiring board.

[Explanation of reference numerals] 1 wiring board having an adhesive resin layer 2 resin substrate 3 wiring conductor pattern 4 adhesive resin layer 8 double-sided wiring board 10 copper foil 11 prepreg 13 conductive metal layer 15 wiring conductor pattern 16 inner conductor pattern 20 insulating resin layer 22 wiring pattern 23 via-hole conductor

Front page continuation (72) Inventor Takashi Endo 2-9-3 Suehiro-cho, Ome-shi, Tokyo Shoei Chemical Industry Co., Ltd. Ome Factory

Claims (4)

[Claims] 1. An insulating resin substrate having a predetermined conductor pattern on one surface and an adhesive resin layer on the entire other surface, and penetrating a predetermined position of the conductor pattern from the conductor surface to the adhesive resin layer on the back surface. A single-sided wiring board having an adhesive resin layer, which has a through hole for a via hole and is filled with a conductive paste in the through hole. 2. The adhesive resin layer is made of any one of a prepreg, a B-stage thermosetting resin and a thermoplastic resin,
The single-sided wiring according to claim 1, wherein the conductive paste filled in the through holes of the wiring board having the adhesive resin layer contains conductive powder and a thermosetting resin or a thermoplastic resin as main components. Board. 3. An n-sided single-sided wiring board according to claim 1 or 2 (where n is an integer of 1 or more) and a predetermined conductor pattern on both sides of an insulating resin substrate, and the conductor patterns on both sides are electrically connected. One double-sided wiring board having a via hole to be electrically connected is prepared, and a single-sided wiring board having the adhesive resin layer on one side or both sides of the double-sided wiring board is aligned through the adhesive resin layer, A method of manufacturing a multilayer wiring board, characterized in that a total of n sheets are stacked and laminated by applying predetermined heat and pressure. 4. A plurality of single-sided wiring boards according to claim 1 or 2 are stacked in a predetermined manner such that both surfaces of the obtained multilayer wiring board are surfaces having conductor patterns and are aligned. A method for manufacturing a multilayer wiring board, which is characterized by stacking layers by applying heat and pressure.