JPH06196862A - Manufacture of multilayer printed-wiring board - Google Patents

Abstract

PURPOSE:To obtain a multilayer printed-wiring board wherein its wiring density is excellent and it is simple and easy by a method wherein an adhesive layer is formed on the surface on the side of an insulating material on a one-sided copper-clad laminated board and the adhesive layer is used as a B stage. CONSTITUTION:A layer by an adhesive 2 is formed on the surface on the side of an insulating material on a one-sided copper-clad laminated board 1, and it is used as a B-stage. In succession, a hole 3 is made in a connecting part in the board 1. Another board is overlapped so as to come into contact with the side of the layer by the adhesive 2 on the board 1 in which the hole 3 has been made, it is pressurized, heated, laminated and integrated. Then, a hole 6 which is passed through the whole of the laminated board is made, and a copper plating operation 7 is performed to the whole surface. Then, an etching resist is formed, inessential copper is etched and removed, and a conductor circuit is formed in a required part on the laminated and integrated board. When the adhesive 2 is used in the state of a B stage in this manner, a working operation such as a hole making operation or the like can be performed easily, and the board can be bonded to another wiring board by a successive pressurization and heating operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art In a multilayer printed wiring board, the number of conductive holes used for electrical connection between one wiring layer and another wiring layer increases as the wiring density increases. Conventionally, this conduction hole is
This is done by stacking a large number of wiring layers and stacking them, then forming a hole penetrating the whole and plating the inner wall of the hole. In this case, holes are drilled up to layers other than the layers that make the necessary connections, and in layers unrelated to the connections, wiring must be performed avoiding the through-holes. This is an obstacle to increasing the density and wiring density.

Therefore, instead of using only holes penetrating the entire wiring board, only adjacent wiring layers are connected.
Methods have been developed for forming so-called via holes. At present, the following two methods are basically known as this method.

The first method is a method in which adjacent wiring layers are first formed, connection holes are formed, and then a multilayer structure is formed.
Specifically, a hole is made in the double-sided copper-clad laminate, electroless plating is performed on the inner wall of the hole, or electrolytic plating is performed when necessary to form a connecting conductor, and only unnecessary portions of the copper foil on one side are removed by etching. Then, leave the copper foil on the entire other surface, and after laminating and integrating with the other substrate, make a hole through the whole and metallize the inner wall of the hole, or wire on the surface of the insulating substrate. A layer is formed on the surface of the wiring layer with a photosensitive insulating material, and the surface of this insulating material is roughened by irradiating with light so as to remove only the portion that becomes a conduction hole and developing, There is a method of using a photosensitive material between the layers of the wiring layers, such as electroless plating on the circuit conductor and the inner wall of the hole to form the conductor. In all of these techniques, further required wiring layers are formed by the same technique to form multiple layers.

The second method is a method of connecting the surface layer and a layer for connecting to the surface layer after being laminated in advance, and the conductive hole is opened only up to the layer to be connected. It is characterized by not having. Specifically, a plurality of wiring layers and insulating layers that support the wiring layers are alternately stacked, and a copper foil is left on the surface, where the surface is connected to the circuit, and the depth to reach the layer to be connected is reached. Drill a hole, electrolessly plate the inner wall of the hole, and if necessary, subsequently perform electrolytic plating to form a circuit on the surface by etching away unnecessary parts, or to make a hole. Use laser light so that the laser light does not reach the layers that do not require connection,
There is a method of leaving a copper foil on the layer to be connected.

[0006]

However, these conventional methods have the following problems. That is, when a double-sided copper-clad laminate is used in the first method, since the circuit is formed on one side, the dimensional change of the substrate is likely to occur, and when a plurality of substrates are stacked and laminated, the positional accuracy between each wiring layer is improved. You have to be very careful, and
The thickness of the other conductor is increased by the plating performed for connecting the inner wall of the conduction hole, making it difficult to reduce the total thickness when the conductor is multilayered. In addition, when a photosensitive material is used as an insulating layer between each wiring layer, there are few materials that can simultaneously satisfy the roughening treatment that enhances the adhesion of plating and the photosensitivity for forming a through hole. Adhesion is not enough. When a drill is used in the second method, there is variation in the thickness of the substrate, and it is not possible to increase the positional accuracy of stopping the progress of the drill at the connecting point. Moreover, when a laser is used, the device is expensive. further,
In this second method, at the place where a hole is made,
No wiring can be provided to other layers between the surface layer and the connection layer.

An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board which is excellent in wiring density and simple.

[0008]

The method for manufacturing a multilayer printed wiring board according to the present invention is characterized by including the following steps. (a) A step of forming an adhesive layer on the surface of the single-sided copper-clad laminate on the side of the insulating material and using this adhesive layer as a B stage (b) A step of making a hole in the substrate (c) A hole having been made Step of stacking on the adhesive layer side of the board so that another board is in contact, pressurizing and heating to laminate and integrate (d) Step of forming a conductor circuit at a necessary portion of the board

Instead of the single-sided copper-clad laminate, a copper foil for printed wiring board having an adhesive layer on the roughened surface can be used. In this case, the manufacturing method is as follows. . (a) A step of providing an adhesive layer on the roughened surface of the copper foil for printed wiring board and using this adhesive layer as a B stage (b) A step of making a hole in the board (c) A board having the hole Step (d) of forming a conductor circuit on a necessary portion of the laminated and integrated substrate by superposing it on the adhesive layer side so that another substrate comes into contact therewith, and applying pressure and heating.

In order to form a multilayer using such a technique, the following steps may be provided after the above steps. (e) A step of providing an adhesive layer on the surface of the other one-sided copper-clad laminate on the side of the insulating material and using this adhesive layer as a B stage (f) A step of making a hole in the other substrate (g) On the adhesive layer side of the other board with holes,
(d) step of superimposing so that the substrates are in contact with each other, step of heating under pressure to integrally integrate the layers (h) step of repeating the steps (e) to (g) to make a multilayer , (E) Providing an adhesive layer on the roughened surface of another copper foil for printed wiring board and making this adhesive layer a B stage (f) Making a hole in the other substrate (g) ) On the adhesive layer side of the other substrate in which the hole is formed, the step
Step of stacking so that the substrates prepared in (d) are in contact with each other, pressurizing and heating to laminate and integrate (h) Steps (e) to (g) are repeated to form multiple layers, if necessary.

The single-sided copper-clad laminate used in the present invention uses an insulating material having a copper foil bonded to one side thereof, for example, a single-sided copper-clad laminate using glass cloth-epoxy resin or a flexible polyimide film. A flexible sheet with copper on one side can be used. The insulating material may be an organic material obtained by impregnating a reinforcing fiber such as paper, non-woven fabric or glass cloth with a resin, a non-reinforced resin product, a flexible film, or a composite material of such a material and ceramics. Can be used. As the resin, a phenol resin, an epoxy resin, a polyimide resin, a polyester resin, a fluorine-containing resin or the like can be used. Furthermore, those in which a catalyst for electroless plating is dispersed in these insulating materials can also be used.

As the adhesive, an epoxy resin adhesive,
An acrylic modified resin-based or polyimide resin-based adhesive or the like can be used, and these can be applied by roll coating, dip coating, curtain coating or the like. Further, a film obtained by further forming these adhesives can be used, and an epoxy adhesive film such as G604 (manufactured by Hitachi Chemical Co., Ltd., trade name), an acrylic modified resin film such as Piralux (manufactured by DuPont, trade name) Alternatively, a polyimide adhesive film such as AS-2210 (trade name, manufactured by Hitachi Chemical Co., Ltd.) can be used. These adhesive films are bonded to a single-sided copper-clad laminate or copper foil, but after bonding, they need to be in the B stage state. The B stage referred to in the present invention is a state in which it is attached to a single-sided copper-clad laminate or copper foil, has no tackiness at 40 ° C. or lower, and has an adhesive strength of 0.8 due to subsequent multi-layer adhesion.
It means a semi-cured state that can give more than kgf / cm ² .
Such a B-stage state method is carried out by heating at a temperature and for a time at which the resin does not completely cure like ordinary resins. This degree is usually obtained experimentally. In addition, in the step of heating and pressurizing to integrate the layers, the B
The flow rate of the adhesive layer of the stage is preferably less than 200 mm with respect to the surface direction of the substrate. When this flow amount is large, when it is pressurized and heated, it spreads over the wiring conductor of another wiring board, the area to be connected by plating becomes small, and the connection reliability deteriorates.

[0013]

In the method of the present invention, since the adhesive is used in the B stage, it is easy to make a hole or the like.
Subsequent pressurization and heating also enables adhesion to other wiring boards.

[0014]

EXAMPLES Example 1 MCL- which is a single-sided copper-clad laminate as shown in FIG.
Adhesive film G604 (manufactured by Hitachi Chemical Co., Ltd.) on the surface of the insulating material side of E-67 (manufactured by Hitachi Chemical Co., Ltd.), pressure 10 kgf / cm ² ,
Heat at 150 ° C for 7 minutes to reach B stage (Fig. 1
Shown in (b). ). Subsequently, as shown in FIG. 1 (c), a hole is drilled in the substrate at a connection point by a numerically controlled drill machine. At this time, the smallest hole diameter is 0.25
It was mm. Subsequently, the substrate having the holes is superposed on the adhesive layer side so that another substrate as shown in FIG. 1 (d) is brought into contact with the substrate, and is pressurized and heated to be laminated and integrated (see FIG. 1 (e ).). The lamination conditions at this time are: pressure 40 kgf / cm ² , temperature 17
It was 45 minutes at 0 ° C. Subsequently, a hole is formed through the entire laminated plate (shown in FIG. 1 (f)), and copper plating is performed on the entire surface (shown in FIG. 1 (g)). Then, an etching resist is formed and unnecessary copper is removed by etching.
As shown in FIG. 3, a conductor circuit is formed at a necessary portion of the laminated and integrated substrate.

Example 2 An adhesive film G604 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was provided on the roughened surface of a copper foil for printed wiring board having a thickness of 18 μm shown in FIG. 2 (a). The adhesive film is heated at a pressure of 10 kgf / cm ² and 150 ° C. for 7 minutes to be in the B stage (shown in FIG. 2 (b)). Then, as shown in FIG. With a numerically controlled drill machine,
Make a hole at the connection point. At this time, the smallest hole diameter was 0.25 mm. Subsequently, another substrate as shown in FIG. 2 (d) is superposed so as to be in contact with the adhesive layer side of the substrate having the holes, and is heated under pressure to be laminated and integrated (see FIG. 2 (e). ).). The stacking conditions at this time are 40 kgf / cm
^{2. The} temperature was 170 ° C. for 45 minutes. Then, a hole is formed through the laminated plates (shown in FIG. 2 (f)), and copper plating is performed on the entire surface (shown in FIG. 2 (g)). Subsequently, an etching resist is formed, and unnecessary copper is removed by etching to form a conductor circuit on a necessary portion of the laminated and integrated substrate as shown in FIG. 2 (h).

Example 3 MCL- which is a single-sided copper-clad laminate as shown in FIG. 3 (a)
Adhesive film G604 (manufactured by Hitachi Chemical Co., Ltd.) on the surface of the insulating material side of E-67 (manufactured by Hitachi Chemical Co., Ltd.), pressure 10 kgf / cm ² ,
Heat at 150 ° C for 7 minutes to reach B stage (Fig. 3
Shown in (b). ). Subsequently, as shown in FIG. 3 (c), a hole is drilled in the connection point on the substrate by a numerically controlled drill machine. At this time, the smallest hole diameter is 0.25
It was mm. Subsequently, the substrate having the holes is superposed on the adhesive layer side so that another substrate as shown in FIG. 3 (d) is brought into contact with the substrate, and is pressurized and heated to be laminated and integrated (see FIG. ).). The lamination conditions at this time are: pressure 40 kgf / cm ² , temperature 17
It was 45 minutes at 0 ° C. Subsequently, the surface of this laminated plate is plated with copper having a thickness of 15 μm (shown in FIG. 3 (f)). Subsequently, an etching resist is formed, and unnecessary copper is removed by etching to form a circuit conductor (shown in FIG. 3G).
The wiring board prepared in this manner is superposed so as to come into contact with the adhesive layer side of the single-sided board prepared separately in the same process as in FIGS. (Fig. 3 (h)
Shown in. ). The lamination conditions at this time were a pressure of 40 kgf / cm ² and a temperature of 170 ° C. for 45 minutes. Such multilayering is repeated, and after the final lamination, an etching resist is formed and unnecessary copper is removed by etching, and as shown in FIG. 3 (i), necessary portions of the laminated and integrated substrate are obtained. Then, a conductor circuit is formed.

Example 4 An adhesive film G604 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was provided on the roughened surface of a copper foil for printed wiring board having a thickness of 18 μm shown in FIG. 4 (a). The adhesive film is heated at a pressure of 10 kgf / cm ² and 150 ° C. for 7 minutes to be in the B stage (shown in FIG. 4 (b)). Then, as shown in FIG. With a numerically controlled drill machine,
Make a hole at the connection point. At this time, the smallest hole diameter was 0.25 mm. Subsequently, another substrate as shown in FIG. 4 (d) is superposed so as to come into contact with the adhesive layer side of the substrate having the holes, and is heated under pressure to be laminated and integrated (see FIG. 4 (e)). ).). The stacking conditions at this time are 40 kgf / cm
^{2. The} temperature was 170 ° C. for 45 minutes. Subsequently, the surface of this laminated plate is plated with copper having a thickness of 15 μm (shown in FIG. 3 (f)). Subsequently, an etching resist is formed and unnecessary copper is removed by etching to form a circuit conductor (FIG. 4).
Shown in (g). ). The wiring board prepared in this manner is superposed so as to come into contact with the adhesive layer side of the substrate prepared separately in the same steps as in FIGS. This is shown in Fig. 4 (h). The stacking conditions at this time are pressure 40k
The temperature was 170 ° C. for 45 minutes at gf / cm ² . Such multilayering is repeated, and after the final lamination, an etching resist is formed and unnecessary copper is removed by etching, and as shown in FIG. 4 (i), necessary portions of the laminated and integrated substrate are obtained. To
Form a conductor circuit.

[0018]

As described above, according to the present invention, it is possible to provide a method for manufacturing a multilayer printed wiring board which is excellent in wiring density and simple.

[Brief description of drawings]

1A to 1H are sectional views for explaining each step of an embodiment of the present invention.

2A to 2H are cross-sectional views for explaining each step of another embodiment of the present invention.

3A to 3I are cross-sectional views for explaining each step of another embodiment of the present invention.

4 (a) to 4 (i) are cross-sectional views for explaining each step of another embodiment of the present invention.

[Brief description of symbols] 1. Single-sided copper clad laminate
2. Adhesive 3. Holes that are non-through holes 4. Wiring conductor 5. Non-through hole 6. Through hole 7. Copper plating 8. Wiring conductor by copper plating 11. Copper foil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akinari Kida 1500 Ogawa, Shimodate, Ibaraki Pref., Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. (72) Shuichi Hatakeyama 1500 Ogawa, Shimodate, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Research Center (72) Inventor Naoyuki Urasaki 1500 Ogawa, Shimodate, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Research Center (72) Inventor Kazuhisa Otsuka 1500 Ogawa, Shimodate, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (5)

[Claims] 1. A method for manufacturing a multilayer printed wiring board, comprising the following steps. (a) A step of forming an adhesive layer on the surface of the single-sided copper-clad laminate on the side of the insulating material and using this adhesive layer as a B stage (b) A step of making a hole in the substrate (c) A hole having been made Step of stacking on the adhesive layer side of the board so that another board is in contact, pressurizing and heating to laminate and integrate (d) Step of forming a conductor circuit at a necessary portion of the board 2. A method for manufacturing a multilayer printed wiring board, comprising the following steps. (a) A step of forming an adhesive layer on the surface of the single-sided copper-clad laminate on the side of the insulating material and using this adhesive layer as a B stage (b) A step of making a hole in the substrate (c) A hole having been made Step of stacking on the adhesive layer side of the board so that another board is in contact, pressurizing and heating to laminate and integrate (d) Step of forming a conductor circuit at a necessary portion of the board (e) A step of providing an adhesive layer on the surface of the other one-sided copper-clad laminate on the side of the insulating material and using this adhesive layer as a B stage (f) A step of making a hole in the other substrate (g) On the adhesive layer side of the other board with holes,
Step of stacking so that the substrates prepared in (d) are in contact with each other, pressurizing and heating to laminate and integrate (h) Steps (e) to (g) are repeated to form multiple layers, if necessary. 3. A method for manufacturing a multilayer printed wiring board, comprising the following steps. (a) A step of providing an adhesive layer on the roughened surface of the copper foil for printed wiring board and using this adhesive layer as a B stage (b) A step of making a hole in the board (c) A board having the hole Step (d) of forming a conductor circuit on a necessary portion of the laminated and integrated substrate by superposing it on the adhesive layer side so that another substrate comes into contact therewith, and applying pressure and heating. 4. A method of manufacturing a multilayer printed wiring board, which comprises the following steps. (a) A step of providing an adhesive layer on the roughened surface of the copper foil for printed wiring board and using this adhesive layer as a B stage (b) A step of making a hole in the board (c) A board having the hole (D) a step of forming a conductor circuit on a necessary portion of the laminated and integrated substrate by superposing on the adhesive layer side of the substrate so that the other substrate is in contact, pressurizing and heating to laminate and integrate. e) a step of providing an adhesive layer on the roughened surface of another copper foil for printed wiring board and making this adhesive layer a B stage (f) a step of making a hole in the other substrate (g) On the adhesive layer side of the other board with holes,
Step of stacking so that the substrates prepared in (d) are in contact with each other, pressurizing and heating to laminate and integrate (h) Steps (e) to (g) are repeated to form multiple layers, if necessary. 5. An adhesive having a flow rate of the adhesive layer of B stage of less than 200 mm with respect to the surface direction of the substrate is used in the step of heating and pressing to laminate and integrate. 5. The method for manufacturing a multilayer printed wiring board according to any one of 4 to 4.