JPH0216796A - Bendable multilayer circuit board and manufacture thereof - Google Patents

Abstract

PURPOSE:To acquire a bendable multilayer circuit board which can correspond properly even to products of multiitem and a small quantity by joining an inner layer wiring section which is provided with a ground pattern and a power source pattern to a bendable lamination board whose one side is coated with a conductive foil. CONSTITUTION:Bendable lamination boards 1, 3 are provided with a proper conductive foil 12, 32 such as copper foil on one side of bendable base materials 11, 31. A standardization inner layer wiring section 2 is provided with a power source pattern 22 and a ground pattern 23 with fixed patterns through etching on the both surfaces of the base material 21 of the lamination boards 1, 3, respectively. The base materials 11, 31 of the lamination boards 1, 3 are laminated and joined to each surface of the wiring section 2. A bendable multilayer circuit board which can correspond properly even to products of multiitem and a small quantity is acquired in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flexible multilayer circuit board having a structure in which a signal pattern, a power supply pattern, and a ground pattern are provided independently for each layer, and a method for manufacturing the same. Specifically, a flexible conductive foil-clad laminate is prepared in advance as a preparation material, which is standardly equipped with an inner layer wiring section in which a ground pattern or the ground pattern and power supply pattern are formed independently in layers in a certain pattern, The present invention relates to a novel flexible multilayer circuit board in which outer layer wiring patterning is performed according to specifications using this laminate, and a method for manufacturing the same.

"Prior art and its problems" In the field of flexible circuit boards, where the wiring pattern is becoming increasingly dense, flexible multilayer circuit boards are becoming more and more popular, similar to multilayer rigid circuit boards. The demand for
Especially in the audio or computer-related fields, there are products in which the signal pattern and power pattern are formed in separate layers, or products in which the signal pattern and power pattern are formed in separate layers, and in order to prevent noise on the signal pattern due to the influence of the magnetic field generated by current changes in the power pattern. A multilayer flexible circuit board with a three- or four-layer structure that has wiring patterns with different functions in separate layers, such as products with a structure in which a ground pattern is interposed in a separate layer for the purpose of shielding between the Many are also produced.

When manufacturing such a flexible multilayer circuit board, conventionally, a ground pattern or a power pattern between the ground pattern and the power supply pattern was prepared for each specification for a flexible conductive foil-clad laminate such as a single-sided or double-sided copper-clad laminate. Starting from the process of performing wiring patterning treatment on the inner layer, which consists of A flexible multilayer circuit board is manufactured by constructing an outer layer wiring section using the above-mentioned method, and then applying conductivity treatment such as through-hole conduction to required portions of both the inner layer wiring section and the outer layer wiring section. Ta.

As mentioned above, the method of forming the inner layer wiring section for each product and then configuring the outer layer wiring section requires a large number of steps, and the positioning of the inner and outer layer wiring sections also depends on the degree of multilayering. Since the process becomes extremely complicated, it is extremely difficult to increase manufacturing efficiency. In addition, it is difficult to meet the current demand for products with a large number of items and small quantities by manufacturing them using the above-mentioned conventional methods in terms of cost.

``Object and Structure of the Invention'' In consideration of the above-mentioned circumstances associated with the production of this type of flexible multilayer circuit board, the present invention provides a standardized flexible multilayer conductive circuit board in which inner layer wiring portions are formed in a fixed pattern. By preparing foil-clad laminates in advance and using a method that allows products to be manufactured according to specifications to immediately start from the forming process of the outer layer wiring, it is possible to suitably handle products with a large number of products in small quantities. A flexible multilayer circuit board and a method for manufacturing the same are provided.

Therefore, in the case of a three-layer structure, the flexible multilayer circuit board according to the present invention has a standardized inner layer having a ground pattern formed in a fixed pattern on one side of the flexible double-sided conductive foil-clad laminate. A flexible single-sided conductive foil-clad laminate comprising a wiring portion and having the base member side bonded to the surface pattern forming side, and a required signal pattern on the other side of the flexible double-sided conductive foil-clad laminate, respectively. A power supply pattern is formed separately to form an outer layer wiring section, and in the inner layer wiring section and the outer layer wiring section, between the ground pattern and the signal pattern and between the power supply pattern and the signal pattern. It is constructed to include conductive parts for interconnection provided at each required location, and in the case of a four-layer structure, a certain amount of electrical conductivity is provided on each side of the flexible double-sided conductive foil-clad laminate. A standardized inner layer wiring section has a grounding pattern and a power supply pattern formed separately with different arrangement positions in the pattern, and a base member side is provided on each side where the ground pattern and the power supply pattern are formed. A required signal pattern is separately formed on each side of each bonded flexible single-sided conductive foil-clad laminate to form an outer layer wiring section, and the ground pattern is formed in the inner layer wiring section and both outer layer wiring sections. and the signal pattern, between the power supply pattern and the signal pattern, and between the upper and lower signal patterns.

The above-mentioned flexible multilayer circuit board having a three-layer or four-layer structure is produced by first forming a standardized inner layer wiring section so as to have a ground pattern consisting of a certain pattern on one side of a flexible double-sided conductive foil-clad laminate; A standardized flexible multilayer conductive foil-clad laminate is prepared in advance by bonding the base member side of a flexible single-sided conductive foil-clad laminate to the ground pattern forming surface side, and the standardized flexible multilayer conductive foil-clad laminate is prepared in advance according to the specifications. After forming an outer layer wiring section by separately etching a required signal pattern and a power supply pattern on both sides of the multilayer conductive foil-clad laminate, the ground pattern and the signal pattern are formed in the inner layer wiring section and the outer layer wiring section. It is manufactured by applying through-hole conduction treatment for interconnection formed at each required location between the patterns and between the power supply pattern and the signal pattern, or it is manufactured using a flexible double-sided conductive foil-clad laminate. A standardized inner layer wiring section is formed so as to separately provide an earth pattern and a power supply pattern on both sides in a fixed pattern and at different positions with respect to each other, and on each surface side on which the earth pattern and the power supply pattern are formed. A standardized flexible multilayer conductive foil-clad laminate is prepared in advance by bonding the base member side of each flexible single-sided conductive foil-clad laminate to the base member side of each flexible single-sided conductive foil-clad laminate, and the standardized flexible multilayer conductive 7IU is prepared in advance according to the specifications. After forming the outer layer wiring section by separately etching the required signal patterns on both sides of the stretched laminate, the inner layer wiring section and the outer layer wiring section are formed between the ground pattern and the signal pattern and the power supply pattern. Each can be manufactured easily and with high efficiency by applying through-hole conduction processing for interconnection formed at each required location between the signal pattern and the upper and lower signal patterns.

"Example" Hereinafter, the present invention will be described in more detail with reference to the drawings. In FIGS. 1 and 2, 1 and 2 respectively represent a flexible base material 1). 31 is a flexible single-sided conductive foil-clad laminate with a suitable conductive foil 12 and 32 bonded to one side of the board, and 2 is a base material 21 of the flexible double-sided conductive foil-clad laminate.
A standardized inner layer wiring section in which a power supply pattern 22 and a ground pattern 23 are formed separately in a fixed pattern on both sides of the board by etching means, the double-flexible single-sided conductive foil-clad laminate l,
3 is a base material 1) on each side of the standardized inner layer wiring section 2.
A standardized flexible multilayer conductive foil-clad laminate is prepared by laminating and bonding the 31 side as shown in FIG. 2 and having the inner layer wiring portion 2 treated with a certain pattern in advance. This laminate is used when manufacturing a flexible multilayer circuit board with a four-layer structure, but for a three-layer circuit board, a ground pattern is placed in the above manner on one side of the flexible double-sided conductive foil-clad laminate. A similar standardized flexible multilayer conductive foil-clad laminate can be prepared by forming a similar standardized flexible multilayer conductive foil-clad laminate by laminating and bonding one flexible single-sided conductive foil-clad laminate on the ground pattern forming surface side. P is a double-sided flexible single-sided conductive foil-clad laminate l;
3, these are guide holes used for positioning when forming signal patterns as outer layer wiring parts, and can be formed with through holes at the four corners of these laminated plates, for example, as shown in the figure.

As shown in FIG. 3, the power supply pattern 22 and the ground pattern 23 of the standardized inner layer wiring section 2 are formed by etching or the like in a certain pattern in the form of a mesh or grid on each surface of the flexible insulating base material 21. In this case, the power supply pattern 22 and the ground pattern 23 are formed so as to be shifted from each other so that the positions thereof are different from each other as shown in the figure. A through hole H3 for mutual conduction required between the required signal pattern and the power supply pattern 22, a similar through hole H3 between the ground pattern 23 and the signal pattern, and both patterns 22 and 23. The configuration can be such that the required number of through holes H3 between the required outer layer signal patterns can be easily secured at any desired locations in locations where the outer layer signal patterns are not formed. Note that in the case of a three-layer quib, it is clear that the through holes H2 and H3 can be easily provided in the same manner as described above.

Since the standardized flexible multilayer conductive foil-clad laminate constructed as described above can be prepared in advance for manufacturing, when manufacturing a product according to the specifications, you can immediately start from this state and use the guide holes P. First, the required through-holes H1, H2, and H3 are drilled in the manner described above, and the required through-hole plating means is used between the inner layer wiring section 2 and the outer layer wiring section, and between the outer layer wiring sections. After carrying out the mutual conduction connection process, as shown in Fig. 4, the required signal patterns 12A and 32A according to the specifications are formed on the conductive foil of each outer layer separately according to a conventional method such as etching. The wiring part can be easily and quickly configured, and finally the product shape can be processed such as punching. In a three-layer flexible multilayer circuit board, the outer layer wiring section is constructed by separately forming the required signal pattern and power supply pattern on the conductive foil of each outer layer, as described above. 6 "Effects of the Invention" As described above, the present invention includes an inner layer wiring section in which the ground pattern alone or both the ground pattern and the power supply pattern are formed separately in a fixed pattern on each surface, and the inner layer A standardized flexible multilayer conductive foil-clad laminate is constructed with a flexible single-sided conductive foil-clad laminate bonded to the wiring side. It becomes possible to manufacture and prepare a large number of preparatory materials such as plates at low cost in advance.

To manufacture products according to specifications, the necessary through holes are immediately drilled in this standardized flexible multilayer conductive foil-clad laminate, and the required signal pattern is printed on both sides of the outer layer, or the signal pattern and power pattern are inserted into the outer layer. Since these can be formed separately, a flexible multilayer circuit board with a three-layer or four-layer structure can be easily manufactured with high efficiency while greatly simplifying the process.

During product manufacturing, only the outer layer wiring is formed and the required conductivity is established between the inner and outer layers, so there is no need to align each layer, resulting in highly accurate, high-density flexible multilayer circuits. We can provide high quality boards.

Therefore, it is possible to handle many products in small quantities with sufficient margin.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 shows a standardized flexible multilayer conductive foil-clad laminate having a certain inner layer wiring section, which is employed when constructing a flexible multilayer circuit board with a four-layer structure according to the present invention. A conceptual exploded perspective configuration diagram. Figure 2 is a conceptual cross-sectional diagram of the standardized flexible multilayer conductive foil-clad laminate. Figure 3 is the arrangement of the ground pattern and power supply pattern in the standardized inner layer wiring. A conceptual partial enlarged plan configuration diagram of the standardized inner layer wiring section for explaining the mode, the mutual conduction between the inner layer wiring section pattern and the outer layer wiring section pattern, and the mode of ensuring mutual conduction between the outer layer wiring section patterns, and , 4th
The figure is a conceptual cross-sectional configuration diagram of a flexible multilayer circuit board with a four-layer structure obtained by performing through-hole conduction processing and required outer layer wiring patterning processing according to specifications. 1, 3: 2: 4: 1). 31: 12, 32: 21 = 22: 23: 12A: 32 A: H1 to H3 P: Flexible single-sided conductive foil-clad laminate Standardized inner layer wiring section Standardized multilayer conductive foil-clad laminate Flexible insulation base material Copper foil Conductive foil such as Flexible insulating base material Fixed power pattern Fixed earth pattern Signal pattern Signal pattern Through hole for conduction Alignment guide hole Figure 3 Figure 2 Figure 4

Claims (1)

[Scope of Claims] (1) A flexible double-sided conductive foil-clad laminate is provided with a standardized inner layer wiring section having a ground pattern formed in a certain pattern on one side, and a base member on the side where the ground pattern is formed. A required signal pattern and a power supply pattern are separately formed on the other side of the flexible single-sided conductive foil-clad laminate whose sides are joined and the flexible double-sided conductive foil-clad laminate to form an outer layer wiring section. , in the inner layer wiring section and the outer layer wiring section, conductive sections for interconnection are provided at required locations between the ground pattern and the signal pattern and between the power supply pattern and the signal pattern. A flexible multilayer circuit board characterized by being configured as follows. (2) A standardized inner layer wiring section having a ground pattern and a power supply pattern formed separately on both sides of the flexible double-sided conductive foil-clad laminate in a fixed pattern and arranged at different positions with respect to each other; A required signal pattern is separately formed on each side of each flexible single-sided conductive foil-clad laminate, the base member side of which is bonded to each forming side of the ground pattern and the power supply pattern, thereby forming an outer layer wiring section. , provided at each required location between the ground pattern and the signal pattern, between the power supply pattern and the signal pattern, and between the upper and lower signal patterns in the inner layer wiring portion and both outer layer wiring portions. A flexible multilayer circuit board characterized in that it is configured to include conductive parts for interconnection. (3) Claim (1) wherein the ground pattern and power supply pattern formed in the inner layer wiring section have a mesh or grid shape.
Or (2) the flexible multilayer circuit board. (4) A flexible double-sided conductive foil-clad laminate that is equipped with a standardized inner layer wiring section having a ground pattern formed in a certain pattern on one side, and the base member side is bonded to the surface on which the ground pattern is formed. A standardized flexible multilayer conductive foil-clad laminate configured to include a single-sided conductive foil-clad laminate. (5) A standardized inner layer wiring section is provided on both sides of the flexible double-sided conductive foil-clad laminate, each having a ground pattern and a power supply pattern formed separately in a fixed pattern at different positions with respect to each other, and A standardized flexible multilayer conductive foil-clad laminate comprising flexible single-sided conductive foil-clad laminates each having a base member side bonded to each forming surface of the ground pattern and the power supply pattern. (6) Claim (4) wherein the ground pattern and power supply pattern formed in the inner layer wiring section have a mesh or grid shape.
Or the standardized flexible multilayer conductive foil-clad laminate of (5). (7) A standardized inner layer wiring section is formed so that one surface of the flexible double-sided conductive foil-clad laminate is provided with a ground pattern consisting of a certain pattern, and the surface on which the ground pattern is formed is coated with flexible single-sided conductive foil. A standardized flexible multilayer conductive foil-clad laminate is prepared in advance by bonding the base member side of the laminate.
After forming the outer layer wiring section by separately etching the required signal pattern and power supply pattern on both sides of this standardized flexible multilayer conductive foil-clad laminate according to the specifications, the inner layer wiring section and the outer layer wiring section are formed. Flexibility, characterized in that through-hole conduction processing is performed for interconnection formed at each required location between the ground pattern and the signal pattern and between the power supply pattern and the signal pattern. Method for manufacturing multilayer circuit boards. (8) Standardized inner layer wiring portions are formed on both sides of the flexible double-sided conductive foil-clad laminate, each having a ground pattern and a power supply pattern with different placement positions in a fixed pattern, and Prepare a standardized flexible multilayer conductive foil-clad laminate prepared in advance by bonding the base member side of a flexible single-sided conductive foil-clad laminate to each forming surface of the ground pattern and the power supply pattern, After forming the outer layer wiring portion by etching the required signal patterns on both sides of this standardized flexible multilayer conductive foil-clad laminate separately according to the specifications, the above-mentioned inner layer wiring portion and the outer layer wiring portion are etched. It is characterized by performing through-hole conduction processing for interconnection formed at each required location between the ground pattern and the signal pattern, between the power supply pattern and the signal pattern, and between the upper and lower signal patterns. A method for manufacturing flexible multilayer circuit boards. (9) The method for manufacturing a flexible multilayer circuit board according to claim (7) or (8), wherein the ground pattern and power supply pattern of the standardized inner layer wiring section are etched into a mesh or grid pattern.