JP2002151842A - Method of manufacturing multilayer board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer board, with which maintenance of quality is compatible with enhancement of multilayer stacking efficiency. SOLUTION: A plurality of multilayer boards are manufactured, by arranging a plurality of inner circuit boards on a plane, and multilayer stacking is performed using prepregs and metal foils or caplayer base material members, wherein the distance between adjoining inner circuit boards arranged on a plane is adjusted, depending on the characteristics of inner circuit boards and of prepregs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, printed wiring boards have been increased in density and multilayered due to higher performance, thinner and lighter weight of electronic equipment, and the demand for the printed wiring boards has been increased. , Lower price, and stable supply have been strongly demanded. The multilayer board is manufactured by arranging a prepreg and a metal foil on the upper and lower sides of an inner board having an inner layer circuit, forming a multilayer laminate, and then forming an outer layer circuit on the outermost metal foil surface. In general, multi-layer lamination molding for obtaining a multi-layer board is usually performed for each unified individual product size.However, in order to improve efficiency and productivity, the same configuration is used in a medium or large press. A method has been developed in which a plurality of products are arranged and molded. In this method of arranging a plurality of multi-layered laminates, it is assumed that troubles due to overlapping and slipping of the inner circuit boards are likely to occur,
As disclosed in Japanese Patent Application Laid-Open No. 7-44340, a plurality of inner-layer circuit boards are arranged in contact with each other, fixed in a single-plate form, prepregs and metal foils are placed, and then a plurality of presser feet are attached. A method using a slip stopper top plate has also been devised.

[0003]

However, in these methods, the inner-layer circuit boards are arranged without gaps.
The thickness of the contacting part becomes thicker than other normal parts, and the resin flow of the prepreg becomes uneven for each product, which affects the pressure distribution and causes deformation of the inner circuit board. And problems such as copper wrinkles occur. Further, the relationship between the length and the strength of the inner layer and the outer layer (prepreg layer) in which the ratio of the length of the long side to the short side (long side / short side) of the inner layer plate is 1.5 or more is as follows: inner layer = outer layer or inner layer <In the product having the outer layer relationship, it was confirmed that the deformation of the inner layer plate was enlarged.

[0004] It is an object of the present invention to provide a method for manufacturing a multilayer board which can maintain both the quality and the efficiency of multilayer lamination.

[0005]

The present invention is characterized by the following. (1) In a method of manufacturing a multilayer board in which a plurality of inner circuit boards are arranged side by side and laminated and laminated using a prepreg and a metal foil or an outer layer material, an inner layer arranged and arranged according to each characteristic of the inner circuit board and the prepreg. A method of manufacturing a multilayer board for adjusting the distance between circuit boards. (2) The multi-layer lamination using a pre-component in which a predetermined number of inner circuit boards are arranged on a large prepreg and the inner circuit board is fixed to a prepreg arranged immediately below the inner circuit board is described in (1). Of manufacturing a multilayer board. (3) The multilayer according to (1) or (2), wherein when the thickness and strength of the inner layer and the outer layer (prepreg layer) are such that inner layer = outer layer and inner layer <outer layer, the distance between the inner circuit boards is 5 to 30 mm. Plate manufacturing method. (4) The method for producing a multilayer board according to any one of (1) to (3), wherein the resin flow of the prepreg used is 12% or less. (5) When the thickness and strength of the inner layer and the outer layer (prepreg layer) are in the relation of inner layer> outer layer, and when using a prepreg having a resin flow of 12% or less, the distance between the inner layer circuit boards should be 0.5 to 0.5%.
The method for producing a multilayer board according to any one of (1) to (4), wherein the thickness is 30 mm.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the prepreg used in the present invention, conventionally known prepregs can be appropriately used. Specifically, as a substrate, a glass woven fabric, a glass nonwoven fabric, or the like can be used. Examples of the resin to be impregnated with the resin include epoxy resin, polyimide resin, triazine resin, phenol resin, unsaturated polyester resin, melamine resin, and modified resins of these resins. Further, two or more kinds of the above resins may be used in combination, or if necessary, various known curing agents and curing accelerators may be used in combination. Also,
When arranging the inner circuit boards by a large press or the like and performing multilayer lamination molding, it may be adjusted to the size of one inner circuit board,
It is preferable that the size is set in consideration of the number of sheets to be arranged and a necessary interval between the substrates. The resin flow of the prepreg is preferably 12% or less both in the case of performing multilayer lamination molding with an integrated inner layer circuit board and in the case of performing multilayer lamination molding in a form in which a plurality of inner layer circuit boards are arranged. Contests and minimum melt viscosity properties may be adjusted, but need not be adjusted. The evaluation of the resin flow characteristics here
Laminate molding is performed at a heating temperature of 140 ° C. and a pressure of 1 MPa for 10 minutes. After cooling, the weight of the resin flowing out is measured, and the resin outflow ratio is expressed in weight% based on the weight before lamination molding. However, the present invention is not limited to this. Although there is no particular limitation on the inner circuit board used in the present invention, it is possible to use a circuit board obtained by etching copper of a copper-clad laminate from the viewpoint of economical and electrical reliability. Regarding the relationship between the inner layer circuit board and the prepreg used in the present invention, the inner layer board> the prepreg layer is preferable in terms of thickness and strength, but any other value may be used. As the size, the relationship of inner layer plate <prepreg is preferable, but not limited to this. The copper foil used in the multilayer lamination molding used in the present invention is preferably larger than the inner layer plate and the prepreg, and larger than the end plate used as the molding die. In the present invention, the distance between the inner circuit boards in which a plurality of sheets are arranged is preferably adjusted according to the characteristics of the inner substrate and the prepreg, and the relationship of the thickness and strength is defined as the relationship of inner layer = prepreg layer, inner layer> prepreg layer. Sometimes 5
~ 30 mm is preferred. When the relationship between the thickness and strength is inner layer> prepreg layer, or when using a prepreg having a resin flow of 12% or less, the distance between the substrates is 0.5 to 30 mm.
May be. Also, when assembling the materials, after arranging a predetermined number of inner layer circuits on a single prepreg while maintaining a necessary interval, the prepreg and the inner layer circuit board are taped or glued,
The use of a pre-component that is appropriately selected and fixed from various fixing means such as heat welding can prevent the inner circuit board from shifting or overlapping. Further, the multilayer lamination molding conditions are performed at a temperature of 150 to 220 ° C. and a pressure of about 1 to 6 MPa. The lower pressure is preferable to prevent deformation of the inner layer circuit, and the pressure in the heating process is adjusted. You may. Thus, by adjusting the distance between the inner circuit boards according to the characteristics of the inner circuit boards and the prepreg, or using a prepreg having a resin flow of 12% or less and adjusting the relationship between the strength of the inner layer and the prepreg, deformation, It is possible to manufacture a multilayer board in which thickness variations and copper wrinkles are suppressed. The effect of improving the deformation, thickness variation, copper wrinkles, and the like of the prepreg having a resin flow of 12% or less is not limited to the case where the inner circuit boards are arranged side by side and is laminated, and is also effective when an integrated inner circuit board is used. It is. Hereinafter, the present invention will be specifically described with reference to the drawings showing examples, but the present invention is not limited thereto.

[0007]

EXAMPLES Example 1 Glass cloth-based epoxy resin copper-clad laminate (FR-4, 0.
After laminating a photosensitive film generally used by an etched foil method on a 1 mm, 35 μm copper foil) and printing (exposure) using a negative film for forming a circuit, etching treatment and oxidation treatment of the copper foil surface are performed. Thus, an inner layer circuit board 1 was obtained. On the prepreg 2 having a thickness of 0.20 mm and a resin flow of 15%, the distance 6 between the inner circuit boards is arranged at 10 mm, and the inner prepreg 2 and the lower prepreg 2 are fixed with the tape 5 and then the upper side. Another pre-preg 2 is arranged in the pre-composition 3. 18 above and below this pre-component
The product on which the copper foil 4 of μm is arranged is used as a product under reduced pressure atmosphere.
After heating and pressing at 3 MPa and 170 ° C. for 90 minutes, the mixture was cooled for 30 minutes to obtain a four-layer plate.

Example 2 A four-layer board was obtained in the same manner as in the example except that prepreg 2 having a resin flow of 10% was used and the distance 6 between the inner circuit boards was set to 0.5 mm.

Comparative Example 1 Except that a prepreg 2 having a resin flow of 15% was used, the distance 6 between the inner circuit boards was set to 0 mm, and the inner circuit board 1 was not fixed but was used as a pre-configured product. A four-layer plate was obtained in the same manner as in the example.

Comparative Example 2 Except that prepreg 2 having a resin flow of 15% was used, distance 6 between the inner circuit boards was set to 10 mm, and pre-component 3 was used without fixing the inner circuit board. A four-layer plate was obtained in the same manner as in the example.

The effects of the four-layer plates produced in Examples 1 and 2 and Comparative Examples 1 and 2 on deformation, plate thickness, copper wrinkles, and substrate displacement were evaluated. Table 1 shows the results. In Table 1, the amount of deformation is calculated by measuring the coordinates of the other marks installed at the four corners of the product with reference to the distance between the guide marks for drilling and comparing with the design value of the product (the original position). Was calculated, and the maximum value was expressed as a deformation amount. After measuring the plate thickness with a micrometer, the dispersion (σn-1) was calculated and compared. The copper wrinkles and the displacement of the substrate were visually confirmed.

[0012]

[Table 1]

[0013]

According to the manufacturing method of the present invention, it is possible to obtain a multi-layered board which is small in deformation and thickness variation and in which copper wrinkles and the like are suppressed. In particular, the effect is large when a plurality of inner circuit boards are arranged side by side and multilayered, and the method of controlling the resin flow of the prepreg to be low can obtain a great effect even when an integrated inner layer board is used. Therefore, it is possible to realize a manufacturing method in which quality maintenance and improvement and efficient production are compatible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a product according to an embodiment of the present invention.

FIG. 2 is a plan view showing an inner circuit board arrangement and a fixing method on a lower prepreg according to an embodiment of the present invention.

[Explanation of symbols]

1. 1. inner layer circuit board Prepreg 3. Pre-components 4. Copper foil 5. 5. Tape (for fixing board) Distance between inner circuit boards

Claims (5)

[Claims] 1. A method for manufacturing a multilayer board in which a plurality of inner-layer circuit boards are arranged side by side and laminated by using a prepreg and a metal foil or an outer layer material, wherein the inner-layer circuit board and the prepreg are arranged and arranged according to respective characteristics. A method of manufacturing a multilayer board for adjusting the distance between inner circuit boards. 2. A multi-layer laminate comprising a plurality of inner circuit boards arranged in a predetermined number on a large-sized prepreg, and a pre-component in which the inner circuit boards are fixed to a prepreg arranged immediately below the inner circuit board. 3. The method for producing a multilayer board according to item 1. 3. The multilayer according to claim 1, wherein the distance between the inner circuit boards is 5 to 30 mm when the thickness and strength of the inner layer and the outer layer (prepreg layer) are such that inner layer = outer layer and inner layer <outer layer. Plate manufacturing method. 4. The resin flow of the prepreg used is 12
% Or less. 5. When the thickness and strength of the inner layer and the outer layer (prepreg layer) are in the relation of inner layer> outer layer, and when using a prepreg having a resin flow of 12% or less, the distance between the inner circuit boards is 0.5 to 30 mm. The method for producing a multilayer board according to any one of claims 1 to 4.