JPH03237797A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To prevent position deviation of inner layer circuit boards without using an adhesive tape, by forming a recessed part in the width direction, at the side end portion of one inner layer circuit board, forming a protruding part whose size in the width direction is nearly equal to the recessed part, at the side end portion of the other inner layer circuit board, and fitting and bonding them. CONSTITUTION:An inner later circuit board 1 is provided with a recessed part 4 or a protruding part 5, at the side end portion for fitting. The recessed part 4 is formed by cutting down the side end portion of the board 1 in the width direction. The protruding part 5 is formed as the residual part by cutting out both sides of the side end portion of the board 1. The recessed part 4 and the protruding part 5 are engaged with each other. Thus a plurality of the inner layer circuit boards 1 are bonded in the manner in which the respective side end faces are made to abut. Thereon and thereunder metal foils 3 like copper foils or outer layer circuit boards are stacked. These are made one unit; about ten units are set for one stage; these are heated and compression-bonded by a pressing machine. Thereby a multilayer wiring board wherein the metal foils 3 or the outer layer circuit boards are laminated on both sides of the inner circuit board 1 can be obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method of manufacturing a multilayer wiring board using a plurality of inner layer circuit boards.

[Conventional technology]

In manufacturing a multilayer wiring board, metal foil or an outer layer circuit board is layered on top and bottom of the inner layer circuit board via prepreg, and then heated and pressure molded using a press machine (i.e., multilayer molding). There is. When performing multilayer molding in this manner, the molding size is adjusted to match the size of the inner layer circuit board. However, if the size of the inner layer circuit board is smaller than the press size, the size of the multilayer molding must also be smaller than the press size, which poses a problem in terms of productivity. Therefore, when the size of the inner layer circuit board is small, multiple inner layer circuit boards are arranged with their side edges butted against each other.
In this state, it is being considered to manufacture a multilayer wiring board of a size that matches the press size by stacking metal foil or an outer layer circuit board on top and bottom of this with prepreg interposed therebetween and molding it under heat and pressure. However, this method has a problem in that the inner layer circuit board may be moved by the resin 70- from the prepreg during molding, and the positions of the plurality of inner layer circuit boards may be shifted from each other. For this reason, Japanese Patent Application Laid-Open No. 1-136695 discloses an attempt to prevent mutual displacement of the inner layer circuit boards by joining the butted inner layer circuit boards with adhesive tape.

[Problem to be solved by the invention]

However, as in JP-A-1-136695, #
To bond the inner layer circuit board using adhesive tape,
As disclosed in Japanese Patent Application Laid-open No. 1-136695,
This requires a special adhesive tape that has high heat resistance and shear adhesive strength, low elongation, and is extremely thin, making it difficult to put it into practical use due to cost. The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a multilayer wiring board that can prevent displacement of an inner layer circuit board without using adhesive tape. It is.

[Means for Solving the Problems] A method for manufacturing a multilayer wiring board according to the present invention includes arranging a plurality of inner layer circuit boards 1 with their side end surfaces butted against each other, and placing metal foils 3 through prepregs 2 above and below the inner layer circuit boards 1. Alternatively, when manufacturing a multilayer wiring board by stacking outer layer circuit boards and molding them under heat and pressure, a recess 4 is formed in the width direction at the side end of one of the inner layer circuit boards 1 to be matched. At the same time, a protrusion 5 having approximately the same dimension in the width direction as the recess 4 is provided at the side end of the other inner layer circuit board 1, and when the recess 4 and the protrusion 5 are fitted together, This is characterized in that the II end faces of the inner layer circuit board 1 are butted against each other. The present invention will be explained in detail below. The inner layer circuit board 1 is made of, for example, a prepreg prepared by impregnating and drying a thermosetting resin varnish such as an epoxy resin on a base material such as glass cloth, and a metal foil such as TI4TRI, which is then heated and pressure molded. It is produced by creating a metal laminate and etching the metal foil of the metal laminate to form a circuit. As shown in FIG. 1(a), the inner layer circuit board 1 is provided with a recess 4 or a protrusion 5 at the ends to be butted. The recess 4 is formed by notching the side end of the inner layer circuit board 1 in the width direction, and the protrusion 5 is formed as the remainder of notching both sides of the Ill end of the inner layer circuit board 1. It is something that l! 1 part 4 and protrusion 5
are formed so that their width dimensions are substantially the same, and the depth dimension d of the recess 4 and the protrusion dimension p of the protrusion 5 are also preferably formed to be substantially the same. The depth dimension d of the recess (the protrusion dimension p of the protrusion 5) is preferably set to 2- or more. When performing multilayer molding using the inner layer circuit board 1 formed as described above, the plurality of inner layer circuit boards 1 are molded by fitting the recesses 4 and the protrusions 5 together.
The l#1 surfaces are butted and joined, and as shown in Fig. 1(b), a metal foil 3 such as copper foil or a circuit board for the outer layer is layered on top and bottom of this through the prepreg 2, and this is assembled in one stage as a set. This can be done by setting about 10 sets per set and performing heat and pressure molding using a press machine, and it is possible to obtain a multilayer wiring board in which the metal M3 or the outer layer circuit board is laminated on both sides of the inner layer circuit board 1. In addition, when performing multi-M molding, the resin of prepreg 2 is 70-
Even if a force is applied to move each inner layer circuit board 1 when
Since each inner layer circuit board 1 is joined by fitting the recess 4 and the protrusion 5, it is possible to prevent mutual movement and misalignment.

【Example】

Next, the present invention will be further explained by examples. Inner layer circuit board 1 with length x width = 500mm x 500mm on Trakamee 2
A recess W 64 and a protrusion 5 were formed at the 1 m end of each inner layer circuit board 1 with dimensions of d, p = 5 am, and sound = 20 cm, and the recess 4 and the protrusion 5 were fitted together. These two inner layer circuit boards 1 are joined and arranged as shown in FIG. 2(a), and then, as shown in FIG. Three sheets of prepreg 2 were stacked on top of each other, and copper Wi3 with a thickness of 18μ was hung on top and bottom of the prepreg 2, and 5 sets per stage were set in a press machine using this as one layer, and the heating conditions for molding were 130°C for 30 minutes and 170°C.
for 90 minutes, cooling for 30 minutes, and pressurizing conditions at 5 kg/c.
m' for 5 minutes and 40 kg/cm'' until the end of cooling.
After setting, multilayer molding was performed. Three inner-layer circuit boards 1 of 500m x 330s+s are used, and each inner-layer circuit board 1 has the same dimensions as Example 1.
A recess 4 and a protrusion 5 were formed at the end. Then, the concave YIS 4 and the protrusion 'n5 were fitted together, and the three inner layer circuit boards 1 were joined and arranged as shown in FIG. Ta. ! JLILL Four inner layer circuit boards 1 having length x width = 500 mm x 250+a+a were used, and recesses 4 and protrusions 5 were formed at the side ends of each inner layer circuit board 1 with the same dimensions as in Example 1. and recess 4
The four inner layer circuit boards 1 were joined and arranged as shown in FIG. 2 (C) by fitting the and protrusions 5 together, and the rest was multi-N shaped in the same manner as in Example 1. . Shijo jLL Length x Width = 500 Same x 500 m Using two internal layer circuit boards 1, without forming recesses 4 and protrusions 5, these two inner layer circuit boards 1 are assembled as shown in Figure 3 (a). ), the side edges were butted against each other and multilayer molding was performed in the same manner as in Example 1. This is the inner layer circuit board 1 of length x width = 500mm x 330m.
The three inner layer circuit boards 1 are arranged with their side edges abutted against each other as shown in FIG. Multilayer molding was performed. Figure 3(c) shows the four inner layer circuit boards 1, each measuring 500 mm x 250 mm (length x width), without forming the recesses 4 and protrusions 5. They were arranged with their side edges butted together as shown in the figure, and then multilayer molding was performed in the same manner as in Example 1. Regarding the multilayer circuit boards of each Example and each Comparative Example obtained by multilayer molding as described above, the number of defective boards due to occurrence of positional shift of the inner layer circuit board 1 was investigated. The number of defective boards per stage of the press machine (the number of multilayer circuit boards molded in the - stage is 5) is shown in barley. Further, the yield was calculated and shown in the following table. As shown in the table, as in each embodiment, the inner layer circuit board 1 is provided with a recess 4 and a protrusion 5. ll5
It is confirmed that by fitting the inner layer circuit board 1 with the inner layer circuit board 1, it is possible to prevent misalignment from occurring during multilayer molding.

【Effect of the invention】

As described above, in the present invention, E in the width direction is attached to the side end of one of the inner layer circuit boards to be matched. At the same time, at the opposite end of the other inner layer circuit board, a protrusion having approximately the same width dimension as the recess is provided in the width direction, and when the recess and the protrusion are fitted together, this inner layer circuit board is formed. Since the side end surfaces of the boards are butted against each other, even if a force is applied to move each inner layer circuit board when the prepreg resin is heated during multilayer molding, each inner layer circuit board will not touch the recess. Since the inner layer circuit boards are joined by fitting with each other, there is no need to use adhesive tape, and it is possible to reduce the occurrence of defects due to mutual movement and misalignment of the inner layer circuit boards. It is.

[Brief explanation of drawings]

Fig. 1 (aHb) is a schematic plan view and a schematic front view showing each step of the present invention, and Fig. 2 (a), (b), and (c) are the states of butting of the inner layer circuit boards in each embodiment of the present invention. FIGS. 3(a), 3(b), and 3(e) are schematic plan views showing the state of butting of the inner layer circuit boards in each of the above comparative examples. 1 is an inner layer circuit board, 2 is a prepreg, 3 is a metal foil, 4 is a recess, and 5 is a protrusion.

Claims (1)

[Claims] (1) A multilayer wiring board is created by arranging a plurality of inner layer circuit boards with their side edges butted against each other, stacking metal foil or outer layer circuit boards on top and bottom of these with prepreg interposed therebetween, and molding them under heat and pressure. During manufacturing, a recess is provided in the width direction at the side end of one of the inner layer circuit boards to be matched, and a recess is provided in the width direction at the side end of the other inner layer circuit board with approximately the same size as the recess. A protrusion is provided in the width direction,
A method for manufacturing a multilayer wiring board, characterized in that the side end surfaces of the inner layer circuit board are butted against each other with the recess and the protrusion fitted together.