JPH0427021B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a method for manufacturing a multilayer laminate used as a multilayer printed wiring board or the like. [Background Art] Semiconductor package substrates such as pin grid arrays formed of multilayer printed wiring boards have been provided in the past. The manufacturing of such a semiconductor package is carried out as shown in FIG. That is, a recess 6 for mounting the semiconductor chip 4 is formed on the surface of one wiring board 1a, and the recess 6 is centered so that the bonding part 7 for connecting to the semiconductor chip 4 is located near the recess 6. Radial circuit 5
The other wiring board 1b has an opening 3 larger than the recess 6 penetrating the front and back sides thereof, and a metal foil 8 such as copper foil is laminated on the surface. Then, as shown in FIG. 10a, one wiring board 1a is stacked on the other wiring board 1b with alignment such that the recess 6 and the bonding part 7 of the circuit 5 are exposed in the opening 3. At this time, an adhesive material 2 made of prepreg is sandwiched between the wiring board 1a and the wiring board 1b in a portion other than the opening 3, and the first
As shown in Figure 0b, the wiring board 1a,
A multilayer laminate in which 1b is laminated and integrated can be obtained. In the multilayer laminate thus produced, a circuit 9 is formed by etching or the like on the metal foil 8 of the wiring board 1b. This circuit 9
serves as an outer layer circuit, and the circuit 5 provided on the wiring board 1a serves as an inner layer circuit. Thereafter, the semiconductor chip 4 is mounted and mounted in the recess 6 inside the opening 3, and the semiconductor chip 4 is mounted between the semiconductor chip 4 and the bonding part 7 of the circuit 5, and the end of the circuit 9 near the opening 3 is mounted. A wire 11 such as a gold wire is bonded between the bonding part 10 of the semiconductor chip 4 and the circuits 5 and 9, thereby completing a semiconductor package. However, in this case, wiring boards 1a and 1b
By applying heat and pressure to the adhesive resin, the adhesive resin of the adhesive material 2 is melted and then hardened, thereby exerting an adhesive effect and making it possible to bond the wiring boards 1a and 1b in a laminated manner. Due to the pressure action, a large flow of the molten adhesive resin of the adhesive material 2 occurs, which may cause large variations in the thickness of the multilayer laminate or cause warping. Particularly when a multilayer board is used as a substrate for a semiconductor package, if a large flow occurs in the adhesive resin of the adhesive 2, the adhesive resin from between the laminated boards 1a and 1b will protrude, as shown in FIG. There is a risk that the protruding portion 2a of the adhesive resin acts on the bonding portion 7 of the circuit 5, and the bonding portion 4 is covered with the adhesive 2, making it impossible to ensure the reliability of the electrical connection between the semiconductor chip 4 and the circuit 5. There was a problem that there was. . [Objective of the Invention] The present invention has been made in view of the above points, and provides a method for manufacturing a multilayer laminate that allows wiring boards to be stacked without the risk of large flow of adhesive resin of adhesive material. The purpose is to [Disclosure of the Invention] However, in order to manufacture a multilayer laminate by laminating and bonding wiring boards 1a and 1b together via an adhesive 2 made of a thermosetting resin, the adhesive 2 is attached to at least one side of the adhesive 2. The wiring boards 1a and 1b are heated and bonded in advance to the wiring boards 1a and 1b through the adhesive 2.
The wiring boards 1a and 1b are laminated and bonded by stacking the wiring boards 1a and 1b on top of each other and applying heat and pressure.
Adhesive material 2 is bonded to adhesive material 1b by heating.
Advance the degree of curing of the adhesive resin, and then apply adhesive 2.
The adhesive resin has a high melt viscosity and low fluidity.The present invention will be described in detail below with reference to Examples. First, the present invention is applied to a first embodiment in which a multilayer laminate is formed by laminating a pair of wiring boards 1a and 1b, and this multilayer laminate is used as a substrate of a semiconductor package.
The embodiment shown in the figure will be explained. Wiring board 1a, 1
b is formed of a resin laminate or the like, and a circuit 5 is provided by laminating metal foil such as copper foil on the surface of the wiring board 1a on one side and etching this. . Further, a recess 6 for mounting the semiconductor chip 4 is formed on the surface of the wiring board 1a at approximately the center thereof, and a bonding portion 7 for connecting the circuit 5 to the semiconductor chip 4 is located near the recess 6. They are formed in a radial pattern with the recess 6 at the center. A metal foil 8 such as a copper foil is laminated and bonded to one surface of the other wiring board 1b, and an opening 3 larger than the recess 6 is provided approximately in the center thereof, penetrating the front and back sides. When manufacturing a multilayer laminate using these wiring boards 1a and 1b, adhesive material 2 is first bonded to one wiring board 1b in advance. The adhesive material 2 is made of glass woven fabric or glass non-woven fabric as a base material, impregnated with thermosetting resin such as epoxy resin or polyimide, and heated and dried to semi-cure the thermosetting resin (B stage). ) prepreg for bonding can be used. Of course, in addition to prepreg, it is also possible to use the adhesive 2 prepared by mixing glass fiber or the like into a thermosetting resin. In this way, the adhesive material 2 made of prepreg or the like is layered on one wiring board 1b and heated and, if necessary, pressurized to adhere it to the other wiring board 1b in advance. . At this time, the heating temperature, time, and pressure are set within a range that does not completely cure the resin of the adhesive material 2, does not flow too much, and does not significantly impair adhesive performance. For example, when the adhesive resin of the adhesive material 2 is an epoxy resin, the time is about 5 to 120 minutes at 90 to 170°C, and when it is polyimide, it is about 5 to 120 minutes at 90 to 220°C. The pressure is about 1 to 70 kg/cm ² , respectively. Furthermore, in forming the opening 3 in the wiring board 1b as described above, after adhering the adhesive 2 to the wiring board 1b, the wiring board 1b is punched together with the adhesive 2 to form the opening 3. It is better to provide a After the adhesive 2 is heat-bonded to the wiring board 1b in advance in this way, the recess 6 and the bonding part 7 of the circuit 5 are aligned in the opening 3 as shown in FIG. 1a. The wiring board 1b is stacked on the surface of the wiring board 1a. Then, the wiring board 1 is bonded through the adhesive 2 by heating and pressure molding.
A and 1b are laminated and integrated to obtain a multilayer wiring board A. In this molding, the heating conditions are set so that the adhesive resin of adhesive material 2 is completely cured. For example, if the adhesive resin of adhesive material 2 is epoxy resin, polyimide In this case, the temperature is 200-250℃ for about 50-120 minutes.
At this time, the adhesive resin of the adhesive material 2 is once melted by the heating action and then hardened, but the degree of hardening of this adhesive resin has already progressed due to the heating when it is bonded to the wiring board 1b, and this time Even if it is melted during molding, its fluidity is low due to its high melt viscosity, and it is possible to prevent the adhesive resin from flowing out from between the wiring boards 1a and 1b due to the pressure action. It is possible to prevent the wiring board A from having a large variation in thickness or from being warped. Particularly when this multilayer wiring board A is used in a semiconductor package, it is possible to prevent the adhesive resin from flowing inwardly into the opening 3 and covering the bonding portion 7 of the circuit 5 with the adhesive resin. In processing the thus obtained multilayer wiring board A into a semiconductor package, first, a circuit 9 is formed by etching the metal foil 8 of the wiring board 1b. This circuit 9 is formed in a radial pattern centered on the opening 3, and this circuit 9 serves as an outer layer circuit, and the circuit 5 provided on the wiring board 1a is embedded between the wiring boards 1a and 1b. This becomes an inner layer circuit. After this, in the recess 6
A semiconductor chip 4 such as an IC chip is mounted and mounted, and the semiconductor chip 4 is further mounted as shown in FIG. 1b.
and the bonding part 7 of the circuit 5, and the circuit 9
bonding portion 10 at the end close to the opening 3 of the
A wire 11 such as a gold wire is bonded between the semiconductor chip 4 and the circuits 5 and 11, thereby forming a semiconductor package. Each of the circuits 5 and 11 is connected to a connection terminal portion to the outside, and by using, for example, a pin as the connection terminal portion, the semiconductor package can be formed as a pin grid array. In the embodiment shown in FIG. 1, the adhesive 2 is bonded to the wiring board 1b in advance, but in the embodiment shown in FIG. 2, the adhesive 2 is bonded to the wiring board 1a side. Alternatively, as shown in FIG. 3, adhesive material 2 may be bonded to both wiring boards 1a and 1b in advance. In addition, the embodiment shown in FIG.
Opening 3 of wiring board 1b to which adhesive 2 has been bonded in advance
In the embodiment shown in FIG. 5, an opening 3 is also formed in the wiring board 1a corresponding to the above, and in the embodiment shown in FIG. The embodiment shows an adhesive 2 bonded to both wiring boards 1a, 1b in advance, and the embodiment shown in FIG. 7 uses three wiring boards 1a, 1b, 1c to form a multilayer structure. A laminate A is formed. Further, in each of the above embodiments, the opening 3 is provided in at least one of the wiring boards 1a, 1b, and 1c, but as shown in FIGS. 8 and 9, the wiring board 1 without the opening 3
A, 1b, and 1c may be used to create a multilayer laminate A. Furthermore, through holes can be formed in the multilayer laminate A by drilling. When forming a through hole in this way, if a material containing a base material is used as the adhesive material 2 as in the above embodiment, the base material will be exposed on the inner surface of the through hole, making it difficult to plate the through hole. This increases the adhesion with the through-hole plating and prevents it from peeling off. The present invention can be applied not only to the semiconductor package described above, but also to chip-on-board substrates, printed wiring boards, and the like. The invention will now be illustrated by specific examples. Example 1 Glass woven fabric base epoxy resin laminates were used as the wiring boards 1a and 1b, and a glass woven fabric base epoxy resin prepreg was used as the adhesive 2, and the adhesive 2 was bonded to the wiring board 1b in advance. (Figure 1a). Table 1 shows the conditions for adhesion. Next, by stacking the wiring boards 1a and 1b and molding them under heat and pressure, the wiring boards 1a and 1b are bonded via the adhesive 2.
1b was laminated and integrated to obtain a multilayer laminate A (first
Figure b). The molding conditions at this time are shown in Table 1. Examples 2 to 6 The wiring boards 1a and 1b used are those shown in Table 1, and the adhesive 2 is used as shown in Table 1, and the rest is carried out in the same manner as in Example 1 according to the conditions in Table 1. A multilayer laminate A was obtained. Comparative Examples 1 to 3 The wiring boards 1a and 1b were used as shown in Table 1, and the adhesive 2 was as shown in Table 1, without having to adhere the adhesive 2 to the wiring boards 1a and 1b in advance. , the adhesive 2 is attached to the wiring boards 1a, 1
A multilayer laminate A was obtained by performing molding in accordance with the conditions shown in Table 1 while sandwiching between the two layers. Regarding the above Examples 1 to 6 and Comparative Examples 1 to 3, the flow of adhesive resin of adhesive material 2 and multilayer laminate A
The variation in thickness was measured. The thickness variation was measured on test pieces measuring 300 mm x 300 mm in length and width. The results are shown in Table 1.

[Table] As shown in Table 1, in each of the examples in which the adhesive 2 is bonded to the wiring board 1b in advance, if the flow of the adhesive resin becomes small, the plate thickness will vary. It is confirmed that the plate thickness accuracy increases as the value decreases. [Effects of the Invention] As described above, in the present invention, an adhesive is heat-bonded to a wiring board in advance, and the wiring boards are stacked on top of each other via the adhesive and heated and pressurized to form a wiring board. Since the adhesive resin is laminated and bonded, the degree of hardening of the adhesive resin is progressing due to heating when it is bonded to the wiring board in advance, and even if this adhesive resin is melted during lamination, the melt viscosity increases. This makes it possible to prevent the adhesive resin from flowing significantly.

[Brief explanation of drawings]

FIGS. 1a and 1b are partially cutaway sectional views of one embodiment of the present invention, FIGS. 2 to 9 are partially reduced sectional views of other embodiments of the present invention, and FIGS. 10a and b 11 is a sectional view of a conventional example, and FIG. 11 is a perspective view of a part of the conventional example. 1 is a wiring board, 2 is an adhesive, 3 is an opening, and 4 is a semiconductor chip.

Claims (1)

[Scope of Claims] 1. When manufacturing a multilayer laminate by laminating and bonding wiring boards to each other via a thermosetting resin adhesive, the adhesive is heat-bonded to at least one wiring board in advance. 1. A method for manufacturing a multilayer laminate, characterized in that the wiring boards are laminated and bonded by stacking the wiring boards on top of each other via the adhesive and applying heat and pressure. 2. The method for manufacturing a multilayer laminate according to claim 1, wherein the adhesive is a prepreg for bonding. 3. The multilayer according to claim 1 or 2, wherein at least one wiring board to be laminated is provided with a penetrating opening, and a semiconductor chip is mounted inside the opening. Method of manufacturing laminates.