JP3227969B2 - Manufacturing method of multilayer laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a multilayer laminate used for electronic equipment and electric equipment.
The present invention relates to a method for manufacturing a multilayer laminate in which a pressure-bearing body in which an inner-layer wiring board and a prepreg are overlapped is heated and pressed.

[0002]

2. Description of the Related Art Conventionally, a multi-layer laminated board used for electronic equipment and electric equipment is superimposed via a prepreg on one or more inner wiring boards on which conductive circuits are formed to form a pressure-receiving body. A metal foil such as a copper foil is stacked on a body, sandwiched by a forming plate, set in a press forming apparatus, and heated and pressed to form.

In order to prevent a displacement between the inner wiring board and the prepreg due to the flow of the resin during the heat and pressure molding, a pressurized body in which one or more inner wiring boards are stacked via the prepreg. A method is known in which an eyelet is passed through a through hole and heated and pressed.

However, the method using the eyelet pins is insufficient for the positioning accuracy required in recent years for increasing the density of printed wiring boards. This is because the through-hole of the eyelet pin is a hole, and the eyelet pin pressurized during molding is easily bent and deformed, resulting in displacement of the inner wiring board and the prepreg.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has as its object to heat and press a pressure-bearing body in which inner wiring boards are stacked via a prepreg. In view of the above, an object of the present invention is to provide a method for manufacturing a multilayer laminate having good positioning accuracy by preventing a displacement between an inner wiring board and a prepreg.

[0006]

According to the present invention, there is provided a method for producing a multilayer laminate, comprising: an inner layer wiring board (3); a substrate mounted on the inner layer wiring board (3); When the pressed body (6) composed of the prepreg (2) and the metal foil (1) stacked on and under the prepreg (2) is heated and pressed, the heating is performed at 1.0 ° C./min or less. A step of completely curing the resin in the prepreg (2) at an elevated temperature and at a low pressure of 5 kg / cm ² or less;
Thereafter, a step of heating at a high pressure of 20 to 40 kg / cm ² is included.

[0007]

According to the method for producing a multilayer laminate according to the present invention,
Inner-layer wiring board (3), prepreg (2) mounted on this inner-layer wiring board (3), which is semi-cured by impregnating the base material with resin, and metal foil mounted on and under the prepreg (2) In the heating and press-forming of the pressure-receiving body (6) composed of (1), heating is performed at a temperature rise of 1.0 ° C./min or less.
Further, the method includes a step of completely curing the resin in the prepreg (2) at a low pressure of 5 kg / cm ² or less, and a step of heating the resin at a high pressure of 20 to 40 kg / cm ^2. At this stage, the resin contained in the prepreg (2) is completely cured by the temperature rise of not more than / kg / min and the low pressure of not more than 5 kg / cm ² to form the resin layer, ) To improve the strength. Further, thereafter, by applying a high pressure of 20 to 40 kg / cm ² , bending deformation of the pressure-receiving body (6) due to molding pressure can be prevented at this stage, and the inner wiring board (3) and the prepreg (2) can be prevented. The positional deviation between them can be prevented, and the positioning accuracy can be improved.

Hereinafter, the present invention will be described in detail. FIG.
FIG. 2 is a cross-sectional view of a pressure-receiving body according to one embodiment of the present invention.

As the inner wiring board (3) used in the present invention, for example, a substrate such as a glass epoxy resin laminated board or a glass polyimide resin laminated board covered with a metal foil such as a copper foil, an aluminum foil, a nickel foil and a stainless steel foil is used. In which a conductive circuit is formed on the surface of the substrate by etching. One or more inner wiring boards (3) are stacked via the prepreg (2). This prepreg (2)
In addition to glass cloth, it is possible to use epoxy resin, polyimide resin, phenolic resin, unsaturated polyester resin, polybutadiene resin, polyphenylene on substrates such as inorganic fiber cloth such as quartz fiber, non-woven cloth or high heat-resistant organic fiber cloth and non-woven cloth. Examples thereof include those which are impregnated with a thermosetting resin such as an oxide resin, a fluororesin, a polyethylene terephthalate resin, and a polyphenylene sulfide resin and are semi-cured.
The number of the inner layer wiring board (3) and the number of the prepregs (2) are appropriately determined according to the configuration of the multilayer laminate (8) to be obtained, and are not particularly limited.

In the present invention, the prepreg (2)
As shown in FIG. 1, an inner layer wiring board (3), a prepreg (2) and a pressure-receiving body (6) sandwiching the metal foil (1) are constituted from above and below by metal foils (1) stacked on the upper and lower sides. are doing.
As the metal foil (1), for example, a copper foil, an aluminum foil, a nickel foil, a stainless steel foil or the like used for the inner layer wiring board (3) is used.

In the method for producing a multilayer laminate according to the present invention, the heating is performed at a temperature of 1.0 ° C. /
min and a pressure of 5 kg / cm ²
Since it includes a step of completely curing the resin in the prepreg (2) at the following low pressure and a step of heating at a high pressure of 20 to 40 kg / cm ² thereafter, the temperature is raised to 1.0 ° C./min or less, and At this stage, the resin contained in the prepreg (2) is completely cured by the low pressure of 5 kg / cm ² or less, and the strength of the pressure-receiving body (6) is improved while forming a resin layer. After that, the pressure is 20 to 40 kg / c.
With the high pressure of m ² , it is possible to prevent bending deformation of the pressure-receiving body (6) due to molding pressure at this stage, to prevent displacement between the inner-layer wiring board (3) and the prepreg (2), and to perform positioning. The accuracy can be improved.

[0012] When at least one of the prepregs (2) has a resin amount of 45 wt% or less,
The above effects can be further improved, and the positioning accuracy can be further improved. Similarly, when the prepreg (2) contains a filler, the flow of the resin due to the heat and pressure molding is reduced, so that the displacement between the inner wiring board (3) and the prepreg (2) hardly occurs. Can be further improved. Therefore, the accuracy of the manufactured multilayer laminate (8) can be improved. As the filler, for example,
Inorganic fillers such as aluminum hydroxide, silica, calcium carbonate, talc, clay, barium sulfate, and alumina are used. The amount of filler added to the resin
It is used in a weight ratio between the resin and the filler of 6: 4 to 4: 6.

When the prepreg (2) is used in combination with a prepreg based on two or more types of glass cloths having different filament diameters, the resin contained in the prepreg (2) is completely cured to form a resin layer. It is easy to form, can further prevent bending deformation of the pressure-receiving body (6) due to molding pressure, and can improve the positioning accuracy of the manufactured multilayer laminate (8). Similarly, if the prepreg (2) has a filament diameter of 9 μm or more, the above effect can be further improved, and the positioning accuracy of the manufactured multilayer laminate (8) can be further improved. You can do it. Furthermore, when the prepreg (2) is used in combination with a prepreg based on two or more types of glass cloths having different densities, the resin contained in the prepreg (2) is completely cured to form a resin layer. And the bending deformation of the pressure-receiving body (6) due to the molding pressure can be further prevented.
The positioning accuracy of the manufactured multilayer laminate (8) can be improved.

When the metal foil is left around the inner wiring board (3), the outer metal foil supports the inner wiring board (3) and reduces the mechanical strength of the inner wiring board (3). The inner wiring board (3) that can be held and is caused by the heat and pressure molding
Since the distortion of the multilayer laminate (8) can be reduced, the positioning accuracy of the manufactured multilayer laminate (8) can be further improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments.

Example 1 80 parts by weight of a low bromo epoxy resin, 20 parts by weight of a novolak type epoxy resin, 3 parts by weight of dicyandiamide, 2E4M
Z 0.1PHR made of FR-4 resin made of Asahi Schwebel 216L type glass cloth with 0.1mm thickness and 1550 specification
The prepreg (2a), the prepreg (2c) and the resin content 50 each having 50% resin content were impregnated and dried on each of the 0.15 mm-thick plain woven glass cloths.
% Of prepreg (2b) was obtained.

As shown in FIG. 1, resin content 50
% 216L type glass cloth base material prepreg (2
a), a prepreg (2a), a prepreg (2c), and a copper foil having a thickness of 18 μm arranged on one side of the prepreg (2c).
After forming an inner layer circuit pattern on the copper foil on the other surface of the other two sheets of c), an inner layer wiring board (3) is formed as an inner layer circuit board by blackening the inner layer circuit pattern surface. 50% resin content between the two inner-layer wiring boards (3)
Specification 1550 type glass cloth base material prepreg (2b)
Are arranged to form a pressure-receiving body (6), and the lamination molding conditions are heating at 100 ° C. for 10 minutes, and heating at 100 ° C. to 170 ° C. for 0.1 minute.
The temperature is increased at 8 ° C / min, and the pressure is increased by prepreg (2).
75 minutes, including 5 minutes from the start of the curing of the impregnated and semi-cured resin contained in the resin, are performed at a low pressure of 5 kg / cm ² , and then cooled at a high pressure of 30 kg / cm ² until the molding is completed. 45 minutes including time, 50
A 6-layer multilayer laminate (8) having a thickness of 0 mm and a width of 330 mm was obtained.

Example 2 Thickness 0.1 mm of specification 216L type manufactured by Asahi Schwebel
Each of the glass cloth of specification 1550 type and 0.15 mm thickness of plain woven glass cloth and the specification of 7628W type and 0.18 mm thickness of glass cloth are impregnated and dried, and then each resin content 50
% Prepreg (2a), 43% resin content prepreg (2b) and 45% resin content prepreg (2c), and as shown in FIG. 1, a 216L type glass cloth base material having 50% resin content. Prepreg (2a), resin content 45% specification 7628W type prepreg (2c), 18μm thick copper foil is arranged on one side, and the other two of prepreg (2a), prepreg (2c) The inner wiring board (3) is arranged on one side of the substrate, and the resin content is 43% between the two inner wiring boards (3).
Specification 1550 type glass cloth base material prepreg (2b)
Was obtained in the same manner as in Example 1 except that two pressure-sensitive members were arranged to obtain a pressure-receiving body (6), thereby obtaining a six-layer multilayer laminate (8) having a length of 500 mm and a width of 330 mm.

Example 3 An inner layer circuit pattern was formed on a copper foil on the surface, and 20
After the copper foil having a width of mm was left, an inner wiring board (3) was formed as an inner circuit board by subjecting the surface of the inner circuit pattern to blackening treatment.
A 0 mm six-layer laminate (8) was obtained.

Example 4 80 parts by weight of low bromo epoxy resin, 20 parts by weight of novolak type epoxy resin, 3 parts by weight of dicyandiamide, 2E4M
A resin of FR-4 consisting of 0.1 PHR and a filler of aluminum hydroxide were mixed in a weight ratio of 5: 5, and each of the glass cloths was impregnated and dried in the same manner as in Example 1 except that the length was 500 mm.
A 6-layer multilayer laminate (8) having a width of 330 mm was obtained.

Comparative Example 1 The lamination molding conditions were as follows: heating was performed at 130 ° C. for 50 minutes and at 170 ° C.
, For 70 minutes, and pressurizing was performed at a high pressure of 40 kg / cm ² including the cooling time until the completion of molding, in the same manner as in Example 1 except that the six-layer multilayer laminate (500 mm in length and 330 mm in width) was used. ) Got.

Six-layer multilayer laminate (8) obtained as described above
Was evaluated for positioning accuracy as follows.

FIG. 2 is a schematic diagram showing a method for evaluating a multilayer laminate (8) obtained by the method for producing a multilayer laminate of the present invention.

As shown in FIG. 2, the height is 500 mm and the width is 33
Two 0 mm six-layered laminated boards (8) are arranged and the origin (4)
And the terminal (7) were fixed, and the difference between the design value and the measured value at an arbitrary measuring point (5) was examined. In the same heat and pressure molding, the first and fifth stages of the six-layer multilayer laminate (8) were selected, and an arbitrary measurement point (5) was determined for each of the six-layer multilayer laminates (8).
About six places, the difference between the design value and the measured value in a total of 24 places was examined, and the results are shown in Table 1.

[0025]

[Table 1]

As shown in Table 1, the minimum value of the difference between the design value and the measured value in each of Examples 1 to 4 is 0 μm, while that in Comparative Example 1 is 30 μm. 1 to
While the maximum value of the difference between the design value and the measured value of Example 4 is 50 to 80 μm, Comparative Example 1 shows 170 μm, and similarly, the difference between the design value of Examples 1 to 4 and the measured value. Average value is 2
5 to 45 μm, whereas in Comparative Example 1, 95 μm
showed that. Thus, as can be seen by comparing Examples 1 to 4 and Comparative Example 1, a multilayer laminate (8) having good positioning accuracy was obtained.

[0027]

According to the method for manufacturing a multilayer laminate of the present invention, the displacement between the inner wiring board and the prepreg can be prevented at the time of heating and pressing, and a multilayer laminate having good positioning accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pressure-receiving body according to one embodiment of the present invention.

FIG. 2 is a schematic view showing a method for evaluating a multilayer laminate obtained by the method for producing a multilayer laminate of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal foil 2 Prepreg 3 Inner layer wiring board 6 Pressure object

Continuation of the front page (56) References JP-A-54-163359 (JP, A) JP-A-5-21956 (JP, A) JP-A-3-184841 (JP, A) JP-A-1-235296 (JP) JP-A-62-56141 (JP, A) JP-A-62-104196 (JP, A) JP-A-59-37770 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) H05K 3/46 B32B 15/08 105

Claims (7)

(57) [Claims] An inner wiring board (3), said inner wiring board
The substrate loaded in (3) was impregnated with resin and semi-cured
Prepreg (2) and above this prepreg (2)
Pressurized object (6) consisting of metal foil (1)
Heating at 1.0 ° C / min or less for hot pressing
Temperature rise and pressurization 5kg / cm ^TwoBelow low pressure
Completely curing the resin in the prepreg (2) with
Then pressure 20-40kg / cm^TwoHeating at high pressure
A method for producing a multilayer laminate, comprising: 2. The method according to claim 1, wherein at least one of the prepregs has a resin content of 45 wt% or less. 3. The method according to claim 1, wherein the prepreg (2) contains a filler. 4. The prepreg (2) according to claim 1, wherein a prepreg based on two or more kinds of glass cloths having different filament diameters is used in combination. A method for manufacturing a multilayer laminate. 5. The prepreg (2) having a filament diameter of 9 μm or more.
5. The method for producing a multilayer laminate according to claim 4. 6. The prepreg (2) having a density:
The method for producing a multilayer laminate according to any one of claims 1 to 5, wherein a prepreg using two or more different types of glass cloth as a base material is used in combination. 7. The method for manufacturing a multilayer laminate according to claim 1, wherein a metal foil is left around the inner wiring board (3).