JPS6398189A - Manufacture of ic chip mounting multilayer board - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for manufacturing a multilayer board for mounting an IC chip, and is a method for manufacturing a multilayer board for mounting an IC chip. It reliably protects the formed terminal connections from contamination, and in a particularly preferred embodiment, has migration resistance (under high humidity, the insulation between wiring conductors is destroyed by the diffusion of conductor metal ions). The purpose of the present invention is to provide a multilayer board that is less likely to cause this phenomenon and has excellent water vapor resistance.

[Conventional technology and its problems]

Ceramics are used as multilayer boards for mounting IC chips, such as multilayer pin grid array (multilayer PGA) substrates. However, ceramics have problems such as poor impact resistance, high dielectric constant, and poor workability.

Moreover, because of the need to mount IC chips, which are rapidly increasing in density, there is now a demand for lower dielectric constants, easier processing, and lower costs.

Also, plastic double-sided PGA boards are manufactured using plastic double-sided boards, but from the viewpoint of processability, when the number of pins is set to 150 or more, the line width and the line spacing must be narrower. Since this is essential, there is a problem in that defects are likely to occur.

One way to reduce the occurrence of defects is to use multiple layers, but known low-flow multilayer adhesive sheets have practical problems such as poor migration resistance and insufficient water vapor resistance. be. Furthermore, if the resin flow of this adhesive sheet is less than 100ρ, the resin will not be sufficiently filled between the printed wiring metal foils (usually copper foils), resulting in poor interlayer adhesion. If this is set to a necessary and sufficient level, the problem arises that the resin flows to the tip of the terminal and contaminates the terminal, resulting in defective wire bonding. A conventional solution to this problem has been to use a printed wiring board in which the gaps between the printed wiring copper foils are filled with resin in advance, but this is disadvantageous in terms of the process.

[Means for solving problems]

As a result of extensive research into methods for solving the above problems, the present invention has developed a method for applying resin flow from a multilayer adhesive sheet to the periphery of the terminal connection part of a multilayer printed wiring board prior to multilayer lamination molding. To prevent the terminal connection from being contaminated! A method for forming layer ii was discovered and completed based on this method.

That is, the present invention provides a method for manufacturing a multilayer board having at least a hole for mounting an IC chip and a terminal portion for connection.
As the printed wiring board forming the inner layer, a multilayer printed wiring board is used in which the periphery is coated with a photo- or thermosetting resist, leaving the terminal connection part for connecting the IC chip, and this is coated in a specified manner. A method for producing a multilayer board for mounting an IC chip, which is characterized by performing multilayer lamination molding using a low-flow adhesive sheet in which holes of a predetermined size are formed at positions, and in a preferred embodiment, the low-flow adhesive sheet The adhesive sheet includes (a) a polyfunctional cyanate ester resin composition, (b)
) A sheet or film of a thermosetting resin composition containing a substantially amorphous thermoplastic saturated polyester resin and (c) a curing catalyst as essential components, or a reinforcing base material is impregnated with the thermosetting resin composition and dried. 100mmH of multilayer lamination molding.
This method is characterized in that it is carried out under a reduced pressure of less than 100 g.

The configuration of the present invention will be explained below.

The multilayer board for mounting an IC chip of the present invention (hereinafter simply referred to as "this multilayer board") is a hole for mounting an IC chip and a hole for connecting the IC chip mounted around the hole, which is usually gold-plated. , usually width 0.1-2mm, interval 0.1-1m
It is a multilayer board that has at least one intermediate layer with a terminal section formed by forming a large number of terminals for connection with an IC chip with a length of 1 to 5 mm, and has interlayer wiring by through-hole plating and a large number of pins. This includes the so-called ``pin grid array,'' which is a ``pin grid array.''

In the manufacturing process of this multilayer board, a normal multilayer lamination molding method is used. For example, a wiring network including a terminal part, an IC chip mounting part, or an IC chip mounting part is drilled on one side of a double-sided copper-clad laminate using a known method. A printed wiring board (substrate I) formed by digging a hole and forming a desired wiring network on the other side, a single-sided copper-clad laminate (single-sided board ■) formed with a wiring network including desired holes and terminals, and Prepare adhesive sheet (I) with desired holes formed,
A method of forming a multilayer board by aligning a single-sided board (■) to a substrate I via an adhesive sheet I and laminating a desired number of sets in one go; wiring including a terminal portion on one side of a double-sided copper-clad laminate using a known method. An adhesive sheet made by digging holes in the net or the IC chip mounting part or the IC chip mounting part, and forming predetermined holes as necessary between the untreated substrate on the other side and the copper-clad laminate on one side.
A wiring network including terminals is formed based on reference marks pre-set on the laminated copper foil surface, and a single-sided copper-clad laminate is laminated on top of this again to create a wiring network. After repeating these steps, if necessary, through-hole plating is performed, wiring networks are formed on both sides, and cutting is performed to expose the IC mounting portion and terminal portion, or any other method may be used.

The laminates for printed wiring boards used in this multilayer board include conventional nonwoven fabrics or woven fabrics reinforced with glass fibers, quartz fibers, wholly aromatic polyamides, polyimides, semicarbon fibers, etc., used alone or in combination. Double-sided or single-sided metal? δ
Any stretched laminate can be used, but specifically, glass cloth epoxy laminates, heat-resistant glass cloth epoxy laminates, quartz fiber cloth epoxy laminates, glass cloth cyanate ester resin laminates (Mitsubishi Manufactured by Gas Kagaku G1.), CCL-
II 800゜(:CL-II 830.CCL-II
870, etc.), thermosetting resin-based laminates such as quartz fiber cloth cyanate ester-based resin laminates, glass cloth polyimide-based laminates, and highly heat-resistant thermoplastic resin-based laminates.

Board 11 laminated single-sided board with terminals and wiring formed
Alternatively, as the photo- or thermosetting resist used to form a thin frame around the connection terminal part of the single-sided board (■), a photo- or thermosetting resist that is normally used in the manufacture of printed wiring boards can be used. Therefore, the usual screen method or photoresist method, and especially when the terminal spacing is narrow, the method using photoresist is suitable. The coating layer formed around the periphery of the terminal connection part is formed by a method of covering the space between the terminals and the outer periphery of each terminal connection part, usually leaving about 1 to 5 mm from the inner part of the terminal part. do.

The low-fluidity adhesive sheet for multi-mouth adhesive of the present invention includes:
In the case of a normal multilayer adhesive sheet, the resin flow is 0.0
Anything in the range of 5 to 3 mm can be used. If the resin flow is too small, the adhesion with the board will be poor, and the resin will not be filled between the wiring conductors formed with copper 9I rubber.
On the other hand, if the resin flow is too large, the resin will exceed the resin frame described above and contaminate the terminal portion. In addition to these properties, from the viewpoint of adhesion, adhesion, and other physical properties, the present invention uses (a) a polyfunctional cyanate ester resin composition, (b) a substantially non-crystalline thermoplastic saturated B-8tage is obtained by impregnating a reinforcing base material with a sheet or film of a thermosetting resin composition containing a polyester resin and (c) a curing catalyst as essential components, or a nuclear thermosetting resin composition and drying it. Kaisho 60-192779, Kaisho 60-2
33175) is preferred. Here, the resin component (a
) is a polyfunctional cyanate ester resin composition that contains a polyfunctional cyanate ester having a cyanato group, its prepolymer, etc. as essential components, and is a cyanato resin (Japanese Patent Publication No. 41-1928, No. 45). -11712,
44-1222, DIE-1, 190, 184, etc.)
, cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Japanese Patent Publication No. 54-3044
0, 52-31279, USP-4,110,364
etc.), cyanate ester-epoxy resin (Special Publication No. 46-
41112) and others. Also, (b)
The substantially non-crystalline thermoplastic saturated polyester resin as a component is one obtained by polycondensing an aromatic or aliphatic dicarboxylic acid with an aliphatic or alicyclic diol or its prepolymer as a main component. It is. In the present invention, the number average molecular weight calculated from the number of terminal functional groups is usually 1
．． 500-25,000, preferably 5,000-22
．． 000 is preferable due to compatibility. Moreover, those having a hydroxyl value of 1 to 30 mg-KOII/g are suitable.

This means that if the polyester resin has an excess of free hydroxyl groups or carboxyl groups, these groups and (
This is because the cyanato group of component a) gradually reacts even at room temperature, resulting in poor storage stability of the composition. Further, the lower the crystallinity, the better, and the type and amount ratio of the acid and alcohol components to be used are selected.

As such a substantially non-crystalline thermoplastic saturated polyester resin, one commercially available from Nippon Gosei Kagaku Kogyo Co., Ltd. under the trade name "Polyester" is suitable.

The blending ratio of component (a) and component (b) described above is not particularly limited, but usually component (a) is 30 to 9
5 parts by weight, 70 to 5 parts by weight of component (b), and 70 to 5 parts by weight of component (a).
) and (b) are not particularly limited, but usually,
A method of preparing a solution of component (a) and mixing it with a solution of (b) IliW or component (b); A resin composition is prepared in advance by a method of making a solvent-free liquid or paste composition using a reactive diluent among the components that can be used in combination, and if necessary, a known catalyst, especially an organic A method of adding and mixing a peroxide, an organic metal salt, etc.; a method of using a catalyst or the like at the time of mixing as described above; and the like. Suitable examples of the organic solvent include methyl ethyl ketone, acetone, toluene, xylene, trichloroethylene, dioxane, etc., and the concentration is selected depending on the amount of resin and viscosity required for impregnation, but usually 20 to 60% by weight is preferable. It is.

Furthermore, as the reinforcing base material of component (c), the above-mentioned substrate I
Examples include fiber cloth substrates similar to those used in , and open-cell porous substrates made of tetrafluoroethylene, and usually have a thickness of about 0.03 to 0.2 mm.

After impregnating the reinforcing base material of component (c) with the resin solution prepared above so that the resin amount is in the range of 35 to 85%,
The solvent is removed by dry blasting at 120 to 170° C. for 1 to 20 minutes, resulting in so-called r[3-3-stage J.

The conditions for multilayer lamination molding vary depending on the catalyst, composition components, type of base material, etc., but are usually 100 to 300% or 0%.
．． 1-100 kg/cnf, preferably 5-50
kgZC, especially within the range of 10-40 kg/cnf. In addition, in the present invention, multilayer lamination molding is carried out in 10
It is particularly preferable to carry out the process under reduced pressure of 0 mmHg or less in order to avoid the occurrence of voids.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, parts in Examples and Comparative Examples are parts by weight unless otherwise specified.

Example-1 2,2-bis(4-cyanatophenyl)propane 750
A prepolymer was obtained by preliminarily reacting a portion at 160° C. for 4 hours. This prepolymer is a substantially non-crystalline thermoplastic saturated polyester resin (trade name: POLYNISK LP-0).
35, manufactured by Nippon Gosei Chemical Industry 0 Kiku, number average molecule ffi calculated from the number of terminal functional groups: 16,000, hydroxyl value: 6
mg KOII/g) 250 parts, and bisphenol A epoxy resin (trade name: Epicote 828,
50 parts of Yuka Shell Epoxy (manufactured by Kiku) was added and dissolved and mixed in methyl ethyl ketone (hereinafter referred to as MCK) to form a solution with a concentration of 60% (referred to as FES (a)).

Add 0.12 parts of zinc octylate as a catalyst to the adhesive layer (a) and mix uniformly. Apply this solution continuously to one side of surface-treated release paper with a thickness of 150 mm to form an adhesive layer with a thickness of 4 mm. An adhesive sheet with a release paper (hereinafter referred to as "Sheet 1-I") of Jun's 1313-stage was manufactured.

On the other hand, thermosetting polyimide resin (product name: KIERI
700 parts of MID 601 (manufactured by Roth-Boulin) and 300 parts of an epoxy resin (product name: Epicote 1001, Yuka Shell Epoxy 01) were dissolved in N-methylpyrrolidone, and 1 part of benzoyl peroxide was added as a catalyst. The material was impregnated into a 0.1 mm thick glass woven cloth and dried.
Ill-stage prepreg was used, and using this prepreg and electrolytic copper foil with a thickness of 35ρ, 20 kg was heated at 180°C.
/cITI for 1 hour, and after further increasing the temperature to 230°C,
Laminated for 15 minutes at 0kg/crd to a thickness of 0.3m.
A single-sided copper-clad laminate with a thickness of 0.7 mm and a double-sided copper-clad laminate with a thickness of 0.7 mm were manufactured.

On this double-sided copper-clad laminate, a gold-plated terminal part 11 with a terminal connection part 11, a pitch of 0.5 mm, and a length of 1.0 mm was formed by a known method, and a blue IC chip mounting part was engraved. A desired wiring network and its protective film were formed to form a substrate (2), and a single-sided copper-clad laminate was similarly plated with gold at the terminals and a protective film was formed on the surrounding wiring network to produce a single-sided board (2). The terminal part of the board I has a width of 0.5 mm between the terminal connecting parts and the outer periphery of the terminal, leaving 1.1 m + n from the inner end of the terminal.
The coating layer was printed with a polyfunctional cyanate ester resist (trade name: 01M450, manufactured by Mitsubishi Gas Chemical Co., Ltd.) by a screen method, and was heated and cured at 150° C. for 40 minutes.

Next, the sheet I obtained above was stacked on the back side of the single-sided plate H obtained above, and the adhesive layer was applied to the single-sided plate H using a hot roll at a temperature of 120°C.
After the image was transferred to , the IC chip mounting portion was punched out to a predetermined size.

Align and stack the single-sided board with an adhesive sheet layer on the terminal forming side of the circuit board, and apply a temperature of 175℃ and a pressure of 20kg.
/ cnt for 2 hours to obtain a multilayer board.

Holes were drilled at predetermined pin positions in this multilayer board, the external shape was processed, and pin positions were formed without through-hole plating, resulting in a three-layer plastic PGA. Occasionally, smear formation was observed during hole opening, but no smear formation was observed.

The surface resistance deterioration of the inner layer of this plastic PGA is 130
As a result of measuring with a pressure tester at ℃ and 2.8 atm, the time it takes for the resistance value to decrease to 108 Ω or less is 38 Ω.
It was 0 hours.

In addition, the protrusion of the adhesive sheet I beyond the resist coating layer to the terminal gold-plated portion is limited to 85 μm or less, and the flow on the inter-terminal coating layer is 0.5 μm from the outer edge of the coating layer.
6 mm (2 mm if there is no resist coating layer)
). Regarding the gaps between the inner layer wiring networks, microscopic observation of cross-sectional samples revealed no gaps at all, and no defects such as delamination or blistering occurred even after floating in a 260°C solder bath for 20 seconds. .

[Operation and effects of the invention]

As is clear from the above detailed description of the invention and examples, the method for manufacturing a multilayer board for mounting an IC chip of the present invention uses a resin that can be used as a sheet for interlayer adhesion to sufficiently fill the gaps between conductors in a wiring network. Even if an adhesive sheet with a relatively large flow is used, contamination of terminal parts etc. due to resin flow can be prevented, and it can solve the problems that occur during multi-layer stack molding, and can be used as a new industrial manufacturing method. It is extremely practical.

Further, the adhesive sheet used in a preferred embodiment of the present invention has a remarkable effect of preventing copper migration and has excellent long-term reliability during actual use.

Claims (1)

[Claims] 1. In a method for manufacturing a multilayer board having at least holes for mounting an IC chip and terminal portions for connection, the printed wiring board forming an inner layer may leave a connection portion for a terminal for connecting an IC chip. A multilayer printed wiring board whose periphery is coated with photo- or thermosetting resist is used, and this is multilayered using a low-flow adhesive sheet with holes of a predetermined size formed at predetermined positions. I characterized by laminated molding
A method for manufacturing a multilayer board for mounting a C chip. 2. The low-fluidity adhesive sheet is a thermosetting adhesive sheet containing (a) a polyfunctional cyanate ester resin composition, (b) a substantially non-crystalline thermoplastic saturated polyester resin, and (c) a curing catalyst as essential components. A sheet or film of the thermosetting resin composition or the thermosetting resin composition is impregnated into a reinforcing base material and dried.
-Claim 1, which is obtained by converting it into a stage.
A method for manufacturing a multilayer board for mounting an IC chip as described in . 3. A method for manufacturing a multilayer board for mounting an IC chip according to claim 1 or 2, wherein the multilayer lamination molding is carried out under a reduced pressure of 100 mmHg or less.