JPS6381998A - Manufacture of multilayer board for mounting ic chips - 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 achieves protection of the formed terminal from dirt with good reliability, and in a particularly preferred embodiment, it 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 substrates for multilayer boards for mounting IC chips, such as multilayer bin grid arrays (multilayer PGAs). However, ceramics have problems such as poor impact resistance, high dielectric constant (and poor workability).Moreover, due to the need to mount IC chips, which are rapidly increasing in density, ceramics are currently being made with lower dielectric constants. Therefore, there is a demand for something that can be processed easily and at a lower price.

Also, plastic double-sided PGA boards are manufactured using plastic double-sided boards, but from the viewpoint of processability, when the number of bins 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 this defect is to create multiple layers, but known low-flow multilayer adhesive sheets have practical problems such as poor migration resistance and inadequate water vapor resistance. There is. Furthermore, if the resin flow of this adhesive sheet is set to 100 or less, the resin will not be sufficiently filled between the printed wiring metal foils (usually copper foils), resulting in poor adhesion between the eyebrows. If the flow is set to a sufficient level, the resin will flow to the tip of the terminal portion, contaminating the terminal portion and causing wire bonding defects. 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 intensive studies on methods to solve the above problems, the present invention has been developed to prevent resin from flowing from a multilayer adhesive sheet around the outer periphery of the terminal portion of a multilayer printed wiring board prior to multilayer lamination molding. He discovered a method to form a frame that would allow for the creation of a frame, and completed it 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 a frame is made in advance using photo- or thermosetting resist around the outer periphery of the terminal part for connecting the IC chip, and this is A method for manufacturing a multilayer board for mounting an IC chip, characterized by performing multilayer lamination molding using a low-flow adhesive sheet with holes of a predetermined size formed at positions,
In preferred embodiment B, the low fluidity adhesive sheet comprises (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. The present invention is characterized in that a B-stage material is used, and the multilayer lamination molding is performed under a reduced pressure of 100 wHg or less.

The structure of the present invention will be explained below.The multi-N board for mounting an IC chip of the present invention (hereinafter simply referred to as "this multi-layer board")
is a multilayer board that has at least an intermediate layer (IN) consisting of a hole for mounting an IC chip and a terminal, usually gold-plated, for connection to the IC chip mounted around the hole. It includes plating wiring between the eyebrows and a so-called ``bin grid array'' with a large number of bins.

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 an adhesive sheet I in which desired holes are formed,
A method of forming a multilayer board by aligning a single-sided board (■) to a substrate (I) via an adhesive sheet (■) and laminating the desired number of sets in one go; Wiring including a terminal portion on one side of a double-sided copper-clad laminate by a known method. Adhesive sheet l formed by drilling holes in the net or IC chip mounting part or IC chip mounting part, and forming predetermined holes as necessary between the substrate I, which is untreated 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 the process, if necessary, through-hole plating, forming a diameter of 2 mm on both sides, cutting to expose the IC mounting part and the terminal part, or any other method may be used.

The laminates for printed wiring boards used in this multilayer board are conventional double-sided nonwoven fabrics or woven fabrics reinforced with glass fibers, quartz fibers, wholly aromatic polyamides, polyimides, semi-carbon fibers, etc., used alone or in combination. Alternatively, any one-sided metal foil-clad laminate can be used, but specifically, glass cloth epoxy laminate, heat-resistant glass cloth epoxy laminate, quartz fiber cloth epoxy laminate, glass cloth cyanate ester resin. Laminated board (Mitsubishi Gas Chemical side type, CCL-H800
゜CCL-H830, CCL-H870, 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. Illustrated.

Substrate I with terminals and wiring formed, laminated single-sided board I
Alternatively, as the photo- or thermosetting resist used to create a thin frame around the outer periphery of the terminal portion of the single-sided board H, a photo- or thermosetting resist that is normally used in the manufacture of printed wiring boards can be used. It is made using the usual screen method or photoresist method. The width of this frame is usually in the range of 0.1 to 1 square inch, and it is usually located outside the gold-plated or coated terminal part, and is usually 1 square inch from the inner edge of the terminal part.
~ Form at the position of 5 dragons.

The low fluidity adhesive sheet for multilayer 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 31 breaths 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 foil, and on the other hand, if the resin flow is too large, the resin will exceed the resin frame explained above. This will contaminate the terminal area. In addition to these properties, in the present invention, from the viewpoint of adhesion, adhesion, and other physical properties, (al polyfunctional cyanate ester resin composition, (
b) A sheet or film of a thermosetting resin composition containing a substantially amorphous thermoplastic saturated polyester resin and a c1 curing catalyst as an essential component, or a reinforcing base material is impregnated with the thermosetting resin composition and dried. (JP-A-60-192779, JP-A-60-2331)
75) is preferred. Here, the polyfunctional cyanate ester resin composition that is the resin component (a) is one that contains a polyfunctional cyanate ester having a cyanato group, a prepolymer thereof, etc. as essential components, and a cyanato resin (
Special Publication No. 41-1928, No. 45-11712, No. 44
-1222, DE-1,190,184, etc.), cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Japanese Patent Publication No. 54-30440.
2-31279, [JSP-4, 110, 364, etc.),
Cyanate ester-epoxy resin (Special Publication No. 46-411
12), etc. In addition, the substantially non-crystalline thermoplastic saturated polyester resin of component (b) is a polycondensation resin mainly composed of an aromatic or aliphatic dicarboxylic acid and an aliphatic or alicyclic diol or a prepolymer thereof. It is something that can be done. In the present invention, the number average molecular weight calculated from the number of terminal functional groups is usually 1 or 5.
00-25,000, preferably 5.000-22.0
00 is preferable due to compatibility and other considerations. Further, those having a hydroxyl value of 1 to 30 .KOH/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 the al component 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 under the trade name "Polynisku" is suitable.

The blending ratio of component (a) and component (b) described above is not particularly limited, but usually component (a) is 30 to 95
parts by weight, component (b) 70 to 5 parts by weight, component (a)
The method of mixing and (b) is not particularly limited, but usually (
a) A method of preparing a solution of the components and mixing therewith a solution of the component (mountain) or (bl component); a method of melting and mixing each component without a solvent and then forming a solution; A resin composition is prepared in advance by a method of making a solvent-free liquid or paste composition using a reactive diluent, etc., and if necessary, a known catalyst, especially an organic peroxide, an organic A method of adding and mixing metal salts, etc.;
The above-mentioned mixing method may be performed by using a catalyst or the like at the time of mixing. Preferred examples of the organic solvent include methyl ethyl ketone, a7tone, toluene, xylene, trichloroethylene, and dioxane, and the concentration is selected depending on the amount of resin and viscosity required for impregnation, but is usually 20 to 6
0% by weight is preferred.

Furthermore, as the reinforcing base material for component (c), the above-mentioned substrate ①
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 the c1 component with the resin solution prepared above to a resin content in the range of 35 to 85% by weight, the solvent was removed by drying at 120 to 170°C for 1 to 20 minutes. It becomes so-called rB-stageJ.

The conditions for multilayer lamination molding vary depending on the catalyst, composition components, type of base material, etc., but are usually 100 to 300°C, 0.
．． 1-100 kg/cd, preferably 5-50 kg/cd
d, especially within the range of 10 to 40 kg/cd. Further, in the present invention, it is particularly preferable to carry out the multilayer lamination molding under a reduced pressure of 100 mHg or less, in order to eliminate the occurrence of voids and the like.

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: Polyester-LP-03).
5. Manufactured by Nippon Gosei Kagaku Kogyo ■, number average molecular weight calculated from the number of terminal functional groups: 16,000, hydroxyl value: 6 ■KOH/
g) 250 parts and further 50 parts of bisphenol A type epoxy resin (trade name: Epicoat 828, oil-based shell epoxy side type) were added, and methyl ethyl ketone (hereinafter referred to as ME
(referred to as K) and mixed to make a solution with a concentration of 60% (referred to as FES (referred to as al).

Add 0.12 parts of zinc octylate as a catalyst to the face (8), mix uniformly, and 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 40 mm. A B-stage adhesive sheet with release paper (hereinafter referred to as sheet ①) was manufactured.

On the other hand, thermosetting polyimide resin (product name: ERIM)
700 parts of epoxy resin (trade name: Epicoat 1001, manufactured by Yuka Shell Epoxy) were dissolved in N-methylpyrrolidone, and 1 part of benzoyl peroxide was added as a catalyst. Impregnated it into a 0.1mm thick glass woven cloth and dried it to form B.
-stage prepreg and using this prepreg and 35u-thick electrolytic copper foil, 180℃, 20kg/a
d for 1 hour, and after further raising the temperature to 230℃, 40kg/
A single-sided copper-clad laminate with a thickness of 0.3H and a double-sided copper-clad laminate with a thickness of Q of 7 mm were manufactured by lamination molding in CIJ for 15 minutes.

This double-sided copper-clad laminate was plated with gold on the terminals and engraved with an IC chip mounting area using a known method, and the desired wiring network and its protective film were formed on the back side to form a substrate (2). For the A-layer board, a single-sided board (2) in which the terminal portion was plated with gold and a protective film was formed on the surrounding wiring network was fabricated. Screen a medium 0.5 fin frame at a position 1 m from the inner edge of the terminal on the outer periphery of the terminal part of the board (■) using a polyfunctional cyanate ester resist (trade name: BT M 450, manufactured by Mitsubishi Gas Chemical ■). It was printed and cured by heating at 150° C. for 40 minutes.

Next, the sheet I obtained above was placed on the back side of the single-sided board ■ obtained above, and the adhesive layer was applied to the single-sided board ■ 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 (JW) on the terminal forming surface of the board () at 175℃ and pressure.
Lamination molding was carried out for 2 hours at 20 kg/cd to obtain a multilayer board.

A hole was made in this multilayer board at a predetermined position for a bottle stand, and then the outer shape was processed, and a bottle stand was 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 by pressure tester at ℃ and 2.8 atm, the time required for the resistance value to decrease to 108 Ω or less was 32 Ω.
It was 0 hours.

In addition, the protrusion of the adhesive sheet beyond the resist frame to the terminal side should be limited to 30 units or less (if there is no resist frame, it would be about 21 units), and the cross-sectional cut with respect to the gap between the inner layer wiring networks. As a result of microscopic observation of the sample, no voids were observed, and no defects such as glabellar peeling or blistering occurred even when floated in a 260° C. solder bath for 20 seconds.

Example-2 850 parts of 1,3-dicyanatobenzene and 150 parts of bis(4-maleimidophenyl)methane were mixed at 150°C for 1.5 parts.
A prepolymer was prepared by pre-reacting for a period of time. This prepolymer is a substantially non-crystalline thermoplastic saturated polyester resin (trade name: Polyester-LP-033, manufactured by Nippon Gosei Kagaku Kogyo ■, with a number average molecular weight of 1 calculated from the number of terminal functional groups).
6,000, hydroxyl value 6■KO)I/g) 550 parts and a substantially non-crystalline thermoplastic saturated polyester resin (
Product name: Polyester LP-044, manufactured by Nippon Gosei Kagaku Kogyo ■, number average molecule calculated from the number of terminal functional groups i7,
000, hydroxyl value 15 ■KOH/g) was added and dissolved in liver K to form a solution with a concentration of 60% (referred to as varnish (1)).

0007 parts of zinc octylate was added as a catalyst to the varnish (varnish pile) and mixed uniformly, and this solution was impregnated into a 0.04 mm thick glass woven cloth and dried to form B with a thickness of 40 mm on the upper and lower resin layers. −
A stage prepreg (hereinafter referred to as 1, sheet 2) was manufactured.

On the other hand, polyfunctional cyanate ester glass cloth copper clad laminates (trade name, CCL Hl, 830, Mitsubishi Gas Chemical Co., Ltd. (11 Using a double-sided copper-clad laminate (manufactured by J.D. Co., Ltd.), a gold-plated IC chip mounting portion is formed on one side of the double-sided copper-clad laminate using a known method, and a desired wiring network and its protective film are formed on the back side to form a board.
Similarly, for the single-sided copper-clad laminate, a single-sided plate n-i with gold plating on the terminal part and a single-sided plate Tl-2 with a protective film formed on the wiring network around the terminal part were fabricated. Board■
A frame with a width of 0.6 is placed on the outer periphery of the gold-plated part and the terminal part of the single-sided plate n-1 at a position one crane from the inner ring of the terminal using polyfunctional cyanate ester resist (trade name: BT?I 450).
, manufactured by Mitsubishi Gas Chemical Co., Ltd.) using the screen method, 150
It was heat-cured at ℃ for 40 minutes.

Next, the sheet ■ obtained above was combined with the single-sided plate ■-1 obtained above,
After stacking on the back surface of ll-2, each IC chip mounting portion was punched out to a predetermined size.

On the side of the gold-plated IC chip mounting part of the board ■, place the adhesive sheet II and the single-sided plate ■-1, the adhesive sheet ■ and the single-sided plate ll-
2 aligned and stacked, temperature 175℃, pressure 20k
Lamination molding was carried out for 2 hours at g/cd to obtain a multilayer board.

Holes were made in this multilayer board at predetermined bottle stand positions, and the outer shape was punched out to form a bottle stand 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 1011Ω or less is 3.
It was 62 hours.

In addition, the protrusion from the adhesive sheet to the terminal side beyond the resist frame is limited to 35 or less (approximately 21 if there is no resist frame), and the cut sample was As a result of microscopic observation, no defects such as delamination or blistering were observed, and even when floated in a solder bath at 260° C. for 20 seconds, no defects such as delamination or blistering occurred.

[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 large flow is used, contamination of terminal parts etc. due to resin flow can be prevented, and problems that occur during multilayer lamination molding can be solved, making it a practical new industrial manufacturing method. It is extremely large.

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 a hole for mounting an IC chip and a terminal part for connection, as a printed wiring board forming an inner layer, around the outer periphery of the terminal part for connecting the IC chip, A printed wiring board for multilayering is used, in which a thin frame is made in advance using photo- or thermosetting resist, and this is multilayered using a low-flow adhesive sheet with holes of a predetermined size formed at predetermined positions. A method for manufacturing a multilayer board for mounting an IC chip, which is characterized by lamination molding. 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.