JPH11330697A - Manufacture of glass ceramic multilayer wiring circuit board, glass ceramic multilayer wiring circuit laminate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provided a manufacturing method of a circuit board having surface copper metallizing which has high bonding strength and no voids in a surface. SOLUTION: An electrolytic copper foil 2 or a rolled copper foil in which either one of a mat surface or a drum surface is worked to have surface roughness Rt greater than or equal to 3 μm is subjected to pattern formation. Lamination compression bonding is so performed that the surface worked to have surface roughness Rt greater than or equal to 3 μm turns to a bonding surface to a green sheet. After the lamination compression bonding is so performed that the surface worked to have surface roughness Rt greater than or equal to 3 μm turns to the bonding surface to the green sheet, a glass ceramic multilayer wiring circuit laminate 1 obtained by pattern formation is baked. As a result, the bonding area of a Cu/glass ceramic interface is increased, and anchor junctions are formed, so that a circuit board having surface copper metallizing exhibiting high bonding strength is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer circuit board suitable for mounting a semiconductor component or mounting a pin for electrical input / output to form a functional module and a method of manufacturing the same.

[0002]

2. Description of the Related Art A glass-ceramic multilayer wiring board comprises a low-resistance conductor copper and a ceramic insulating portion mainly composed of glass which can be sintered at a temperature lower than the melting point of copper. The glass ceramic multilayer wiring board is a glass ceramic powder and a binder, a solvent, a green sheet comprising a solvent and other auxiliaries is manufactured, after drilling necessary holes in the green sheet, a conductive paste composition is filled and printed with a pattern, A method of manufacturing by sintering a glass ceramic multilayer wiring circuit laminate obtained by aligning the green sheets and laminating and pressing a plurality of the sheets is disclosed in IBM. J. RES. DEVELO
P. VOL36 NO. 5 P889-904.

Normally, a circuit board has, on its surface, conductive pads for bonding functional elements such as LSIs by solder, and a sealing metallization for bonding a sealing frame with solder, and a wiring layer and a power supply inside. It has a layer and the like, and has a conductor pad on the back surface for joining terminals of other electronic components or input / output pins for connecting other electronic components by soldering. In many cases, the metallization on the front and back surfaces of the conductive pad and the sealing portion
Before joining input / output pins for connecting functional elements such as SI, terminals of electronic components, sealing frames or other electronic components, Au, Ni, etc. Plating is applied.

[0004]

However, in a circuit board manufactured by using the above-mentioned prior art, the bonding strength at the interface between the copper metallization and the glass ceramic is very low.
Therefore, when the input / output pins for connecting functional elements such as LSIs, terminals of electronic components, sealing frames or other electronic components are soldered, the interface between copper and glass ceramic is easily peeled off by a slight external force. Then, these members come off.

[0005] In addition, since copper metallization in a circuit board manufactured by using the above-mentioned prior art is obtained as a result of sintering of copper metal powder, it has countless grain boundary voids on the surface and inside. Therefore, in a wet process such as a plating step and a cleaning step, a chemical solution remains in voids on the surface of the copper metallized surface of the circuit board, causing corrosion of the copper metallized surface of the circuit board. In addition, the chemical solution remaining in the voids due to the heat treatment after plating is vaporized, which causes the plating film to swell or break.

Accordingly, an object of the present invention is to have a high adhesive strength,
Another object of the present invention is to provide a method for manufacturing a circuit board having a surface copper metallization having no voids on the surface.

[0007]

In order to achieve the above object, according to the present invention, a conductor portion mainly composed of copper and an insulating portion mainly composed of glass which can be sintered at a temperature lower than the melting point of copper. A glass-ceramic multi-layer circuit board made of a conductor having a matt surface or a drum surface with a surface roughness Rt of 3
After forming an electrolytic copper foil or rolled copper foil processed into a desired pattern into a desired pattern, the copper foil surface roughness Rt is laminated and pressure-bonded so that the surface processed into a surface of 3 μm or more becomes an adhesive surface with a green sheet, or After laminating and pressing the surface of the copper foil having a surface roughness Rt of 3 μm or more so as to be an adhesive surface with the green sheet, a glass ceramic multilayer wiring circuit laminate obtained by forming the copper foil into a desired pattern is obtained. It was formed by sintering.

Further, in the present invention, an electronic device package is constituted including the glass ceramic multilayer wiring circuit board manufactured by the above method and the semiconductor element mounted on the glass ceramic multilayer wiring circuit board.

In the present invention, after forming a pattern on an electrolytic copper foil or a rolled copper foil in which either the mat surface or the drum surface is processed to have a surface roughness Rt of 3 μm or more, the surface roughness Rt of the copper foil is reduced to 3 μm. This is a glass-ceramic multilayer wiring circuit laminate obtained by laminating and pressing the surface processed as described above to be an adhesive surface with a green sheet.

Further, the present invention provides an electrolytic copper foil or a rolled copper foil in which either the mat surface or the drum surface is processed to have a surface roughness Rt of 3 μm or more, the surface roughness Rt of the copper foil is 3 μm.
This is a glass ceramic multilayer wiring circuit laminate obtained by laminating and pressing so that a surface processed to m or more becomes an adhesive surface with a green sheet, and then forming a copper foil in a desired pattern.

Further, the present invention is a method for producing a glass ceramic multilayer wiring circuit laminate, which comprises sintering the above glass ceramic multilayer wiring circuit laminate.

That is, in order to simultaneously solve the above two problems, the present invention provides a method of forming an electrolytic copper foil or a rolled copper foil in which one of a mat surface and a drum surface is processed to have a surface roughness Rt of 3 μm or more. After that, the copper foil is processed to have a surface roughness Rt of 3 μm or more by laminating and pressing so as to be an adhesive surface with a green sheet, or a ceramic multilayer wiring circuit laminate or a surface roughness Rt of 3 μm or more. After laminating and pressing the processed surface so as to be an adhesive surface to the green sheet, a glass ceramic multilayer wiring circuit laminate obtained by forming the copper foil into a desired pattern is sintered.

In the present invention, the copper foil is processed to have a surface roughness Rt of 3 μm or more, and the processed surface of the copper foil is used as an adhesive interface, whereby C
A high bonding strength can be obtained by increasing the bonding area at the u / glass-ceramic interface and forming the anchor joint. At the same time, since the electrolytic copper foil or the rolled copper foil has no voids, the surface copper metallization after sintering has no voids.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

In a method for manufacturing a glass ceramic multilayer wiring board, first, a slurry for forming a green sheet is prepared.

The slurry is produced by adding 37 parts by weight of mullite particles having an average particle diameter of 3 μm and 17 parts by weight of an acrylic binder to 63 parts by weight of borosilicate glass powder having an average particle diameter of 3 μm and a softening temperature of 820 ° C., and wet-mixing with a ball mill for 24 hours. To make.

Next, the viscosity is adjusted appropriately by vacuum degassing.
Next, this slurry was applied on a polyester film to a thickness of 0.5 μm using a doctor blade and then dried to produce a green sheet.

Next, the green sheet is punched with a diameter of 1 mm.
Holes of 60 μm were drilled at 450 μm intervals, copper paste was printed and filled, and a surface layer, a power supply layer, and a wiring layer were formed by printing the copper paste.

The copper paste is reduced copper powder 1 having an average particle size of 3 μm.
10 parts by weight of ethyl cellulose as a binder and 90 parts by weight of a solvent were added to 00 parts by weight, and 10 parts by weight of a vehicle prepared was added thereto.
The roll was kneaded several times, kneaded and adjusted to an appropriate viscosity, and then filled and printed.

Next, the matte surface is subjected to a zinc alloying treatment, and a polyimide tape is applied to both surfaces of an electrolytic copper foil having a surface roughness Rt of 3 μm and a gauge thickness of 18 μm, and unnecessary portions are removed by etching with nitric acid. The polyimide tape was peeled off to form a pattern, aligned with 50 green sheets, and pressed by a hot press. Crimping, temperature 13
0 ° C. and pressure 150 kgf / cm 2.

The pressed green sheet is degreased to obtain 1
The temperature was raised at a temperature rising rate of 00 ° C./h or less and maintained at 850 ° C. for 10 hours. The atmosphere was an N2 + H2O + H2 atmosphere in which binder carbon could be removed and copper was not oxidized. After that, the atmosphere was switched to N2 at 1000 ° C for 2 hours.
Hold and sinter densify. During sintering, 2k is used to control the warpage of the substrate and to control the shrinkage of the substrate in the X and Y directions.
Pressure was applied at gf / cm2.

When the adhesive strength of the produced ceramic substrate was examined, the peel strength was as good as 1000 gf / cm. No void could be found on the copper metallized surface of the substrate surface.

Example 2 Electroless Ni plating was performed on the back surface conductive pads of the ceramic multilayer circuit board produced in Example 1 and then sintered at 600 ° C. As a result, no swelling or tearing of the plating was observed. Then, using an AuSn solder, a CuZr electric signal input / output pin was brazed to a 1.6 mm-diameter conductive pad. As a result, the tensile strength was as good as 4 kgf or more (FIG. 2).

Embodiment 3 Through-holes 3 and line wirings 7 are formed in the glass ceramic multilayer wiring board 1 manufactured in Embodiments 1 and 2. Further, a thin-film multilayer circuit 8 is formed on the upper surface of the glass-ceramic multilayer circuit board 1 using copper and polyimide, and an LSI chip 10 is mounted by soldering 9 and then pinned according to the procedure of the second embodiment. FIG. 3 is a schematic diagram of a module connected to the LSI chip 10 in this manner.

[0025]

Since the present invention is configured as described above, the following effects can be obtained.

That is, in a glass-ceramic multilayer circuit board composed of a conductor portion and an insulating portion mainly composed of glass sinterable at a temperature equal to or lower than the melting point of the conductor portion, either the mat surface or the drum surface has a surface roughness. After forming a pattern of electrolytic copper foil or rolled copper foil with Rt processed to 3 μm or more,
The copper foil has a surface processed to a surface roughness Rt of 3 μm or more, and is laminated and pressed so as to be an adhesive surface with a green sheet, or a surface processed to a surface roughness Rt of 3 μm or more is an adhesive surface with a green sheet. As a result of sintering a glass-ceramic multilayer wiring circuit laminate obtained by patterning a copper foil on the surface of a ceramic multilayer wiring circuit laminate obtained by laminating and crimping, the contact area at the Cu / glass-ceramic interface increases. In addition, by forming the anchor joint, it is possible to obtain a surface copper metallized having high adhesive strength and having no void.

[Brief description of the drawings]

FIG. 1 is an enlarged schematic cross-sectional view of an interface between a copper conductor and a glass ceramic according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a glass-ceramic multilayer circuit board to which an electric signal input / output pin according to an embodiment of the present invention is joined.

FIG. 3 is a schematic cross-sectional view of a glass ceramic multilayer circuit board showing one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass ceramic board, 2 ... Copper conductor, 3 ... Through-hole, 4 ... Surface conductive pad, 5 ... AuSn brazing material, 6 ... Electric signal input / output pin, 7 ... Line wiring,
8 ... Thin film multilayer circuit 9 ... Solder 10 ... LSI chip

Continuation of the front page (72) Inventor Norihiro Ami 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture, Hitachi, Ltd.

Claims (5)

[Claims] 1. A glass ceramic multilayer circuit board comprising a conductor portion mainly composed of copper and an insulating portion mainly composed of glass which can be sintered at a temperature equal to or lower than the melting point of copper. Either of the drum surfaces has a surface roughness Rt
After forming into a desired pattern an electrolytic copper foil or a rolled copper foil processed to 3 μm or more, the copper foil is subjected to lamination pressing so that the surface processed to a surface roughness Rt of 3 μm or more becomes an adhesive surface with a green sheet. Or the surface roughness Rt of the copper foil is 3 μm
After the above-processed surface is laminated and pressed so as to be an adhesive surface with a green sheet, the glass ceramic multilayer wiring circuit laminate obtained by forming the copper foil into a desired pattern is formed by sintering. A method for manufacturing a glass-ceramic multilayer wiring circuit board, comprising: 2. An electronic device package comprising a glass ceramic multilayer wiring circuit board manufactured by the method according to claim 1 and a semiconductor element mounted on the glass ceramic multilayer wiring circuit board. 3. After forming a pattern on an electrolytic copper foil or a rolled copper foil having a surface roughness Rt of at least 3 μm on one of a mat surface and a drum surface, the surface roughness Rt of the copper foil is reduced by 3 μm.
A glass-ceramic multilayer wiring circuit laminate obtained by laminating and press-bonding a surface processed to m or more to be an adhesive surface with a green sheet. 4. An electro-deposited copper foil or a rolled copper foil in which either the matte surface or the drum surface is processed to have a surface roughness Rt of 3 μm or more, the surface in which the surface roughness Rt of the copper foil is processed to be 3 μm or more is green. A glass-ceramic multilayer wiring circuit laminate obtained by laminating and pressing to form an adhesive surface with a sheet and then forming the copper foil into a desired pattern. 5. A method for manufacturing a glass ceramic multilayer wiring circuit laminate, comprising sintering the glass ceramic multilayer wiring circuit laminate according to claim 3.