JPH081986B2 - Manufacturing method of wiring board - Google Patents

Description

The present invention relates to a method for manufacturing a wiring board, particularly a high-density wiring board suitable for chip-on-board.

[Conventional technology]

As LSI chips become more highly integrated and faster, there are strong demands for wiring boards with high-density wiring and low dielectric constant. In particular, recently, there has been a demand for a chip-on-board in which a bare chip is directly mounted on a substrate for the purpose of shortening the wiring length between chips. As a method of manufacturing a wiring board that is inexpensive and has high mass productivity and is suitable for chip-on-boarding, a copper layer is provided on a holding substrate such as an SHS board, and a wiring conductor and a heat-resistant material such as polyimide are formed on the copper layer. A method of performing necessary circuit forming processing after a multilayer wiring board obtained by peeling a holding substrate after forming a multilayer wiring made of a resin and a wiring board substrate on which another general laminated board is laminated and integrated There is.

According to this method, since no gas is released from the material (laminated plate) under the vacuum (under reduced pressure) required for vacuum vapor deposition or sputtering, a wiring conductor can be easily formed and a high-density wiring board can be manufactured. .

[Problems to be solved by the invention]

However, this wiring board manufacturing method has the following problems. A SUS plate is used as the holding substrate, a copper layer is provided on this surface, the necessary wiring is formed on this, and the curing temperature of the polyimide resin is usually 300-400 ℃ in the process of applying and curing the polyimide resin. Therefore, the copper on the SUS plate is thermally diffused when the polyimide is cured, and the adhesion between the SUS plate and the copper is increased. For this reason, the interface between the SUS plate and the copper layer may not be easily separated after the multilayer wiring is formed.

The present invention provides a method for manufacturing a wiring board in which a copper layer is provided on a holding substrate, a wiring conductor and multilayer wiring made of a heat-resistant resin such as polyimide are formed on the copper layer, and then the holding substrate can be easily peeled off. To do.

[Means for solving problems]

The present invention provides a multilayer wiring obtained by providing a copper layer on a holding substrate having at least a glass surface, forming a multilayer wiring made of a wiring conductor and an insulating resin such as polyimide on the holding substrate, and then peeling the holding substrate. After the board and other wiring boards are laminated and integrated, necessary circuit forming processing is performed.

As the holding substrate having at least a glassy surface, there are a glass substrate and a substrate having a glassy surface.

As the glass substrate, soda lime glass, lead alkali glass, borosilicate glass, barium borosilicate glass, aluminosilicate glass, 96% silicate glass, quartz glass, etc. can be used.

Substrates with glassy surfaces are iron, iron alloys, aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, chromium, chromium alloys, ceramics, etc., soda lime glass, lead alkali glass , Those coated with borate silicate glass, barium silicate glass, alumina silicate glass, 96% silicate glass, and quartz glass can be used.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a vacuum resistance heating vapor deposition method is applied to the glass substrate 1,
The copper layer 2 is formed by the electron beam evaporation method, the sputtering method, and the electroless plating method. At this time, electrolytic copper plating may be used together if necessary. Next, a resist layer is formed by a method of laminating a photosensitive resist film on the surface of the copper layer 2 or by applying a liquid photosensitive resist and then drying, and a resist pattern is formed by exposing and developing, The copper plating is formed on the part where there is no resist by electrolytic copper plating or electroless copper plating, the resist is peeled off, and the second
A metal column for interlayer connection as shown in FIG. 3 is formed. Then, after the polyimide layer 4 is provided by a method of applying liquid polyimide and then curing it or a method of laminating and curing a B-stage polyimide film, the polyimide is mechanically, physically and chemically planarized, and the interlayer connection column is shown in FIG. To expose it to the surface. Next, a wiring conductor as shown in FIG. 4 is formed. As a forming method, a wiring conductor is deposited on the surface of the polyimide layer and the exposed interlayer connection column by vacuum resistance heating vapor deposition method, electron beam vapor deposition method, sputtering method, electroless plating method, or a combination of these and electroplating method, and thereafter. A method of etching unnecessary conductors by providing a resist pattern in the area to be the wiring, or vacuum resistance heating evaporation method, electron beam evaporation method, sputtering method on the surface of the polyimide layer and the exposed interlayer connection metal pillar,
A wiring conductor is deposited by electroless plating, etc., and then a resist pattern is provided in a place where wiring is not formed. After thickening the wiring conductor by electroless plating or electroplating, the resist is peeled off to etch the unnecessary portion of the conductor. There is a way to do it.

Copper is preferably used as such a wiring conductor material, but chromium, nickel, gold or the like may be used together. After that, the steps of FIGS. 2 to 4 are repeated a necessary number of times to form the multilayer structure shown in FIG. 5, and then the glass substrate 1 is mechanically (a glass substrate and a copper layer are provided between the glass substrate and the copper layer). Peeling is performed (by applying a peeling force) to obtain a single-sided copper foil polyimide multilayer wiring board 6 shown in FIG. The single-sided copper foil polyimide multilayer wiring board 6 may be formed on both sides of the glass substrate 1 at the same time.

After that, the single-sided copper foil polyimide multilayer wiring board 6 is arranged via a prepreg 7 with a circuit-formed copper clad laminate 8 in which a power source layer and a ground layer are previously formed as shown in FIG. obtain.

As the prepreg 7, glass cloth, Kevlar cloth, or quartz cloth impregnated with polyester resin, epoxy resin, or polyimide resin and cured to the B stage state can be used. It may also be a B-stage polyimide film. The circuit-formed copper clad laminate 8 may be a laminate using the material of the prepreg 7 described above or a metal core copper clad laminate. At this time, the material of the metal may be copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy or clad of these. Further, a non-material substrate such as a ceramic substrate or an enamel substrate may be used as the core material. Then, as shown in FIG. 8, through holes 9 are formed in necessary places by a drill or the like, and after electroless plating or a combination of electroless plating and electroplating to form a copper plating layer in the through holes and on the surface of the laminate, A wiring pattern shown in FIG. 8 is obtained by forming a resist pattern at a necessary portion and etching copper in an unnecessary portion.

In addition, after forming the through hole 9, a copper plating layer is formed in the through hole and on the surface of the laminated body by electroless plating or a combination of electroless plating and electroplating, and finally a resist is applied to a portion where a conductor is not required. After forming a pattern and depositing copper, nickel, gold in sequence, nickel, gold in sequence, copper solder in sequence, or solder on electroless plating or electroplating on the part where there is no resist pattern. A method of etching the copper plating layer may be used.

〔The invention's effect〕

In the present invention, since a glass substrate or a substrate whose surface is made of glass is used as the holding substrate, the copper formed on the holding substrate is not diffused into the glass even after high temperature heat treatment at 300 to 400 ° C. Instead, the appropriate adhesion between glass and copper is maintained during the structure process, and the multilayer wiring board formed on the holding board can be easily peeled off.

[Brief description of drawings]

1 to 8 are cross-sectional views showing a manufacturing process of a wiring board according to the present invention. References 1: Glass substrate 2: Copper layer 3: Interlayer connection metal pillar 4: Polyimide 5: Wiring conductor 6: Single-sided copper foil Polyimide multilayer wiring board 7: Prepreg 8: Circuit-formed copper clad laminate 9: Through hole 10 : Through hole plating

Claims (1)

[Claims] 1. (A) A copper layer is provided on a holding substrate having at least a glass surface, (B) a plating resist pattern on the copper layer is formed, and metal columns for interlayer connection are formed by plating. ) The plating resist pattern is removed, an insulating resin layer is formed on the entire surface, the insulating resin surface is removed to expose the heads of the metal columns for interlayer connection, and (D) the heads of the metal columns for interlayer connection are connected. A wiring conductor is formed, and (E) an insulating resin layer is formed on a portion other than the exposed head portion of the metal pillar for interlayer connection and the metal pillar for interlayer connection, which is connected to the wiring conductor on the wiring conductor and the head is exposed, (F) The steps (D) and (E) are repeated a required number of times to form a multi-layered wiring made of a wiring conductor and an insulating resin, and (G) a wiring conductor connected to the head of the interlayer connecting metal column. , (F) An insulating resin layer is formed on the entire surface of the wiring conductor, (H) a surface of the insulating resin layer, which is a surface of the multilayer wiring board obtained by peeling the holding substrate, the surface being opposite to the surface from which the holding substrate is peeled
The multilayer wiring board and the circuit-formed copper-clad laminate are laminated and integrated by facing the circuit-formed surface of the circuit-formed copper-clad laminate through a prepreg, and (I) through-hole formation, through-hole plating layer A wiring board characterized by forming a resist pattern on a required portion of the surface of a laminated body of a multilayer board and a circuit-formed copper-clad laminate, and removing metal in an unnecessary portion. Manufacturing method.