JP2697661B2 - Manufacturing method of polyimide multilayer wiring board - 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 manufacturing a polyimide multilayer wiring board having a multilayer wiring layer in which a polyimide resin is used for interlayer insulation on a ceramic substrate, and more particularly to a method for laminating a polyimide resin layer.

[0002]

2. Description of the Related Art As a method of manufacturing a multilayer wiring board, there is a method of manufacturing by dividing a board into a plurality of blocks. An example of a method for manufacturing a polyimide multilayer wiring board using this method is described in Japanese Patent Application Laid-Open No. Hei 5-206664. In this method, by connecting a plurality of blocks manufactured in advance, a final polyimide multilayer wiring board is obtained.

[0003]

In the technique described in the above publication, a block is formed using an aluminum substrate as a support substrate, and the substrate is dissolved in an aqueous hydrochloric acid solution as a method of peeling the support substrate. However, this method has a problem that the polyimide multilayer wiring itself is deteriorated in the melting step. Also, there is a method in which a support substrate itself having blocks formed thereon is left inside a final product as in the method for manufacturing a polyimide multilayer wiring board described in Japanese Patent Application Laid-Open No. 5-95191. However, in this method, since the thermal expansion coefficient is different between the substrate and the polyimide layer, there is a problem that the polyimide film or the substrate is cracked at the time of connection under heating and pressing.

It is an object of the present invention to provide a method for manufacturing a polyimide multilayer wiring board which prevents deterioration of the polyimide multilayer wiring itself, the polyimide film and the substrate.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a first step of forming a polyimide multilayer wiring layer on a substrate which transmits ultraviolet light, and forming at least one wiring layer therein. A second step of temporarily weakly bonding the polyimide wiring layer formed on the substrate including the substrate and the substrate, a third step of exposing the support substrate by irradiating ultraviolet rays, and the above steps 1 to 3. After repeating until the required number of layers is obtained, a fourth step of performing pressure bonding under heat and pressure is included.

[0006] A first manufacturing method of the present invention is a method of forming a polyimide multilayer wiring layer on a supporting substrate that transmits ultraviolet light.
A second process for forming a polyimide wiring layer including at least one wiring layer therein on the main substrate; a polyimide multilayer wiring layer formed in the first process; and a second process for forming the polyimide wiring layer. A third process of temporarily bonding the applied polyimide wiring layer,
A fourth process of irradiating ultraviolet light to the object temporarily adhered in the above process to peel off the support substrate.

[0007] A second manufacturing method of the present invention comprises the first process in the first manufacturing method and the third process.
Process and the fourth process are repeated several times for the required number of layers, and then the fifth pressure bonding under heat and pressure is performed.
The process is characterized by including.

In a third manufacturing method according to the present invention, the first process in the first manufacturing method may include forming a via hole in an uppermost layer of the polyimide multilayer wiring layer to form a wiring inside the polyimide multilayer wiring layer. Forming a metal bump electrically connected to the layer, the second process forming a via hole in the uppermost layer of the polyimide wiring layer to form a metal bump electrically connected to the polyimide wiring layer; The metal bumps formed in the first process and the metal bumps formed in the second process are bonded and electrically connected.

In a fourth manufacturing method of the present invention, in the third manufacturing method, a via hole is formed in the surface of the uppermost polyimide insulating layer after the support substrate is peeled off by the fourth process, and the polyimide multilayer wiring is formed. Forming a metal bump electrically connected to a wiring layer inside the layer, and electrically connecting the metal bump to the metal bump formed in the first process and the metal bump formed in the second process; It is characterized by doing.

According to a fifth manufacturing method of the present invention, in the first manufacturing method, the support substrate is a quartz glass substrate;
The main substrate is a ceramic substrate.

In a sixth manufacturing method according to the present invention, in the first manufacturing method, the support substrate is a quartz glass substrate;
The main substrate is a polyimide resin molded substrate.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

In a multilayer wiring board manufactured by the manufacturing method according to one embodiment of the present invention, the thickness of the wiring interlayer insulating film is 20 μm (μm) and the width of the wiring is 25 μm (μm).
m) and the thickness of the wiring film is 10 microns (μm). Further, the diameter of the via hole connecting the wirings is 10
0 microns (μm). The polyimide resin is a photosensitive polyimide having a low coefficient of thermal expansion, the adhesive layer is a polyimide resin having a glass transition point, and the wiring metal is gold. The low thermal expansion polyimide refers to a polyimide having a thermal expansion coefficient of 10 ppm to 30 ppm. First, a method of manufacturing one set of signal wiring layers, one grounding and connection layer on a flat plate of quartz glass having a thickness of 2 mm (hereinafter abbreviated as a glass flat plate) will be described below with reference to FIGS. I do.

Referring to FIG. 1, it transmits ultraviolet rays, for example, low thermal expansion coefficient photosensitive polyimide 2 on the quartz glass plate 1 is formed with a uniform layer having a thickness of 10 microns ([mu] m).

Referring to FIG. 2, patterning is performed by photolithography using a photoresist, and electrolytic gold plating is performed to form a grounding and connection wiring layer 3.

Referring to FIG. 3, a polyimide layer 2 having a low coefficient of thermal expansion on a glass plate 1 formed in the process shown in FIG.
A photosensitive polyimide varnish 4 having a low coefficient of thermal expansion is applied on the ground and connection wiring layer 3 on the polyimide layer 2, and exposure and development are performed. Thereafter, via holes are formed at predetermined positions of the polyimide varnish 4, and curing is performed.

Referring to FIG. 4, a pair of signal wiring layers 6 are formed using photosensitive polyimide having a low coefficient of thermal expansion for interlayer insulation. In this formation, the signal wiring layer 6 is formed by the same method as the method of forming the ground and connection wiring layer 3 shown in FIG. The formation of the signal wiring interlayer insulating layer is performed by the same method as the method of forming the insulating layer shown in FIG.

Referring to FIG. 5, a polyimide resin having a glass transition point is applied to the uppermost layer of the pair of signal wiring layers 6 shown in FIG. 4, and exposure and development are performed. afterwards,
Via holes 7 are formed at predetermined positions and cured, and a polyimide adhesive layer 8 having a thickness of 10 microns (μm) is formed.
Is formed.

Referring to FIG. 6, a connection is made to the uppermost layer of the multilayer wiring layers formed in the required number of layers in the step shown in FIG. 5, at a position where electrical connection is made with the multilayer wiring layer formed in the following steps. The use bump 9 is formed. This bump 9 is patterned by photolithography using a photoresist,
It is formed by plating. This bump metal is formed from four layers of metal. The layers are formed by electrolytic plating in the order of nickel, gold, tin and gold from the layer closest to the wiring pattern. The thickness of the nickel layer is 3 microns (μm), the thickness of the gold layer is 8 microns (μm), the thickness of the tin layer is 11 microns (μm), and the thickness of the gold layer is 8 microns (μm). ).

Further, tin / lead solder plating is applied on a 3 micron (μm) nickel layer to a thickness of 30 μm (μm).
Can also be formed. In this case, the tin / lead ratio is eutectic (63/37) or 95: 5.

Next, a process of forming a set of signal wiring layers and a set of grounding and connecting layers sandwiching these signal wiring layers on a ceramic substrate different from the glass flat plate formed with reference to FIGS. Will be described in detail with reference to FIGS.

Referring to FIG. 7, a ground and connection wiring layer 11 is patterned on the surface of a ceramic substrate 10 having input / output pins and power supply pins 12 on the back surface by photolithography using a photoresist, and is subjected to electrolytic gold plating. You.

Referring to FIG. 8, a photosensitive polyimide varnish 13 having a low coefficient of thermal expansion is applied on the ceramic substrate on which the grounding and connection layers are formed in the process shown in FIG.
Development takes place. Next, via holes 14 are formed at predetermined positions of the polyimide varnish 13, and curing is performed.

Referring to FIG. 9, in this step, a pair of signal wiring layers 15 are formed using photosensitive polyimide having a low coefficient of thermal expansion for interlayer insulation. In this formation, the signal wiring layer is formed by the same method as the method of forming the ground and connection layers shown in FIG. The insulating layer between signal lines is formed by the same method as the method of forming the insulating layer shown in FIG.

Referring to FIG. 10, a photosensitive polyimide varnish having a low coefficient of thermal expansion is applied on the signal wiring layer 15 formed in the step shown in FIG. 9, and exposure and development are performed. next,
Via holes 16 are formed at predetermined positions of the polyimide varnish, and curing is performed.

Referring to FIG. 11, a second grounding and connection wiring layer 17 is formed on the polyimide layer formed in the step shown in FIG. This forming method is the same as the method of forming the ground and connection wiring layer 11 in the step shown in FIG.

Referring to FIG. 12, a polyimide adhesive layer 19 having a glass transition point is formed on the second-layer grounding and connection wiring layer 17 formed in the step shown in FIG. Thereafter, via holes 18 are formed at predetermined positions of the polyimide adhesive layer 19. These forming methods are the same as the forming method in the step shown in FIG.

One of the features of one embodiment of the present invention is shown in FIG.
This will be described below with reference to FIGS.

The operation in the step shown in FIG. 13 is as follows.

First, a polyimide multi-layer wiring layer on a glass flat plate formed in the steps shown in FIGS. 1 to 6 and a polyimide layer having connection metal bumps formed in the step shown in FIG. The alignment with the polyimide multilayer wiring layer having the metal bumps on the ceramic substrate formed in the steps shown in FIGS. Thereafter, the gel-like Shianoakuri les over preparative based adhesive on the polyimide adhesive layer 8 and 19 is applied by a dispenser, is temporarily temporary adhesion.

Referring to FIGS. 14 and 15, FIG.
The excimer laser 20 is irradiated from the side of the quartz glass plate 1 temporarily bonded in the process shown in FIG. By this irradiation, the polyimide at the interface between the quartz glass flat plate 1 and the polyimide uniform layer made of the low thermal expansion polyimide 2 is removed by a photochemical reaction, and the glass flat plate 1 can be peeled off. The irradiation conditions of the excimer laser are as follows. The laser gas is krypton fluorine KrF, the energy density is 0.8 joules (J) / cm ² , the frequency is 50 Hz (Hz), and about 1 micron (μm) of polyimide can be removed.

Referring to FIG. 16, FIG. 14 and FIG.
The polyimide uniform layer made of polyimide 2 having low thermal expansion was newly exposed by the irradiation of the excimer laser performed in the step indicated by.

Referring to FIG. 17, the newly exposed low thermal expansion polyimide shown in FIG. 16 is dry-etched to form via holes 21 at predetermined positions.

Referring to FIG. 18, connection bumps 22 are formed on the polyimide layer formed in the step shown in FIG. The method of forming the connection bumps 22 is the same as the method of forming in the step shown in FIG.

Referring to FIG. 19, a polyimide adhesive layer 24 having a glass transition point is formed on the polyimide uniform layer of the low thermal expansion coefficient polyimide 2 exposed in the step shown in FIG. This forming method is the same as the forming method in the step shown in FIG. Thereafter, via holes 23 are formed at predetermined positions of the polyimide adhesive layer 24.

The steps from FIG . 1 to FIG.
Steps from 13 to 19 are repeated until the wiring layer designed.

Referring to FIG. 20, a uniform polyimide layer made of polyimide 2 having a low thermal expansion coefficient
A polyimide wiring layer including the signal wiring layer 6, a polyimide adhesive layer 8, and a connection bump 9 are formed. These forming methods are the same as the forming method in the steps shown in FIGS. The polyimide multilayer wiring board on the quartz glass plate 1 thus formed is aligned with the polyimide multilayer wiring board formed in the steps of FIGS.
It is temporarily provisionally bonded by gel Shianoakuri les over preparative based adhesive.

Referring to FIG. 21, an excimer laser is irradiated from the quartz glass flat plate 1 side of the polyimide multilayer wiring substrate temporarily bonded in the step shown in FIG. By this irradiation, the quartz glass flat plate 1 can be peeled. The manufacturing method in these steps is the same as the manufacturing method in the steps shown in FIGS.

These steps are repeated until a designed wiring layer is obtained.

Referring to FIG. 22, the polyimide multilayer wiring board manufactured in the steps up to FIG. 21 is heated to a temperature exceeding the glass transition point of the polyimide resin, and is simultaneously pressurized, so that the polyimide films of each other are formed. Glued and fixed. At this time, the formed metal bumps are joined together,
The two laminated structures are electrically connected. The pressurizing and heating methods are as follows. Pressurization and heating are performed using an autoclave type vacuum press, nitrogen gas is used as a pressurized gas, and pressurization is performed at a substrate temperature of 350 ° C. for 60 minutes at 20 kg / cm ² . At this time, the substrate is placed on a platen, sealed with a polyimide film, and the inside is evacuated. In addition, a low-resistance metal such as copper can be used as the other metal wiring material in the above example. In addition, as a material of the polyimide adhesive layer, a melt-curable maleimide resin, a melt-type fluorine-based film, for example, a copolymer of ethylene fluoride and a perfluoroalkyl perfluorovinyl ether (PFA) can be used. In the above-described embodiment, the polyimide multilayer wiring layer is formed on the ceramic substrate. However, a hard organic resin substrate, for example, a polyimide resin molded substrate can be used in addition to the ceramic substrate. In this case, the input / output pins 12 are formed by forming through-holes in the polyimide resin molded substrate and driving the input / output pins 12. The polyimide multilayer wiring board using this polyimide resin molded board can accurately match the thermal expansion coefficient of the polyimide resin molded board serving as a base and the polyimide multilayer wiring layer having a wiring layer, Suitable for manufacturing substrates. By using the method of one embodiment described above, the substrate supporting the laminated body can be easily peeled off, and a high-layer-density polyimide multilayer wiring substrate having a high number of laminated layers can be formed.

[0041]

According to the manufacturing method of the present invention, the quartz glass flat plate, which is the supporting substrate of the block, is not dissolved by the hydrochloric acid aqueous solution to exfoliate the substrate, and the excimer laser is used. It has the effect of saving.

In the manufacturing method of the present invention, a photosensitive polyimide having a low coefficient of thermal expansion having a coefficient of thermal expansion of 10 ppm to 30 ppm close to the coefficient of thermal expansion of the supporting substrate is used as a material of the polyimide uniform layer in contact with the supporting substrate. Therefore, there is an effect that the polyimide film and the substrate are not cracked at the time of connection under heating and pressure.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method of manufacturing one set of signal wiring layers, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 2 is a view for explaining a method of manufacturing one set of signal wiring layers, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 3 is a view for explaining a method of manufacturing one set of signal wiring layers, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 4 is a view for explaining a method of manufacturing one set of signal wiring layer, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 5 is a view for explaining a method of manufacturing one set of signal wiring layers, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 6 is a view for explaining a method of manufacturing one set of signal wiring layer, one grounding and connection layer on a glass flat plate in one embodiment of the present invention.

FIG. 7 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching these signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 8 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching the signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 9 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching these signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 10 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching these signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 11 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching the signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 12 illustrates a method of manufacturing a set of signal wiring layers and a set of grounding and connection layers sandwiching the signal wiring layers on a ceramic substrate different from a glass flat plate in one embodiment of the present invention. FIG.

FIG. 13 is a view showing a process of combining one laminate manufactured in the process shown in FIGS. 1 to 6 and another laminate manufactured in the process shown in FIGS. 7 to 12 into one; is there.

FIG. 14 is a diagram showing a process of combining one laminate manufactured in the process shown in FIGS. 1 to 6 and another laminate manufactured in the process shown in FIGS. 7 to 12 into one; is there.

FIG. 15 is a view showing a step of combining one laminate manufactured in the steps shown in FIGS. 1 to 6 with another laminate manufactured in the steps shown in FIGS. 7 to 12; is there.

FIG. 16 is a view showing a process of combining one laminated body manufactured in the steps shown in FIGS. 1 to 6 and another laminated body manufactured in the steps shown in FIGS. 7 to 12 into one; is there.

FIG. 17 is a view showing a step of combining one laminate manufactured in the steps shown in FIGS. 1 to 6 with another laminate manufactured in the steps shown in FIGS. 7 to 12; is there.

FIG. 18 is a view showing a process of combining one laminate manufactured in the process shown in FIGS. 1 to 6 and another laminate manufactured in the process shown in FIGS. 7 to 12 into one; is there.

FIG. 19 is a view showing a step of combining one laminate manufactured in the steps shown in FIGS. 1 to 6 with another laminate manufactured in the steps shown in FIGS. 7 to 12; is there.

FIG. 20 is a view showing a step of temporarily bonding another laminated body to the laminated body manufactured up to the step shown in FIG. 19 in one embodiment of the present invention and bonding the laminated body under heat and pressure.

FIG. 21 is a view showing a step of temporarily bonding another laminated body to the laminated body manufactured up to the step shown in FIG. 19 in one embodiment of the present invention and bonding the laminated body under heat and pressure.

FIG. 22 is a view showing a step of temporarily bonding another laminated body to the laminated body manufactured up to the step shown in FIG. 19 in one embodiment of the present invention and bonding the laminated body under heat and pressure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Quartz glass plate 2,13 Low thermal expansion coefficient polyimide 3,11 Grounding and connection wiring layer 4 Photosensitive polyimide varnish 5,7,14,16,18,21,23 Via hole 6,15 Signal wiring layer 8,19,24 Polyimide adhesive layer 9,22 Connection bump

Claims (3)

(57) [Claims] 1. A first process for forming a polyimide multilayer wiring layer on a support substrate that transmits ultraviolet light, and a second process for forming a polyimide wiring layer including at least one wiring layer therein on a main substrate. A third process for temporarily bonding the polyimide multilayer wiring layer formed in the first process and the polyimide wiring layer formed in the second process, and a third process for temporarily bonding the polyimide wiring layer formed in the second process. The support substrate and the polyimide multilayer wiring layer by irradiating ultraviolet rays to the
And a fourth process of removing the support substrate by removing the polyimide at the interface between them . 2. The method according to claim 1, wherein the first process and the third process are performed.
Process and the fourth process are repeated several times for the required number of layers, and then the fifth pressure bonding under heat and pressure is performed.
2. The method according to claim 1, further comprising the step of: 3. The first process includes forming a via hole in an uppermost layer of the polyimide multilayer wiring layer to form a metal bump electrically connecting a wiring layer inside the polyimide multilayer wiring layer, The second process includes forming a via hole in the uppermost layer of the polyimide wiring layer to form a metal bump electrically connected to the polyimide wiring layer, and forming the metal bump formed in the first process and the second bump.
2. The method for manufacturing a polyimide multilayer wiring board according to claim 1, wherein the metal bumps formed in the above process are bonded and electrically connected.