JPH07202424A - Production of multilayer wiring board - Google Patents

Abstract

PURPOSE:To reduce man-hours by forming more than three polyimide wiring layers simultaneously on one board, cutting the board for every layer and laminating to produce a single muitilayer polyimide wiring board. CONSTITUTION:A polyimide resin layer 11 is formed on a silicon glass substrate 10 and then pads 12 for mounting four types of LSI, a first signal wiring pattern 13, a second signal wiring pattern 118, a power supply and a ground pattern 14, and alignment marks 15 are formed thereon. A photoresist 17 is then applied onto a polyimide based adhesive 16 and patterning is effected at a predetermined position using an excimer laser 19. Subsequently, the substrate 10 is divided into four using a blade 112. A board having the first signal wiring pattern 13 is aligned with a multilayer wiring board 115 using the alignment marks 15 and then the boards are bonded through a temporary bonding adhesive. Finally, the silicon glass substrate 10 is stripped from the laminate by means of the excimer laser 19.

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 multi-layer wiring board in which each layer is formed by laminating and laminating boards.

[0002]

2. Description of the Related Art As a wiring board on which an LSI chip is mounted, Japanese Patent Laid-Open No. 2-228095 can be referred to as an example of a conventional method for manufacturing a multilayer printed wiring board. An example of a multilayer printed wiring board is configured by using a copper clad laminate as a core material and a prepreg as an adhesive for the core material, and the core material and the prepreg are alternately laminated and integrated by using a hot press. For electrical connection between the laminated plates, a through-hole is formed by a drill after the core material and the prepreg are integrated, and the inner wall of the through-hole is plated with copper. Further, in recent years, a multilayer wiring board in which a polyimide resin is used for interlayer insulation on a ceramic substrate has been used as a wiring board for a large computer, which is required to have a higher wiring density than a multilayer printed wiring board. This polyimide / ceramic multilayer wiring board is manufactured by coating a polyimide precursor varnish on a ceramic substrate, drying it, and forming a via hole in the coating film, a polyimide resin insulating layer forming step, and photolithography, vacuum deposition and plating methods. And a wiring layer forming step using the same, and the polyimide multilayer wiring layer was formed by repeating this series of steps.

In addition to the above-described method for forming a polyimide / ceramic multilayer wiring board, the polyimide multilayer wiring patterns formed on a large number of auxiliary boards are simultaneously aligned on the ceramic board, temporarily laminated and then heated and pressed to form a multilayer wiring. There is also a method of forming a substrate. In this case, the auxiliary substrate may be left in the polyimide multilayer wiring layer or may be peeled off. This method makes it possible to perform an electrical inspection for each auxiliary substrate and to select and stack defect-free auxiliary substrates, which can increase the manufacturing yield compared to the above-described successive lamination method, and also enables parallel production on the auxiliary substrates. Since the polyimide layers can be laminated, the number of manufacturing days of the polyimide multilayer wiring layer can be shortened.

[0004]

In the above-mentioned multilayer printed wiring board, since the electrical connection between the laminated plates is made by the through holes formed by drilling, it is impossible to form fine through holes. Therefore, the number of wires that can be formed between the through holes is limited. In addition, one through-hole is required for connection between one laminated board, and as the number of laminated layers increases, the signal wiring accommodability decreases, making it difficult to form a multilayer printed wiring board with high wiring density. There was a drawback that it came.

Further, in order to make up for the above-mentioned drawbacks of the conventional multilayer printed wiring board, the polyimide / ceramic multilayer wiring board recently developed has the same number of polyimide precursor layers as the polyimide precursors on the ceramic substrate. It is necessary to repeat the steps of applying varnish, drying, forming a via hole, and curing. Therefore, it takes a very long time to stack the multilayer wiring boards. Further, since the step of forming the polyimide insulating layer is repeated, the polyimide resin in the lower layer portion of the multilayer wiring layer is subjected to thermal stress in a number of curing steps, which causes the polyimide resin to deteriorate. Further, this polyimide multi-layer wiring layer has a drawback that it is difficult to improve the manufacturing yield because it is a sequential lamination method.

Further, as a method of manufacturing a multilayer wiring board which improves the manufacturing yield and shortens the number of days for manufacturing the board, a stacking method using an auxiliary board does not reduce the number of steps for manufacturing the board, and the method can be performed on a plurality of boards in parallel. However, the polyimide varnish, the waste of the resist coating, and the amount of other materials used are larger than those of the sequential lamination method.

[0007]

According to a first method of manufacturing a multilayer wiring board, a pattern of each layer required for one multilayer wiring board is formed on a large-sized board having an area at least four times as large as that of the board. And a cutting step of cutting the large-sized board created in this creating step for each pattern of each layer, and a board having a conductor layer inside serving as a base of a multilayer wiring board, cut in the cutting step. The substrate on which the bottom layer pattern is formed is aligned, temporarily bonded and laminated, and then only the substrate is separated, and the lower layer pattern is formed on the laminated substrate formed by this lamination separation process. Repeating step of repeating the alignment, temporary fixing lamination, and substrate peeling from the formed substrate until a predetermined number of layers and the laminated substrate formed in this repeating step are pressed under a predetermined pressure and temperature, Between layers Electrical, characterized in that it comprises a step of obtaining a mechanical connection.

In a second method for manufacturing a multilayer wiring board according to the present invention, a pattern of the same layer as the lowermost layer required for a plurality of multilayer wiring boards is formed on a large-sized board having an area of at least four times the area of the board. And a cutting step of cutting the large-sized board created in this creating step for each pattern, and cutting on the board having a conductor layer inside serving as a base of a plurality of multilayer wiring boards by the cutting step. Each substrate on which the pattern of the lowermost layer has been formed is aligned and temporarily bonded and laminated, and then only the substrate is peeled off, and the upper layer is formed on the plurality of laminated substrates formed in this laminating step. Repeating the steps of aligning each pattern-formed substrate, temporarily fixing and laminating, and peeling the substrate until a predetermined number of layers are reached, and the laminated substrate formed in this repeating step is subjected to a predetermined pressure and temperature. so Resushi, electrical of the layers, characterized in that it comprises a step of obtaining a mechanical connection

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

First, a first embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to (1) to FIG. 3 (4).

Referring to FIG. 1A, first, a quartz glass substrate 10 that transmits an excimer laser is prepared. In this first embodiment, a substrate having a size of 210 mm × 210 mm is used.

Referring to FIG. 1 (2), next, a polyimide precursor is applied on the quartz glass substrate 10, pre-cured and cured to form a 0.2 μm-thick polyimide resin layer 11 ( Hereinafter, a polyimide resin layer forming step). The polyimide resin layer 11 is not required to have a large film thickness because it is etched when the quartz glass substrate 10 is peeled off in a later step.

Referring to FIG. 1C, four kinds of metal patterns are formed on the polyimide resin 11. In the case of one embodiment, the four types of metal patterns are the LSI mounting pad 12, the first signal wiring pattern 13, the second signal wiring pattern 118, the power supply and ground pattern 14.
Is. The metal pattern is patterned by photolithography using a photoresist and is formed by electrolytic plating to have a layer structure of gold Au / nickel Ni / gold Au.
The film thickness of each layer is 4 for gold Au / nickel Ni / gold Au.
μm / 2 μm / 4 μm. Nickel Ni is a barrier layer against the solder metal used in the subsequent process. In addition, at this time, X used for alignment at the time of temporary fixing lamination in the subsequent process
, Y, θ positioning alignment marks 15 are simultaneously formed at three locations for each metal pattern.

Referring to FIG. 1D, a polyimide adhesive 16 is applied on the metal pattern, and baking and curing are performed. The film thickness after curing is 10μ
m. Polyimide-based resin is a high-quality insulator having a high insulating property and a low dielectric constant, and is often used as an insulating material for a thin film multilayer wiring portion of a multilayer wiring board.

Referring to FIG. 1 (5), a photoresist 17 is next coated on the polyimide adhesive 16 and patterned at a predetermined position by using a photolithography technique. At this time, the thickness of the polyimide-based adhesive is 10
The film thickness is required to be at least twice as large as μm. A KrF excimer laser is used as the excimer laser 19, and scanning is performed under the conditions of an oscillation frequency of 200 Hz and an energy density of 0.8 J / cm ² under one shot of 200 shots. The excimer laser is about to be used for a wide range of applications as a high-power laser even though it oscillates in the ultraviolet region.

Referring to FIG. 2A, after the excimer laser scanning, the resist is stripped with methyl ethyl ketone.
Oxygen plasma ashing removes the soot remaining at the bottom of the polyimide adhesive via hole. Thus, the via hole 110 of the polyimide adhesive is formed. The via hole system of the first embodiment is 150 μm.

Referring to FIG. 2B, the connection bump 111 is formed by plating on the metal portion exposed at the bottom of the via hole of the polyimide adhesive. The bumps are patterned by photolithography using photoresist and are formed by multilayer plating of electrolytic nickel plating, electrolytic gold plating, electrolytic tin plating, and electrolytic gold plating. Nickel plating is a diffusion prevention layer of gold / tin solder metal on the gold wiring layer. The plating thickness is nickel 3μm, gold 8μm, tin 11μ
m and gold 8 μm, and the bump system is 100 μm. At this time, the weight% of gold and tin is formed with gold: tin = 4: 1.

Referring to FIG. 2C, the substrate formed in the above process is cut for each pattern by using a blade of a dicing saw, that is, a blade 112 (hereinafter, a cutting step). In the case of this embodiment, the substrate is divided into four because it consists of four kinds of metal patterns.

Referring to FIG. 2 (4), a first signal wiring pattern is formed on the inside of the multilayer wiring board 115 including a conductor layer inside and having a power supply layer and a ground wiring layer on the surface cut in the above cutting step. Substrates having 13 are provisionally stacked. At this time, the alignment is performed using the alignment mark 15, and the full-spray type temporary adhesive 1
The substrates are fixed at 14. Temporary stacking is 1 kg / c at room temperature
It takes about 2 minutes under a pressure of m ² . The laminated body thus obtained is irradiated with the KrF excimer laser 19 through the quartz glass substrate. At this time, the polyimide layer formed in the step of forming the polyimide resin layer is etched through the quartz glass substrate, and the quartz glass substrate 10 is separated from the laminated body. The KrF excimer laser has an oscillation frequency of 200 Hz, 0.
Scan at an energy density of 8 J / cm ² under the condition of 2 shots in 1 place.

Referring to FIG. 2 (5), next, after peeling the quartz glass substrate, soot on the surface of the laminate is removed by oxygen plasma ashing to expose the surface of the metal pattern.

Referring to FIG. 3 (1), a substrate having a second signal wiring pattern 118 inside is temporarily laminated on the surface of the laminate under the same conditions as in the steps after the cutting step, The quartz glass substrate is peeled off.

Referring to FIG. 3B, similarly, temporary stacking and substrate peeling are repeated in the order of a substrate having a power source and a ground pattern inside and a substrate having an LSI mounting pad inside thereof on the surface of the laminate. One stack is obtained.

Referring to FIG. 3 (3), the laminate formed in such a process is pressed and heated under vacuum using an autoclave device, and polyimide adhesives between the layers are temporarily fixed to each other. The main adhesion between the electrodes is performed. The main adhesion is performed using a press profile in which the pressure is maintained at 350 ° C. and a pressure of 20 kg / cm ² for about 30 minutes. At this time, the polyimide-based adhesive exhibits fluidity and the polyimide-based adhesives are integrated with each other, so that good adhesion between layers can be obtained. At the same time, the bump formed by multi-layer plating of gold and tin is melted at its eutectic point of 280 ° C. and connected to the metal metal of the other party, and good electrical connection between layers can be obtained after pressing. Become. 3 for temporary adhesive
It is completely pyrolyzed at 50 ° C and does not hinder the electrical connection between layers.

Referring to FIG. 3 (4), finally, the input / output signal pin and the power supply pin 11 are assembled at predetermined positions on the back surface of the base multilayer wiring board.

Next, the second embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to (1) to FIG. 6 (3).

Referring to FIG. 4A, first, a quartz glass substrate 20 that transmits an excimer laser is prepared. In the second embodiment, a substrate having a size of 210 mm × 210 mm is used.

Referring to FIG. 4B, a polyimide precursor is coated on the quartz glass substrate 20, pre-cured and cured to form a polyimide resin layer 21 having a thickness of 0.2 μm (hereinafter referred to as polyimide layer). Forming step).
This polyimide resin layer 21 is used for the quartz glass substrate 2 in the subsequent process.
A thick film is not required because it is etched at the time of peeling 0.

Referring to FIG. 4C, one kind of metal pattern is formed on the polyimide resin 21 for four layers. In the case of the second embodiment, the metal pattern to be formed is the first signal wiring pattern 22. The metal pattern is patterned by photolithography using a photoresist, and is formed by electrolytic plating to have a layer structure of gold Au / nickel Ni / gold Au. The thickness of each layer is gold A
u / nickel Ni / gold Au = 4 μm / 2 μm / 4 μm. Nickel Ni is a barrier layer against the solder metal used in the subsequent process. At this time, alignment marks 23 for positioning X, Y, and θ used for alignment during temporary stacking in the subsequent process are simultaneously formed at three locations for each metal pattern of one layer.

Referring to FIG. 4 (4), a polyimide adhesive is applied on the metal pattern, and baking and curing are performed. The film thickness after curing is 10 μm. Polyimide-based resin is a high-quality insulator having a high insulating property and a low dielectric constant, and is often used as an insulating material for a thin film multilayer wiring portion of a multilayer wiring board.

Referring to FIG. 4 (5), a photoresist 25 is applied on the polyimide adhesive 24, and patterning is performed at predetermined positions by using a photolithography technique. At this time, the thickness of the polyimide-based adhesive is 10
The film thickness is required to be at least twice as large as μm. The excimer laser 27 uses a KrF excimer laser and has an oscillation frequency of 200.
20 at 1 place with an energy density of 0.8 J / cm ^{2 at} Hz
Scan under the condition of 0 shots. Excimer laser
As a high-power laser despite oscillating in the ultraviolet region,
It is currently being used for a wide range of purposes.

Referring to FIG. 5A, after excimer laser scanning, methyl ethyl ketone is peeled off, and soot remaining on the bottom of the via hole of the polyimide adhesive is removed by oxygen plasma ashing. Thus, the via hole 28 of the polyimide adhesive is formed. The via hole system of the second embodiment is 150 μm.

Referring to FIG. 5B, a bump 29 for connection is formed by plating on the metal portion of the polyimide adhesive exposed on the bottom of the via hole. The bumps are patterned by photolithography using photoresist,
Electrolytic nickel plating is formed by multilayer plating of electrolytic gold plating, electrolytic tin plating, and electrolytic gold plating. Nickel plating is a diffusion prevention layer of gold / tin solder metal on the gold wiring layer. Each plating layer is nickel 3μm, gold 8μm, tin 11μ
m and gold 8 μm, and the bump system is 100 μm. At this time, the weight% of gold and tin is formed with gold: tin = 4: 1.

Referring to FIG. 5C, the substrate formed in the above process is cut into patterns for each one layer by using a blade of a dicing saw and a blade 211 (hereinafter referred to as a cutting step). In the case of the second embodiment, the substrate is divided into four because it consists of metal patterns for four layers.

Referring to FIG. 5 (4), signal wiring is cut inside the four multi-layer wiring boards 212 including a conductor layer inside and having a power supply layer and a ground wiring layer on the surface. Substrates having the pattern 122 are temporarily stacked. At this time, the alignment is performed using the positioning alignment mark 23, and the adhesive 214 for temporary fixing of the entire surface spray type is fixed between the substrates. Temporary lamination requires about 2 minutes under a pressure of 1 kg / cm ^{2 at} room temperature. The laminated body obtained in this way was placed over the quartz glass substrate
Irradiation with rF excimer laser 27 is performed. At this time, the polyimide layer formed in the polyimide layer forming step is etched through the quartz glass substrate, and the quartz glass substrate is peeled from the laminated body (hereinafter, temporary laminating and peeling step). Kr
The F excimer laser has an oscillation frequency of 200 Hz and 0.8 J / c.
Scan under the condition of two shots at one place with an energy density of m ² .

Referring to FIG. 5 (5), after the quartz glass substrate is peeled off, soot on the surface of the laminate is removed by oxygen plasma ashing to expose the surface of the metal pattern.

Referring to FIG. 6A, a substrate having a first signal wiring pattern 22 therein is formed in the steps from the first step to the cutting step of the second embodiment, and at the same time, the substrate is formed in a similar manner. Then, a substrate having the second signal line pattern 218, the power supply and ground pattern 215, and the LSI mounting pad 216 is created. Then, in the same manner as in the temporary stacking and peeling step, a substrate having the signal wiring pattern 2 inside, a substrate having a power source and a ground pattern inside, and an LSI mounting pad inside are formed on the surface of the above four laminated bodies. Position in the order of the boards,
The temporary lamination and the peeling of the substrate are repeated to obtain four laminated bodies.

Referring to FIG. 6 (2), the four laminated bodies are pressed and heated in a vacuum using an autoclave device, and a book of polyimide adhesives and electrodes between the layers is temporarily fixed. Bonding is done. The main adhesion is 350 ° C,
It is carried out using a press profile such that it is held under a pressure of 20 kg / cm ² for about 30 minutes. At this time, the polyimide-based adhesive exhibits fluidity and the polyimide-based adhesives are integrated with each other, so that good adhesion between layers can be obtained. At the same time, the bump formed by multi-layer plating of gold and tin melts at its eutectic point of 280 ° C. and is connected to the metal metal of the other party, and good electrical connection between the layers can be obtained after pressing. The temporary fixing adhesive is completely pyrolyzed at 350 ° C. and does not hinder the electrical connection between the layers.

Referring to FIG. 6 (3), finally, the input / output signal pins and the power supply pins 217 are assembled at predetermined positions on the back surface of the base multilayer wiring board to obtain four multilayer wiring boards.

In this embodiment, the method of simultaneously forming four kinds of metal patterns or four layers of metal patterns on one quartz glass substrate is adopted, but the required size of the multilayer wiring board is required. Alternatively, the number of divisions can be changed depending on the number of layers. Further, it is possible to form a multi-layered metal layer formed on the quartz glass substrate, for example, it is also possible to form the connection bump after stacking the power supply and ground pattern and the signal pattern.

[0039]

According to the method of manufacturing a multilayer wiring board of the present invention, four or more layers of polyimide wiring layers are simultaneously formed on one board, and each layer is cut and laminated to form one polyimide multilayer wiring board. By forming the substrate or the first layer of four or more multilayer wiring boards, the number of man-hours can be significantly reduced as compared with the method for manufacturing a multilayer wiring board in which successive lamination is performed. In addition, the manufacturing method in which each polyimide wiring layer is formed by using a large number of auxiliary substrates has an effect that the number of man-hours is significantly reduced and the materials used can be reduced.

[Brief description of drawings]

FIG. 1 (1) to (5) are views showing a first embodiment of the present invention.

2 (1) to (5) are views showing a first embodiment of the present invention.

FIG. 3 is a diagram showing (1) to (3) of a first embodiment of the present invention.

4 (1) to (5) are views showing a second embodiment of the present invention.

5 (1) to (5) are views showing a second embodiment of the present invention.

6A to 6C are views showing a second embodiment of the present invention.

[Explanation of symbols]

 10 Quartz Glass Substrate 11 Polyimide Resin 12 LSI Mounting Pad 13 First Signal Wiring Pattern 14 Power and Ground Pattern 15 Alignment Mark 16 Polyimide Adhesive 17 Resist Mask 18 Resist Patterning Section 19 Excimer Laser 20 Quartz Glass Substrate 21 Polyimide Resin 22 signal wiring pattern 23 alignment mark 24 polyimide adhesive 25 resist mask 26 resist patterning part 27 excimer laser 28 adhesive via hole 29 interlayer connection bump 110 adhesive via hole 111 interlayer connection bump 112 blade 113 after cutting 114 temporary Fixing adhesive 115 Multilayer wiring board containing inner layer 116 Power supply and ground layer 117 Input / output signal pin 118 Second signal wiring pattern 210 Blade 211 after cutting 212 inner-cored multilayer wiring board 213 power and ground layers 214 temporary fixing adhesive 215 power supply and the ground pattern 216 LSI mounting pad 217 input and output signals and power pins 218 second signal wiring pattern

Claims (2)

[Claims] 1. A creating step of creating a pattern of each layer required for one multilayer wiring board on a large-sized board having an area at least four times as large as that of the board, and the large-sized board created by this creating step. A cutting step for cutting each pattern of each layer, and a substrate having a conductor layer inside which serves as a base of the multilayer wiring board, and a board having the bottom layer pattern formed on the board cut in the cutting step is aligned. Then, a temporary delamination step of performing temporary fixing and laminating, and a delamination step of peeling only the substrate, and an alignment, a temporary fixing lamination, and a delamination of the substrate are performed from the substrate having the lower layer pattern formed on the laminated substrate formed in this delamination step. It includes a repeating step of repeating until a predetermined number of layers is obtained, and a step of pressing the laminated substrate formed in this repeating step under a predetermined pressure and temperature to obtain electrical and mechanical connection between the layers. To Method for manufacturing a multilayer wiring board according to symptoms. 2. A step of forming a pattern of the same layer as the lowermost layer necessary for a plurality of multilayer wiring boards on a large-sized board having an area at least four times as large as that of the board, and a step of creating the pattern A cutting step of cutting the large-sized board into each pattern, and a bottom layer pattern of the board cut in the cutting step is formed on a board having a conductor layer inside which serves as a base of a plurality of multilayer wiring boards. Each substrate is aligned and temporarily fixed to be laminated, and then only the substrate is peeled off, and a plurality of laminated substrates formed in this laminating process are aligned with each other. Repeated steps of repeating stop lamination and peeling of the substrate until a predetermined number of layers are reached, and pressing the laminated substrate formed in this repeated step at a predetermined pressure and temperature to electrically and mechanically separate each layer. Connection Method for manufacturing a multilayer wiring board which comprises a step of obtaining.