JPH11274692A - Wiring board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a wiring board, whereby a high-density and high-performance wiring can be formed and the productivity is good enough to suit to the mass production. SOLUTION: The method of manufacturing a wiring board 180 with the formed wiring 130 is such that, using one or a plurality of transferring original plates 101 having wirings composed of conductive layers of specified shape on a support 110, each transferring original plate 101 is pressure-welded to one surface of a base board 160 for a wiring board, and the support 110 is peeled off to transfer the wiring of each transferring original plate 101 to the base board through an adhesive or viscous insulative resin layer 140 of a shape suited to the wiring of each transferring original plate 101. After transferring the wiring of the transferring original plate 101, the insulative resin layer 140 extruding from the wiring region is removed by the laser irradiation using the wiring as a mask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a wiring board, and more particularly to a method for manufacturing a wiring board capable of manufacturing a multilayer wiring board having high-density wiring with high productivity.

[0002]

2. Description of the Related Art With the rapid development of semiconductor manufacturing technology,
The miniaturization of semiconductor packages, the increase in the number of pins, the fine pitch, and the miniaturization of electronic components have rapidly progressed, and the era of so-called high-density mounting has entered. Along with this, printed wiring boards have also shifted from single-sided wiring to double-sided wiring, and further multilayering and thinning have been promoted. At present, a subtractive method and an additive method are mainly used for forming a copper pattern on a printed wiring board. The subtractive method is
After drilling holes in a copper-clad laminate, copper plating is performed on the inside and surface of the holes, and a pattern is formed by photoetching. This subtractive method is technically highly complete and inexpensive, but it is difficult to form a fine pattern due to restrictions such as the thickness of the copper foil. On the other hand, in the additive method, a resist is formed on the part of the laminate containing the catalyst for electroless plating other than the circuit pattern forming part, and a circuit pattern is formed on the exposed part of the laminate by electroless copper plating or the like. How to This additive method is
Although it is possible to form a fine pattern, there are difficulties in terms of cost and reliability.

In the case of a multilayer wiring board, a method of laminating a single-sided or double-sided printed wiring board prepared by the above method or the like together with a prepreg in a semi-cured state in which a glass cloth is impregnated with an epoxy resin or the like is laminated under pressure. Is used. In this case, the prepreg serves as an adhesive for each layer, and a connection between the layers is made by forming a through hole and performing electroless plating or the like inside. In addition, with the progress of high-density mounting, multilayer wiring boards are required to be thinner and lighter, while at the same time high wiring capacity per unit area is required. Ingenuity has been devised. However, the production of a multilayer wiring board using a double-sided printed wiring board manufactured by the above-described subtractive method requires higher density due to the accuracy of drilling for forming holes in the double-sided printed wiring board and the limit of miniaturization. And it was difficult to reduce the production cost.

On the other hand, a multilayer wiring board which is manufactured by sequentially laminating a conductor pattern layer and an insulating layer on a base material has been developed to satisfy the demand for thinner, lighter weight and higher density wiring. Since this multilayer wiring board is manufactured by alternately performing photo-etching of the copper plating layer and patterning of the photosensitive resin, high-definition wiring and interlayer connection at an arbitrary position are possible. However, the production of this multi-layer wiring board is performed a plurality of times by alternately performing copper plating and photo-etching, which complicates the process.Moreover, if a trouble occurs in an intermediate process due to a series process in which one layer is stacked on the board, Reproduction of the product became difficult, which hindered the reduction of manufacturing costs. Further, in the conventional multilayer wiring board, since the connection between the layers is performed by forming via holes, a complicated photolithography step is required, which hinders a reduction in manufacturing cost.

[0005] As a multilayer wiring board which can cope with miniaturization and high-density wiring, does not require a complicated process, and can cope with mass production, the present applicant has already proposed a multi-layer wiring board which is sequentially transferred onto a base substrate. A multilayer wiring board provided with a wiring portion, wherein the wiring portion of each layer is fixed to a base substrate or a lower wiring portion by an insulating resin layer formed below the wiring portion, and a method of manufacturing the multilayer wiring board is also proposed. Has been proposed.
(Japanese Patent Application No. 6-220962) However, in the production of such a multilayer wiring board, the adhesive in the lateral direction of the wiring portion due to the physical pressure applied to the adhesive (insulating resin layer) during pressure transfer. No sufficient consideration has been given to the control of the protrusion of the (insulating resin layer), and after the wiring portion of the transfer master has been transferred to the base substrate side, an adhesive (absolute insulating resin layer) is applied to the wiring portion. In many cases, it was outside the area.
For this reason, in order to further increase the density of the wiring and to improve the degree of freedom of the wiring, the protruding portion is removed as necessary.
The need to control has arisen. That is, the protruding adhesive (insulating resin layer) has a problem that it is difficult to increase the density of wiring and a problem that wiring formation is restricted and the degree of freedom in design is reduced. . For example, when an attempt is made to realize a multilayer transfer wiring, in the high-density wiring part, the protruding portion of the adhesive (insulating resin layer) of the upper wiring covers the upper surface of the lower wiring, and the desired wiring may not be formed. In addition, the presence of such protruding portions may degrade the electrical characteristics, thermodynamic mechanical characteristics, and the like of the wiring board as the target product, and may cause a reduction in the function of the entire product. For example, when wiring is formed on a member where mechanical spring characteristics are important, such as a magnetic head suspension, there is a problem that the influence of the protrusion of the adhesive (insulating resin layer) cannot be ignored. When the adhesive (insulating resin layer) is formed by electrodeposition following plating of the wiring portion, the thickness of the electrodepositing agent at the time of electrodeposition depends on the wiring shape,
Since the difference easily occurs depending on the wiring density, usually, the transfer is performed by controlling the gap during the transfer compression bonding so that the thickness of the insulating layer is uniform in the plane, but the amount of the adhesive protruding depends on the wiring width and the wiring density. The problem is likely to be uneven.

[0006]

As described above, one or a plurality of transfer original plates having a wiring portion formed of a conductive layer having a predetermined shape on a support are used, and one surface of a transfer substrate is provided on one surface of a base substrate for a wiring substrate. By pressing each transfer master and peeling off its support, the wiring portion of each transfer master is bonded to an insulating resin layer having an adhesive or tacky shape along the wiring portion of each transfer master. In a method of manufacturing a wiring board in which wiring is formed by sequentially transferring to the base substrate side via an adhesive layer), the wiring portion of the transfer original is transferred to the base substrate side, and then the wiring portion is formed. Due to the insulating resin layer (adhesive layer) protruding from the region, there is a problem that the degree of freedom of wiring is reduced, and a solution has been required. The present invention responds to this problem by using one or a plurality of transfer masters provided with a wiring portion made of a conductive layer having a predetermined shape on a support, and transferring each transfer master to one surface of a base substrate for a wiring board. By pressing the printing master and peeling off the support, the wiring portion of each transfer master is converted into an insulating resin layer (adhesive) having an adhesive or tacky shape along the wiring portion of each transfer master. In the method of manufacturing a wiring board in which wiring is formed by sequentially transferring the wiring to the base substrate via the layer), the wiring portion of the transfer original plate is transferred to the base substrate, and then protrudes from the wiring region. An object is to provide a method capable of removing an insulating resin layer (adhesive layer). Another object of the present invention is to provide a method capable of removing an insulating resin layer (adhesive layer) in a desired region as required. That is, an object of the present invention is to provide a method of manufacturing a wiring board which can achieve higher density and higher functionality while maintaining good material use efficiency and process simplicity, which are features of the transfer method.

[0007]

According to the present invention, there is provided a method for manufacturing a wiring board, comprising the steps of: using one or a plurality of transfer original plates provided with a wiring portion comprising a conductive layer having a predetermined shape on a support; By pressing each transfer master on one side of the substrate and peeling off its support, the wiring portion of each transfer master has an adhesive or tacky shape along the wiring portion of each transfer master. A method of manufacturing a wiring board in which wiring is formed by sequentially transferring the wiring to a substrate for a wiring board via an insulating resin layer, wherein the wiring portion of the transfer original plate is transferred to the substrate for the wiring board. After that, the insulating resin layer protruding from the wiring portion area,
Using the wiring portion as a mask, the wiring portion is removed by laser irradiation. Further, the method for manufacturing a wiring board of the present invention uses one or a plurality of transfer masters provided with a wiring portion formed of a conductive layer having a predetermined shape on a support, and transfers each transfer master to one surface of a substrate for a wiring board. By pressing the printing master and peeling off the support, the wiring portion of each transfer master is connected via an insulating resin layer having an adhesive or tacky shape along the wiring portion of each transfer master. A method of manufacturing a wiring board by sequentially transferring to a substrate side for a wiring board to form wiring, wherein the wiring portion of the transfer original is transferred to the substrate side for the wiring board, and At least one region of the protruding insulating resin layer is selectively removed by laser irradiation. And
In the above, the wiring portion made of the conductive layer of the transfer master is formed by plating. Further, in the above, the insulating resin layer having an adhesive or tacky shape along the wiring portion of the transfer master is formed by any one of a dispenser coating method (also referred to as a dispensing method), a printing method, and an electrodeposition method. It should be formed on the wiring part of each transfer master by the method, or formed on the base substrate side by any one of the dispenser coating method, printing method, etching method and photolithography method It is characterized by the following.

[0008] Here, the term "substrate for a wiring board" includes not only a base substrate on which no wiring is formed but also a wiring board on which wiring is formed. The wiring substrate on which the wiring is formed may be a wiring substrate in which a metal thin film is formed on one surface of a base substrate by sticking or the like, and this is etched to form a wiring portion.

The wiring board of the present invention is characterized by being manufactured by the method of manufacturing a wiring board of the present invention, and is a wiring board which can cope with high density.

[0010]

According to the method for manufacturing a wiring board of the present invention, by adopting such a structure, one or a plurality of transfer original plates having a wiring portion formed of a conductive layer having a predetermined shape on a support are used. Each transfer master is crimped on one side of the wiring board substrate,
And, by peeling off the support, the wiring portion of each transfer master is formed through an adhesive or tacky insulating resin layer (adhesive layer) having a shape along the wiring portion of each transfer master. In the method of manufacturing a wiring board in which the wiring is sequentially transferred to the wiring board side to form wiring, the wiring portion of the transfer original is transferred to the wiring board substrate side and then protrudes from the wiring area. It is possible to provide a method capable of removing the insulating resin layer (adhesive layer). This enables further high-density wiring and high-degree-of-freedom wiring while maintaining the material use efficiency and process simplicity, which are the characteristics of the transfer method, and achieves electrical, thermal, and mechanical stability. It enables the production of wiring boards. Specifically, after the wiring portion of the transfer master is transferred to the substrate side for the wiring board, the insulating resin layer protruding from the wiring portion region is removed by laser irradiation using the wiring portion as a mask. Accordingly, there is no side etching of the insulating resin layer (adhesive layer), the insulating resin layer can be removed in a high aspect shape, and high-density wiring can be handled. Further, after the transfer of the wiring portion of the transfer master to the substrate side for the wiring substrate, at least one region of the insulating resin layer protruding from the wiring portion region, by selectively removing by laser irradiation, The degree of freedom in wiring can be increased. Further, since the wiring portion made of the conductive layer of the transfer master is formed by plating, the wiring can be miniaturized, the wiring portion is formed by plating, and the insulating resin layer is further formed by electrodeposition. By forming it on the wiring portion, workability can be improved.

The wiring board according to the present invention has such a structure, thereby enabling high-density wiring and obtaining an electrically, thermally and mechanically stable wiring board.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing steps of a first example of an embodiment of a method of manufacturing a wiring board according to the present invention.
FIG. 2 is a view showing a state before and after laser irradiation. FIG. 3 is a cross-sectional view showing a characteristic portion of a process of a second example of the embodiment. FIG. 4 (a) is a perspective view showing a state before laser irradiation. FIG. 4B is a perspective view in which upper and lower wirings are connected by wires after laser irradiation. FIGS. 3 and 4 show a part of the wiring board for easy understanding of the description, and FIG.
1 shows a cross section taken along line 1-A2. 1 to 4
Medium 101 is a transfer master, 110 is a support, 120 resist, 125 is an opening, 130, 131, 132, 13
Reference numerals 3 and 134 denote wirings (consisting of conductive layers), 140 denotes an insulating resin layer, 145 denotes openings, 160 and 161 denote base substrates, 170 denotes a laser, 180 denotes a wiring substrate, and 190 denotes bonding wires.

First, a first example of an embodiment of a method of manufacturing a wiring board according to the present invention will be described with reference to FIGS. In the first example, one or a plurality of transfer masters provided with a wiring portion formed of a conductive layer having a predetermined shape on a support are used, and each transfer master is pressed on one surface of a base substrate for a wiring board. And, by peeling off the support, the wiring portion of each transfer master is placed on the base substrate side through an adhesive or tacky insulating resin layer having a shape along the wiring portion of each transfer master. In the method of manufacturing a wiring board in which wiring is formed by transferring sequentially,
After transfer forming the wiring part of the transfer master to the base substrate side,
The insulating resin layer protruding from the wiring portion region is removed by laser irradiation using the wiring portion as a mask. Hereinafter, a first example will be described with reference to FIG. First,
A plating-resistant resist 120 is provided on one surface of a support 110 having a conductive surface in a shape corresponding to a wiring portion to be formed. (FIG. 1 (a)) As the support 110 for the transfer original plate, a stainless steel material (S
US304) is commonly used, but is not limited thereto. It is preferable that the surface is conductive, can be subjected to plating treatment for forming a wiring portion, and has good plating releasability. Next, a wiring portion 130 made of a conductive layer is formed by plating in a region of the support 110 exposed from the opening 125 of the resist 120. (FIG. 1B) The resist 120 preferably has plating resistance and good processability. The wiring portion 130 made of a conductive layer is preferably plated copper, but if necessary, Ni (nickel), Au (gold), Cr (chromium), Ag (silver),
Pt (platinum) may be used. In the case of plated copper, the thickness is
1 μm or more is required depending on the width of the wiring. Then
An insulating resin layer 14 is formed on the plated wiring portion 130.
0 is formed to prepare the transfer master plate 101. (Figure 1
(C) The formation of the insulating resin layer 130 is not limited to the electrodeposition method.
Other forming methods include a dispenser coating method and a printing method. As the insulating resin layer 130, epoxy resin, polyimide resin, polyamide resin, melamine resin, which are generally used in various wiring circuits,
An acrylic resin, a benzimidazole resin and the like can be given. Thermosetting resins are preferred, but not limited thereto. Examples of the thermosetting resin include epoxy, phenol, melamine polyester, and silicone. Each,
If necessary, a curing agent, a modifier, a filler and the like are appropriately selected and used. Alternatively, the insulating resin layer 140 may not be formed on the wiring portion 130 but may be selectively formed only on the wiring portion region to be transferred of the base substrate 160 by a dispenser coating method or a printing method. Plating-formed wiring part 130
In addition, when the insulating resin layer 140 is further provided by electrodeposition, the formation of the wiring portion 130 and the formation of the insulating resin layer 140 can be performed continuously, thereby improving mass productivity. Become. In this case, the insulating resin layer 140
It has an electrodeposition property, and it may be any one that shows tackiness at normal temperature or when heated, for example, as a polymer to be used,
Anionic or cationic synthetic polymer resins having tackiness can be mentioned.

As the anionic synthetic polymer resin, an acrylic resin, a polyester resin, a maleated oil resin, a polybutadiene resin, an epoxy resin, a polyamide resin, a polyimide resin, etc., alone or in any combination of these resins Can be used as a mixture. Further, the above-mentioned anionic synthetic resin may be used in combination with a crosslinkable resin such as a melamine resin, a phenol resin and a urethane resin.
In addition, as the cationic synthetic polymer resin, an acrylic resin, an epoxy resin, a urethane resin, a polybutadiene resin, a polyamide resin, a polyimide resin, or the like can be used alone or as a mixture of any combination thereof. Further, the above cationic synthetic polymer resin and a crosslinkable resin such as a polyester resin and a urethane resin may be used in combination. Further, in order to impart tackiness to the polymer resin, a tackifying resin such as a rosin-based resin, a terpene-based resin, or a petroleum resin can be added as necessary. The polymer resin is subjected to an electrodeposition method in a state of being neutralized by an alkaline or acidic substance and solubilized in water, or in a water-dispersed state. That is, the anionic synthetic polymer resin is neutralized with amines such as trimethylamine, diethylamine, dimethylethanolamine, and diisopropanolamine, and with an inorganic alkali such as ammonia and potassium hydroxide. The cationic synthetic polymer resin is neutralized with an acid such as acetic acid, formic acid, propionic acid, and lactic acid. Then, the polymer resin solubilized in the neutralized water is used in a state of being diluted with water as a water dispersion type or a solution type.

Next, the insulating resin layer 140 side of the transfer master 101 is pressed against the base substrate 160 for a wiring board (FIG. 1D), and the support 110 of the transfer master 101 is pressed.
Is peeled off to form the wiring portion 1 on the base substrate 160 side.
30 is transferred and formed via the insulating resin layer 140. (FIG. 1E) As the base substrate 160, a substrate having a thermal expansion coefficient close to the thermal expansion coefficient of the wiring portion 130 is suitable. It is desirable to have one. A metal substrate such as stainless steel (SUS304) is preferred, but not particularly limited thereto. As the pressure bonding means for transfer, there are roll press, flat press, vacuum adhesion, and the like. However, it is necessary to keep the film thickness of the insulating resin layer 140 constant, and a uniform gap is maintained during the pressure bonding. The gap can be adjusted by a method of using beads (fine particles) having a uniform diameter or a plate having a uniform thickness as a spacer, a method of pressing the entire surface to a uniform pressure such as air pressure, and a method of self-alignment. If necessary, energy such as heating, UV, EB or the like is added in a pressure-bonded state or a state after transfer to improve the adhesion. Note that the spread of the insulating resin layer 140 in the lateral direction due to the compression cannot be basically prevented, and the spread width also depends on the initial film thickness of the insulating resin layer 140, the heating conditions during the compression, the shape of the wiring portion, and the like. Because of a large change, it is difficult to control the spread of the insulating resin layer 140 in the lateral direction.

Thereafter, laser irradiation is performed from the transfer-formed wiring portion 130 side (FIG. 1F), and the insulating resin layer 140 protruding from the wiring portion 130 is removed.
0 is formed. (FIG. 1 (g)) The removal of the insulating resin layer 140 by laser irradiation includes ablation treatment using ultraviolet light, heat melting removal treatment using near infrared light to far infrared light, and the like. YAG laser, CO ₂
A laser can be applied, but is not limited to this. Also,
Laser irradiation conditions need to be selected depending on the physical properties of the object to be transferred and the insulating resin layer 140. For example, the removal of the insulating resin layer 140 in the case of using the polyimide layer of 10μm thick as the insulating resin layer 140, it is necessary to 10J / cm ² ~500J / cm ² by a KrF excimer laser.
The removal was performed with an energy density of one pulse of 0.1 J / cm.
It is preferable to carry out at 50 to 200 pulses at ^{2 to 5} J / cm ² . By performing the laser irradiation, the insulating resin layer 140 protruding outside the region of the wiring portion 130 as shown in FIG. 2A is removed as shown in FIG. 2B.

Although the case where only one transfer original plate (101) is used has been described here, the present invention can be applied to a case where a plurality of transfer original plates are used and the wiring portion has a plurality of layers.
When a plurality of transfer masters are used, when the wiring portion of each transfer master is transferred to the base substrate, the insulating resin layer protruding from the transferred wiring portion region is removed by laser processing. If multiple transfer masters are used, if necessary, when the wiring section of each transfer master is transferred to the base substrate, laser processing is not performed and the wiring section of the last transfer master is used. The laser processing may be performed only after the image is transferred. In place of the base substrate 160, a metal thin film is formed on the base substrate 160 by bonding or the like, and a wiring portion is formed by etching the metal thin film. You may.

Next, a second example will be described with reference to FIGS. The second example is an example in which only a predetermined region of an insulating resin layer is removed by laser irradiation. As shown in FIG. 3A, when laser irradiation is performed only on a predetermined region on the wiring portion 131, as shown in FIG. Only the layer is removed. As a result, as shown in FIG.
Electrical connection between the wiring 131 exposed from 45 and the wiring 133 formed thereon becomes possible, and the degree of freedom of wiring is increased. There are various methods for irradiating a desired area, such as a beam scan method, a mask projection method, and a contact mask method. In FIG. 3, laser irradiation is performed only on a predetermined region on the wiring 131, but the irradiation region is not limited to this. For example, a predetermined area of the insulating resin layer 140 between the wirings is irradiated with a laser by using the base substrate 161 as a conductive metal plate, thereby exposing a part of the base substrate surface and bonding a certain wiring to the base substrate side by wire bonding. To form a ground wiring. Here, the description has been given of the wiring board having the two-layer wiring portion. However, the removal of the predetermined region of the insulating layer by laser irradiation can be similarly applied to the wiring board having three or more layers. Also, base substrate 1
Instead of 61, a substrate in which a metal thin film is formed on the base substrate 161 by bonding or the like, and a wiring portion is formed by etching the metal thin film may be used, and the wiring portion may be further transferred and formed on the wiring portion. .

[0019]

(Example 1) In Example 1, a wiring board having a one-layer wiring portion was manufactured by using a first plate for transfer (corresponding to 101 in FIG. 1C) by the manufacturing method shown in FIG. (Figure 1
(Corresponding to the wiring board 180 of FIG. 7G).
This will be described with reference to FIG. First, the transfer master (1
01) was produced as follows. Support 11
A stainless steel plate (SUS304) having a polished surface and having a thickness of 0.20 mm was prepared as 0, and a commercially available photoresist (manufactured by Tokyo Ohka Kogyo Co., Ltd.,
OMR-85) is applied to a thickness of about 2 μm by a spin coating method, dried in an oven at 85 ° C. for 30 minutes, and then exposed using a predetermined photomask corresponding to the shape of the wiring portion to be formed. Contact exposure was performed using P-202-G (manufactured by Dainippon Screen Mfg. Co., Ltd.), and then processing such as development, washing with water, and drying were performed to form a resist 120 layer in a predetermined shape. Next, the support 110 on which the resist is formed and the oxygen-free copper electrode are opposed to each other, immersed in a copper pyrophosphate plating bath having the following composition (pH 8) at a liquid temperature of 55 ° C., and a current density of 10 A / dm ² . A current was applied for a minute to form a conductive layer made of a copper plating film having a thickness of about 4 μm on the exposed portion of the support 110 not covered with the resist, and this was used as wiring. (FIG. 1 (b)) (Composition of copper pyrophosphate plating bath) Copper pyrophosphate 94 g / liter Potassium pyrophosphate 340 g / liter ammonia water 3 g / liter Further, support 1 on which wiring 130 formed of a conductive layer was formed
10 and a platinum electrode are opposed to each other, immersed in an electrodeposition solution prepared as described below for forming an insulating resin layer, and a support 110 is connected to an anode of a DC power supply, and a platinum electrode is connected to a cathode. , 150 V for 150 seconds, and dried on a hot plate at 80 ° C. for 5 minutes to form a 20 μm thick insulating resin layer (also referred to as an adhesive layer) on the conductive layer wiring 130. ) 140 was formed. As a result, a transfer master plate 101 having a resist as shown in FIG. 1C was obtained.

The preparation of the polyimide varnish and the adjustment of the electrodeposition solution are as follows. <Production of Polyimide Varnish> A stainless steel squirrel stirrer, a nitrogen inlet tube, and a reflux condenser equipped with a cooling tube with a ball on a trap with a stopcock are attached to an 11-volume three-neck separable flask. While flowing in a nitrogen stream, a separable flask was placed in a silicone bath equipped with a temperature controller and heated. The reaction temperature is indicated by bath temperature. 3,
32.22 g (0.1 mol) of 4,3 ′, 4′-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), bis (4- (3-aminophenoxy) phenyl)
21.63 g (0.05 mol) of sulfone (m-BAPS), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, NMP (N methyl 2
Abbreviation of pyrrolidone> 200 g, toluene 30 g,
Stir at room temperature for 30 minutes in a silicon bath while passing nitrogen (2
00 rpm), and then the temperature was raised to 180 ° C. for 1 hour for 20 hours.
The reaction is carried out while stirring at 0 rpm. After removing 15 ml of toluene-water distillate, air-cooled and BTDA 16.11 g
(0.05 mol), 3,5 diaminobenzoic acid (hereinafter referred to as DA
15.216 g (0.1 mol), NMP1
After adding 19 g and 30 g of toluene and stirring at room temperature for 30 minutes (200 rpm), the temperature is raised, and the mixture is heated and stirred at 180 ° C. to remove 15 ml of a toluene-water distillate. Then, while removing the toluene-water distillate outside the system, 180
The reaction was completed by heating and stirring at 3 ° C. for 3 hours. A 20% polyimide varnish was obtained. The acid equivalent (the amount of polymer per 1 C00H is 1554) is 70. <Preparation of electrodeposition liquid> 100 g of 20% concentration polyimide varnish
3SN (NMP: tetrahydrothiophen-1, 1-
Dioxide = 1: 3 (weight) mixed solution) 150 g, benzyl alcohol 75 g, methylmorpholine 5.0 g
(Neutralization rate: 200%) and 30 g of water are stirred to prepare an aqueous electrodeposition solution. The obtained aqueous electrodeposition solution was prepared using polyimide 7.4.
%, PH 7.8, is a dark reddish brown transparent liquid.

The transfer master plate 10 thus obtained is obtained.
1 were successively used, and the wiring portion 130 was pressed against the base substrate 160 with the wiring portion 130 facing the base substrate 160 for manufacturing a wiring substrate.
(FIG. 1D) As the base substrate 180, a stainless steel plate (SUS304) having a thickness of 30 μm was used, and the pressure was 10 kg / cm ² ,
It crimped at 0 degreeC for 1 minute. Thereafter, the base substrate 160
The support 110 of the transfer substrate 101 was peeled off from the side, and a wiring portion was transferred and formed on one surface of the base substrate 160 via the insulating resin layer 140. (FIG. 1E) Next, the base substrate 160 on which the wiring portion was formed was subjected to a heat treatment in a nitrogen atmosphere at 300 ° C. for 30 minutes to form an insulating resin layer. The thickness of the insulating resin layer below the wiring portion 130 was 5 μm, and was uniform over almost the entire surface.
There were variations depending on the shape and location of each wiring.

Next, in order to adjust the width of the insulating resin layer 140 to the shape of the wiring portion, the irradiation condition of 100 pulses at an energy density of 0.5 j / cm ² per pulse is applied over the entire wiring portion. Excimer laser irradiation was performed from above. (FIG. 1F) As a result, the insulating resin layer 140 protruding from the region of the wiring portion 130 could be removed without damaging the wiring portion 130 and the base substrate 180. (Figure 1
(G)) In this way, the insulating resin layer 140 could be formed with a uniform thickness only immediately below the wiring portion 130.

(Embodiment 2) In Embodiment 2, a transfer master was used.
Using the printing plates (referred to as 102 and 103), the wiring portions of the respective transfer masters are sequentially transferred onto a base substrate for forming a wiring substrate, and a wiring substrate having two-layer wiring portions is manufactured. According to the method shown, only a predetermined region of the insulating resin layer is removed by laser irradiation. A description will be given based on FIGS. The transfer original plate 2 (102, 103) was prepared as follows. In the same manner as in Example 1, a wiring portion was formed on the transfer original support 110 (FIG. 1B).
Later, a thermoplastic polyimide (UPA Kosan Co., Ltd., UPA
-N111C) is applied on the wiring section 130 by a dispenser application method, and dried at 130 ° C. for 15 ′ to form an insulating resin layer (equivalent to 140) having a thickness of 40 μm, which is transferred. The original version was used. Next, a 2 mm-thick aluminum substrate for heat dissipation is used as a base substrate for a wiring board, and the transfer original plates 2 (102, 103) thus obtained are sequentially superimposed on the base substrate and flattened. The temperature was raised from room temperature to 250 ° C. over 20 minutes at a press pressure of 4 kg / cm ² , held for 1 hour, then cooled to about 50 ° C. by natural cooling, and the transfer master and the base substrate were peeled off. The wiring portion of the transfer master was transferred and formed on the substrate side to obtain a wiring board having two-layered wiring portions. Both the insulating resin layer along the wiring portion under the first wiring portion and the insulating resin layer along the wiring portion under the second wiring portion have a protrusion (thickness of about 15 μm) due to pressure bonding during transfer. And it was uneven at some places. Next, irradiation was performed using the fourth harmonic of a YAG laser at an energy density of 0.7 J / cm ² per pulse under irradiation conditions of 400 pulses (FIG. 3).
(A)), a predetermined region of the insulating resin layer was removed.
(FIG. 3B) Under the same energy conditions, 100
It was possible to selectively irradiate the irradiation area of μm □, and to obtain the required shape at high speed. Thereafter, wire bonding connection between the wiring portion exposed by removing the insulating resin layer by the laser and the uppermost wiring portion was performed, and the upper and lower wirings were electrically connected. (FIG. 4 (b))

[0024]

As described in detail above, according to the present invention,
Using one or more transfer masters provided with a wiring portion made of a conductive layer having a predetermined shape on a support, pressing each transfer master on one surface of a base substrate for a wiring board, and pressing the support. By peeling, the wiring portion of each transfer master is sequentially transferred to the base substrate side via an adhesive or tacky insulating resin layer having a shape along the wiring portion of each transfer master, and wiring is performed. In the method for manufacturing a wiring substrate formed with the above, after the wiring portion of the transfer original is transferred to the base substrate side by using laser irradiation, the insulating resin layer (adhesive layer) protruding from the wiring portion region is removed. It is possible to provide a method that can be removed. As a result, it has become possible to provide a method of manufacturing a wiring board capable of achieving higher density and higher functionality while maintaining good material use efficiency and process simplicity, which are features of the transfer method.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a process in a first example of an embodiment of a method of manufacturing a wiring board according to the present invention;

FIG. 2 is a perspective view showing a state before and after laser irradiation in a first example of the embodiment of the method of manufacturing a wiring board according to the present invention;

FIG. 3 is a schematic cross-sectional view showing a characteristic portion of a process in a second example of the embodiment of the method of manufacturing a wiring board according to the present invention;

FIG. 4A is a perspective view showing a state before laser irradiation, and FIG. 4B is a perspective view showing a state in which an opening is formed by laser irradiation and wire bonding is performed.

[Explanation of symbols]

Reference Signs List 101 Transfer master 110 Support 120 Resist 125 Opening 130 to 134 Wiring (consisting of conductive layer) 140 Insulating resin layer 145 Opening 160 Base substrate 170 Laser 180 Wiring substrate 190 Bonding wire

Claims (5)

[Claims] 1. A transfer master having a conductive portion having a predetermined shape provided on a support is provided with one or a plurality of transfer masters, and each transfer master is pressed on one surface of a substrate for a wiring board, and By peeling off the support, the wiring portion of each transfer master is separated from the substrate side for the wiring board through an adhesive or tacky insulating resin layer having a shape along the wiring portion of each transfer master. Is a method for manufacturing a wiring board, in which the insulating resin layer protruding from the wiring part area is formed by transferring the wiring part of the transfer original plate to the wiring board substrate side. And removing the wiring portion by laser irradiation using the wiring portion as a mask. 2. The method according to claim 1, wherein one or a plurality of transfer masters provided with a wiring portion formed of a conductive layer having a predetermined shape on a support are used, and each transfer master is pressed on one surface of a substrate for a wiring board. By peeling off the support, the wiring portion of each transfer master is separated from the substrate side for the wiring board through an adhesive or tacky insulating resin layer having a shape along the wiring portion of each transfer master. A method for manufacturing a wiring board, wherein the wiring portion of a transfer original is transferred to a substrate side for a wiring board, and then the insulating resin layer protrudes from the wiring portion region. Characterized in that at least one region of the wiring substrate is selectively removed by laser irradiation. 3. The method for manufacturing a wiring board according to claim 1, wherein the wiring portion made of the conductive layer of the transfer original plate is formed by plating. 4. The method according to claim 1, wherein the insulating resin layer having an adhesive or tacky shape along the wiring portion of the transfer master is any one of a dispenser coating method, a printing method, and an electrodeposition method. It should be formed on the wiring part of each transfer master by the method, or formed on the base substrate side by any one of the dispenser coating method, printing method, etching method and photolithography method A method for manufacturing a wiring board, comprising: 5. A wiring board manufactured by the method for manufacturing a wiring board according to claim 1.