JPH09172257A - Manufacture of multilayer printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer printed-wiring board, which laminates boards to form each gold film on conductor circuits in an electronic component housing hole, can prevent the generation of an abnormal precipitation of plated metal films at the time when an electrolytic plating is applied to through holes, thus decreasing the occurrence of an improper short circuit. SOLUTION: A multilayer printed-wiring board is manufactured in such a way that the processes ranging from the following process (1) to the process (5) are provided. (1) Trough holes 3 are formed in a multilayer board 15 formed with the through holes 3 in such a way that they are exposed through the multilayer board 15 to cover an electronic component housing hole 2 with film bodies, such as dry film bodies 8. (2) plated catalysts 6 are respectively given to the holes 3 using a plating pretreating liquid, then, a plating is applied to the holes 3 to form metal films 9. (3) Metal film pieces 11 precipitated on the film bodies 8 are removed. (4) The remaining film bodies 8 are removed. (5) Gold films are respectively formed on conductor circuits 4 in the hole 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pin grid array (PG) for mounting electronic parts such as semiconductor chips.
A), a method of manufacturing a multilayer printed wiring board used for a device for mounting electronic components such as a ball grid array (BGA) and a chip carrier.

[0002]

2. Description of the Related Art In recent years, electronic parts such as semiconductor chips and chip parts have been reduced in size and weight. Along with this, the density of multilayer printed wiring boards for mounting electronic components has been increasing. Conventionally, ceramic substrates were used as substrates on which semiconductor chips were mounted.However, ceramic substrates were expensive, so organic substrates that could be densified and realized at low prices were used. Multilayer printed wiring boards have been used. In addition, the substrate on which the semiconductor chip is mounted is provided with a storage hole for storing the semiconductor chip and a conductor circuit having a gold film on the surface for bonding or connecting (bonding) with the mounted semiconductor chip. General.

A conventional method for manufacturing a multilayer printed wiring board for mounting a semiconductor chip is, for example, Japanese Patent Laid-Open No. 5 (1999) -53187.
There is one shown in -343849. This method
As shown in FIG. 5, a plurality of organic substrates 1 each having a conductor circuit 4 formed thereon are provided with an adhesive material 7 while forming a concave electronic component housing hole 2 in which the conductor circuit is exposed at a predetermined position. Laminating [Fig. 5 (a)] and then adhering (integrating)
After forming the multilayer board 15, the through holes 3 are formed [FIG.
(B)] Next, the surface of the multilayer board 15 and the electronic component storage hole 2
And plating catalyst 6 is applied to the through holes 3 [Fig.
(C)] Next, the dry film 8 is adhered to the entire surface of the multilayer plate 15, the dry film 8 is exposed, and the dry film 8 in the portion facing the through hole 3 is developed and removed, and the other portions are dry film. 8 is left [Fig. 5
(D)] Next, plating is applied to the through holes 3 to form a metal film 9, and then the dry film 8 is removed.
Next, the plating catalyst 6 remaining on the surface of the multilayer plate 15 and the electronic component housing hole 2 is removed by soft etching [FIG.
(E)] A method for producing a multilayer printed wiring board.

However, in the above method, the dry film 8 is removed in the step of FIG.
Although the plating catalyst 6 remaining on the surface and the like is removed by soft etching, it is difficult to completely remove it. Therefore, the plating catalyst 6 often remains, and when the plating catalyst 6 remains, in order to form a gold film on the conductor circuit 4 exposed in the electronic component housing hole 2,
When electrolytic nickel plating or electrolytic gold plating is applied in a later process, abnormal deposition of plated metal occurs between the conductor circuits 4,
There is a problem that short circuits frequently occur.

The through hole 3 in the above method is also used.
The step of plating the inside to form the metal film 9 is usually high temperature (liquid temperature is about 55 to 90 ° C.), strong alkaline (pH
Since a thin film (about 1 μm) of a copper film is formed using an electroless copper plating solution of about 11 to 12), a copper film having a desired film thickness is generally formed by electrolytic plating.
The high temperature strong alkaline electroless copper plating solution damages the dry film 8 covering the electronic component housing hole 2 and the electroless copper plating solution or the electrolytic plating solution penetrates into the electronic component housing hole 2. There is also a problem that the inside of the hole 2 for storing the electronic component cannot be protected by the dry film 8.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a plurality of organic substrates on which conductor circuits are formed with a conductor circuit. Laminating and bonding while forming the exposed electronic component storage hole at a predetermined position, then forming a through hole in a place other than the electronic component storage hole, plating this through hole, and then placing in the electronic component storage hole A method for manufacturing a multilayer printed wiring board, wherein electrolytic plating is performed on an exposed conductor circuit, and finally a gold film is formed on the conductor circuit in the electronic component housing hole. An object of the present invention is to provide a manufacturing method capable of preventing abnormal deposition of plated metal when electrolytic plating is applied to the substrate, and thus reducing the occurrence of short circuit defects.

[0007]

According to a first aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, wherein a plurality of organic substrates having conductor circuits are formed on an electronic component storage hole in which the conductor circuits are exposed. Laminate and bond while forming at a predetermined position, then form through holes in places other than electronic component storage holes,
A method for manufacturing a multilayer printed wiring board, wherein the through holes are plated to manufacture a multilayer printed wiring board, comprising the following steps (1) to (5): . (1) The step of covering the electronic component storage hole with a film body so as to expose the through hole in the multilayer plate having the through hole formed, (2) applying a plating catalyst to the through hole using a plating pretreatment liquid. , And then plating the through holes with a plating solution to form a metal film,
(3) A step of removing the metal film pieces deposited on the film body by the plating of the step (2), (4) a step of removing the remaining film body, and (5) an exposure in the electronic component storage hole. The process of forming a gold film on a conductor circuit.

According to a second aspect of the present invention, there is provided a method for producing a multilayer printed wiring board according to the first aspect, wherein the film body is a dry film having photosensitivity and the electronic component storage in the step (1) is carried out. The method of covering the holes with a film body, by sticking a dry film on both surfaces of the multilayer board and covering the electronic component storage holes and the through holes with a dry film, exposing and developing this dry film,
The method is characterized in that the dry film in the portion facing the through hole is removed and the dry film in the portion covering the electronic component storage hole is left.

A method for manufacturing a multilayer printed wiring board according to a third aspect of the present invention is the method for manufacturing a multilayer printed wiring board according to the first or second aspect, wherein the film body is a photosensitive alkali peelable dry film. The pretreatment liquid for plating in the step 2) has a pH of 10 or less and a liquid temperature of 80 ° C. or less, or a pH in the range of pH 10 or more and a pH of 12.5 or less and a liquid temperature of 40 ° C. or less. The plating solution is a solution having a pH of 10 or lower and a temperature of 80 ° C. or lower, or a pH in the range of pH 10 or higher and a pH of 12.5 or lower and a temperature of 40 ° C. or lower. It is characterized by

A method for manufacturing a multilayer printed wiring board according to a fourth aspect of the present invention is the method for manufacturing a multilayer printed wiring board according to any one of the first to third aspects, after the step (3) of removing the metal film piece. Before the step of removing the film body of (4), the through hole is again plated by electrolytic plating to increase the film thickness of the metal film in the through hole.

A method for manufacturing a multilayer printed wiring board according to a fifth aspect of the present invention is the method for manufacturing a multilayer printed wiring board according to any one of the first to fourth aspects, wherein both surfaces of the multilayer board which has undergone the step (2) are finished. A portion of the secondary dry film that is pasted, then exposed and developed to leave the portion of the secondary dry film that faces the through-hole, and that is located on the film body that covers the electronic component storage hole. The second dry film is removed, and then the metal film pieces deposited on the film body are removed by etching in the step (3).

A method for manufacturing a multilayer printed wiring board according to a sixth aspect of the present invention is the method for manufacturing a multilayer printed wiring board according to any one of the first to fifth aspects, in which both surfaces of the multilayer board after the step (2) are finished. A secondary dry film is attached, and then exposed and developed, and only the part facing the through hole is exposed.
The next dry film is allowed to remain, and then, in the step (3), metal film pieces deposited on the film body are removed by etching.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

Step (1): As shown in FIG. 1A, a plurality of organic substrates 1 having conductor circuits 4 formed therein are provided with electronic component storage holes 2 in which conductor circuits 4 are exposed at predetermined positions. Laminate while forming. The organic substrate 1 forming the bottom surface 5 of the electronic component storage hole 2 is shown in FIG.
In (a), one having no opening is used, but an opening is formed in the organic substrate 1 forming the bottom surface 5,
An opening may be provided on the bottom surface 5 of the electronic component storage hole 2 when stacked. As the organic substrate 1 forming the conductor circuit 4, an epoxy resin glass cloth base material copper clad laminate, a polyimide resin glass cloth base material copper clad laminate, or the like is used.
An epoxy resin film, a polyimide resin film, an epoxy resin glass cloth base material prepreg, a polyimide resin glass cloth base material prepreg, or the like is used as the adhesive material 7 for laminating the organic base materials 1 and adhering them. Further, in the present invention, a plurality of organic substrates 1 on which the conductor circuits 4 are formed are laminated and adhered, but an organic substrate having no conductor circuits 4 may be laminated simultaneously if necessary. When a plurality of organic substrates 1 are stacked, adhered and integrated, a metal foil such as a copper foil having no conductor circuit is provided on the outer surface of the outermost organic substrate. The circuit may be formed on this metal foil at an appropriate stage after a plurality of organic substrates 1 are laminated, adhered and integrated.

Next, as shown in FIG. 1B, through holes 3 are formed in the multilayer board 15 which is laminated, adhered, and integrated into a part other than the electronic component housing hole 2. The method of forming the through hole 3 is not particularly limited, and can be formed by, for example, drilling. Next, as shown in FIG. 1C, the electronic component housing hole 2 is covered with a film body such as a dry film 8 so that the through hole 3 is exposed with respect to the multilayer plate 15 in which the through hole 3 is formed. It is preferable to use a dry film 8 having photosensitivity as the film body of the present invention, because the through hole 3 can be exposed and the electronic component storage hole 2 can be easily covered with the film body. However, in the present invention, a general film such as a polypropylene film may be used as the film body. When using a general film as a film body, for example, a film body previously formed into a predetermined shape,
The through hole 3 may be exposed and the electronic component storage hole 2 may be covered with an adhesive or the like so as to be attached to the multilayer board 15. When a dry film having photosensitivity is used as the film body, as shown in FIG. 1C, the dry film 8 is exposed and developed to remove the dry film 8 in the portion facing the through hole 3. Then, the dry film 8 in the portion covering the electronic component storage hole 2 is left. As a result, the electronic component storage hole 2 is sealed by the dry film 8 and is protected from the outside. In this case, the dry film 8 in the portion facing the through hole 3 may be removed, and the dry film 8 in the portion covering the electronic component storage hole 2 may remain. Regarding the dry film 8 in the other portions, You may choose to remove it or keep it as needed. Further, when the dry film 8 is an alkali peeling type, the development can be performed using a weakly alkaline solution such as a sodium carbonate solution. The "portion facing the through hole 3" in the present invention includes not only the portion that exactly corresponds to the through hole 3 but also the periphery of the through hole 3 that is a portion that forms a so-called land.

Step (2): As shown in FIG. 1 (d), a plating catalyst 6 such as palladium is applied to the through holes 3 by using a plating pretreatment, and then, as shown in FIG. 2 (e). The through hole 3 is plated with a plating solution to form a metal film 9 of copper or the like.
In the case of using the alkali peelable dry film 8 having photosensitivity as the film body, the plating pretreatment liquid in the step (2) has a pH of 10 or less and 80 ° C.
PH below 12.5 or below pH 10
A liquid having a pH within the following range and a liquid temperature of 40 ° C. or lower, and the plating liquid having a pH of 10 or lower and a liquid temperature of 80 ° C. or lower, or a pH range of more than pH 10 and pH 12.5 or less. With a liquid having a pH of 40 ° C. and a liquid temperature of 40 ° C. or lower, the dry film 8 is not damaged in the plating pretreatment and the plating process if an appropriate treatment time is selected.
The electronic component housing hole 2 is sealed by the dry film 8 and can be kept protected from the outside. Therefore, the through hole 3 is plated with metal without adding a plating catalyst to the electronic component housing hole 2. It is desirable because the film 9 can be formed. On the other hand, when using a general film such as a polypropylene film or a solvent-releasing dry film as the film body, the plating pretreatment liquid and the plating liquid are used so that the film body is not damaged in the plating pretreatment and plating steps. By selecting the conditions, the electronic component storage hole 2 is sealed by the film body,
The state of being protected from the outside can be maintained.

Step (3) In the above step (2), the plating catalyst 6 such as palladium is applied to the through holes 3 of the multilayer plate 15. At this time, the plating catalyst 6 is used as the electronic component storage hole 2 It is unavoidable that they remain on the surface of the film body such as the dry film 8 covering the. Therefore, in the next plating step, unnecessary metal film pieces 11 are partially deposited on the film body such as the dry film 8 as shown in FIG. 2E, and the dry film 8 etc. are partially deposited in the subsequent step. There is a problem that it is difficult to remove the film body, and a problem that the desired conductor circuit cannot be formed because the unnecessary metal film piece 11 remains. Therefore, in the step (3), the unnecessary metal film pieces 11 deposited on the film body such as the dry film 8 are removed to remove the remaining film body such as the dry film 8 as shown in FIG. 2 (f). Expose the surface. The metal film pieces 11 referred to here include not only those partially deposited on the film body but also those deposited as a film on the entire surface of the film body. By performing the step (3), it is possible to solve the problem that it is difficult to remove the film body such as the dry film 8 and the problem that the desired conductor circuit cannot be formed because the unnecessary metal film pieces 11 remain. can do. A specific method for removing the unnecessary metal film piece 11 is not particularly limited. For example, a mechanical method such as a method of peeling off with a jig such as tweezers, a method of polishing with a polishing buff, or an etching method. And the like. However, when the unnecessary metal film piece 11 is removed by the etching method, some protection is provided so that the metal film 9 formed by plating on the through hole 3 in the step (2) is not etched by the etching. is required. Therefore, in the invention according to claim 5 and claim 6 of the present invention, as shown in FIG. 4, a secondary dry film 82 is attached to both surfaces of the multilayer board 15 which has undergone the step (2), Next, by exposing and developing, the secondary dry film 82 in the portion facing the through hole 3 is left, and the second dry film 82 in the portion located on the film body (dry film 8 or the like) covering the electronic component storage hole 2 is exposed. The secondary dry film is removed. In addition,
In the invention according to claim 6, as shown in FIG. 4, the secondary dry film 8 is formed only in the portion facing the through hole 3.
2 is left. Thus, by protecting the metal film 9 formed on the through hole 3 by plating [FIG.
It is possible to remove unnecessary metal film pieces 11 deposited on the film body such as the dry film 8 by etching (see FIG. 4B). In the invention according to claim 5, the secondary dry film of the portion located on the film body covering the electronic component storage hole 2 is removed, but the secondary dry film of other portions is removed. Since it is possible to leave the metal foil on the outermost surface of the multilayer board 15, if the metal foil is arranged on the outermost surface of the multilayer board 15, the metal foil is processed using this secondary dry film to form the conductor circuit in the multilayer board 1.
It is also possible to form it on the outermost surface of 5.

Step (4): The film body such as the dry film 8 remaining on the multilayer board 15 after the above step (3) is removed to remove the electronic component storage hole 2 as shown in FIG. 2 (g). Expose. The method for removing the film body is not particularly limited and may be a method suitable for the film body to be used. For example, in the case of an alkali peeling type dry film, the pH exceeds 10,
The peeling can be performed using an alkaline solution having a liquid temperature of higher than 40 ° C.

Step (5): A gold film is formed on the conductor circuit 4 exposed in the electronic component housing hole 2 by electrolytic plating. Regarding the formation of this gold film, first, a base film of nickel or the like may be formed by electrolytic plating, and then a gold film may be formed by electrolytic plating.

Next, an embodiment of the invention according to claim 4 of the present invention will be described with reference to the drawings. In the invention according to claim 4, steps (1) to (3) [Fig. 1 (a) to 2 (f)]
Process] is performed in the same manner as in the above-described embodiment. Then, the unnecessary metal film piece 11 of (3)
3 after the step of removing [step of FIG. 2 (f)].
As shown in (a), the through hole 3 is formed by electrolytic plating.
Is plated again to form the secondary plating layer 12,
The thickness of the metal film 9 in the through hole 3 is increased, and then the steps (4) and (5) are performed. The reason why the through hole 3 is re-plated by electrolytic plating in this way is described below. When the unnecessary metal film piece 11 is removed in the step (3), the unnecessary metal film piece 11 deposited on the film body such as the dry film 8 is removed by a polishing method, an etching method, or the like when the thickness is thin. Will be easier. However, when attempting to reduce the thickness, the thickness of the metal film 9 formed by plating on the through holes 3 is also reduced, which causes a problem that a desired film thickness cannot be obtained. Therefore, in order to solve this problem, the thickness of the metal film 9 formed by plating the through holes 3 in the step (2) is reduced, and the unnecessary metal film piece 11 is removed in the step (3). After exposing the surface of the remaining film body such as the dry film 8, the through hole 3 is plated again by electrolytic plating to increase the thickness of the metal film 9 in the through hole 3. . In the electrolytic plating in this case, since the plating catalyst does not remain on the surface of the film body such as the dry film 8, the secondary plating layer 12 is not formed on the film body. Further, as the film body such as the dry film 8 or the like, the one provided in the previous step may be used as it is, but it may be removed once and used again in the same shape.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

(Example 1) Four organic substrates 1 in which a conductor circuit 4 was formed on a polyimide resin glass cloth substrate copper clad laminate
A polyimide resin glass cloth base material prepreg used as the adhesive material 7 was prepared. The organic substrate 1 and the adhesive material 7 excluding the organic substrate 1 arranged at the bottom are provided with a quadrangular cutout portion for forming the electronic component housing hole 2, and the organic substrate 1 and the adhesive material 7 are attached. As shown in FIG. 1 (a), a multilayer board 15 is formed by laminating, then heating, pressing and adhering to form an integrated electronic component housing hole 2 in which the conductor circuit 4 is exposed at the step portion, and an integrated multi-layer board 15. Obtained.

Next, as shown in FIG. 1 (b), through holes 3 were formed by drilling in the multi-layer plate 15 at positions other than the electronic component housing holes 2. Then, an alkali peeling dry film 8 (product number 411Y-50 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is attached to both surfaces of the multilayer board 15 using a laminator to cover the electronic component storage hole 2 and the through hole 3, and then As shown in FIG. 1C, the dry film 8 is exposed and developed to remove the dry film 8 in the portion facing the through hole 3 and to dry the dry film 8 in the portion covering the electronic component storage hole 2. Was left. The dry film 8 was developed using an aqueous sodium carbonate solution.

Next, as shown in FIG. 1 (d), pH 1
Using a plating pretreatment liquid having a temperature of 0 or less and a liquid temperature of 60 ° C. or less, colloidal palladium is attached to the through holes 3, and then palladium is activated to remove the organic polymer covering the palladium, and the plating catalyst 6 Was formed. Next, as shown in FIG. 2 (e), electrolytic copper plating is applied to the through-holes 3 using a plating solution (containing copper sulfate) having a pH of 1 and a liquid temperature of 80 ° C. or less to have a thickness of 2
A metal film 9 made of copper having a thickness of μm was formed.

Then, the unnecessary metal film pieces 11 partially deposited on the dry film 8 shown in FIG. 2 (e) are removed by using a buffing machine and left as shown in FIG. 2 (f). The surface of the dry film 8 to be exposed was exposed. Then, as shown in FIG. 2G, the remaining dry film 8 is
Peeling was performed using an aqueous sodium hydroxide solution with H exceeding 10.

Next, a nickel film is deposited in a thickness of 3 to 5 μm on the metal film 9 formed in the conductor circuit 4 and the through hole 3 exposed in the electronic component housing hole 2 by electrolytic nickel plating using a Watts bath. After that, a gold coating was deposited to 1 to 2 μm by electrolytic gold plating to obtain a multilayer printed wiring board. In the multilayer printed wiring board thus obtained, there was no abnormal deposition of nickel or gold between the conductor circuits 4 exposed in the electronic component housing hole 2, and therefore no short circuit failure occurred.

(Embodiment 2) Similar to Embodiment 1, FIG.
From the process shown in (a) to the process shown in FIG. 2 (f),
The unnecessary metal film pieces 11 partially deposited on the dry film 8 were removed by using a buffing machine to expose the remaining surface of the dry film 8.

Next, as shown in FIG. 3 (a), electrolytic copper plating is performed again on the through holes 3 using a plating solution (containing copper sulfate) having a pH of 1 and a liquid temperature of 80 ° C. or lower. A secondary plating layer 12 made of copper having a thickness of 10 μm was formed, and the thickness of the metal film 9 in the through hole 3 was increased.

Then, as shown in FIG. 3B, the remaining dry film 8 was peeled off using an aqueous sodium hydroxide solution having a pH of more than 10.

Then, on the metal film 9 formed in the conductor circuit 4 and the through hole 3 exposed in the electronic component housing hole 2, a nickel film is deposited in a thickness of 3 to 5 μm by electrolytic nickel plating using a Watts bath. After that, a gold coating was deposited to 1 to 2 μm by electrolytic gold plating to obtain a multilayer printed wiring board. In the multilayer printed wiring board thus obtained, there was no abnormal deposition of nickel or gold between the conductor circuits 4 exposed in the electronic component housing hole 2, and therefore no short circuit failure occurred.

(Embodiment 3) Similar to Embodiment 1, FIG.
From the step shown in (a) to the step shown in FIG. 1 (d),
A film of the plating catalyst 6 was formed on the through holes 3. Then, as shown in FIG. 2 (e), the through-holes 3 are electrolytically copper-plated with a plating solution (containing copper sulfate) having a pH of 1 and a liquid temperature of 80 ° C. or less to form copper having a thickness of 10 μm. A metal coating 9 made of Then, as a secondary dry film 82 on both surfaces of the multilayer board 15, an alkali peeling dry film (product number 411 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
Y-50) was attached using a laminator, exposed and developed to leave the secondary dry film 82 only in the portion facing the through hole 3, as shown in FIG. Then, unnecessary metal film pieces 11 partially deposited on the dry film 8 shown in FIG.
It is removed using a hydrogen peroxide-based etching solution, and FIG.
The surface of the remaining dry film 8 was exposed as shown in (b). Then, the remaining dry film 8 and the secondary dry film 82 were peeled off using an aqueous sodium hydroxide solution having a pH of more than 10, and processed into the state shown in FIG. 2 (g).

Next, on the metal film 9 formed in the conductor circuit 4 and the through hole 3 exposed in the electronic component housing hole 2, a nickel film is deposited by 3 to 5 μm by electrolytic nickel plating using a Watts bath. After that, a gold coating was deposited to 1 to 2 μm by electrolytic gold plating to obtain a multilayer printed wiring board. In the multilayer printed wiring board thus obtained, there was no abnormal deposition of nickel or gold between the conductor circuits 4 exposed in the electronic component housing hole 2, and therefore no short circuit failure occurred.

(Example 4) Regarding the application of the plating catalyst 6 to the through holes 3 in Example 1, colloidal palladium was attached to the through holes 3 using a plating pretreatment liquid having a pH of 12 and a liquid temperature of 35 ° C. A multilayer printed wiring board was obtained in the same manner as in Example 1 except that palladium was activated to remove the organic polymer covering palladium and the plating catalyst 6 was changed to form a film. Also in this case, as in Example 1, there was no problem that the dry film 8 covering the electronic component storage hole 2 was damaged during the process and the plating solution entered the electronic component storage hole 2. Then, in the obtained multilayer printed wiring board, there was no abnormal deposition of nickel or gold between the conductor circuits 4 exposed in the electronic component housing hole 2, and therefore no short circuit failure occurred.

(Embodiment 5) With respect to the plating on the through holes 3 in Embodiment 1, an electroless copper plating solution having a pH of 12.5 and a liquid temperature of 20 ° C. was used to form electroless copper on the through holes 3. Plating was performed to form a copper film having a thickness of 1 to 2 μm. Then, using a plating solution (containing copper sulfate) having a pH of 1 and a liquid temperature of 80 ° C. or lower, the through hole 3
A multilayer printed wiring board was obtained in the same manner as in Example 1 except that electrolytic copper plating was applied to the substrate to form a metal film 9 made of copper having a total thickness of 10 μm. In the case of this example, as in the case of the first embodiment, the problem that the dry film 8 covering the electronic component storage hole 2 is damaged during the process and the plating solution enters the electronic component storage hole 2 occurs. There wasn't. Then, in the obtained multilayer printed wiring board, there was no abnormal deposition of nickel or gold between the conductor circuits 4 exposed in the electronic component housing hole 2, and therefore no short circuit failure occurred.

[0035]

As described above, in the method for manufacturing a multilayer printed wiring board according to the first to third aspects of the present invention, since the steps (1) to (5) are included, a plurality of conductor circuits are formed. The organic substrate is laminated and adhered while forming the electronic component housing hole where the conductor circuit is exposed at a predetermined position, and then forming a through hole at a position other than the electronic component housing hole.
This through hole is plated, then electrolytic plating is applied on the conductor circuit exposed in the electronic component storage hole, and finally a gold film is formed on the conductive circuit in the electronic component storage hole to form a multilayer printed wiring board. It is possible to prevent abnormal deposition of plated metal when electrolytic plating is performed on the conductor circuit in the electronic component housing hole in the case of manufacturing, and thus to reduce the occurrence of short circuit defects. Further, since the metal film pieces deposited on the film body covering the electronic component storage hole are removed in the step (3), it is difficult to remove the film body in the subsequent steps, and The multilayer printed wiring board can be manufactured without causing the problem that the desired conductor circuit cannot be formed due to the metal film pieces remaining.

According to the method for manufacturing a multilayer printed wiring board of the invention according to claim 4, in addition to the effects of the inventions according to claims 1 to 3, the thickness of the metal coating piece deposited on the film body is increased. Even when the thickness of the through hole is reduced to facilitate its removal, there is an effect that the thickness of the metal film formed by plating on the through hole can be set to a desired film thickness.

According to the method for manufacturing a multilayer printed wiring board of the invention according to claims 5 and 6, claims 1 to 3 are provided.
In addition to the effect of the invention according to (1), when the metal film piece deposited on the film body is to be removed by etching, the metal film formed by plating on the through hole is not damaged by this etching.

[Brief description of the drawings]

FIG. 1 is a model cross-sectional view illustrating a method for manufacturing a multilayer printed wiring board according to the first to third aspects of the invention.

FIG. 2 is a model cross-sectional view illustrating a method for manufacturing a multilayer printed wiring board according to the first to third aspects of the invention.

FIG. 3 is a model cross-sectional view for explaining a method for manufacturing a multilayer printed wiring board according to a fourth aspect of the invention.

FIG. 4 is a model cross-sectional view for explaining a method for manufacturing a multilayer printed wiring board according to the fifth and sixth aspects of the invention.

FIG. 5 is a cross-sectional view for explaining a model of a conventional method for manufacturing a multilayer printed wiring board.

[Explanation of symbols]

 1 Organic Substrate 2 Electronic Component Storage Hole 3 Through Hole 4 Conductor Circuit 5 Bottom Surface 6 Plating Catalyst 7 Adhesive Material 8, 82 Dry Film 9 Metal Film 11 Metal Film Piece 12 Secondary Plating Layer 15 Multilayer Board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuaki Arai, 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Shoji Ishikawa, 1048, Kadoma, Kadoma City, Osaka 72) Inventor Keiji Kaiji 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. (72) Toru Higuchi, 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. 1048 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (6)

[Claims] 1. A plurality of organic substrates on which conductor circuits are formed are stacked and adhered while forming an electronic component storage hole where the conductor circuit is exposed at a predetermined position, and then a portion other than the electronic component storage hole. A method for manufacturing a multilayer printed wiring board, comprising forming a through hole in a substrate and plating the through hole to manufacture a multilayer printed wiring board, characterized by comprising the following steps (1) to (5): Manufacturing method of multilayer printed wiring board. (1) The step of covering the electronic component storage hole with a film body so as to expose the through hole in the multilayer plate having the through hole formed, (2) applying a plating catalyst to the through hole using a plating pretreatment liquid. , And then plating the through holes with a plating solution to form a metal film,
(3) A step of removing the metal film pieces deposited on the film body by the plating of the step (2), (4) a step of removing the remaining film body, and (5) an exposure in the electronic component storage hole. The process of forming a gold film on a conductor circuit. 2. The film body is a dry film having photosensitivity, and the method of covering the electronic component storage hole in the step (1) with the film body is to attach the dry film to both surfaces of the multilayer board. After covering the electronic component storage hole and the through hole with a dry film, the dry film is exposed and developed to remove the dry film in the portion facing the through hole, and the dry film in the portion covering the electronic component storage hole. The method for producing a multilayer printed wiring board according to claim 1, wherein is a method of leaving. 3. The film body is a photosensitive alkali peeling type dry film, and the pretreatment liquid for plating in the step (2) has a pH of 10 or less and a liquid temperature of 80 ° C. or less, or a pH of 10 or less. Is a liquid having a pH within the range of 12.5 or less and a liquid temperature of 40 ° C or less, and the plating liquid has a liquid temperature of 10 or less and 80 ° C or less, or a liquid temperature of 10 or more. The method for producing a multilayer printed wiring board according to claim 1 or 2, wherein the liquid has a pH within the range of 12.5 or less and a liquid temperature of 40 ° C or less. 4. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein (3)
After the step of removing the metal film piece of, and before the step of removing the film body of (4), the through hole is plated again by electrolytic plating to reduce the thickness of the metal film in the through hole. A method for manufacturing a multilayer printed wiring board, which comprises performing an increasing step. 5. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein (2)
After attaching the secondary dry film to both surfaces of the multilayer board, after which exposure and development are performed, the secondary dry film in the portion facing the through hole is left and the electronic component storage hole is formed. A multi-layer print characterized in that the second dry film in the portion located on the covering film body is removed, and then the metal film pieces deposited on the film body are removed by etching in the step (3). Wiring board manufacturing method. 6. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein (2)
The secondary dry film is adhered to both surfaces of the multilayer board which has completed the step of 1. and then exposed and developed to leave the secondary dry film only in the portion facing the through hole, and then (3 A method for producing a multilayer printed wiring board, characterized in that the metal film pieces deposited on the film body are removed by etching in the step (4).