JP2003017853A - Manufacturing method of wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board with high-density, wiring where the connection reliability between a through conductor and an inner-layer conductor is superior, without generating peeling in the through-conductor. SOLUTION: Laser machining is applied to an insulating resin plate 1, thus drilling a plurality of through-holes 4, where a carbonization layer 8 is formed on an inner wall, depositing a plating metal layer 13A for pretreatment to the carbonization layer 8, making the plating metal layer 13A for pretreatment to be subjected to etching removal with the carbonization layer 8, and depositing a through conductor 5 onto the inner surface of the through-hole 4, where the plating metal layer 13A for pretreatment and carbonization layer 8 have been removed.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic material-based multilayer.
The present invention relates to a method for manufacturing a wiring board. Conventionally, an organic material for mounting a semiconductor element is used.
For example, a glass-epoxy board as a material-based wiring board
Inner layer conductors made of copper foil are formed on both upper and lower surfaces of the insulating resin plate.
Epoxy resin is mainly formed on both upper and lower surfaces of the coated double-sided copper-clad board.
Insulating resin layer is applied and insulation
Multiple through holes that penetrate the resin plate and insulating resin layer vertically
On the inner wall of the through hole and on the surface of the through conductor and insulating resin layer
Surface layer conductors for electroless plating and electrolytic copper plating, respectively
A multi-layered wiring board that is more deposited is used. This
In the wiring board, the penetration that is attached to the inner wall of the through hole
Inner layer conductor and surface layer conductor positioned above and below the conductor
Three-dimensional high-density wiring is possible by electrical connection
It has become. It is to be noted that such an organic material-based multilayer wiring board is used.
The plate is, for example, a glass-epoxy having a thickness of about 0.35 to 0.45 mm.
Thickness 7-12μ on both upper and lower surfaces of insulating resin plate
Double-sided copper with inner layer conductor made of copper foil
Insulating resin layers with a thickness of 25 to 45 μm are applied to the upper and lower surfaces of the tension plate.
The diameter is 200 from the upper surface to the lower surface.
Drill through holes of ~ 500μm by drilling
Then, copper plating with a thickness of about 15-50μm on the inner wall of the through hole
A surface conductor on the surface of the through-conductor and insulating resin layer
Deposit by electroless plating and electrolytic plating
It is produced by. However, such a problem is to be solved.
For organic material-based multilayer wiring boards, the wiring density
To further increase the diameter of the through hole, for example, about 75 to 130 μm
Attempts have been made to make it small. like this
To form small through holes with a diameter of about 75 to 130 μm
For example, a carbon dioxide laser drilling method is used.
The However, drilling was performed with a carbon dioxide laser.
In some cases, a brittle carbonized layer is formed on the inner wall of the through-hole,
A through conductor made of a copper plating layer was deposited on the inner wall of the hole.
Afterwards, peeling to the through conductor starting from the carbonized layer on the wall surface of the through hole
Occurs, and conduction failure occurs between the through conductor and the inner layer conductor.
There was a problem of causing good. The present invention has been devised in view of such conventional problems.
The purpose of this is to peel off the through conductor
The through conductor and the inner conductor are always in good contact with each other.
Wiring board capable of extremely high density wiring
It is in providing the manufacturing method of. SUMMARY OF THE INVENTION Manufacturing of a wiring board of the present invention
The method uses laser processing on the insulating resin plate to
Drilling a plurality of through-holes having a carbonized layer formed on a wall
And then depositing a pretreatment plating metal layer on the carbonized layer
And then carbonizing the pretreatment plating metal layer.
Etching together with the layer, and then the pretreatment
The inner wall of the through-hole from which the plated metal layer and carbonized layer have been removed
And a step of depositing the through conductor by a plating method.
It is characterized by. According to the method for manufacturing a wiring board of the present invention,
On the carbonized layer of the inner wall of the through-hole formed by laser processing
After depositing the scientific plating metal layer,
Etching is removed, and the pretreatment plating metal layer is further removed.
The inner wall of the through-hole from which the carbonized layer has been removed is penetrated by plating.
Since the conductor is deposited, the through conductor starts from the carbonized layer.
And will not peel off. DETAILED DESCRIPTION OF THE INVENTION Next, a method for manufacturing a wiring board according to the present invention.
The method will be described in detail. FIG. 1 shows a manufacturing method according to the present invention.
It is a fragmentary sectional view showing an example of an embodiment of a wiring board
The In FIG. 1, 1 is an insulating resin plate, 2A and 2B are inner layers
Conductor, 3A and 3B are insulating resin layers, 4 is through-holes, and 5 is through-holes
Conductors, 6A and 6B are surface conductors, mainly insulating resin
Inner layer conductors 2A and 2B and insulating resin layers on the upper and lower surfaces of the plate 1
3A and 3B are attached and the insulating resin plate 1 and the inside
It penetrates the layer conductors 2A and 2B and the insulating resin layers 3A and 3B.
A plurality of through-holes 4 are formed on the inner wall of the through-holes 4.
The through conductor 5 is deposited and the insulating resin layer 3A.
Surface layer conductors 6A and 6B are deposited on the surface of 3B.
Thus, the wiring board of the present invention is configured. Actually
In the embodiment, the inside of the through hole 4 and the insulating resin layer 3A
-Solder resist 7 is provided on 3B. The insulating resin plate 1 is used as a core member of a wiring board.
E.g. glass cloth or aramid cloth
Xy resin, bismaleimide triazine resin, polypheny
Organic insulating material impregnated with resin such as lenether resin
Is a flat plate with a thickness of 0.35 to 0.45 mm
Inner layer conductor 2A made of copper foil with a thickness of 7-12μm on both sides
It constitutes a so-called double-sided copper-clad board with 2B attached
The This insulating resin plate 1 has a thickness of less than 0.35 mm.
Insulating resin layers 3A and 3B are applied to the upper and lower surfaces,
Or insulating resin plate 1 and inner layer conductors 2A and 2B
A plurality of through holes 4 are formed through the edge resin layers 3A and 3B.
When the circuit board is warped or deformed by the influence of heat or external force.
The flatness required for the wiring board cannot be secured due to the shape.
On the other hand, the risk of becoming
If it exceeds mm, it will penetrate to the inner wall of the through hole 4 as will be described later.
When forming the body 5, the plating solution enters the through-hole 4.
It becomes difficult to form the through conductor 5 well.
The Therefore, the thickness of the insulating resin plate 1 is 0.35 to 0.45 mm.
The range of is preferable. The insulating resin plate 1 is made of glass cloth or aluminum.
Epoxy resin or bismaleimi impregnated into ramid cloth
Trees such as dotriazine resin and polyphenylene ether resin
Made of silica, alumina, or aramid resin in the fat
Filler fiber parts such as glass cloth and aramid cloth
To the extent that the transmittance of the laser beam is approximately equal between the minute and the resin part
If it is contained in the insulating resin plate 1 as described later,
When the through hole 4 is drilled with the laser beam, the through hole 4 is insulated with resin.
It becomes possible to form on the plate 1 with a substantially uniform size.
The Therefore, glass cloth and aramid of the insulating resin plate 1
Epoxy resin or bismaleimide to be impregnated into the cloth
In resin such as lyazine resin and polyphenylene ether resin
Consists of silica, alumina or aramid resin
Filler fiber parts such as glass cloth and aramid cloth
And the resin part so that the laser beam transmittance is almost equal
It is preferable to make it contain. Also, the insulating resin plate 1 was attached to the upper and lower surfaces.
Inner layer conductors 2A and 2B are made of copper foil, and are mainly power supply layers.
And inner-layer wiring conductor pattern W that functions as a ground layer
Dummy electrically independent from the inner layer wiring conductor pattern W
-Conductor pattern D, with a thickness of 7-12 μm,
The centerline average roughness Ra of the surface is about 0.2-2 μm
The The inner layer conductors 2A and 2B have a thickness of less than 7 μm.
Inner layer wiring conductor pattern as power supply layer and ground layer
Unable to give sufficient electrical properties to W, etc.
On the other hand, if it exceeds 12 μm, the insulating resin plate 1 will be described later.
And inner layer conductors 2A and 2B and insulating resin layers 3A and 3B
When penetrating through-hole 4 by laser processing,
It becomes difficult to form the through holes 4 stably. But
Therefore, the thickness of the inner layer conductors 2A and 2B is in the range of 7 to 12 μm.
Is preferred. The inner layer conductors 2A and 2B are formed in the through holes 4.
The inner part is further penetrated and is in contact with a through conductor 5 described later.
All layer wiring conductor pattern W or dummy conductor pattern D
If it is formed so as to correspond to all the through holes 4,
All through-holes when drilling through-holes 4 by laser processing
In FIG. 4, the absorption and reflection of the laser beam is substantially the same,
The through holes 4 can be formed in a substantially uniform size and shape.
Yes. Therefore, the inner layer conductors 2A and 2B are formed in the through holes 4.
Inner layer wiring conductor pattern W or dummy conductor penetrated more
To have body pattern D corresponding to all through holes 4
It is preferable to form it. In this case, dummy conductor pads
The diameter of the turn D is 40 to 100 than the diameter of the through hole 4
What is necessary is just a substantially circular pattern of about μm, and the inner layer arrangement
An interval with a width of about 30-60 μm between the line conductor pattern W
What is necessary is just to provide. The diameter of the dummy conductor pattern D is the through hole 4
If it is less than 40μm larger than the diameter of
When the through-hole 4 is drilled, the dummy conductor pattern D is
It becomes difficult to penetrate accurately, on the other hand, it exceeds 100μm
If it is large, increase the area of the inner-layer wiring conductor pattern W.
Difficult to take. Dummy conductor pattern D
When the distance between the wiring pattern and the inner wiring pattern W is less than 30μm
Includes a dummy conductor pattern D and an inner wiring conductor pattern W.
Tend to be unable to maintain good electrical insulation between
On the other hand, if it exceeds 60 μm, the surface of the inner layer wiring conductor pattern W
It becomes difficult to take products widely. The inner layer conductors 2A and 2B have surface
When the center line average roughness Ra is less than 0.2 μm, the inner layer conductor 2
A ・ 2B and insulating resin layers 3A ・ 3B are not firmly attached
Strip between inner layer conductors 2A and 2B and insulating resin layers 3A and 3B
Tends to be separated, and exceeds 2 μm
And to form such rough surfaces stably and efficiently
Tend to be difficult. Therefore, the inner layer conductor 2A.
The center line average roughness Ra of the 2B surface is in the range of 0.2-2 μm.
preferable. Also, the insulating resin plate 1 was attached to the upper and lower surfaces.
Insulating resin layers 3A and 3B are epoxy resin and bismaleimide
Thermosetting of triazine resin, polyphenylene ether resin, etc.
It is made of a curable resin, and the degree of decomposition against laser light is insulated.
It is larger than the resin plate 1, and the surface conductors 6A and 6B are on the surface.
Is attached. The insulating resin layers 3A and 3B are mutually insulated.
The inner layer conductors 2A and 2B and the surface layer conductors 6A and 6B to be bordered
For providing an insulation interval for electrical insulation
And the thickness is 25 to 45 μm on the inner layer conductors 2A and 2B.
It is. The insulating resin layers 3A and 3B have an inner layer thickness.
If conductors are less than 25μm on conductors 2A and 2B, they should be insulated from each other.
Electrical connection between inner layer conductors 2A and 2B and surface layer conductors 6A and 6B
On the other hand, 45 μm
If it exceeds, insulation resin plate 1 and inner layer conductors 2A and 2B
And through holes 4 that penetrate through the insulating resin layers 3A and 3B.
Forming the through-hole 4 well when drilling by machining
It becomes difficult. Therefore, the thickness of the insulating layers 3A and 3B is
The range of 25 to 45 μm is preferable on the inner layer conductors 2A and 2B. The surface conductors 6A and 6B have a thickness of 8 to 30 μm.
Power copper wiring and ground wiring.
And a surface wiring pattern including signal wiring is formed.
The For example, one surface layer conductor 6A on the upper surface side is exposed.
The electrode of the electronic component (not shown) is connected to the part via solder.
In addition, the exposed part of the surface layer conductor 6B on the lower surface side is shown in FIG.
It is connected to other wiring boards not shown via solder. These surface layer conductors 6A and 6B have a thickness of
Is less than 8 μm, the electrical resistance of the surface layer wiring pattern is
On the other hand, if the thickness exceeds 30 μm, the surface wiring layer
It becomes difficult to form turns with high density. Therefore
The thickness of the surface layer conductors 6A and 6B is in the range of 8 to 30 μm.
preferable. Furthermore, it is manufactured by the manufacturing method of the present invention.
In the wiring board, the insulating resin plate 1 and the inner layer conductor 2
Through-holes through A · 2B and insulating resin layers 3A · 3B
4 is formed by laser processing.
A through conductor 5 is formed on the inner wall. The through hole 4 is
The through conductor 5 is insulated from the upper surface of the insulating resin layer 3A by the insulating resin layer 3B.
To provide a lead-out path for the lead-out
belongs to. This through hole 4 is formed by laser processing.
As a result, the insulating resin plate 1 has a diameter of 75.
The inner wall is approximately vertical at ˜115 μm, and the insulating resin layer 3A
・ In 3B, the inner wall has an angle of 10-30 from the vertical direction.
It becomes the shape which inclines and expands toward the outside. this
In this case, the insulating resin layers 3A and 3B are separated from the laser beam.
Since the solution level is larger than that of the insulating resin plate 1, the laser
Since it is disassembled larger than the insulating base 1 during processing, it penetrates
The shape of the hole 4 faces outward in the insulating resin layers 3A and 3B.
The shape expands. Thus, it is manufactured by the manufacturing method of the present invention.
According to the printed wiring board, the through hole 4 is formed by laser processing.
Formed and its diameter is 75 to 115 μm in the insulating resin plate 1.
m and the inner wall of the insulating resin layers 3A and 3B
Inclined at an angle of 10-30 from the vertical direction and expanded outward
Because of the shape of the diameter, the through conductor 5 and the surface
The layer conductors 6A and 6B can be arranged with high density,
To obtain a wiring board having extremely high density wiring
Can do. Further, the diameter of the through hole 4 is the insulating resin plate 1.
The inner wall is insulated at 75 to 115 μm.
In the resin plate 1, the insulating resin layers 3A and 3B are substantially vertical.
At an angle of 10-30 from the vertical direction
Since it has a shape that expands in diameter, as will be described later
When the through conductor 5 is deposited on the inner wall of the through hole 4,
Plating solution for forming conductor 5 is good inside through hole 4
As a result, the through conductor 5 is good in the through hole 4.
It can be formed well. It should be noted that the through hole 4 in the insulating resin plate 1 is directly
When the diameter is less than 75 μm, the through conductor 5 is covered with the inner wall of the through hole 4.
Plating solution for forming through conductors 5 when forming
Does not enter the inside of the through-hole 4 well, and the inner wall of the through-hole 4
It becomes difficult to form the through conductor 5 well,
If it exceeds 115 μm, the through conductor 5 and the surface layer conductor 6A.
It becomes difficult to arrange 6B at a high density. Therefore
The diameter of the through hole 4 in the insulating resin plate 1 is 75 to 115.
The range of μm is preferable. Further, the inside of the through hole 4 in the insulating resin plate 1
When the wall is not substantially vertical, the through conductor 5 is covered on the inner wall of the through hole 4.
Air bubbles are easily left inside the through-holes 4 during the formation.
Therefore, the plating solution for forming the through conductor 5 is
On the inner wall of the through-hole 4 without reaching well where the foam is left
It becomes difficult to form the through conductor 5 satisfactorily. But
Thus, the inner wall of the through hole 4 in the insulating resin plate 1 is substantially vertical.
Preferably there is. The inner wall of the through-hole 4 has an insulating resin layer 3A.
The angle of inclination toward the outside in 3B is 10 degrees from the vertical direction.
If it is less, the through conductor 5 is deposited on the inner wall of the through hole 4.
At this time, the plating solution for forming the through conductor 5 is formed in the through hole 4.
The through conductor 5 does not penetrate into the inside of the through hole 4 in the inner wall.
Is difficult to form well, on the other hand, over 30 degrees
Then, the through-hole 4 whose inner wall expands at such an angle is stabilized.
It becomes difficult to form efficiently. Therefore, penetrating
The inner wall of the hole 4 faces outward in the insulating resin layers 3A and 3B
The tilt angle is preferably in the range of 10-30 degrees from the vertical direction.
Yes. A through conductor formed on the inner wall of the through hole 4
5 is made of a copper plating film having a thickness of about 8 to 25 μm.
Up and down across the edge resin plate 1 and insulating resin layers 3A and 3B
Positioned inner layer conductors 2A and 2B and surface layer conductors 6A and 6B
Functions as a connection conductor that electrically connects each other
The The through conductor 5 has a thickness of less than 8 μm.
Tends to be too high in electrical resistance of the through conductor 5
On the other hand, if it exceeds 25 μm, the through conductor 5 is covered.
A solder resist 7 to be described later is placed inside the attached through hole 4.
It becomes difficult to fill well. Therefore, the penetration
The thickness of the body 5 is preferably in the range of 8-25 μm.
Yes. Furthermore, the surfaces of the insulating resin layers 3A and 3B and
And through-holes 4 have epoxy resin and bismaleimide inside.
Thermosetting of triazine resin, polyphenylene ether resin, etc.
Solder resist 7 made of curable resin is deposited and filled
It is. The solder resist 7 includes the through conductor 5 and the surface layer.
Protects conductors 6A and 6B, and surface conductors 6A and 6B
Electrically insulates the surface wiring patterns from each other
Function as a protective layer for the surface conductors 6A and 6B
It is formed in a predetermined pattern that exposes the portion. The solder resist 7 is composed of a surface layer conductor.
When the thickness on 6A and 6B is less than 10 μm, the surface layer
The conductor 6 cannot be well protected and
Electricity between the surface wiring patterns of the layer conductors 6A and 6B
Tend to be unable to insulate well
On the other hand, when the thickness exceeds 40 μm, the solder resist 7 is set to a predetermined pattern.
Tends to be difficult to form. Therefore
The thickness of the solder resist on the surface conductors 6A and 6B
Is preferably in the range of 10 to 40 μm. Next, the wiring board shown in FIG. 1 is manufactured according to the present invention.
2 (a) to 2 (h) regarding the manufacturing method by the manufacturing method.
Will be described with reference to FIG. First, as shown in a partial cross-sectional view in FIG.
For example, epoxy resin on glass cloth or aramid cloth
Fat, bismaleimide triazine resin, polyphenylene ether
-Made of organic insulating material impregnated with resin of resin
Thickness on the upper and lower surfaces of insulating resin plate 1 with a thickness of 0.35-0.45 mm
Inner layer conductors 2A and 2B made of 7-12 μm copper foil are attached.
Prepare a double-sided copper-clad board. Inner layer conductor 2A
2B has a surface centerline average roughness Ra of about 0.2 to 2 μm.
The surface is roughened so as to obtain a degree. The insulating resin plate 1 has a thickness of less than 0.35 mm.
Then, insulating resin layers 3A and 3B were deposited on the upper and lower surfaces.
Or insulating resin plate 1 and inner layer conductors 2A and 2B
And a plurality of through holes 4 penetrating the insulating resin layers 3A and 3B.
Warping or deformation of the wiring board due to the effects of heat, external force, etc.
The flatness required for the wiring board cannot be secured due to the shape.
On the other hand, the risk of becoming
If it exceeds mm, it will penetrate to the inner wall of the through hole 4 as will be described later.
When forming the body 5, the plating solution enters the through-hole 4.
As a result, disconnection is likely to occur in the through conductor 5. did
Therefore, the thickness of the insulating resin plate 1 is in the range of 0.35 to 0.45 mm.
preferable. The inner layer conductors 2A and 2B have a thickness of
If the thickness is less than 7 μm, the pattern of the inner conductors 2A and 2B
Provide sufficient electrical properties as a source layer or ground layer
If it exceeds 12 μm, it will be described later.
Insulating resin plate 1, inner layer conductors 2A and 2B, and insulating resin layer
Drilling through-hole 4 that penetrates 3A and 3B by laser processing
When drilling, the through hole 4 with a diameter of 75 to 130 μm is stabilized.
It becomes difficult to form. Therefore, the inner layer conductor 2
The thickness of A · 2B is preferably in the range of 7 to 12 μm. The inner layer conductors 2A and 2B are formed on the surface thereof.
When the center line average roughness Ra is less than 0.2 μm, it will be described later.
Insulating resin layers 3A and 3B are formed on the upper and lower surfaces of insulating resin plate 1.
Inner layer conductors 2A and 2B and insulating resin layer 3A
Inner layer conductors 2A and 2B and insulation tree without being in close contact with 3B
In a tendency that peeling easily occurs between the oil layers 3A and 3B.
Yes, if it exceeds 2μm, such rough surface is stable
And it tends to be difficult to form efficiently. Shi
Therefore, the centerline average roughness R of the surface of the inner layer conductors 2A and 2B
a is preferably in the range of 0.2 to 2 μm. Further, the inner layer conductors 2A and 2B have through holes 4.
Conductor putter penetrated by the through hole 4 at the position to be formed
If a hole is provided corresponding to all the through-holes 4, laser processing is performed.
When the through holes 4 are formed by work, all the through holes 4
As a result, the absorption and reflection of the laser light becomes uniform, and all the through holes 4
It can be formed substantially uniformly. Therefore, inner layer conductor
2A and 2B are formed at the positions where the through holes 4 are formed.
Corresponding conductor patterns that penetrate through all through holes 4
It is preferable to provide it. Such inner layer conductors 2A and 2B are made of insulating trees.
A copper foil having a thickness of about 8 to 16 μm is pasted on the entire upper and lower surfaces of the fat plate 1.
At the same time, a photosensitive dry film
This is the photosensitive dry film register.
Exposure of strikes using conventional photolithography techniques
・ Develop and dry film resist at pattern formation position
An etching mask having
Copper foil exposed from the disc is cupric chloride aqueous solution or chloride
Etching with etchant consisting of ferric aqueous solution
After removing and finally removing the etching mask,
The surface using a roughening solution containing formic acid in a 2 copper aqueous solution
It is formed by etching and roughening. Next, as shown in a partial sectional view in FIG.
And both of the insulating resin plate 1 and the inner layer conductors 2A and 2B.
Thickness on the upper and lower surfaces of the surface copper-clad plate on the inner layer conductors 2A and 2B
Insulating resin layers 3A and 3B of 25 to 45 μm are deposited. This
The insulating resin layers 3A and 3B are made of epoxy resin or bismale
Heat of dotriazine resin, polyphenylene ether resin, etc.
Made of curable resin, for laser light such as carbon dioxide laser
The degree of decomposition is larger than that of the insulating resin plate 1. The insulating resin layers 3A and 3B have a thickness of
Insulating each other when less than 25μm on inner layer conductors 2A and 2B
The inner layer conductors 2A and 2B and the surface layer conductors 6A and 6B to be
Cannot be insulated well and, on the other hand, 45μ
If m is exceeded, insulating resin plate 1 and inner layer conductors 2A and 2B
In addition, the through hole 4 penetrating the insulating resin layers 3A and 3B
-When drilling by laser processing, the diameter is 75-130μm
It becomes difficult to form the holes 4 well. Therefore,
The thickness of the insulating layers 3A and 3B is 25 to 25 on the inner conductors 2A and 2B.
A range of 45 μm is preferred. The inner layer conductor 2 is formed on the upper and lower surfaces of the insulating resin plate 1.
Insulating trees on the upper and lower surfaces of double-sided copper-clad plates with A and 2B attached
In order to deposit the oil layers 3A and 3B, semi-cured thermosetting
Vacuum laminating film of curable resin on both upper and lower surfaces of double-sided copper-clad board
One that is temporarily bonded with a nota and then heat-treated to cure.
The law is adopted. Next, as shown in a partial sectional view in FIG.
Insulating resin layers 3A and 3B and inner layer by laser processing
The diameter penetrating the conductors 2A and 2B and the insulating resin plate 1 is 75.
A plurality of through-holes 4 of ~ 130 μm are drilled. At this time
Decomposition degree of edge resin layers 3A and 3B with respect to laser light is absolutely
Since it is larger than the edge resin plate 1, the through-hole 4 is made of an insulating tree.
In the fat layers 3A and 3B, the diameter increases toward the outside.
The Thus, the diameter of the through hole 4 is 75 to 130 μm.
Since it is as small as m, it will penetrate as described later.
When forming the body 5 and the surface conductors 6A and 6B, the through conductor
5 and surface conductors 6A and 6B can be arranged at high density
That can provide a high-density wiring board
The Moreover, the hole diameter of the through hole 4 is a portion of the insulating resin layers 3A and 3B.
It will be described later because it spreads outward
When the through conductor 5 is deposited on the inner wall of the through hole 4,
A plating solution for forming the conductor 5 is formed in the through hole 4.
As a result, the through conductor 5 is inserted into the through hole 4 as a result.
It can be formed satisfactorily. It should be noted that when the hole diameter of the through hole 4 is less than 75 μm
When the through conductor 5 is deposited on the inner wall of the through hole 4,
A plating solution for forming the conductor 5 is formed in the through hole 4.
The penetration conductor 5 does not penetrate well and the penetration conductor 5 is favorably formed on the inner wall of the penetration hole 4.
Can not be formed, on the other hand, exceeds 130μm
The through conductor 5 and the surface conductors 6A and 6B are arranged with high density.
Difficult to place. Therefore, the diameter of the through hole 4
Is preferably in the range of 75 to 130 μm. In addition, the diameter at the opening of the through hole 4 is completely different.
When the diameter is larger than the diameter of the edge resin plate 1 by less than 10 μm
When the through conductor 5 is deposited on the inner wall of the through hole 4,
A plating solution for forming the conductor 5 is formed in the through hole 4.
Improve penetration conductor 5 on inner wall of through hole 4 without entering well
Difficult to form, but larger than 50μm
In such a case, the through-hole 4 having such a shape is stabilized.
It becomes difficult to form. Therefore, the through-hole 4
The diameter at the opening is larger than the diameter at the insulating resin plate 1.
Is preferably 10 to 50 μm larger. The insulating resin layers 3A and 3B and the inner layer conductor
The through holes 4 are formed in the bodies 2A and 2B and the insulating resin plate 1.
For example, the energy of the laser beam is formed on the insulating resin layers 3A and 3B.
Has black or near black color that absorbs luge well
A laser processing sheet made of resin
-Carbon dioxide with an output of 7-12mJ from the top of the sheet for processing
Irradiate a laser beam at a predetermined position with a pulse width of 50 to 500 microseconds
Then, a method of drilling the through hole 4 is employed. At this time,
If the output of the carbon dioxide laser beam is less than 7 mJ, the through hole 4 will be
Tend to be difficult to perforate
On the other hand, if it exceeds 12 mJ, it will penetrate through the insulating resin layers 3A and 3B.
The hole diameter of the through hole 4 tends to be too large. Shi
Therefore, the carbon dioxide laser light to be irradiated has an output of 7
~ 12mJ and pulse width should be in the range of 50 ~ 500μs
preferable. The laser processing sheet is provided with a through hole 4.
It peels after making a hole. In this way, the through hole 4 is laser processed.
With a diameter of 75 to 130 μm,
In the edge resin layers 3A and 3B, the shape expands toward the outside.
The through-hole 4 can be easily formed. In addition, this
In this case, the inner wall of the through-hole 4 has a thickness due to laser processing.
A carbonized layer 8 of about several μm or less is formed. Next, as shown in a partial sectional view in FIG.
The carbonized layer 8 on the inner wall of the through hole 4 and the insulating resin layers 3A and 3
The surface of B is composed of an electroless copper plating layer with a thickness of 1 to 3 μm.
A pretreatment plating metal layer 13A is deposited. The predecessor
In order to deposit the theoretical plating metal layer 13A, for example, chloride
Palladium activity containing ammonium-based palladium acetate
Using the liquid, the inner wall of the through hole 4 and the insulating resin layers 3A and 3B
A palladium catalyst is attached to the surface of the
Pretreatment plating with copper sulfate based electroless copper plating solution
A metal layer 13A may be deposited. At this time, the through hole 4
The diameter of the insulating resin layers 3A and 3B increases toward the outside.
Therefore, the electroless copper plating solution is good in the through hole 4
As a result, the carbonized layer 8 on the inner wall of the through hole 4 and the
Pretreatment plating metal layer 13A on the surface of the edge resin layers 3A and 3B
Can be satisfactorily applied to a substantially uniform thickness. Na
Before applying the pretreatment plating metal layer 13A
The surface of the oil layers 3A and 3B and the inner wall of the through hole 4 are, for example, excessive
From potassium ganate solution or sodium permanganate solution
Pre-treated plating metal after roughening with a roughening solution consisting of
The layer 13A can be firmly applied. Therefore,
Before applying the pretreatment plating metal layer 13A, insulating resin layer
The surface of 3A and 3B and the inner wall of the through hole 4 are, for example, permanganese
Consists of potassium acid solution and sodium permanganate solution
It is preferable to roughen using a roughening liquid. Next, as shown in a partial sectional view in FIG.
In addition, a pretreatment coating deposited on the carbonized layer 8 on the inner wall of the through-hole 4
Etching and removing the precious metal layer 13A together with the carbonized layer 8
The As an etchant used for this etching
Is a mixed solution of sulfuric acid and hydrogen peroxide or cupric chloride
Use an etchant consisting of a solution or aqueous ferric chloride solution
It only has to be. In this case, the pretreatment plating metal layer 13A is formed.
Sometimes the pretreatment plating metal layer 13A is microscopic unevenness of the carbonized layer 8
When the metal layer 13A for pretreatment is deposited,
The force acts well on the carbonized layer 8 and the carbonized layer 8 is easily peeled off.
It has become. Therefore, pretreatment plating metal layer 13A
When removing by etching, the carbonized layer 8 is pre-plated metal.
It is well removed with the layer 13A. Next, as shown in FIG.
Through hole 4 from which plating metal layer 13A and carbonized layer 8 have been removed
The inner wall and the surface of the insulating resin layers 3A and 3B have a thickness of 1 to 3
Electroless plated metal layer 13B composed of μm electroless copper plating
Adhere. In addition, electroless plating made of electroless copper plating
To deposit the plated metal layer 13B, for example, ammonium chloride
Palladium active solution containing palladium
Use the inner walls of the through holes 4 and the surfaces of the insulating resin layers 3A and 3B.
A palladium catalyst is attached to
Cover the electroless copper plating layer with a copper-based electroless copper plating solution.
Just wear it. At this time, the through hole 4 is formed of the insulating resin layer 3.
Because A.3B is expanding toward the outside,
Electroless copper plating solution penetrates well into the through hole 4 and
As a result, on the inner walls of the through holes 4 and the surfaces of the insulating resin layers 3A and 3B
Electroless plating metal layer 13B is deposited with a uniform thickness.
Can be made. In addition, the non-electrolytic copper plating film
Before applying the electroplating metal layer 13B, the insulating resin layer 3A
-The 3B surface and the inner wall of the through hole 4 are, for example, permanganate
Roughening consisting of sodium and sodium permanganate solutions
The center line average roughness Ra is about 0.2 to 2 μm.
If it is roughened to become electroless plating metal film 13B
It can be firmly attached. Therefore, electroless
Before applying the plated metal layer 13B, the insulating resin layers 3A and 3B
The surface and the inner wall of the through hole 4 are, for example, potassium permanganate
Use roughening solution consisting of solution or sodium permanganate solution
And the center line average roughness Ra is about 0.2 to 2 μm.
It is preferable to roughen as described above. At this time, the through hole
4 Since the carbonized layer 8 is removed from the inner wall,
The electroless plating metal layer 13B peels off from the carbonized layer 8 on the inner wall.
No electrolysis with respect to the inner wall of the through hole 4
The plated metal layer 13B can be firmly applied. Next, as shown in FIG. 2 (g), the insulating layer 3A
・ Plating mask 14 is deposited on electroless copper plating on 3B
Electroless exposed from the plating mask 14
Electrolytic copper plating with a thickness of about 10 to 35 μm is coated on the copper plating.
The inner wall of the through hole 4 and the insulating resin layers 3A and 3B table
Electroless with selective thick deposition of surface patterning sites
Plating film 13C consisting of plating and electrolytic copper plating is formed
The The plating mask 14 is, for example, photosensitive.
No dry film resist on insulating resin layers 3A and 3B
It is deposited on the electrolytic copper plating film and
Film resist exposure using photolithography technology
・ Forming by developing and processing into a predetermined pattern
To do. Also, an electrode for depositing electrolytic copper plating is used.
For example, an electrolytic solution made of copper sulfate
A copper plating solution may be used. At this time, the through hole 4 is completely closed.
In the edge resin layers 3A and 3B, the diameter is increased toward the outside.
Therefore, the electrolytic copper plating solution penetrates well into the through hole 4
As a result, the inner wall of the through hole 4 and the insulating resin layers 3A and 3
Electrolytic copper plating film is deposited on the surface of B with a uniform thickness.
Is done. Next, as shown in a partial sectional view in FIG.
In addition, the plating mask 14 is peeled off and the plating mask 14 is removed.
Electroless copper plating until the electroless copper plating underneath disappeared
Etching plating and electrolytic copper plating, through hole 4 inner wall
A through conductor 5 is formed on the insulating resin layers 3A and 3B.
Surface layer conductors 6A and 6B are formed on the surface of the substrate. Incidentally, the electroless copper plating film and the electrolytic copper plating film.
To etch the film, a mixture of sulfuric acid and hydrogen peroxide
Solution or cupric chloride aqueous solution or ferric chloride aqueous solution
An etching solution comprising the following may be used. At this time, the carbonized layer 8 is formed on the inner wall of the through conductor 4.
The through conductor 5 starts from the carbonized layer 8 because it is removed.
And will not peel off. Therefore,
According to the manufacturing method of the present invention, the through conductor 5 and the inner layer conductor 2A
・ High reliability and high density with 2B always connected well
A wiring board for wiring can be obtained. Finally, the surfaces of the insulating resin layers 3A and 3B and
Epoxy resin or bismaleimide tri
Thermosetting resins such as azine resin and polyphenylene ether
Depositing and filling a solder resist 7 comprising
Thus, the wiring board of the present invention shown in FIG. 1 is completed. It should be noted that the solder resist 7 is a solder resist.
A photosensitive resin paste for GIST 7
Insulating layer 3A side and 3B side penetrating
Print and apply so as to fill the through-hole 4, and apply this to the well-known film.
Adopt photolithographic technology to expose the pattern.
It is formed by light and development. At this time, penetration
The holes 4 expand outward in the insulating resin layers 3A and 3B.
Due to the diameter, the solder resist 7 is placed in the through hole 4.
Resin paste penetrated well, and as a result, through-hole 4
The inside can be filled well with the solder resist 7.
The According to the method for manufacturing a wiring board of the present invention,
Previously on the carbonized layer of the inner wall of the through hole formed by laser processing
After depositing the plating metal layer for treatment,
Etching is removed, and this pretreatment plating metal layer
And the inner wall of the through hole with the carbonized layer removed
Because the through conductor is deposited, the through conductor is the inner wall of the through hole.
Penetration without starting from the carbonized layer
A conduction failure does not occur between the conductor and the inner layer conductor.
Therefore, the connection reliability between the through conductor and the inner layer conductor is excellent.
A high-density wiring board can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view showing an example of an embodiment of a wiring board manufactured by a manufacturing method of the present invention. FIGS. 2A to 2H are partial cross-sectional views for each process for explaining a method of manufacturing a wiring board according to the present invention. FIGS. [Explanation of symbols] 1 .... Insulating resin plates 2A, 2B ... Inner conductors 3A, 3B ... Insulating resin layer 4 ... Through holes 5 ...・ Penetration conductor 6A ・ 6B ・ ・ ・ Surface conductor 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Carbide layer 13A ・ ・ ・ ・ ・ ・ Plating metal layer for pretreatment

Claims (1)

What is claimed is: 1. A step of drilling a plurality of through holes each having a carbonized layer formed on an inner wall by laser processing an insulating resin plate; A step of depositing a plating metal layer, a step of etching and removing the pretreatment plating metal layer together with the carbonized layer, and then a through hole inner wall from which the pretreatment plating metal layer and the carbonization layer have been removed. And a step of depositing the through conductor by a plating method.