JP2002076556A - Printed circuit board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve electrical connecting reliability and productivity of a printed circuit board. SOLUTION: A method for manufacturing the printed circuit board comprises the steps of providing a hole 4 in a copper-clad laminate 5 on which a copper foil 3 is laminated, adhering a conductor sheet 8 having an adhesive layer 6 on the laminate 5, and exposing a copper foil 7 of the sheet 8 via the hole 4 by laser processing. The method further comprises the steps of forming a conductor pattern 10 for interlayer-connecting the sheet 8 adhered to a lower surface of the laminate 5 to the foil 7, and forming a circuit pattern 11 by etching or the like based on the pattern 10 and the foil 7 of the sheet 8 to manufacture the board 1 having a non-penetrating via hole 2 in a front layer. Thus, the copper-clad laminate 5 can be perforated without apprehension of exudating an adhesive, and the adhesive can be efficiently and accurately removed. Accordingly, the electrical connecting reliability and the productivity of the printed circuit board can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having a multilayer structure for realizing high-density mounting of electronic components and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become more multifunctional and lighter and smaller, electronic components such as semiconductor chips have been increasingly integrated. Meanwhile, printed wiring boards for mounting such highly integrated electronic components are required to have higher densities. Therefore, a printed wiring board on which an integrated circuit component such as an LSI is mounted uses, in addition to through holes and the like, non-penetrating via holes and the like for connecting conductors between adjacent layers to reduce the thickness and increase the number of layers. .

One of the methods for manufacturing a printed wiring board having the above-described non-penetrating via holes is a method shown in FIG. That is, this manufacturing method is similar to that shown in FIG.
As shown in FIG. 5A, an adhesive sheet 53 is attached to the other surface of a copper-clad laminate 52 having a copper foil 51 laminated on one surface, and is drilled or punched as shown in FIG. 5B. The hole 54 is formed by processing. Next, FIG.
As shown in (5), a copper foil 55 (or a copper plate) is bonded to the adhesive sheet 53 bonded to the copper-clad laminate 52 by a method such as lamination pressing. Further, as shown in FIG. 5D, the copper foil 51 on the upper surface and the copper foil 5
The conductor pattern 56 for connecting the first and second through the hole 54 is formed by copper plating or the like. Thereafter, as shown in FIG. 5E, a printed wiring board 59 having a non-penetrating via hole 58 is manufactured by forming a circuit pattern 57 by etching or the like.

[0004]

However, such a conventional method of manufacturing a printed wiring board is not suitable for making a hole in a state where the copper-clad laminate 52 and the adhesive sheet 53 are bonded to each other or for bonding the copper foil 55. At the time of laminating press or the like when sticking to the sheet 53, the uncured adhesive of the adhesive sheet
There was a problem of seeping into No. 4. For this reason,
When plating the inner wall of the hole 54 with through-hole plating or the like, it is necessary to remove the exuded adhesive. However, the generally used desmear treatment or the like cannot remove the adhesive well, and as a result, the hole is not removed. The turnability of the inner wall of the portion 54 with plating is deteriorated, and the electrical connection reliability is reduced.

Further, as described above, the conventional method of manufacturing a printed wiring board includes a copper-clad laminate 52 and an adhesive sheet 5.
Because the exudation of the adhesive occurs when drilling 3
It is difficult to drill holes by stacking multiple substrates,
It also led to a drop in productivity. At the same time, consideration must be given to suppressing the exudation of the adhesive, so that the usable adhesive sheet material is limited and an expensive sheet must be used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a printed wiring board capable of improving connection reliability and productivity and a method of manufacturing the same.

[0007]

In order to achieve the above object, a printed wiring board according to claim 1 of the present invention has a first conductor layer laminated on one surface and a hole provided. And a sheet comprising an adhesive layer and a second conductor layer, wherein the adhesive layer is attached to the other surface of the substrate so as to cover the hole from the other surface side of the substrate. A conductor sheet and the adhesive layer of the conductor sheet adhered to the other surface of the substrate are removed from the one surface side of the substrate through the hole, and the second conductor layer is exposed from the hole. And a connecting portion formed on the second conductive layer and a conductive pattern connecting the connecting portion and the first conductive layer through the hole.

According to a second aspect of the present invention, there is provided a printed wiring board comprising: a substrate having a conductor layer laminated on one surface and a hole; and a hole formed from the other surface of the substrate. A conductive plate provided so as to cover the substrate, an adhesive sheet interposed between the other surface of the substrate and the conductive plate, and adhering to each other; and A connection portion formed by exposing the conductor plate from the hole portion through a hole, and a conductor pattern connecting the connection portion and the conductor layer formed on the conductor plate through the hole portion. It is characterized by the following.

Further, according to a third aspect of the present invention, there is provided a method for manufacturing a printed wiring board, comprising the steps of: forming a hole in a substrate having a first conductor layer laminated on one surface; Bonding the adhesive layer of the conductive sheet including the adhesive layer and the second conductive layer to the other surface of the substrate so as to cover the hole from the side, and bonding the adhesive layer to the other surface of the substrate. Removing the adhesive layer of the conductive sheet from one side of the substrate through the hole to expose the second conductor layer from the hole; and forming the first and second through the hole. And a step of connecting the conductive layers.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a printed wiring board, comprising the steps of: forming a hole in a substrate having a conductor layer laminated on one surface; Bonding a conductive plate to the other surface of the substrate via an adhesive sheet so as to cover the hole, and bonding the adhesive sheet interposed between the substrate and the conductive plate to one side of the substrate. And removing the conductor plate from the hole through the hole, and connecting the conductor layer and the conductor plate through the hole.

Further, according to a fifth aspect of the present invention, there is provided a method for manufacturing a printed wiring board according to the third or fourth aspect, wherein the adhesive layer or the adhesive sheet of the conductor sheet is a laser. Characterized by being removed by

According to the above-described inventions, a hole is formed in a substrate on which a conductor layer is laminated, and a conductor sheet having an adhesive layer, or a conductor plate is bonded to the substrate via the adhesive sheet, and laser processing or the like is performed. By exposing the surface of the conductor plate or the conductor layer of the conductor sheet from the hole portion, and further connecting the conductor layer laminated on the substrate and the conductor layer of the conductor plate or the conductor sheet adhered to the substrate by interlayer connection, printed wiring A board is obtained.

In other words, according to these inventions, it is possible to pierce the substrate without fear of exuding the adhesive, for example, so that a plurality of substrates can be pierced at the same time, and productivity can be improved. Improvement can be achieved.

Further, according to the present invention, the adhesive is removed after the substrate and the conductive sheet or the conductive plate are bonded to each other, so that consideration for suppressing the exudation of the adhesive becomes unnecessary. As a result, restrictions on the material of the adhesive sheet that can be used are reduced, and an inexpensive sheet can be used. Further, at this time, by using a sheet in which the adhesive layer and the conductor layer are integrally formed, the cost can be further reduced and the workability can be improved.

Further, the present invention provides a semiconductor device comprising:
Since the adhesive layer with a substantially uniform thickness is removed by laser, it is easier to set the conditions for removing the adhesive layer compared to, for example, desmear treatment using an oxidizing agent, and to remove the adhesive efficiently and with high precision. Can be.

Therefore, according to the present invention, the productivity of the printed wiring board to be manufactured can be improved, and the inner wall of the hole provided in the substrate and the conductor portion from which the adhesive has been removed are plated. The roundness is improved, and the connection reliability of the printed wiring board can be improved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view schematically showing a printed wiring board according to an embodiment of the present invention.

As shown in FIG.
Is a wiring board in which a non-penetrating via hole 2 for performing interlayer connection is provided in a surface layer, a copper-clad laminate 5 having a copper foil 3 laminated on the upper surface and a hole 4 provided therein, 6 and a copper foil 7, a conductive sheet 8 having an adhesive layer 6 attached to the lower surface of the copper-clad laminate 5 so as to cover the hole 4 from the lower surface side of the copper-clad laminate 5, and a lower surface of the copper-clad laminate 5 The adhesive layer 6 of the conductor sheet 8 attached to the copper-clad laminate 5 is removed from the upper surface side through the hole 4 to expose the copper foil 7 from the hole 4, 7 and the copper foil 3 on the upper surface of the copper-clad laminate 5
And a circuit pattern 11 formed by etching the conductive pattern 10 and the copper foil 7 of the conductive sheet 8.

Next, a method of manufacturing the printed wiring board 1 configured as described above will be described with reference to FIG.

First, as shown in FIG. 2A, a copper-clad laminate 5 having a copper foil 3 laminated on its upper surface is prepared, and is processed by a processing method such as drilling, router processing or pressing. A hole (through hole) 4 is provided as shown in b). In this case, a plurality of copper-clad laminates 5 may be stacked and drilled simultaneously. Thereafter, the copper foil (or copper plate) 7 and the adhesive layer 6
As shown in FIG. 2 (c), the lower surface side of the laminated plate 5 and the conductive sheet 8 are closed by the conductor sheet 8 in which the holes 4 are closed from the lower surface side of the copper-clad laminated plate 5. Adhesive layer 6
Glue the side. At this time, for example, instead of the conductor sheet 8 in which the adhesive layer 6 and the copper foil 7 are integrated, an adhesive sheet of another component and a copper foil (or a copper plate) are bonded by lamination hot pressing, roll lamination, or the like. Those may be used in the present manufacturing process.

Next, as shown in FIG. 2D, the adhesive layer 6 of the conductor sheet 8 adhered to the lower surface of the copper-clad laminate 5
Is removed from the upper surface side of the copper-clad laminate 5 through the hole 4 by laser processing, and the copper foil 7 of the conductor sheet 8 is exposed from the hole 4 to form the connection portion 9. At this time, since the adhesive layer 6 having a substantially uniform thickness is removed by a laser, the adhesive removal conditions can be easily set, and the adhesive can be removed efficiently and with high precision, as compared with, for example, desmear treatment using an oxidizing agent. can do. Thereby, the productivity of the manufactured printed wiring board can be improved.

Thereafter, as shown in FIG.
Connecting part 9 formed on the copper foil 3 on the upper surface of the copper-clad laminate 5
Are formed by copper plating or the like, which connects the through holes 4. Here, as described above, the hole 4
Since the adhesive on the inner wall and the surface of the connection portion 9 is surely removed, the turning performance with plating during the formation of the conductor pattern 10 is improved, and the electrical connection reliability can be improved. Next, as shown in FIG. 2F, the printed wiring board 1 having the non-penetrating via holes 2 is formed by forming a circuit pattern 11 based on the conductive pattern 10 and the copper foil 7 of the conductive sheet 8 by etching or the like. Is produced.
After that, by performing a well-known manufacturing process such as outer shape processing, a desired printed wiring board can be completed.

As described above, the method for manufacturing a printed wiring board according to the present embodiment is a method for manufacturing a copper-clad laminate 5 on which a copper foil 3 is laminated.
The conductor sheet 8 having the adhesive layer 6 is attached to the laminate 5, and the copper foil 7 of the conductor sheet 8 is exposed from the hole 4 by laser processing or the like. The printed wiring board is manufactured by interlayer connection between the copper foil 3 on the upper surface and the copper foil 7 of the conductor sheet 8 adhered to the lower surface of the laminate 5.

Therefore, according to the present embodiment, the copper-clad laminate 5 can be drilled without fear of exuding the adhesive, so that a plurality of copper-clad laminates can be simultaneously drilled. It is possible to improve productivity.

Further, according to the present embodiment, the adhesive is removed after the copper-clad laminate 5 and the conductive sheet 8 are bonded to each other, so that it is not necessary to take measures to suppress the exudation of the adhesive. As a result, the number of available materials for the bonding sheet and the like are increased, and an inexpensive sheet can be used.

As described above, the present invention has been specifically described with reference to the embodiments. However, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. For example, as shown in FIG. 3 or FIG. 4, by removing a part of the adhesive layer 6 by laser processing, a printed wiring board realizing higher-density wiring can be manufactured.

[0028]

Next, an embodiment of the present invention will be described with reference to FIG.

First, as shown in FIG. 2A, four single-sided glass epoxy copper-clad laminates 5 each having a thickness of 0.3 mm and a copper foil 3 laminated on the upper surface thereof were prepared, and a drill having a diameter of 0.5 mm was prepared. As shown in FIG. 2B, a hole (through hole) 4 is formed by laminating four sheets by using. Further, the lower surface side of the perforated copper-clad laminate 5 and the adhesive layer 6 (the adhesive thickness 20) of the conductor sheet 8 with the copper foil 7 having a thickness of 18 μm.
μm) are laminated by a lamination hot press as shown in FIG.

Next, as shown in FIG. 2D, a conductor sheet adhered to the lower surface of the copper-clad laminate 5 by a carbon dioxide gas laser using the copper foil 3 on the upper surface of the copper-clad laminate 5 as a conformal mask. The adhesive layer 6 is removed from the upper surface side of the copper-clad laminate 5 through the hole 4, and the copper foil 7 of the conductor sheet 8 is exposed from the hole 4 to form the connection 9.

Thereafter, as shown in FIG.
Connecting part 9 formed on the copper foil 3 on the upper surface of the copper-clad laminate 5
2 (f) after forming a conductive pattern by a tenting method, forming a photo solder resist, electroless gold plating, and external processing by a router after performing copper through-hole plating for connecting the holes 4 to each other. Thus, printed wiring board 1 having non-penetrating via hole 2 is obtained.

As a result, a comparison result between the manufacturing cost of the printed wiring board according to the above embodiment and the manufacturing cost according to the conventional method shown in FIG. 5 is as shown in the following table.

[0033]

[Table 1] That is, in the drilling step, in the conventional method, the copper-clad laminate 5 is drilled one by one because there is a need to worry about the exudation of the adhesive. Could be implemented. In addition, regarding the material cost, the conventional method requires consideration to suppress the exudation of the adhesive, so that the usable adhesive sheet material is limited and an expensive sheet is used. In addition, since consideration for suppressing the exudation of the adhesive becomes unnecessary, an inexpensive sheet could be used.

Further, in the conventional method of pre-laminating the adhesive sheet, a separate adhesive sheet and a copper foil (or copper plate) are used in the conventional method. However, in the embodiment, the adhesive layer 6 and the copper foil 7 are integrated. Since the used conductor sheet 8 was used, the number of steps in the subassembly process could be eliminated. In the removal of the residual adhesive, in the example, the laser processing was used, so that the cost was higher than that of the conventional desmear treatment. However, the above-described drilling process, the material cost of the sheet, the preliminary bonding of the adhesive sheet, etc. When the subtotal of the costs was calculated by adding the costs described above, the cost was significantly reduced as compared with the conventional method.

Further, there was a difference between this embodiment and the conventional method in addition to the contents shown in Table 1. That is, with respect to the plated roundness of the hole 4 provided in the copper-clad laminate,
In the conventional method, the adhesive is removed by desmear treatment.Therefore, the removal of the adhesive is incomplete and the rotation with plating is poor. As a result, the turnability with plating was good. In addition, the embodiment provides better electrical connection reliability than the conventional method. Further, in the setting of the adhesive removing conditions, in the embodiment, since the adhesive layer 6 having a substantially uniform thickness is removed by a laser, the adhesive removing conditions can be set in a shorter time than in the conventional desmear processing. Was completed.

[0036]

As described above, according to the present invention,
Drilling can be performed on the substrate without fear of exuding the adhesive, so that a plurality of substrates can be drilled simultaneously, and productivity can be improved. Further, according to the present invention, the adhesive is removed after the substrate and the conductive sheet or the conductive plate are bonded to each other, so that consideration for suppressing the exudation of the adhesive becomes unnecessary. As a result, restrictions on the material of the adhesive sheet that can be used are reduced, and an inexpensive sheet can be used. Further, at this time, by using a sheet in which the adhesive layer and the conductor layer are integrally formed, the cost can be further reduced and the workability can be improved.

Further, according to the present invention, through a hole of a substrate,
Since the adhesive layer with a substantially uniform thickness is removed by laser, it is easier to set the conditions for removing the adhesive layer compared to, for example, desmear treatment using an oxidizing agent, and to remove the adhesive efficiently and with high precision. Becomes possible. Therefore,
According to the present invention, it is possible to improve the productivity of the printed wiring board to be manufactured, and to improve the plating turnability on the conductor portion from which the inner wall of the hole provided in the substrate and the adhesive have been removed. Thus, the connection reliability of the printed wiring board can be improved.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a view for explaining a method of manufacturing the printed wiring board of FIG. 1;

FIG. 3 is a view showing another printed wiring board different from the printed wiring board of FIG. 1;

FIG. 4 is a view showing another printed wiring board different from the printed wiring boards of FIGS. 1 and 3;

FIG. 5 is a view for explaining a conventional method for manufacturing a printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed wiring board 2 ... Non-penetrating via hole 3, 7 ... Copper foil 4 ... Hole 5 ... Copper clad laminated board 6 ... Adhesive layer 8 ... Conductor sheet 9 ... Connection part 10 ... Conductor pattern 11 ... Circuit pattern

Claims (5)

[Claims] 1. A sheet comprising: a substrate having a first conductor layer laminated on one surface and a hole provided therein; and a sheet comprising an adhesive layer and a second conductor layer, wherein A conductor sheet having the adhesive layer adhered to the other surface of the substrate so as to cover the hole from the surface side, and the adhesive layer of the conductor sheet adhered to the other surface of the substrate, A connection portion formed by removing the second conductor layer from one side of the substrate through the hole portion to expose the second conductor layer from the hole portion; and a connection portion formed in the second conductor layer, A printed wiring board comprising: a conductive pattern connecting the first conductive layer to the first conductive layer through the hole. 2. A substrate having a conductor layer laminated on one surface and provided with a hole, a conductor plate provided to cover the hole from the other surface side of the substrate, and the substrate An adhesive sheet interposed between the other surface of the substrate and the conductive plate to adhere to each other; and removing the adhesive sheet from the one surface side of the substrate through the hole to expose the conductive plate from the hole. A printed wiring board, comprising: a connection portion formed by the above-described process; and a conductor pattern connecting the connection portion and the conductor layer formed on the conductor plate through the hole. 3. A step of forming a hole in a substrate having a first conductor layer laminated on one surface, and a step of forming an adhesive layer and a second layer so as to cover the hole from the other surface of the substrate. Attaching the adhesive layer of the conductor sheet made of a conductor layer to the other surface of the substrate; and attaching the adhesive layer of the conductor sheet attached to the other surface of the substrate to one surface of the substrate. A step of removing the second conductor layer from the hole by removing the hole from the side through the hole, and a step of connecting the first and second conductor layers through the hole. Manufacturing method of wiring board. 4. A step of forming a hole in a substrate having a conductor layer laminated on one surface, and a step of bonding the conductor plate via an adhesive sheet so as to cover the hole from the other surface side of the substrate. Adhering to the other surface of the substrate; removing the adhesive sheet interposed between the substrate and the conductor plate from the one surface side of the substrate through the hole to remove the conductor plate from the hole A method for manufacturing a printed wiring board, comprising: a step of exposing the conductor layer and the conductor plate through the hole; and a step of connecting the conductor layer and the conductor plate through the hole. 5. The method for manufacturing a printed wiring board according to claim 3, wherein the adhesive layer or the adhesive sheet of the conductor sheet is removed by a laser.