JP2003188545A - Laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated sheet in which the surface of metal foil (inner face) facing a metal plate is not damaged, which is maintained in a suitable state for a subsequent etching process, and which is superior in recycle property. <P>SOLUTION: The laminated sheet A where metal foils 2 are laminated and integrated on one face of the metal plate 1 is overlapped with the end face of a wiring board laminated body B where thermosetting resin plates 4 and printed wiring boards 5 in which printed circuits are formed on double faces of an insulating substrate are alternately laminated so that the thermosetting resin plate 4 becomes the outermost layer in a state where the metal foils 2 face thermosetting resin plates 4. Then they are heated and integrated. The metal foils 2 are removed from the metal plate 1 to manufacture a multilayer printed board. The metal plate 1 and the metal foil 2 in the laminated sheet A are bonded and integrated without using adhesive at the outer peripheral part of the confronted face. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminated sheet used in a process of manufacturing a multilayer printed circuit board.

[0002]

2. Description of the Related Art In recent years, in order to reduce the size, weight and density of electronic equipment, printed wiring boards have been laminated in multiple layers to form a multilayer printed board. As a method of manufacturing such a multilayer printed circuit board, Japanese Patent No. 310 is available.
No. 0983, a semi-cured thermosetting resin plate and a printed wiring board having printed circuits formed on both surfaces of an insulating substrate are alternately laminated so that the thermosetting resin plate is the outermost layer. After a plurality of wiring board laminates are stacked and heat-integrated with a laminated sheet in which metal foils are laminated and integrated on both surfaces of the metal plate interposed between the wiring board laminates, A method for manufacturing a multilayer printed circuit board is described, in which a plurality of multilayer printed circuit boards are manufactured by separating metal foils.

The laminated sheet is formed by superimposing copper sheets on both sides of an aluminum sheet and joining the outer peripheral portions of the opposing surfaces of the aluminum sheet and the copper sheet together by an adhesive.

However, as described above, since the adhesive is used to join and integrate the aluminum sheet and the copper sheet of the above-mentioned laminated sheet, the adhesive component or the adhesive generated when the adhesive is dried is used. There has been a problem that the inner surface of the copper sheet is damaged by the solvent component, which hinders the subsequent etching process.

In manufacturing the above laminated sheet,
First, after applying an adhesive to the outer peripheral portion of one surface of the aluminum sheet, a copper sheet is superposed on one surface of this aluminum sheet. However, if the copper sheet is superposed on one surface of the aluminum sheet, it will adhere to the copper sheet. Since the agent will adhere, the aluminum sheet and the copper sheet cannot be overlaid again, so
There is a problem that the aluminum sheet and the copper sheet must be carefully overlapped with each other, which complicates the production process.

Further, in the above-described method for manufacturing a multilayer printed circuit board, after laminating a plurality of wiring board laminated bodies between the wiring board laminated bodies and heating and integrating them, the aluminum sheet and the copper sheet of the laminated sheet are unnecessary. The part is removed.
And, although unnecessary parts of these laminated sheets are sent to recycling, since the unnecessary part contains an adhesive layer, the adhesive component cannot be completely removed from the aluminum sheet and the copper sheet, and thus the recyclability is improved. However, there was a problem that it was decreasing.

[0007]

DISCLOSURE OF THE INVENTION According to the present invention, a metal foil surface (inner surface) facing a metal plate is kept intact in a state suitable for the subsequent etching step and is excellent in recyclability. Provide the seat.

[0008]

A laminated sheet according to claim 1, wherein the thermosetting resin plate is a semi-cured thermosetting resin plate and a printed wiring board having printed circuits formed on both surfaces of an insulating substrate. At the end face of the wiring board laminate, which is alternately laminated so as to be the outermost layer, a laminated sheet in which a metal foil is integrally laminated on at least one surface of the metal plate is provided. The metal foil faces the thermosetting resin plate. The laminated sheet used in the method for producing a multilayer printed circuit board, comprising: stacking in a state and heating and integrating, and then manufacturing a multilayer printed circuit board by separating a metal foil from the metal plate; The plate and the metal foil are characterized in that they are joined and integrated at the outer peripheral portions of these facing surfaces without using an adhesive.

Further, in the laminated sheet according to claim 2, in the laminated sheet according to claim 1, the metal plate and the metal foil are joined and integrated by ultrasonic bonding at the outer peripheral portions of these facing surfaces. Is characterized by.

The laminated sheet according to claim 3 is
The laminated sheet according to claim 1, wherein the metal plate and the metal foil are joined and integrated by bending a projecting piece projecting on the outer peripheral edge of the metal foil at the outer peripheral portions of these facing surfaces toward the metal plate side. Is characterized by.

Further, in the laminated sheet according to claim 4, in the laminated sheet according to claim 1, the metal plate and the metal foil are integrally deformed, and a space between the metal plate and the metal foil in the deformed portion is formed. The metal plate and the metal foil are joined and integrated at the outer peripheral portions of these facing surfaces by the frictional force of.

Finally, the laminated sheet according to claim 5 is
The laminated sheet according to any one of claims 1 to 4, wherein the surface of the metal foil facing the metal plate has an average surface roughness Rz of 5 µm or less.

[0013]

In the laminated sheet of the present invention, the metal foil is superposed on at least one surface of the metal plate, and the metal plate and the metal foil are joined and integrated at the outer peripheral portions of their facing surfaces without using an adhesive. The adhesive does not exist in the unnecessary portion of the laminated sheet that is removed in the manufacturing process of the multilayer printed circuit board, so that the metal plate and the metal foil can be completely separated to improve recyclability.

Moreover, since the adhesive is not used for joining and integrating the metal plate and the metal foil, the surface of the metal foil is not affected by the adhesive component or the solvent component of the adhesive, and the metal The foil can be etched accurately and reliably to produce an accurate printed circuit.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An example of the laminated sheet of the present invention will be described with reference to the drawings. The laminated sheet A is shown in FIGS.
As shown in FIG. 2, at least one surface of the flat rectangular metal plate 1 having a constant thickness with both surfaces formed flat, that is, one or both surfaces of the metal plate 1, has the same shape and the same size as the metal plate 1. Of the flat rectangular metal foil 2 having a constant thickness are overlapped, and the outer peripheral edge portions of the facing surfaces of the metal plate 1 and the metal foil 2 are joined and integrated in a rectangular frame shape without using an adhesive over the entire circumference. It becomes.

The metal plate 1 is not particularly limited as long as both surfaces are formed as smooth surfaces, and examples thereof include an aluminum plate and a stainless plate. The metal plate 1 is
Usually, those having a thickness of 0.15 to 0.5 mm are used.

The metal foil 2 is not particularly limited as long as it can form a printed circuit by etching, and examples thereof include electrolytic copper foil, rolled copper foil,
Copper alloy foil containing about 10% by weight of zinc and 4% by weight of tin
Examples include copper alloy foils containing about a certain amount. The metal foil 2 usually has a thickness of 9 to 70 μm.

If the surface average roughness Rz of the surface (inner surface) of the metal foil 2 facing the metal plate 1 is rough, it may be difficult to remove the synthetic resin applied during the etching process. Therefore, it is preferably 5 μm or less,
5 μm is more preferable. The surface average roughness Rz of the metal foil 2 is one measured according to JIS B0601 (revised in 1994).

On the other hand, the outer surface of the metal foil 2 is subjected to a roughening treatment in order to improve the adhesiveness with the thermosetting resin plate 4 of the wiring board laminate B described later. As a roughening treatment method for the outer surface of the metal foil 2, a general-purpose method has been conventionally used. For example, in an acidic electrolyte, at a high current density near the limiting current density, copper, copper alloy, zinc and zinc alloy are used. A method of electrodepositing one or more metal thin films selected from the group consisting of (GB Patent GB203246A and JP-A-63-8969).
No. 8) and the like.

Further, the metal plate 1 and the metal foil 2 are
As shown in FIG. 1, without using an adhesive on the entire circumference of the outer peripheral edge portions of the facing surfaces, that is, in a state where the metal plate 1 and the metal foil 2 directly contact their facing surfaces. Is continuously integrated into a rectangular frame by ultrasonic bonding. The metal plate 1 and the metal foil 2 may be partially (intermittently) ultrasonically bonded along the entire circumference of the outer peripheral edge of the facing surfaces thereof.

The ultrasonic bonding strength between the metal plate 1 and the metal foil 2 is such that the metal plate 1 and the metal foil 2 are bonded to each other in such a way that they are not accidentally separated in the manufacturing process of the multilayer printed circuit board. The metal plate 1 and the metal foil 2 may be integrated so that the metal plate 1 and the metal foil 2 can be separated from each other by hand in order to easily separate the metal plate 1 and the metal foil 2 at the time of separate collection. It is preferably joined and integrated. The ultrasonic bonding conditions for the metal plate 1 and the metal foil 2 are preferably a pressure of 50 to 80 N and a bonding speed of 3 to 4 m / min.

Further, the metal foil 2 is laminated and integrated on at least one surface of the metal plate 1 by bonding and integrating only the outer peripheral edge portions of these facing surfaces, and the metal plates other than the bonding portion 3 are integrated. The opposing surfaces of the metal plate 1 and the metal foil 2 are not integrated, and the metal plate 1 and the metal foil 2 are not integrated.
And are just overlaid.

Next, the usage of the laminated sheet A will be described. First, as shown in FIG. 2, a thermosetting resin plate 4 made of a thermosetting resin such as a semi-cured epoxy resin containing a glass fiber, and printed circuits 52, 52 are formed on both surfaces of an insulating substrate 51. The printed wiring board 5 thus formed is alternately laminated so that the thermosetting resin plates 4 and 4 are the outermost layers to produce a plurality of wiring board laminates B, B .... The thermosetting resin 4 and the printed wiring board 5 are formed in a plane rectangular shape having the same size and shape.

Then, as shown in FIG. 3, the plurality of wiring board laminated bodies B, B ...
Between B, the metal foils 2, 2 are bonded to both sides of the metal plate 1 at the rectangular frame-shaped bonding portions 3 formed on the outer peripheral surfaces of the facing surfaces of the metal plates 1 and 2. The inner laminated sheets A1 which are integrally laminated are integrated with each other, with the inner laminated sheets A1 interposed therebetween. A rectangular frame-shaped joint part in which the metal foil 2'is formed only on one surface of the plate 1'on the outer peripheral surface of the facing surface between the metal plate 1'and the metal foil 2 '.
The upper and lower laminated sheets A2 and A2, which are laminated and integrated by joining and integrating with the metal plate 1 ′ at 3 ′,
A multilayer wiring board laminate C is produced by stacking 2'and 2'on top of each other so as to face the thermosetting resin plates 4 and 4.

At this time, when the rectangular frame-shaped joint portions 3 and 3'of the inner laminated sheet A1 and the upper and lower laminated sheets A2 are projected in the vertical direction (thickness direction), the thermosetting resin plate 4 and the printed wiring The size of the rectangular frame-shaped joints 3 of the laminated sheets A1 and A2 and the thermosetting resin plate 4 and the printed wiring board 5 are arranged so that all the plates 5 are located in the rectangular frame-shaped joints 3. The size is adjusted appropriately.

Thereafter, the multilayer wiring board laminate C is heated from above and below while applying pressure in the compression direction to cure the thermosetting resin plates 4, 4 ... At the same time as forming the printed wiring boards 5 and 5, the printed wiring boards 5 and 5, the inner laminated sheet A1, the printed wiring boards 5 and 5, the upper and lower laminated sheets A2 and A2, and the insulating plate 4 '. Integrate through.

At this time, since the outer surface of the metal foil 2 (2 ') of the inner laminated sheet A1 (upper and lower laminated sheets A2) has been roughened, part of the thermosetting resin plate 4 is heated. During the curing process, it is in a state of being embedded in the uneven portion of the outer surface of the metal foil 2 (2 ') of the laminated sheet A, and the laminated sheet A1
The metal foil 2 (2 ') of the (upper and lower laminated sheet A2) and the insulating plate 4'obtained by curing the thermosetting resin 4 facing the metal foil 2 (2') are firmly integrated.

Next, as shown in FIG. 4, the metal plate 1 and the metal foils 2 and 2 in each inner laminated sheet A1 are separated, and the metal plate 1 in the upper and lower laminated sheets A2 and A2 is separated. By separating the metal foils 2'and 1'from the metal foils 2'and 2 ', the printed wiring boards 5 and 5 are laminated and integrated via the insulating plate 4'and the metal foils 2 and 2 are formed on the upper and lower end surfaces.
A plurality of multilayer substrates D in which (2 ') are laminated and integrated are obtained.

At this time, the metal plates 1 and 1'and the metal foil 2 in the inner laminated sheet A1 and the upper and lower laminated sheets A2,
2'is only integrally joined to the extent that it can be separated from each other only at the joints 3 and 3'by hand,
The metal plates 1 and 1'and the metal foils 2 and 2'can be easily and reliably separated.

The metal plates 1 and 1'and the metal foils 2 and 2 '
Is only integrated by ultrasonic bonding, and there is no adhesive between the metal plates 1 and 1'and the metal foils 2 and 2 ', and therefore the metal plates 1 and 1 are 'And above metal foil 2, 2'
Can be completely separated, and the metal plates 1 and 1'can be completely recycled.

Then, the metal foils 2, 2 of each of the above-mentioned multilayer substrates D
The outer peripheral portion 20, 20 (20 ') of (2') is the printed wiring board 5 described above.
After cutting along the outer edge of the metal foil 2, 2 (2 ')
By etching to form a desired printed circuit, and further by short-circuiting the printed circuits 52, 52 ... Of the plurality of printed wiring boards 5, 5, ... By forming through holes or the like. It is possible to obtain a plurality of multilayer printed circuit boards. Further, no adhesive is present on the cut outer peripheral portions 20 and 20 (20 ') of the metal foils 2 and 2 (2'), and complete recycling as in the case of the metal plates 1 and 1 '. Can be achieved.

Since the surfaces of the metal foils 2, 2 (2 ') on the upper and lower end surfaces of the multi-layer substrate D are formed as smooth surfaces, the metal foils 2, 2 in the etching process for forming a printed circuit are formed. (2 ′) The synthetic resin can be smoothly and reliably removed after the application of the synthetic resin and the etching treatment.

In the laminated sheet A, the case where the metal plate 1 and the metal foil 2 are integrated by ultrasonic bonding has been described. However, as shown in FIGS. 5 and 6, a flat rectangular metal is used. Projecting pieces 21, 21 ... Are provided outwardly over the entire lengths of the outer peripheral edges of the foils 2, 2 facing each other, and the metal foils 2 are formed on both sides of the flat rectangular metal plate 1. 2 are piled up, and the projecting pieces 21 and 21 of the metal foil 2 are attached to the metal plate 1.
The metal plate 1 is bent and held on the side, that is, on the outer peripheral edge portion of the metal foil 2 which is superposed on the surface opposite to the surface of the metal plate 1 on which the metal foil 2 is superposed. It may be a laminated sheet A in which the above and the metal foils 2 and 2 are laminated and integrated. In addition, between the metal foils 2, 2 laminated on both sides of the metal plate 1, the pair of projecting pieces 21, 21 projecting on the one metal foil 2 and the pair of the projecting pieces projecting on the other metal foil 2. The protrusions 21 and 21 are orthogonal to each other, and the description of the same structural parts as the laminated sheet A shown in FIG. 1 will be omitted. Also in this laminated sheet A, the metal foil 2 may be laminated and integrated only on one surface of the metal plate 1.

Further, as the laminated sheet A, as shown in FIG. 7, the metal foils 2 and 2 are superposed on both sides of the metal plate 1 and the outer peripheral edges of the metal plate 1 and the metal foils 2 and 2 are overlapped. The metal plate 1 is pressed integrally from both sides toward the center in the thickness direction to form a recess A3, and the metal plate 1 is locked by the frictional force between the metal plate 1 and the metal foils 2 and 2 in the recess A3. The metal foil 2 and the metal foil 2 may be joined and integrated at outer peripheral edge portions of these facing surfaces. The description of the same structural parts as the laminated sheet A shown in FIG. 1 will be omitted. Also in this laminated sheet A, the metal foil 2 may be laminated and integrated only on one surface of the metal plate 1.

Finally, as the laminated sheet A, as shown in FIGS. 8 and 9, the metal foils 2 and 2 are superposed on both sides of the metal plate 1, and the metal plate 1 and the metal foil 2 are Through-holes A4, A4 of a certain size penetrating both outer surfaces of the outer peripheral edge portion 2 at regular intervals along both surfaces.
・ It may be formed by penetrating.

At this time, in the through hole A4 portion of the laminated sheet A, as shown in FIG. 9, the metal foil 2 superposed on one surface of the metal plate 1 bites into the metal plate 1 side and the metal plate 1 1 is also in a state of biting into the side of the metal foil 2 superposed on the other surface of the metal plate 1, and the metal plate 1 and the metal plate 1 and the metal foil 2 are locked by frictional force between the metal plate 1 and the metal foil 2. The foils 2 and 2 are joined and integrated. or,
Description of the same structural parts as the laminated sheet A shown in FIG. 1 will be omitted. Also in this laminated sheet A, the metal foil 2 may be laminated and integrated only on one surface of the metal plate 1.

[0037]

In the laminated sheet of the present invention, a semi-cured thermosetting resin plate and a printed wiring board having printed circuits formed on both sides of an insulating substrate have the thermosetting resin plate as the outermost layer. On the end surface of the wiring board laminated body alternately laminated to
A metal foil is laminated and integrated on at least one surface of a metal plate, and a laminated sheet is laminated in a state where the metal foil faces the thermosetting resin plate and integrated by heating, and then the metal foil is separated from the metal plate. The laminated sheet used in the method for producing a multilayer printed circuit board for producing a multilayer printed circuit board, wherein the metal plate and the metal foil in the laminated sheet use an adhesive at the outer peripheral portions of their facing surfaces. Since it is characterized by being integrally joined without bonding, the surface of the metal foil laminated and integrated on at least one surface of the metal plate is not affected by the adhesive or the solvent of the adhesive, and the metal The desired printed circuit can be manufactured accurately and precisely by smoothly and surely performing the etching process applied to the foil.

Moreover, since the metal plate and the metal foil laminated and integrated on at least one surface of the metal foil are joined and integrated without using an adhesive, they are removed in the manufacturing process of the multilayer printed circuit board. The metal plate and the metal foil can be separated from the laminated sheet portion for complete separate collection, and the recyclability can be improved.

The laminated sheet according to claim 2 is the laminated sheet according to claim 1, wherein the metal plate and the metal foil are joined and integrated by ultrasonic bonding on the outer peripheral portions of the facing surfaces. Therefore, the metal plate and the metal foil can be surely joined and integrated with each other by a simple operation such as stacking the metal foil on at least one surface of the metal plate and irradiating them with ultrasonic waves.

Further, the laminated sheet according to claim 3 is the laminated sheet according to claim 1, wherein the metal plate and the metal foil project from the outer peripheral edge of the metal foil at the outer peripheral portions of the facing surfaces. It is characterized in that it is joined and integrated by bending it to the metal plate side, so that the metal foil is superposed on at least one surface of the metal plate, and the projecting piece protruding from the outer peripheral edge of the metal foil is attached to the metal plate side. The metal plate and the metal foil can be joined and integrated by a simple operation such as bending.

The laminated sheet according to claim 4 is
The laminated sheet according to claim 1, wherein the metal plate and the metal foil are integrally deformed, and a frictional force between the metal plate and the metal foil in the deformed portion causes the metal plate and the metal foil to face each other. It is characterized in that the outer peripheral portion is integrally joined, so that the metal plate and the metal foil can be securely joined and integrated by a simple work such as superposing a metal foil on at least one surface of the metal plate and deforming these. Can be converted.

Finally, the laminated sheet according to claim 5 is
In the laminated sheet according to any one of claims 1 to 4, since the surface average roughness Rz of the surface of the metal foil facing the metal plate is 5 µm or less,
To easily and reliably apply or remove the synthetic resin applied to the surface of the metal foil when the metal foil is subjected to etching treatment, and to accurately and surely produce a desired printed circuit from the metal foil. You can

[Brief description of drawings]

FIG. 1 is a plan view showing a laminated sheet of the present invention.

FIG. 2 is an exploded vertical sectional view showing a multilayer wiring board laminate.

FIG. 3 is a vertical cross-sectional view showing a multilayer wiring board laminate.

FIG. 4 is a vertical cross-sectional view showing a state in which a multilayer substrate is manufactured.

FIG. 5 is an exploded perspective view showing another example of the laminated sheet of the present invention.

FIG. 6 is a vertical sectional view showing the laminated sheet of FIG.

FIG. 7 is a vertical cross-sectional view showing another example of the laminated sheet of the present invention.

FIG. 8 is a perspective view showing another example of the laminated sheet of the present invention.

9 is an enlarged vertical cross-sectional view showing a through hole portion of the laminated sheet of FIG.

[Explanation of symbols]

1 metal plate 2 metal foil 21 Projection piece 3 joints 4 Thermosetting resin plate 4'insulation board 5 printed wiring board 51 insulating plate 52 printed circuit A1, A2 laminated sheet A3 recess A4 through hole B wiring board laminate C Multilayer wiring board laminate D Multi-layer board

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5E346 AA05 AA06 AA12 AA15 AA22                       AA26 BB01 CC02 CC08 CC31                       CC60 DD02 DD12 EE02 EE06                       EE09 EE13 GG01 GG28 GG40                       HH33 HH40

Claims (5)

[Claims] 1. A semi-cured thermosetting resin plate and a printed wiring board having printed circuits formed on both surfaces of an insulating substrate are alternately laminated so that the thermosetting resin plate is the outermost layer. On the end face of the wiring board laminate, after laminating and stacking a laminated sheet in which a metal foil is laminated and integrated on at least one surface of the metal plate in a state where the metal foil faces the thermosetting resin plate, and integrated by heating, The above-mentioned laminated sheet used in a method for producing a multilayer printed circuit board for producing a multilayer printed circuit board by separating a metal foil from a metal plate, wherein the metal plate and the metal foil in the laminated sheet are facing surfaces thereof. A laminated sheet, characterized in that it is joined and integrated in the outer peripheral portion without using an adhesive. 2. The laminated sheet according to claim 1, wherein the metal plate and the metal foil are bonded and integrated by ultrasonic bonding at the outer peripheral portions of the facing surfaces. 3. The metal plate and the metal foil are joined and integrated by bending a projecting piece projecting on the outer peripheral edge of the metal foil at the outer peripheral portions of these facing surfaces toward the metal plate side. Item 2. The laminated sheet according to item 1. 4. A metal plate and a metal foil are integrally deformed,
The laminated sheet according to claim 1, wherein the metal plate and the metal foil are joined and integrated at the outer peripheral portions of the facing surfaces by a frictional force between the metal plate and the metal foil in the deformed portion. 5. The laminated sheet according to claim 1, wherein the surface of the metal foil facing the metal plate has an average surface roughness Rz of 5 μm or less.