JPH04236481A - Manufacture of metal plate base circuit board - Google Patents

Abstract

PURPOSE:To reduce the height of a burr generated when a conductive circuit board is punched to the height not more than the board, to improve solder cream printability and to prevent thermal conductivity malfunction of a heat dissipation plate by punching with a die press having a punch of a special structure of its bottom to obtain a metal plate base circuit board. CONSTITUTION:A plurality of metal plate base circuit board original plates are secured to a die press 12 having a punch 4 and a die 5 with conductive circuits 3 thereof being directed upward. Then, an upper die set 9 is moved down by a press, the peripheral edge of a conductive circuit board is punched by the punch 4 having a cutting die 6 and a recess 8 at the peripheral edge of its bottom, and stacked in a through hole 13 of the die 5. The punched boards are generated with burrs 7 at the peripheral edge of an aluminum plate, but the burrs 7 do not reach the surfaces of the circuits 3 to obtain an excellent metal plate base circuit board.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a press tool having a punch with a special structure at the bottom in order to obtain each conductive circuit board from a metal plate-based circuit board original plate on which a plurality of conductive circuits are attached. The present invention relates to a method for manufacturing a metal plate-based circuit board that is punched and divided using a die.

0002

2. Description of the Related Art In general, a metal plate-based circuit board on which a plurality of conductive circuits are mounted is punched out using a press die when it is divided into parts.

However, in the conventional punching method using a press die, because the punch 4 of the press die has a flat bottom punching surface as shown in FIG. There was a drawback in that a burr 7 protruding beyond the surface height of the circuit board as shown in FIG. 5 was generated around the periphery.

Since the protrusion of the burr 7 protrudes from the conductive circuit portion of the circuit board, it becomes an obstacle during a later process such as solder cream printing, significantly reducing work efficiency and causing product defects. do.

On the other hand, there is a method in which the punch 4 of a press mold is punched from the back side of the metal plate 1 on the side opposite to the conductive circuit of the metal plate base circuit board to prevent the burrs 7 from appearing on the surface of the product.
Even with this method, since the burrs 7 protrude from the back surface of the metal plate 1, a gap is created when it is attached to a heat sink, which impairs thermal conductivity, which is a characteristic of metal plate-based circuit boards.

[0006]

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and its object is to attach a metal foil to a metal plate via an insulating layer, and to form a plurality of conductive circuits. When dividing each conductive circuit board from a metal-based circuit board master plate on which is applied, a press die with a punch with a special structure at the bottom is used, and this occurs at the peripheral edge of the punched product. To provide a method for manufacturing a metal plate-based circuit board that has good solder cream printability in a subsequent process and does not impair thermal conductivity since the height of the burrs is kept below the height of the product. .

[0007]

[Means for Solving the Problems] That is, the present invention provides a method for forming a plurality of conductive circuits from a metal plate-based circuit board original plate in which a plurality of conductive circuits are formed by pasting a metal foil onto a metal plate through an insulating layer and etching it. When dividing a conductive circuit board with a press die consisting of a punch and a die, the punch is provided with a blade shape at the peripheral edge of the bottom, and the divided conductive circuit board can be contained inside the blade mold. This method of manufacturing a metal plate-based circuit board is characterized in that the conductive circuit board original plate is divided using the punch provided with a recess.

[0008]

[Operation] The present invention will be explained in detail below with reference to the drawings. Figure 1
is an original board consisting of a plurality of metal plate-based circuit boards used in the manufacturing method of the present invention, on which a conductive circuit 3 obtained by pasting a metal foil to a metal plate 1 via an insulating layer 2 is formed. FIG. 2 is a schematic plan view (a) and a cross-sectional view (b).

The metal plate 1 constituting the conductive circuit board is a copper plate,
Any of iron plates, aluminum plates, brass plates, stainless steel plates, etc. can be used, and those having a normal wall thickness in the range of 0.5 to 5.0 mm can be used.

The insulating layer 2 may be made of any insulating material, such as glass cloth impregnated with epoxy resin, phenol resin, unsaturated polyester resin, polyimide resin, etc., or inorganic filler. There are types that are filled, those that are formed only with a resin layer, and those that are bonded to a film.

Furthermore, when it comes to the conductive circuit 3, the metal foil to be attached may be copper foil, aluminum foil, brass foil, nickel foil, or a bonding foil of these.

[0012] The metal plate-based circuit board used in the manufacturing method of the present invention was prepared by providing an insulating layer 2 on both sides of the metal plate 1 shown in FIG. There is no problem even if it is something.

Next, a method of dividing a plurality of metal plate-based circuit board original plates into boards having respective conductive circuits will be explained.

FIG. 2 shows a schematic external view (a) of a press mold 12 equipped with a punch 4 and a die 5 whose bottom part has a special structure used in the manufacturing method of the present invention, and a schematic plan view (a) of the punch 4. b) and a schematic sectional view (c) of the punch 4 and die 5.

The press mold 12 is composed of an upper die set 9, a lower die set 10, and a guide post 11. The punch 4 is fixed to the upper die set 9, and the lower die set 10
Dice 5 is fixed to. The press mold 12 consisting of the punch 4 and the die 5 may have one or more punching surfaces.

The punch 4 fixed to the upper die set 9 is
The punch 4 is lowered by the press and inserted so that the peripheral edge of the punch 4 does not come into contact with the inner wall of the die 5 as shown in FIG. 2(c).

The punch 4 has a blade 6 at the peripheral edge of the bottom, and a recess 8 is provided inside the blade 6. The width of the blade type 6 is
It varies depending on the material being cut, but it is 0.1 to 2.0 mm.
, preferably 0.2 to 1.0 mm. If the width of the blade type 6 is less than 0.1 mm, the blade will be severely worn out, and if the width is less than 2.0 mm
If the length exceeds m, the length of the burr 7 will protrude from the punched surface side of the conductive circuit board, which is not preferable.

[0018] The angle of the blade die 6 toward the recessed direction is 25~
The angle is 90 degrees, preferably 40 to 60 degrees; angles other than this have the disadvantage that the blade is severely worn out and the length of the burr 7 becomes long. Furthermore, the recess 8 only needs to have a size and depth that can accommodate the conductive circuit board punched out by the punch 4.

Furthermore, the die 5 fixed to the lower die set 10 has a through hole 13 large enough to insert the punch 4, and each of the conductive circuit boards divided by the punch 4 is inserted into the through hole 13. They are stacked and can be removed one by one from below.

[0020]

[Example] A copper foil with a thickness of 35 μm is bonded to an aluminum plate with a thickness of 1.5 mm as a metal plate 1 through an insulating layer 2 with a thickness of 80 μm, and a conductive circuit 3 is formed by etching. A plurality of metal plate-based circuit board blanks shown in FIG. 1 were fixed to a press die 12 having a punch 4 and a die 5 capable of punching three pieces at a time, with the conductive circuits 3 facing upward.

Next, the upper die set 9 starts to descend by a press machine (not shown), and a width of 0.5 m is formed at the bottom periphery.
The periphery of each conductive circuit board was punched out using a punch 4 having a blade 6 having an angle of 45 degrees and a recess 8 of 2 mm, and stacked in the through hole 13 of the die 5.

Each punched conductive circuit board has a step of 0.7 mm and a height of 0.1 mm on the periphery of the aluminum plate.
Although a burr 7 of 5 mm was generated, the burr 7 did not reach the surface of the conductive circuit 3, and a good metal plate base circuit board as shown in FIG. 3 could be obtained.

[0023]

As described above, in the present invention, when obtaining a metal plate base circuit board as in the above embodiment, a conductive circuit is formed by punching with a press die having a punch with a special structure at the bottom. A crushed step is formed at the periphery of the board, and a burr is also formed in this step, so the height of the burr is less than the surface height of the conductive circuit board on the punched side. It does not interfere with the solder cream printing process and provides extremely good workability, and there is no gap even when a heat sink is attached to the metal plate side, resulting in good thermal conductivity, which is a characteristic of metal plate-based circuit boards. It has characteristics that allow it to be maintained.

[0024]

[Brief explanation of the drawing]

FIG. 1 shows a schematic plan view (a) and a schematic cross-sectional view (b) of a metal plate-based circuit board on which a plurality of conductive circuits are mounted.
) is shown.

FIG. 2 shows a schematic cross-sectional view of a press mold (a), a schematic plan view of a punch (b), and a schematic cross-sectional view of a punch and a die (c) used in the production of the present invention. .

FIG. 3 is a schematic plan view (a) and a schematic cross-sectional view (
b).

FIG. 4 is a schematic plan view of a punch used in a conventional press mold (a) and a schematic cross-sectional view of the punch and die (b).
) is shown.

FIG. 5 is a schematic cross-sectional view of a metal plate-based circuit board punched and divided using a conventional press die.

[Explanation of symbols]

1 Metal plate 2 Insulating layer 3 Conductive circuit 4 Punch 5 Dice 6 Blade type 7 Kaeri 8 Hollow 9 Upper die set 10 Lower die set 11 Guide post 12 Press mold 13 Through hole

Claims (1)

[Claims] [Claim 1] Each conductive circuit board is formed by punching and dicing a metal plate-based circuit board original plate in which a metal foil is attached to a metal plate via an insulating layer and etched to form a plurality of conductive circuits. When dividing with a press die, the punch is provided with a blade mold on the periphery of the bottom, and a recess inside the blade mold that can contain the divided conductive circuit board. A method for manufacturing a metal plate-based circuit board, characterized in that the conductive circuit board original plate is divided by using a method.