JP2001244611A - Circuit board and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board of high quality at a low cost capable of being manufactured at a small number of steps without being specially shaped in a wiring section, and a method for manufacturing the circuit board for manufacturing the board. SOLUTION: A punched piece 10 punched from a copper foil 9 is adhered to a polyimide tape 1 by a die 7 and a punch 8, thereby forming wirings 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board and a method for manufacturing the same, and more particularly, to a wiring board having a small number of processing steps and advantageous in quality and a manufacturing method for manufacturing the same.

[0002]

2. Description of the Related Art A wiring board in which wiring of a predetermined pattern is formed on a flex insulating sheet such as a polyimide tape,
It is widely used as a chip mounting substrate for semiconductor devices.
FIG. 4A shows a BGA which is one of such wiring boards.
This shows a procedure for manufacturing a wiring board for (Ball Grid Array). First, (1) a hole is formed in a polyimide tape such as a via hole or a transport sprocket hole by a press, and (2) one side thereof is formed. Laminate copper foil.

Next, (3) a resist material is applied to the copper foil,
(4) After the resist material is cured by performing an exposure process of irradiating light through a mask having a predetermined pattern, (5) the uncured portion of the resist material is removed, and (6)
A protective layer for protecting the copper foil exposed in the via hole is formed on the back surface of the substrate.

[0004] Next, (7) a wiring having a predetermined pattern is formed by etching the copper foil.
(8) The removal of the protective layer on the back surface and (9) the removal of the cured resist are performed, thereby forming a predetermined wiring board. Since this method is based on photo-etching, it is suitable for forming fine wiring, and is used for manufacturing various wiring substrates including a BGA substrate.

[0005]

However, according to the conventional method for manufacturing a wiring board, the manufacturing steps are basically (1) to (1).
(9) Since the process consists of the nine steps, it takes time and effort to complete the product, which greatly affects the cost. In addition, since the wiring is formed by etching, the cross section of the wiring has an irregular shape. Quality problems.

FIG. 4B shows a cross section of the wiring formed by the etching process. The side surface 2a of the wiring 2 formed on the polyimide tape 1 is eroded by the etching solution in an inclined manner. When a small dimension is set for the interval A between the upper surfaces 2b of the wiring 2, the distance B between the lower portions 2c is set.
May become too narrow, which may hinder the insulation.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a low-cost, high-quality wiring board which can be manufactured in a small number of steps and has no deformed wiring cross section, and a manufacturing method for manufacturing the same.

[0008]

In order to achieve the above object, the present invention comprises a flex insulating sheet such as a polyimide tape and wiring formed in a predetermined pattern on the flex insulating sheet. The present invention also provides a wiring board comprising punched pieces punched out of a copper foil and attached to the flex insulating sheet.

In order to achieve the above object, the present invention provides a method of manufacturing a wiring board for forming a wiring of a predetermined pattern on a flex insulating sheet such as a polyimide tape. A method for manufacturing a wiring board, comprising preparing a piece, and attaching the punched piece onto the flex insulating sheet to form the wiring of the predetermined pattern.

In the manufacturing method of the present invention, the punched pieces punched out by the press may be attached to the flex insulating sheet in a separate step, but it is preferable to attach them in the extension of the punching operation of the press punch. In such a case, the work is ensured and the work efficiency can be improved. The integration of the flex insulating sheet and the punched pieces is performed via an adhesive, for example, by heating a flex insulating sheet on which an adhesive layer has been formed in advance, and pressing the punched pieces against the heated sheet.

[0011]

Next, an embodiment of a wiring board and a method of manufacturing the same according to the present invention will be described. FIG. 1 (a)
In the figure, 1 is a polyimide tape, 2 is a wiring formed on the polyimide tape 1, and has bonding pads 3 and solder ball lands 4 at both ends. A penetrating via hole 5 is formed in a portion of the polyimide tape 1 where the solder ball land 4 is located, and the solder ball is mounted on the land 4 from the opposite surface illustrated through the via hole 5.

FIG. 1 (b) is an enlarged view of a part of FIG. 1 (a). The wiring 2 is formed by cutting a punched piece from a copper foil into an adhesive layer on the surface of a polyimide tape 1. (Not shown). FIG.
Shows an example of a press used for manufacturing a wiring board in the present invention, a die 7 having a punched hole 6 having the same shape as the wiring 1, and a punch 8 for punching a copper foil 9 by engaging with the punched hole 6. The punch 8 is punched out of the copper foil 9 placed on the die 7, and the punched-out piece 10 is attached to the polyimide tape 1 in the extension of the punching operation of the punch 8.

The polyimide tape 1 has a heater block 1
1, which is heated by the punch 1 and pressed against the polyimide tape 1 by the punch 8.
Are bonded via a molten adhesive layer on the surface of the polyimide tape 1. FIG. 2 shows an example of punching for one wiring 2.
(A) are provided with a plurality of punched holes 6 corresponding to the respective shapes and positions of the wirings 2, 2,... And the copper foil 9 placed thereon.
Can be simultaneously punched by a plurality of punches 8 corresponding to the respective punching holes 6.

FIG. 3A is a flow chart showing a manufacturing procedure in the present invention. The steps are (1) a step of forming holes such as via holes and sprocket holes in the polyimide tape 1, and (2) a copper foil 9. Stamping process with a press,
(3) The process is realized by three steps of a step of attaching a punched piece to the polyimide tape 1. Therefore, the number of steps is the same as the conventional one.
When the manufacturing method shown in FIG. 2 is adopted, the process (2) and the process (3) are performed simultaneously, so that there are substantially two processes. Compared with the conventional manufacturing method, the cost can be significantly reduced.

FIG. 3B shows a cross section of the wiring 2 formed according to the present invention. Because it is by punching,
The cross-sectional shape is rectangular, and therefore, there is no problem in insulation due to the deformation of the cross-section due to the erosion of the etching solution as in the conventional etching.

[0016]

As described above, according to the wiring board and the method of manufacturing the same according to the present invention, since the wiring is formed by sticking the punched pieces out of the copper foil, the wiring can be manufactured with a small number of steps and the wiring cross section can be manufactured. Can be prevented, and a low-cost and high-quality wiring board can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a wiring board of the present invention, wherein (a) is a plan view and (b) is an enlarged view of a part of a wiring.

FIG. 2 is an explanatory view showing a press used in an embodiment of the manufacturing method of the present invention.

3A and 3B are explanatory diagrams showing the effect of the present invention, wherein FIG. 3A shows a manufacturing flowchart, and FIG. 3B shows a cross-sectional structure of a wiring.

4A and 4B are explanatory views showing a conventional wiring board and a method for manufacturing the same, wherein FIG. 4A is a manufacturing flowchart, and FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 polyimide tape 2 wiring 3 bonding pad 4 land for solder ball 5 via hole 6 punched hole 7 die 8 punch 9 copper foil 10 punched piece 11 heater block

Continued on the front page F term (reference) 5E319 AA03 AC03 AC12 BB04 CC33 CD26 GG15 5E343 AA07 AA18 AA33 BB67 DD54 DD56 DD62 GG11

Claims (5)

[Claims] 1. A flex insulating sheet such as a polyimide tape, and a wiring formed in a predetermined pattern on the flex insulating sheet, wherein the wiring is punched out of a copper foil and attached to the flex insulating sheet. A wiring substrate, comprising: a punched piece. 2. The wiring board according to claim 1, wherein said wiring is constituted by a punched piece having a bonding pad connected to an electrode of a semiconductor chip and punched from said copper foil. . 3. The wiring comprises a punched piece having a land for a solder ball and punched from the copper foil, and the flex insulating sheet is used for mounting the solder ball on the land for the solder ball. 2. The wiring board according to claim 1, further comprising a via hole. 4. A method of manufacturing a wiring board for forming a wiring of a predetermined pattern on a flex insulating sheet such as a polyimide tape, wherein a punched piece is prepared by punching a copper foil with a press, and A method of manufacturing a wiring board, wherein the wiring is formed on the insulating sheet to form the wiring of the predetermined pattern. 5. A step of attaching the punched piece to the flex insulating sheet includes attaching the punched piece to the flex insulating sheet in an extension of a punching operation of the punch of the press. The method for manufacturing a wiring board according to claim 4, wherein