JPH08181411A - Outer shape processing method of printed wiring board - Google Patents

Abstract

PURPOSE: To provide an outer shape processing method of a printed wiring board which enables proper outer shape processing without leaving a broken place inside an effective region of a substrate. CONSTITUTION: In the title outer shape processing method of a printed wiring board for outer shape processing of a substrate with an effective region 2 wherein a wiring pattern is formed and an invalid region 3 in a periphery thereof, a cutting blade part of a machining tool is first inserted into the invalid region 3 apart by a specified distance D from the effective region 2 of the substrate 1 and then outer shape processing is performed for a substrate according to a prescribed boundary line L while a relative position of the machining tool and the substrate 1 is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing the outer shape of various printed wiring boards used for mounting electronic parts or as constituent parts of electronic devices.

[0002]

2. Description of the Related Art Generally, in addition to punching or milling, NC is generally used for external processing of printed wiring boards.
Outline processing by a router is known. Depending on the method used, the degree of finish differs for each board's outer shape processing. Especially, in the case of the outer shape processing with an NC router, the cut edge surface is smooth and a high squareness can be obtained. Has been done. In the future, as high-density wiring is advanced, it is expected that the number of router-specification products for the purpose of preventing disconnection due to small pieces from the board end face will increase. In normal router machining, a cutting tool called a router bit similar to a drill is used. This cutting tool is provided with a cutting edge on the outer peripheral portion on the tip side of the bit, and the substrate is scraped off by the cutting edge portion when the outer shape of the substrate is processed.

2A and 2B are views for explaining a conventional external shape processing method for a printed wiring board, in which FIG. 2A is a partial plan view showing the externally processed substrate, and FIG. 2B is an enlarged view of part A thereof. Here, a printed wiring board used as a base material for a semiconductor device or the like will be described as an example. First,
The substrate 1 to be processed has already been subjected to a process such as formation of a wiring pattern and a protective film (resist film), plating on the electrode portion and character printing for identification in the substrate manufacturing process before that. There is. The substrate 1 thus manufactured is provided with an effective area 2 having a wiring pattern (not shown) and an ineffective area 3 having no pattern in the periphery of the effective area 2. Boundary line (indicated by a dashed line in the figure) that serves as a cut path (moving path) L
Is specified.

At the time of processing the outer shape of the substrate, first, while the cutting tool is rotated at a high speed, the cutting edge portion thereof is bordered by the boundary line L of the substrate 1.
When the cutting edge portion of the cutting tool penetrates through the substrate 1 by inserting it above, the cutting tool is moved laterally along the specified boundary line L while changing the relative position of the substrate 1 and the cutting tool. As a result, as shown in FIG.
A slit 4 is formed at the boundary between the effective area 2 and the ineffective area 3 by cutting with a cutting tool, and the cutting surface 4a of the slit 4 on the effective area 2 side is the final end surface of the printed wiring board. By the way, in the case of a printed wiring board used as a base material for semiconductor devices, each semiconductor device is separated by a broken line in the drawing at the stage where component mounting and semiconductor element resin sealing are completed. Since the substrate 1 is divided into individual pieces, the slits 4 (broken line portions in the drawing) are not separated at this point. Further, in the drawings, for convenience of description, the boundary line L is shown inside the slit 4 with a dashed-dotted line, but in reality, the outer shape processing is performed so that the end surface of the slit 4 coincides with the boundary line L. .

[0005]

By the way, in the conventional method for processing the outer shape of a printed wiring board, as shown in FIG. 2B, the P position (circle mark position) on the boundary line L defined in the substrate 1 is used. ), The cutting tool was moved in the direction indicated by the arrow in the figure to form the slit 4. However, a cutting tool such as a router bit is provided with a cutting blade only on the outer peripheral portion thereof, and the substrate 1 is provided on the tip surface.
Since there is no cutting blade for shaving, it is on the boundary line L (marked with a circle in the figure) that separates the effective area (pattern formation area) 2 in the substrate 1 from the ineffective area 3 around it, unlike the conventional method. When the cutting tool is inserted at the position (P) shown in Fig. 3), as shown in Fig. 3 (a), a damaged portion V (hatched portion in the drawing) such as a chip or a burr is generated in the peripheral area where the cutting tool is inserted. The portion remains in the effective area 2 of the substrate, that is, in the peripheral portion of the printed wiring board that is finally divided into individual pieces. In particular, recently, since there is a tendency to attach importance to the appearance after the outer shape processing, in the printed wiring board having the outer shape processing, the above-mentioned damaged portion V has been pointed out as an inferior appearance.

Therefore, as a provisional processing method, FIG.
As shown in (b), first, the middle position of the boundary line (◎ in the figure)
After inserting the cutting tool to the end position of the boundary line L as indicated by the arrow in the drawing, and then reversing the cutting direction as indicated by the arrow in the drawing, the damage point in the effective area 2 is inserted. It is possible to make the area of V as small as possible, but even in such a case, the damaged portion V in the effective area 2
Is left, and the time required for the outer shape processing becomes long.

The present invention has been made in order to solve the above problems, and an object thereof is to perform an outer shape processing of a printed wiring board capable of performing outer shape processing without leaving a damaged portion in an effective area of a substrate. To provide a method.

[0008]

The present invention has been made in order to achieve the above-mentioned object, and a substrate having an effective area in which a wiring pattern is formed and an ineffective area around it is provided with a prescribed boundary line. It is a contouring method for a printed wiring board that contours with a cutting tool.First, the cutting edge portion of the cutting tool is inserted into an ineffective area that is separated from the effective area of the board by a predetermined distance, and then the cutting tool is used. The outer shape of the substrate is processed according to a prescribed boundary line while changing the relative position of the substrate.

[0009]

In the method for processing a printed wiring board according to the present invention, the cutting edge portion of the cutting tool is inserted into the ineffective area sufficiently separated from the effective area of the substrate. Even if such a damaged portion occurs, it does not remain in the effective area of the substrate.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1A and 1B are views showing an embodiment of a method for processing an outer shape of a printed wiring board according to the present invention, in which FIG. 1A is a partial plan view showing an outer shape processed substrate, and FIG. is there. In this embodiment, the same components as those in the conventional example will be designated by the same reference numerals. First, the substrate 1 to be processed is subjected to processing such as formation of a wiring pattern and a protective film, plating on the electrode portion and character printing for identification as in the conventional case. No wiring pattern is formed on the substrate 1 together with an effective area 2 having a wiring pattern (not shown) formed by patterning a conductive material such as copper foil by etching or the like.
A so-called patternless invalid area 3 is provided around the valid area 2. Further, at the boundary between the effective area 2 and the ineffective area 3, a cutting tool cutting path (moving path) described later is provided.
A boundary line (indicated by a one-dot chain line in the drawing) L is defined.

Here, at the time of processing the outer shape of the substrate in this embodiment, first, while rotating a cutting tool such as a router bit at a high speed, the cutting edge portion thereof is removed from the effective area 2 of the substrate 1 as shown in FIG. 1 (b). Invalid area 3 separated by a predetermined distance D
Insert it inside (P position indicated by ◎ in the figure). The separation distance D from the effective area 2 to the tool insertion position P (⊚) is such that a damaged portion V (hatched portion in the figure) such as a chip or a burr generated when the cutting tool is inserted into the substrate 1 is within the effective area 2. It is set to a distance that does not remain.

Therefore, in setting the above-mentioned separation distance D, various processing conditions such as the size of the damaged portion V, the thickness of the substrate 1, the specifications of the cutting tool, the number of revolutions and the cutting speed of the cutting tool during processing, etc. Therefore, for example, the outer shape may be experimentally determined to determine the maximum area of the damaged portion V, and the maximum area may be set in consideration of the appropriate margin.

In this way, the cutting tool is inserted into the ineffective region 3 of the substrate 1, and when the cutting edge portion of the cutting tool penetrates the substrate 1 in this way, for example, either one of the substrate 1 and the cutting tool is horizontally moved. Then, the relative position between the substrate 1 and the cutting tool is changed, and the cutting tool is moved toward the boundary line L as shown by the arrow in FIG.

Subsequently, when the cutting tool reaches the boundary line L, the cutting tool is moved laterally along the boundary line L as indicated by an arrow in the figure. After that, when the cutting tool reaches the terminal end of the boundary line L, the cutting tool may be pulled out from the substrate 1 as it is. However, in the present embodiment, the cutting tool is intentionally disabled in order to prevent even minute damage at the time of pulling the tool. The cutting tool was pulled out after being moved to the region 3 side. As a result, as shown in FIG. 1A, a slit 4 is formed by cutting the cutting tool at the boundary between the effective area 2 and the ineffective area 3 of the substrate 1, and the cutting surface of the slit 4 on the effective area 2 side. 4a is the final end surface of the printed wiring board.

As described above, in this embodiment, the cutting edge portion of the cutting tool such as the router bit is set to the effective area 2 of the substrate 1.
Inside the ineffective area 3 sufficiently distant from the substrate 1, that is, a damaged portion V such as a chip or a burr generated when the cutting tool is inserted into the substrate 1.
Is separated by a distance D that does not remain in the effective area 2.
Since the outer shape of the substrate 1 is processed according to the prescribed boundary line L after that, even if the damaged portion V occurs at the insertion position P of the cutting tool, it is the effective area of the substrate 1. 2 does not remain in the peripheral part of the printed wiring board that is finally divided into individual pieces.

The method for processing the outer shape of a printed wiring board according to the present invention is not limited to general glass fiber-containing organic printed wiring boards, but can be applied to various other printed wiring boards (including laminated boards). It can also be widely applied when processing.

[0017]

As described above, according to the present invention,
The cutting edge part of the cutting tool is inserted into the invalid area away from the effective area of the board, and after that, the outer shape of the board is processed according to the specified boundary line, so there is no damage on the insertion part of the cutting tool. When it occurs, it does not remain in the effective area of the substrate. As a result, it is possible to reliably avoid damage such as chipping and burrs in the peripheral portion of the printed wiring board, and it is possible to greatly improve the appearance level of the printed wiring board.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a method for processing an outer shape of a printed wiring board according to the present invention.

FIG. 2 is a diagram illustrating a conventional method.

FIG. 3 is a diagram illustrating a problem of a conventional method.

[Explanation of symbols]

 1 Board 2 Effective area 3 Invalid area L Boundary P Tool insertion position

Claims (1)

[Claims] 1. A contour cutting method for a printed wiring board, wherein a board having an effective area in which a wiring pattern is formed and an ineffective area around the board is contour-machined by a cutting tool along a prescribed boundary line. After inserting the cutting edge portion of the cutting edge portion into the ineffective area which is separated from the effective area of the substrate by a predetermined distance, the outer shape of the substrate is processed according to the specified boundary line while changing the relative position of the cutting tool and the substrate. A method for processing the outer shape of a printed wiring board, the method comprising: