JPS596594A - Brush wheel for polishing printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brush wheel for polishing printed circuit boards used for deburring.

In the through-hole processing process for conducting conductive plating on single-sided copper-clad laminate boards for printed circuit boards, double-sided copper-clad laminate boards, or multilayer circuit laminate boards, it is necessary to completely remove any particles caused by drilling, bunching, etc. This is extremely important in order to perform the subsequent through-hole plating without any problems, and this deburring is usually done by polishing.

The important thing in this polishing process is, first of all,
The goal is to completely eliminate Paris.

That is, it is necessary to completely remove not only the holes protruding from the outer surface of the printed circuit board, but also the holes extending inside the holes. Second, so-called polishing sag, where the copper foil around the hole is largely scraped off, must not occur.

In order to meet these conditions, conventionally, hard plastic abrasive wheels molded with abrasive grains kneaded into them, hard abrasive wheels molded with abrasive grains bonded to fibers such as nylon, and endless sand bevel wheels have been used. There have been proposals for polishing by pressing with a hard rubber roll, but none of these have been able to completely satisfy the above-mentioned conditions. In other words, pressing with a hard abrasive wheel or a hard rubber roll tends to bend the chips protruding from the outer surface of the printed circuit board toward the inside of the hole. If the pressing force is increased, even the periphery of the hole will be scraped off, resulting in abrasive sagging.

In addition, with the conventional type mentioned above, the position of the polishing wheel and rubber roll is adjusted slightly each time the thickness of the printed circuit board changes, because the amount of force applied to the printed circuit board has an extremely large effect on the peeling. must be adjusted.

In addition, conventional polishing wheels or rubber rolls are undesirable for polishing uniformly and quickly.Furthermore, in order to uniformly remove the polish over the entire surface of the printed circuit board, the outer diameter of the conventional polishing wheel or rubber roll must be adjusted in the axial direction. It is necessary to make it uniform along the axis, but it is not easy to finish the dimensions like a grain, so the axis center length has to be very short.
It was not able to adequately handle the polishing of wide printed circuit boards.

Moreover, the ultra-thin oxide film formed on the surface of the printed circuit board (copper? @ surface) can be removed by thickening the copper foil! Although it is desired to remove it without removing it, we have not been able to adequately meet such a request.

The present invention solves the above-mentioned problems, and it is possible not only to completely remove the notch without causing polishing sag, but also to remove delicate parts of the printed circuit board when polishing the board. To provide a brush wheel for polishing a printed circuit board that allows position adjustment at an annual rate and does not require special attention to external diameter dimension management.

In order to achieve this object, the present invention provides a polishing cloth by attaching one end of each of a large number of small pieces of sandpaper to the outer peripheral surface of a rotating core.

It consists of a rashi wheel.

With this configuration, when the rotating core is rotated, small pieces of the sandblade sweep across the surface of the printed circuit board due to centrifugal force, and this flapping action causes them to sweep outside the printed circuit board. The holes protruding from the surface are removed without bending toward the inside of the hole.
Also, the hole extending to the inside of the hole is completely removed by slightly invading the inside of the hole due to its deformability.In this way, the hole is completely removed, while the Due to the ease of deformation, the strong pressure extends to the inside of the hole without requiring any force. In this case, the small piece of sandpaper only lightly sweeps the surface of the printed circuit board due to centrifugal force, and combined with its ease of deformation, even if the relative distance to the surface of the printed circuit board changes slightly, it has no effect on the surface of the printed circuit board. Therefore, the polishing operation can be performed on printed circuit boards of various thicknesses without making fine adjustments to the relative distance to the board.In this way, the relative distance to the printed circuit board does not matter much. One thing that must be considered is the outer diameter of the brush wheel of the present invention.

%, it means that there is no need to make the outer diameter dimension in the axial direction particularly uniform, and for this reason, the axial length is sufficiently long i.
A plan wheel can be configured, and one that can sufficiently accommodate a wide printed circuit board can be obtained. Of course, the contact of the small piece of sandpaper against the surface of the printed circuit board is soft, so it is possible to remove the oxide film without scraping off the copper foil.

The present invention will be explained in detail below based on drawings showing embodiments thereof. In FIG. 1, reference numeral 1 denotes a rotating core of a brush wheel are fitted and firmly integrated with adhesive, and each one end of a large number of sandpaper pieces 3 is fixed to the outer peripheral surface of the intermediate attachment layer 2 with adhesive. The intermediate attachment layer 2 is made of the material of the sandpaper pieces 3 (
An appropriate material such as paper or cloth is selected depending on the material of the base material to which the abrasive grains are attached. In addition, each sand vapor piece 3 is made by adhering abrasive grains to the surface of a base material made of paper, cloth, or sufficiently flexible plastic, and its width (the axial length of the rotating core 1) Sa) is 1-1
It is preferable that the length is about 7 to 15 QR.

The sand vapor pieces 3 are individually and independently attached to the intermediate attachment layer 2.
However, in order to perform this installation efficiently, it is recommended to do it as follows, for example, as shown in FIG. Then, a large piece of sandpaper 4 having a length slightly (length Im) longer than the length l of the sandpaper small piece 3 (length 1 + 1m) is bent at a length 13 from one end to form a common attachment piece 4a. A large number of slits 5 are formed at predetermined intervals 14 in the width direction of the sandpaper 4, each extending from the other end of the sandpaper 4 to the vicinity of the common attachment piece 4a.

In this way, the width 14 and the length 1. A sand vapor piece group A having a large number of sand vapor pieces 3 is formed, and each of the large number of sand paper pieces group A obtained in this way is adhered to the intermediate attachment layer 2 at its common attachment piece portion 4a. . This bonding may be done so that the common attachment pieces 4a do not overlap each other as shown in FIG. 3, but in order to increase the number of small sandpaper pieces 3 as much as possible, as shown in FIG. On the common attachment piece part 4a of the sandpaper piece group A, the attachment piece parts 4a of other sandpaper pieces groups may be attached so as to partially overlap.

Another aspect of efficiently attaching the sand vapor pieces 3 is as shown in FIGS. 5 and 6, for example, as shown in FIG. Of course, even if the extended common attachment piece 4a is inserted into the slit 6 formed on the outer circumferential surface of the intermediate attachment layer 2 and then adhered, it is possible to attach the sand vapor pieces to each individual sand vapor piece group. The width of both A and B is the total length of rotating core 1 and #! 1 may have a length of 1/2 or 1/3, for example, instead of having a length of n-.

In addition, in both FIGS. 2 and 4, the sand vapor small piece group A with - and the slit 5 with ■ are replaced with the other sand vapor small piece group A.
It is preferable to install the sand paper by covering it with the sand paper pieces 3 of the If it is covered, it is more preferable to prevent uneven polishing.

For example, as shown in FIG. 7, the brush wheel X having the above configuration is arranged along the roller conveyor 8 that conveys the processed printed circuit board 7, and is rotated by a motor while at the same time rotating the shaft. It is attached to a main body of a polishing machine which is oscillated in one direction, and is rotated at a rotation speed of, for example, 1000 pm or more. Two brush wheels X are shown in FIG. 7, and the brush wheel X1 on the left side of the figure is for polishing the top surface of the printed circuit board 7.
Also, for the brush wheel in the right direction, print circuit board 7
For polishing the bottom surface of In such an apparatus, the processed printed circuit board 7 is conveyed from the left side of FIG. 7 to the right side by a roller conveyor 8,
1, the hollows on the upper surface and the oxide film on the surface of the copper foil are removed, and the brush wheel X removes the hollows and oxide film on the lower surface.Then, the removed hollows are collected. Dust turf) is collected through 9A and 9B.

Here, as shown in FIG. 8, if the printed circuit board 7 immediately after Komei has copper foils 7b and 7c affixed to both sides of the base material 7a, holes 10 are formed on both sides. At the periphery of /< riff d, 7e crab exists. During polishing by the brush wheel
Sweep the surface in a sweeping motion. During this sweeping, the small piece of sandpaper 3, due to its ease of deformation, slightly penetrates into the hole 10 and removes the deburr, as shown in FIG. Note that FIG. 9 shows how the top surface of the printed circuit board 7 is removed, and the bottom surface is also removed in the same manner.

In this way, during the deburring operation, the sandpaper small piece 3 is deformed into a slightly convex shape toward the hole 1o as shown in FIG. In order to perform the polishing well (particularly to improve the contact between the abrasive grain surface and the surface of the printed circuit board 70), it is preferable to curve the small piece of sandpaper 3 so that the abrasive grain surface is convex. This shaping can be easily carried out by, for example, hot pressing.

In the above embodiments, the one-rotation core 1 is hollow, but it may also be solid, and the sandpaper pieces 3 may be attached directly to the rotation core 1 without providing the intermediate attachment layer 2, of course.

In order to adjust the force with which the brush wheel (sandpaper piece 3) hits the printed circuit board, the number of rotations of the brush wheel may be controlled, and the relative distance between the brush wheel and the printed circuit board may be controlled. It would be nice if it were adjustable.

As is clear from the above description, the present invention is directed to K.

It is possible to completely remove deburrs while preventing polishing sag, and there is no need to adjust the relative distance of the brush wheel to the printed circuit board, and it is easy to use a long brush wheel that extends in the axial direction of the rotating core. It can be formed into a large size and is fully compatible with wide printed circuit boards.
Furthermore, the ultra-thin oxide film on the surface of printed circuit boards
.

The copper foil can be removed without having to scrape off much of it.

Produces various effects

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a brush wheel according to the present invention, FIG. 2 is a perspective view showing an example of a group of small sandpaper pieces, and FIGS. 6 and 4 are a rotating core 9 of the group of small sandpaper pieces shown in FIG. The cross-sectional view shows an example of how to attach it. FIG. 5 is a perspective view showing another example of a group of small sandpaper pieces. FIG. 6 is a cross-sectional view showing an example of how the group of sandpaper pieces shown in FIG. 5 is attached to a rotating core, and FIG. 7 is a simplified overall view of a polishing device using a brush wheel according to the present invention. FIG. 8 is a sectional view showing the appearance of a burr formed on the periphery of a hole in a printed circuit board, and FIG. 9 is a sectional view showing the appearance of burr removal. 1...Rotating core 5...Sandpaper small piece Applicant Seabee 5-Niji Turf #Twist 4-point type (1 length 42

Claims (1)

[Claims] (1) A plastic wheel for polishing printed circuit boards, in which one end of each of a number of sand vapor pieces is attached to the outer peripheral surface of a rotating core. (2. In claim 1, the sand vapor small piece is curved so that the surface of the abrasive grain is convex.