JPH07276212A - Grinding method and grinding device - Google Patents

Abstract

PURPOSE:To remove foreign matter which adheres on a surface of an object to be ground and a surface of a grinding tape so as to prevent occurrence of grinding scars due to foreign matter by grinding while effecting ultrasonic cleaning for at least either of a face to be ground and the grinding tape. CONSTITUTION:A grinding tape 2 is fed from a tape supply reel 1 to wind it up by a tape winding reel 3. Feed speed of the grinding tape 2 is adjusted by a drive roller 4 on the halfway of winding process to bring the tape 2 into contact with a workpiece 6 by a contact roller 5 for grinding. At this time, the contact roller vibrates to gain distance of grinding. Furthermore, this grinding device is provided with a filter unit 9 for washing a tape for grinding 3 and removing foreign matter, an ultrasonic cleaning bath 7 for grinding tape which is composed of a pump 10, a filter 12 for cleaning an object to be ground and removing the foreign matter, and an ultrasonic cleaning bath 8 for object to be ground on which a pump 13 is mounted. Consequently, it is possible to highly flatten a difference in steps of insulating layers on wires having high aspect ratio on a substrate of electronic circuit and eliminate scars which occur during grinding of a plastic lens.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an organic material, an inorganic material,
Further, the present invention relates to a polishing method and a polishing apparatus for these composite materials, and particularly to a polishing method and a polishing apparatus suitable for precision processing of a thin film multilayer substrate for electronic circuits and plastic lenses, which are averse to polishing scratches on the surface.

[0002]

2. Description of the Related Art In recent years, polishing technology has been used not only for conventional surface polishing of mechanical parts, but also for fields requiring advanced surfaces such as electronic parts (thin film circuit boards and magnetic disks) and optical materials (plastic lenses). It has started to be done. As an example in which polishing is used for electronic parts, there is a method in which after the organic insulating material is cured in the step of forming the insulating layer of the thin film circuit, the insulating agent remaining on the upper surface of the connecting conductor portion is removed by machining and flattened. is there. These are discussed in JP-A-62-263697, JP-A-2-290095 and JP-A-3-268392. Further, Japanese Patent Application Laid-Open No. 4-84495 describes a method of polishing a resin, which has melted from the hole to the surface during lamination of a multilayer printed wiring board, after curing with a belt sander. Further, in Japanese Patent Laid-Open No. 4-119688,
A polishing apparatus that reduces polishing scratches by changing the direction of the substrate and polishing multiple times is described. As described above, as methods for polishing electronic components, methods such as tape polishing, sandpaper, and belt sander polishing have been conventionally used.

[0003]

Since the polishing cloth and the polishing tape that have been conventionally used for polishing are not manufactured in a high cleaning room such as a clean room, there is a concern that the tape surface may be contaminated by foreign matter. Even if the tape is manufactured in a high-cleaning room, there is a concern that the tape surface may be contaminated by the abrasive grains or foreign matters generated from the object to be polished during polishing. These foreign objects are
This is a cause of polishing scratches on the surface when performing fine processing, and is a cause of lowering the yield. Therefore, in the conventional polishing method, a method has been used in which a foreign substance that has come out of the tape or the object to be polished is removed from the polished surface by flowing an abrasive with a polishing liquid or the like. However, when the particles of the foreign matter become finer, the adsorption force between the object to be polished and the foreign matter becomes larger than the size of the foreign matter, and there is a problem that the particles cannot be removed only by flowing the polishing liquid.

It is an object of the present invention to provide a polishing method and a polishing apparatus in which a foreign material attached to the surface of an object to be polished is positively removed to obtain a clean surface and polishing scratches due to the foreign material do not occur. is there.

[0005]

In order to solve the above problems, the present invention is such that at least one of a substrate to be polished and a polishing tape is ultrasonically cleaned and polished. Further, in order to realize the polishing method according to the present invention, at least one of the substrate fixing jig, the polishing tape and the coolant of the polishing apparatus is provided with an ultrasonic cleaning function.

[0006]

According to the present invention, the object to be polished and the polishing tape can be ultrasonically cleaned. For this reason, foreign matter adhering to the surface of the object to be polished or the surface of the polishing tape is removed, and the occurrence of polishing scratches due to the foreign matter can be prevented.

[0007]

FIG. 1 shows an embodiment of the present invention. This figure shows the structure of a tape polishing apparatus to which the present invention is applied. In this device, the tape supply reel 1. To polishing tape 2. The tape take-up reel 3. It is designed to be wound up with. Drive roller on the way 4. Adjust the feed rate of the polishing tape with and contact roller 5. Work 6. It has a structure that contacts with and polishes. At this time, contact roller 5. Vibrates and gains a distance to polish. The feature of the present invention is that the ultrasonic cleaning tank for polishing tape 7 of FIG. 7. Ultrasonic cleaning tank for polishing objects That is the point. Ultrasonic cleaning tank for polishing tape is a filter unit for removing foreign substances 9. And pump 10. It consists of The water flow direction is 11. Shown in. Further, in the ultrasonic cleaning tank for the object to be polished, the filter unit 12. And a pump 13 are mounted. In FIG. 1, the ultrasonic cleaning tank for the object to be polished and the ultrasonic cleaning tank for the polishing tape are shown separately, but the polishing tape cleaning agent and the lubricant for the object to be polished are the same substance. It is also possible to do so, and an example of an apparatus configured by combining them is shown in FIG. Filter unit for removing foreign substances 9. And pump 10. Filter unit for removing foreign matter for ultrasonic cleaning tank for polishing object 12.
And the pump 13 are combined in the filter unit 14 of FIG. FIG. 3 shows an example in which an ultrasonic cleaning machine is attached to the supply port of the polishing liquid. In FIG. 3, an ultrasonic wave generation source 15 is mounted on a nozzle for spraying an abrasive, and a filter unit 16 is also mounted on this.

An example in which polishing by the above apparatus is applied to a thin film substrate will be described below.

(Example 1): FIG. 4 shows an example of a substrate subjected to polishing. Substrate 17. Used glass (Corning 7059 glass). On top of that, Hitachi Chemical Co., Ltd. polyimide varnish PIQ 18. Was spin-coated, cured and baked, and the substrate having a final film thickness of 10 μm was polished. Alumina was used as the abrasive grains, and wet polishing was performed. The polishing conditions are shown in Table 1.

Table 1 Polishing condition No Abrasive grain size Polishing frequency Load 1 # 2000 20 pass (10 reciprocations) 500g / inch 2 # 4000 Same as above 3 Same as above 3 # 8000 Same as above 4 # 10000 Same as above Same as above No ultrasonic cleaning device is installed The surface of the substrate polished by conventional equipment contains polishing scratches, and the depth is about 1.
5μm, the number is about 10 places, the total extension of the scratch is 25mm
It was about.

On the other hand, as a result of newly installing an ultrasonic cleaning machine and a filter unit for removing foreign matters (both tape and object to be polished), scratches having a depth of 1 μm or more disappear, and a depth of 0.025 is found at several places on the substrate. The scratches of μm remained. This effect is apparently caused by polishing while ultrasonically cleaning the surface of the object to be polished and the surface of the polishing tape. In this example, ultrasonic cleaning is applied to both the surface to be polished and the polishing tape, but even when ultrasonic cleaning is applied to either the surface to be polished or the polishing tape,
It is weaker than this example, but the effect is obtained.

(Example 2): In the manufacturing process of high-performance electronic circuit parts which has been demanded in recent years, a method of highly flattening a wiring pattern having a high density and a high aspect ratio is required in order to greatly improve the performance. ing. A method for manufacturing the sample sample is shown in FIG. Alumina substrate 19. Polyimide on top 18. A wiring layer and studs 20. Of the insulating layer 21. To form. Next, the step of the wiring is polished, and the second wiring is formed by sputtering film formation and photoetching. The wiring has a film thickness of 20 ± 2 μm and the pattern shape is a line and space of 20 μm. Insulating layer 21. The film thickness of polyimide was set to 20 μm after full cure. This uneven substrate was polished under the conditions shown in Table 1 using the device according to the present invention.

As a result, the number of substrates produced by the conventional method is 2
Although 40% of the layer wiring was broken due to deep polishing scratches, no deep polishing scratches were found when the device according to the present invention was used, and the breaking rate was 1% or less.

In each of the examples, a surface without polishing scratches, which cannot be obtained by the conventional method, was obtained, and the effectiveness of the present invention was verified.

Further, it is considered that the surface polishing can be performed without generating polishing scratches even in ultra-precision machining of semiconductors and the like by using a more sophisticated device as the mounted filter unit.

On the surface of the substrate that has been highly flattened and finely processed in this manner, various fine processings can be performed with high accuracy, and a more complicated structure can be obtained. There are advantages. For example, in electronic circuit boards, it is possible to form fine patterns and make fine and high-density connections in the vertical direction. By repeating the above steps, it is possible to form high-density thin-film multilayer boards. Is.

[0017]

According to the present invention, it is possible to polish various materials without causing scratches on the surface of the object to be polished. Therefore, in the electronic circuit board, it is possible to highly flatten the step of the insulating layer due to the wiring having the high aspect ratio. Further, there is an effect that a plastic lens or the like can be polished without polishing scratches.

[Brief description of drawings]

FIG. 1 is a device configuration diagram of the present invention.

FIG. 2 is a device configuration diagram of the present invention.

FIG. 3 is a device configuration diagram of the present invention.

FIG. 4 is a structure of a sample subjected to polishing (polyimide coating film)
FIG.

FIG. 5 is a diagram showing a structure of a sample subjected to polishing (polyimide coating film with step).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tape supply reel, 2 ... Polishing tape, 3 ... Tape take-up reel, 4 ... Drive roller, 5 ... Contact roller, 6 ... Work, 7 ... Ultrasonic cleaning tank for polishing tape, 8 ... Ultra for polishing objects Sonic cleaning tank, 9 ... Filter unit, 10 ... Pump, 11 ... Water flow direction, 12 ... Filter unit, 13 ... Pump, 14 ... Filter unit, 15 ... Ultrasonic source, 16 ... Filter unit, 17 ... Glass substrate, 18 ... Polyimide, 19 ... Alumina substrate, 20 ... Wiring layer and stud, 21 ... Insulating layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidetaka Shigi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Engineering Institute, Hitachi, Ltd.

Claims (6)

[Claims] 1. A method of polishing an organic material, an inorganic material, and a composite material thereof, which comprises performing ultrasonic cleaning on at least one of a surface to be polished and a polishing tape. 2. The tape polishing apparatus according to claim 1, wherein the tape polishing apparatus is equipped with an ultrasonic cleaning machine for cleaning the tape and cleaning the substrate. 3. The tape polishing apparatus according to claim 1, wherein an ultrasonic wave generation source is mounted on a coolant supply port of the tape polishing apparatus. 4. A tape polishing apparatus, characterized in that at least one ultrasonic cleaning machine according to claim 2 or 3 is mounted in order to achieve claim 1. 5. A tape characterized by circulating a liquid in an ultrasonic cleaning tank and passing the circulating liquid through a filter unit in order to effectively carry out the cleaning described in claims 3 and 4. Polishing equipment. 6. A component manufactured by the polishing method or the polishing apparatus according to claim 1.