JP3496376B2 - Method and apparatus for cleaning electronic material surface after cutting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method and an apparatus therefor after cutting electronic materials such as quartz, ferrite, glass and semiconductor crystals.

[0002]

2. Description of the Related Art An inner peripheral blade slicer, a wire saw and a blade saw are mainly used for cutting these electronic materials. When cutting with these processing machines, for example, P. of 9 volumes of processing technology data files issued by the Institute for Machinery Promotion, Technical Research Institute, 1985. First, the fixed base is adhered to the material as shown in FIG. An epoxy adhesive is mainly used for this adhesion. After this, cutting is performed. After this cutting, peel off the epoxy adhesive that is the fixed base from the material, and after cleaning the cutting fluid adhering to the surface and side surfaces of the material at the time of cutting and the grease such as grease greased to the moving parts of the equipment,
Next, the electronic materials are sent to a process such as assembling and attaching to electronic parts.

Conventionally, as a method for peeling and cleaning the fixed base, (A) ordinary degreasing cleaning is performed and then the adhesive is peeled off by boiling with acetic acid, or (B) methylene chloride, trichloroethylene, etc. A method of simultaneously performing swelling and peeling of the epoxy adhesive and degreasing cleaning by cleaning with the chlorine-based solvent has been used. In addition, for the degreasing cleaning of (A), for example, P.I. Cleaning with a hydrocarbon solvent as shown in 42,
Or P. issued in 1991. A water-based cleaning method in which a water-soluble solvent as shown in 17 is diluted with water for cleaning has been used.

[0004]

In the case of the above (A),
It is necessary to pass through many complicated steps such as degreasing, drying, washing and boiling with acetic acid, washing with water and drying. Since an organic acid called acetic acid is used, there is a problem that maintenance of the working environment and treatment of wastewater and exhaust are expensive.

In the case of the above (B), the two steps of degreasing and cleaning and peeling of the epoxy adhesive can be carried out at the same time, but a chlorine-based organic solvent, which is harmful to the human body, is used. In addition to being expensive, there is a possibility of causing environmental pollution due to diffusion from exhaust gas.
In particular, trichlorethylene is already causing environmental pollution such as groundwater pollution, and its use is becoming difficult in the future.

[0006]

[Means for Solving the Problems] In order to solve the above problems, degreasing and cleaning are first carried out with naphthene-based or alkylbenzene-based hydrocarbon solvents, and then NM.
It is washed with a water-soluble detergent such as P (N-methylpyrrolidone) or ethyl lactate, and dried by warm air drying or vacuum drying.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION It has been found that hydrocarbon solvents such as naphthene-based and alkylbenzene-based solvents have an extremely high ability to dissolve hydrocarbon oils and fats such as cutting oil and grease. As the hydrocarbon type, the aromatic type is less likely to dissolve the grease, and the aliphatic type is dangerous because of the flash point. Therefore, the naphthene type or the alkylbenzene type is used. Therefore, the cutting oil and grease such as grease attached to the material after cutting can be removed by this. This was confirmed by the experiment this time as shown in Table 1. The oil and fat dissolution time in Table 1 is the time required to dissolve the oil and fat adhering to the glass plate at a liquid temperature of 50 ° C.

[0008]

[Table 1]

Then, by washing with a water-soluble solvent such as NMP or ethyl lactate, the epoxy adhesive swells and the fixed base is peeled off. Epoxy peeling time in Table 1 is liquid temperature 80
This is the time required for peeling off what was adhered between the semiconductor crystal and carbon at ° C. As shown in Table 1, the water-soluble solvent is inferior in oil / fat removal ability to the hydrocarbon type solvent, but the resin dissolving / swelling effect is very excellent. It was found to have a capacity close to that of trichlorethylene. Further, these solvents are safe for human body as shown in Table 2. The LD50 in Table 2 is the dose of a drug that kills 50% of test animals (rats or mice in this table). In addition, the water-soluble solvent is evaporated by finally drying.

As shown in Table 3, hydrocarbon solvents are inexpensive because they are produced from crude oil, but due to the production method, several kinds of derivatives having different boiling points and different molecular weights are produced. Usually, during purification, unless the boiling point range is wide and distillation is carried out, the purification efficiency is deteriorated and the cost is increased.
Conversely speaking, it is very troublesome and technically difficult to extract only the hydrocarbon solvent having the same boiling point. Therefore, the components having a high boiling point are inevitably mixed with each other, which deteriorates the drying property. Also, if the boiling point range is narrowed in an attempt to improve this, the yield of the part that becomes the product will decrease and the part that cannot be made into the product will increase the cost, and if the boiling point is taken low, the flash point will decrease and the risk increases. .

When the drying property is increased, the boiling point is lowered and the flash point is lowered, so that not only the cost is increased but also the risk of ignition is increased. As described above, a naphthene-based or alkylbenzene-based hydrocarbon solvent, which is inexpensive and has a very high ability to dissolve a hydrocarbon oil such as cutting oil or grease, is combined with a water-soluble solvent. It is the present invention that combines the advantages of both, and the former poorness after drying is compensated by a water-soluble solvent, and since both have the ability to separate, the purity of both can be maintained. become.

[0012]

[Table 2]

[0013]

[Table 3]

That is, although chemical products such as NMP and ethyl lactate are expensive in the first place, they are single components and therefore have a narrow boiling point range and good dryability. A hydrocarbon solvent having a small polarity and a water-soluble solvent having a large polarity, such as NMP and ethyl lactate, do not mix even if they are mixed, and are separated by a difference in specific gravity, and NMP and ethyl lactate sink below. Therefore, the residual hydrocarbon solvent (carry-in) can be separated from NMP and ethyl lactate by the difference in specific gravity, and can be returned to the original tank to reduce the loss of hydrocarbon solvent, and the NMP and ethyl lactate side Liquid management is also simplified. Furthermore, since it is water-soluble, it can be extinguished with water, so that no extra fire extinguishing equipment is required. Other examples of the water-soluble solvent include methyl lactate, butyl lactate, 1.3-dimethyl-2-imidazolidinone, and lactic acid, and similar effects were observed. Although lactic acid is an organic acid, it has little harm and is useful without irritating odor.

[0015]

【Example】

(Example 1) FIG. 1 shows an example of a multi-tank cleaning apparatus. For example, after cutting electronic materials such as crystal, ferrite, glass, and semiconductor (hereinafter referred to as an object to be cleaned 22) placed in a transfer container 21 such as a stainless steel basket, the first tank 1 is used.
Degreased with the naphthene-based solvent, transferred to the second tank 2 with the transfer container 21 kept therein, and the epoxy adhesive is swollen and peeled off by NMP. At that time, the naphthene-based solvent that has adhered to the object to be cleaned 22 and is brought is separated and floats on the NMP. The object to be cleaned from which the naphthene-based solvent has been removed in this way is subsequently dried by warm air in the fourth tank 4 after the epoxy adhesive has been swollen and peeled off by the NMP in the third tank 3. The warm air is supplied from the blower 8 after being heated by the warm air heater 7.

The naphthenic solvent brought into the second tank 2 is separated by the oil / water separator 5 and returned to the first tank 1 again.
The NMP separated by the oil-water separator 5 is distilled in the vacuum distillation device 6 and then returned to the third tank 3.

(Embodiment 2) FIG. 2 shows an example of a single tank type cleaning apparatus. First, the object to be cleaned 22 is put in the cleaning tank 9.
The lid 10 of the cleaning tank is closed, the valves of the nitrogen supply valve 12 and the exhaust valve 13 are opened, and the atmosphere of the cleaning tank 9 is filled with N ₂ gas.
The replacement at is started. After that, the valve 11 is opened, and the alkylbenzene-based solvent is injected into the cleaning tank 9 from the alkylbenzene tank 18. The object to be cleaned 22 is
First, an oil and fat such as cutting oil and grease is removed with an alkylbenzene solvent. After that, the drain valve 14 is opened and the exhaust valve 13 is closed at the same time, so that the contained liquid is drained.

Further, the NMP supply valve 15 is opened to N
NMP is injected into the cleaning tank 9 from the MP tank 20,
The object to be cleaned 22 and the cleaning tank 9 are washed. These liquids flow out to the oil / water separation device 5 together with the liquid of the alkylbenzene-based solvent, and the alkylbenzene-based solvent and NMP are separated there. After that, the drain valve 14 is closed and the exhaust valve 13 is opened to fill the tank with NMP. Therefore,
The epoxy adhesive of the cleaning target 22 is peeled off. Then the exhaust valve 13 is closed again and the drain valve 14 is opened N
The MP is drained.

After the drainage is completed, the drainage valve 14 and the exhaust valve 13 are closed again and the vacuum valve 16 is opened, and at the same time, the vacuum pump 17 is operated to evacuate the inside of the tank to accelerate the evaporation of NMP. And the drying is accelerated. Finally, the vacuum valve 16 is closed, the vacuum pump 10 is stopped,
The nitrogen supply valve 12 is opened, the vacuum state is broken, the lid 10 of the cleaning tank is opened, and the cleaning is completed. The alkylbenzene-based solvent in the effluent is reused after being separated by the oil / water separator 5, and NMP is separated by the oil / water separator 5 and then distilled by the distillation apparatus 19.

[0020]

EFFECTS OF THE INVENTION It has become possible to efficiently perform degreasing, resin peeling and drying without using a chlorine-based solvent which is harmful to the environment. That is, by not using a harmful chlorine-based solvent, the adverse effect on the environment was reduced, and the inhalation of chlorine-based solvent vapor also reduced the damage to human health. Since only the solvent is used, rinsing water is not generated at all, so that water pollution due to the rinsing water is not required, and a large investment in a water treatment device for preventing water pollution is unnecessary. Can always supply a clean water-soluble solvent. Since the water-soluble solvent also has a small amount of heat of evaporation and does not require a rinsing (water washing) step, it causes less dry spots. Since the solvent is a single component and the solvents do not mix with each other, it is easy to regenerate the solvent, which can reduce the solvent cost and industrial waste.

[Brief description of drawings]

FIG. 1 is a diagram of a multi-tank cleaning apparatus of the present invention.

FIG. 2 is a diagram of a single-tank cleaning apparatus of the present invention.

[Explanation of symbols]

1: First tank naphthenic cleaning 2: Second tank NMP 3: Third tank NMP 4: Warm air drying tank 5: Oil-water separator 6: NMP distillation device 7: Hot air heater 8: Blower 9: Cleaning tank 10: Cleaning tank lid 11: Alkylbenzene supply valve 12: Nitrogen supply valve 13: Exhaust valve 14: Drain valve 15: NMP supply valve 16: Vacuum valve 17: Vacuum pump 18: Alkylbenzene tank 19: Distillation device 20: NMP tank 21: Container for transfer 22: Object to be cleaned

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI C23G 5/04 C23G 5/04 (58) Fields investigated (Int.Cl. ⁷ , DB name) B08B 3/08 C11D 7/24 C11D 7/26 C11D 7/50 C23G 5/036 C23G 5/04

Claims (3)

(57) [Claims] 1. When the electronic material fixed to the base with an epoxy adhesive is cut and then washed, after degreasing and washing with a naphthene-based or alkylbenzene-based hydrocarbon solvent, N-methylpyrrolidone or A method for cleaning the surface of an electronic material after cutting, which comprises removing an epoxy adhesive with a water-soluble solvent such as ethyl lactate. 2. When carrying out the method of cleaning a surface of an electronic material after cutting according to claim 1, a tank of a hydrocarbon solvent and a tank of a water-soluble solvent for cleaning successively, and a surface of the electronic material surface after cleaning. An apparatus for cleaning the surface of an electronic material after cutting, comprising a drying tank for drying the water-soluble solvent and a specific gravity separator for collecting and circulating the hydrocarbon solvent mixed in the water-soluble solvent . 3. The method for cleaning the surface of an electronic material after cutting according to claim 1, wherein a hydrocarbon solvent and a water-soluble solvent are sequentially supplied in a single tank for cleaning, and the electronic material after cleaning is further cleaned. An apparatus for cleaning an electronic material surface after cutting, characterized in that the water-soluble solvent on the surface is dried.