CN103028482B - Alumina micropowder production process - Google Patents

Abstract

The invention provides an alumina micropowder production process, which can ensure that the grain size distribution of alumina micropowder can be self-designed and that particles with various grain sizes can be optionally proportioned and can remarkably reduce the surface scratches of silicon wafers in the process of lapping. The alumina micropowder production process includes the following steps: (1) using the sedimentation method to extract certain central alumina micropowder particles; (2) then using the overflow method to extract alumina micropowder particles at a certain stage. The alumina micropowder production process is characterized in that: the semifinished particles extracted in the two steps are mixed, the uniformly mixed particle mixture then undergoes overflow again, and therefore the final finished product is obtained.

Description

A kind of production technology of alumina powder

Technical field

The present invention relates to a kind of sorting process of aluminium oxide, especially a kind of production technology of alumina powder.

Background technology

In China Semiconductor Industry, for the material of silicon chip grinding, be to lean on external import substantially.Domestic grinding-material because the reason quality of technique always with the one section of gap that has of external import.Domestic abrasive grain distributes all more concentrated, and distribution of particles can not arbitrarily change, and is in use easy to scratch the surface of silicon chip in silicon chip grinding and chip thinning technique, causes the lattice damage of silicon single crystal.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of production technology of alumina powder is provided, make the alumina powder size distribution can designed, designed, various particle size particle ratios can arbitrarily be allocated, and obviously reduce the surface tear of silicon chip in process of lapping.

Its technical scheme is such, a kind of production technology of alumina powder, and it comprises the following steps:

(1) use sedimentation to extract certain alumina powder centrophyten;

(2) then extract the alumina powder particle of a certain section with press over system;

It is characterized in that: the semi-finished product particle of extracted twice is mixed, then the hybrid particles mixing is re-started to overflow draw last finished product.

The production technology of above-mentioned a kind of alumina powder of the present invention, the finished product finally obtaining is more reasonable than the size distribution obtaining by sedimentation or overflow processing method separately, output is higher, and various particle size particle ratios are arbitrarily suitable, obviously reduces the surface tear of silicon chip in process of lapping.

Detailed description of the invention

In alumina producing, be that overflow or sedimentation all can not be carried out granularity control very accurately.Sedimentation can only be controlled the particle in certain limit, and the particle that simultaneously enters product when being 8.0 μ m is exactly 6 ~ 11 particle, and even this scope can be larger, and it is symmetrical normal distribution centered by 8 μ m; And the particle that simultaneously enters product while being 8.0 μ m when overflow is exactly the particle below 8.0 μ m.But the pellet design that we need not is so simple.

So we have invented following methods, illustrate:

We need a kind of product its central value be 8 μ m, but adopts following methods when not need again it be symmetrical:

1. first use sedimentation to extract certain centrophyten;

2. then extract a certain section of particle with press over system;

3. the semi-finished product that obtain for twice are mixed;

4. re-start overflow;

5. finally obtain product.

Example is as follows:

1. sedimentation process:

In sorting bucket, throw 1 part of the raw material that crushed and test, add 0.4 part, decentralized medium, add 0.1 part of decentralized medium when sorting 15# again, mixing time (when per tour working) is 5 ~ 45 min for the first time, and remaining is 2 ~ 10min;

Technological parameter:

Grain size number	Sedimentation time	Siphon number of times
			15#	12 ~ 15 minutes	6~12

Sub-elect Granularity Distribution:

Granularity:	D0	D3	D50	D94
					15#（μm）	18.4	15.2	10.45	6.94

The semi-finished product that obtain after dry, for a, repeat above technique 10 times, collect neat 10 parts of sedimentation semi-finished product stand-by;

2. overflow process:

In overflow cylinder, throw 1 part of the raw material that crushed and test, add 0.04 part, decentralized medium, because be to do 15# product, so D3% is controlled at 16 μ m;

Technological parameter:

Grain size number	15#
		Overflow time (minute)	Overflow hydraulic pressure (L/S)
60	180
		120	580
180~	780

The semi-finished product that obtain after dry are for a;

3. use batch mixer that 10 parts of sedimentation semi-finished product and a overflow semi-finished product are carried out to mechanical mixture;

4. mixed semi-finished product are dropped into overflow cylinder again and carry out overflow, add 0.04 part, decentralized medium;

Technological parameter:

Grain size number	15#
		Overflow time (minute)	Overflow hydraulic pressure (L/S)
60	180
		120	500
180~	680

Sub-elect Granularity Distribution:

Granularity:	D0	D3	D10	D50	D90	D94
							15#	18.4	15.2	12.2	10.45	8.06	4.54

5. the finished product finally obtaining is more reasonable than the size distribution obtaining by sedimentation or overflow processing method separately in the past, and output is higher, and when client uses, scuffing rate is lower, and surface quality is better.

According to technical scheme provided by the invention, by the ratio of meticulous control size distribution and various particle size particles, reach the object of improving Grinding Quality.

The present invention is compared with original micro mist, and having size distribution can designed, designed, and various particle size particle ratios are the advantage of allotment arbitrarily.More obviously advantage is obviously to reduce and scratch in process of lapping, and quality meets or exceeds the level of same kind of products at abroad, has filled up domestic blank.

Claims (1)

1. a production technology for alumina powder, it comprises the following steps:

(1) use sedimentation to extract certain alumina powder centrophyten;

(2) then extract the alumina powder particle of a certain section with press over system;

It is characterized in that: the semi-finished product alumina powder particle of extracted twice is mixed, then the hybrid particles mixing is re-started to overflow draw last finished product.