WO2019222953A1

WO2019222953A1 - Preparation method for inorganic filler powder without magnetic foreign matter, and inorganic filler powder prepared thereby and application thereof

Info

Publication number: WO2019222953A1
Application number: PCT/CN2018/088128
Authority: WO
Inventors: 陈树真; 沈海斌
Original assignee: 湖州晶矽粉体材料有限公司
Priority date: 2018-05-24
Filing date: 2018-05-24
Publication date: 2019-11-28
Also published as: CN111819161A

Abstract

A preparation method for an inorganic filler powder without magnetic foreign matter, comprising the following steps: S1, providing a powder to be processed, and adding water to prepare a first slurry; S2, removing magnetic foreign matter from the first slurry by using a magnetic iron removal device to form a second slurry; S3, drying and granulating the second slurry to prepare dry granulated powder; and S4, removing magnetic foreign matter in the dry granulated powder by using the magnetic iron removal device to prepare an inorganic filler powder without magnetic foreign matter. By the inorganic filler powder prepared by the method and an application thereof, a hidden danger of short life caused by applying an inorganic filler powder having magnetic foreign matter to chip packaging is avoided.

Description

Preparation method of inorganic filler powder without magnetic foreign matter, prepared inorganic filler powder and application thereof

Technical field

The invention relates to a package for a chip used in the field of automotive electronics, and particularly to a method for preparing an inorganic filler powder without magnetic foreign matter, an inorganic filler powder prepared therefrom, and an application thereof.

Background technique

At present, integrated circuits are developing rapidly in the direction of ultra-large scale, ultra-high speed, high density, high power, high precision, and multi-function, which places higher requirements on integrated circuit chips.

The evaluation time of a general chip is about 5 years, and automotive electronics and other have extreme requirements for safety, and the service life of the chip is required to be at least 15 years or even 20 years. One of the reasons that affects the life of the chip is that the inorganic filler powder used in the packaging material (such as epoxy resin) contains magnetic particles, such as iron, which may cause the chip to conduct electricity and short circuit, thereby shortening the chip life. To this end, the provision of non-magnetic inorganic fillers will avoid short-circuit faults and obtain reliable semiconductor devices with zero defects as much as possible. A common method is to use magnetic iron removal equipment to adsorb the magnetic particles in the dried inorganic filler powder (such as silica powder). However, because the magnetic particles are very small, such as a few microns or dozens of microns, they are also coated with inorganic filler powder, which makes it difficult for magnetic iron removal equipment to detect and adsorb. This causes these magnetic small particles to be mixed in the inorganic filler powder, thereby causing hidden dangers.

Summary of the Invention

Therefore, the purpose of this case is to solve the problem of removing the magnetic foreign matter wrapped in the dry inorganic filler.

The invention provides a method for preparing an inorganic filler powder without magnetic foreign matter, including the following steps: S1, providing powder to be treated, adding water to make a first slurry; S2, using a magnetic iron removing device for the first slurry Remove the magnetic foreign matter to form a second slurry; S3, dry and granulate the second slurry to make dry granulated powder S4, use a magnetic iron removal device to remove the magnetic foreign matter in the dried granulated powder, and make it non-magnetic Foreign filler powder.

Preferably, S2 is specifically sieving the first slurry, removing magnetic foreign matter with a magnetic iron removing device, and forming a second slurry.

Preferably, the inorganic filler powder is prepared by fused silica powder grade, and the particle diameter of the fused silica powder is between 2 μm and 25 μm.

Preferably, the fused silica powder is a spherical fused silica powder or an angular fused silica powder.

Preferably, the water in S1 is deionized water or pure water.

Preferably, the first slurry has a solids content between 40% and 60%.

Preferably, the sieve openings of the sieve are between 5 μm and 55 μm.

Preferably, the particle size of the dried granulated powder is between 100 μm and 1000 μm.

Preferably, the magnetic iron removing device is 6000 Gauss or more.

The present invention also provides an inorganic filler powder prepared according to the above method.

Preferably, the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 5 micrometers or more.

Preferably, the inorganic filler powder does not contain magnetic foreign matter with an average particle diameter of 75 micrometers or more.

Preferably, the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 55 micrometers or more.

Preferably, the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 45 micrometers or more.

Preferably, the inorganic filler powder does not contain magnetic foreign matter with an average particle diameter of 20 micrometers or more.

Preferably, the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 10 micrometers or more.

The invention also provides the application of an inorganic filler powder without magnetic foreign matter in a chip packaging material for an integrated circuit.

Preferably, in the preparation process of the inorganic filler powder, a coupling agent is added to the second slurry, and then spray-dried and granulated to make a dry granulated powder. Adding a coupling agent to the second slurry facilitates the dispersion of the inorganic filler powder in the packaging material.

Preferably, the coupling agent is added in an amount of 0.2 to 2.0% by weight of the powder to be treated.

Preferably, the coupling agent is methacryloxypropyltrimethoxysilane or vinyltrimethoxysilane.

The step S4 of the present invention is to ensure that the magnetic foreign matter contaminants newly brought in the process such as transportation after granulation are removed. If non-magnetic foreign matter pollution can be achieved after granulation, step S4 can be substantially omitted.

In summary, the present invention provides a method for preparing inorganic filler powder without magnetic foreign matter, and the prepared inorganic filler powder and its application, which solves the short life of the inorganic filler powder with magnetic foreign matter in chip packaging. Hidden dangers.

Detailed ways

The technical solutions of the present invention will be described in detail in combination with the specific embodiments of the present invention, but the following examples are only for understanding the present invention, and shall not limit the present invention. The embodiments of the present invention and the features in the embodiments They can be combined with each other and the invention can be implemented in a number of different ways as defined and covered by the claims.

Example 1

A method for preparing an inorganic filler powder without magnetic foreign matter provided according to the present invention includes the following steps:

S1. Provide a powder to be processed. In this embodiment, the powder to be processed is an angular fused silica powder raw material, and is composed of an angular fused silica grade with an average particle diameter of 25 μm, 5 μm, and 2 μm. That is, the stacked voids of 25 μm angular fused silica are filled by adding 5 μm angular fused silica, and the filled voids are then filled by 2 μm angular fused silica. Wherein, the weight ratio of each component is 0.7: 0.25: 0.05, deionized water is added, and the mixture is uniformly mixed to make a first slurry, and the solid content of the first slurry is 50%. In this way, the angular fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign matter.

S2: After passing the first slurry through a 55 μm sieve, the magnetic foreign matter is removed with a 6000 Gauss strong magnetic rod to form a second slurry. In this process, a 6000 Gaussian copper-coated magnetic rod was inserted into the solution after the first slurry was sieved, and stirred with the magnetic rod for 15 minutes. In this way, the magnetic foreign matter was adsorbed by the magnetic rod and separated from the second slurry.

S3: The second slurry is subjected to box drying, and granulated into a dry granulated powder having an average particle diameter of 1000 μm.

S4: Before the packing, a 6000 Gauss strong magnetic rod is used to remove magnetic foreign matter from the dried granulated powder to obtain an angular fused silica powder without magnetic foreign matter. In this process, the dry granulated powder with a particle diameter of 1000 μm will not adhere to the magnetic rod, and it will not wrap magnetic foreign matter. Therefore, the magnetic foreign matter is adsorbed by the magnetic rod, separated from the dry granulated powder, and removed. The magnetic foreign matter that may be mixed in S3 produces angular fused silica powder without magnetic foreign matter.

S5: Take 100 grams of non-magnetic horn-shaped fused silica powder, and add 900 grams of pure water to form a uniformly dispersed third slurry by ultrasonication. A 12,000 Gaussian-coated magnetic rod was inserted into the third slurry, and the magnetic rod was stirred for 15 minutes. Remove the magnetic rod from the sleeve, remove the magnetic rod from the copper sleeve, and wash the magnetic foreign matter from the copper sleeve with pure water. The washed magnetic foreign matter was observed with a microscope, and the number of magnetic foreign matter with different particle diameters (d) was counted.

Comparative Example 1

Comparative Example 1 includes the following steps:

P1, to provide the powder to be processed. In this embodiment, the powder to be processed is an angular fused silica powder raw material, which is composed of an angular fused silica grade with an average particle diameter of 25 μm, 5 μm, and 2 μm, that is, 25 μm angular fused The stacked voids of silica are filled by adding 5 μm angular fused silica, and the filled voids are then filled by 2 μm angular fused silica. Wherein, the weight ratio of each component is 0.7: 0.25: 0.05, deionized water is added, and the mixture is uniformly mixed to make a first slurry, and the solid content of the first slurry is 50%. In this way, the angular fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign matter.

P2: The first slurry is subjected to box drying, and granulated into a dry granulated powder having an average particle diameter of 1000 μm.

P3: Take 100 grams of dry granulated powder, add 900 grams of pure water and ultrasonically form a fourth slurry that is uniformly dispersed. A 12,000 Gaussian-coated magnetic bar was inserted into the fourth slurry, and the magnetic bar was stirred for 15 minutes. Remove the magnetic rod from the sleeve, remove the magnetic rod from the copper sleeve, and wash the magnetic foreign matter from the copper sleeve with pure water. The washed magnetic foreign matter was observed with a microscope, and the number of magnetic foreign matter with different particle diameters (d) was counted.

Table 1: Magnetic foreign object detection results in Example 1 and Comparative Example 1

Example 2

The method for preparing an inorganic filler powder without magnetic foreign matter according to the present invention includes the following steps:

S1, providing the powder to be processed. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, which is composed of a spherical fused silica grade with an average particle diameter of 25 μm, 5 μm, and 2 μm, that is, 25 μm spherical fused silica. The stacked voids of silica are filled by adding 5 μm spherical fused silica, and the filled voids are then filled by 2 μm spherical fused silica. Wherein, the weight ratio of each component is 0.7: 0.25: 0.05, deionized water is added, and the mixture is uniformly mixed to make a first slurry, and the solid content of the first slurry is 60%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

S3: The second slurry is spray-dried and granulated into a dry granulated powder having an average particle diameter of 300 μm.

S4: Use a 6000 Gauss strong magnetic rod to remove magnetic foreign matter from the dried granulated powder before packaging, to obtain a spherical fused silica powder without magnetic foreign matter. In this process, the dry granulated powder with a particle size of 300 μm will not adhere to the magnetic rod and will not wrap magnetic foreign matter. Therefore, the magnetic foreign matter is adsorbed by the magnetic rod, separated from the dry granulated powder, and removed. S3 may be mixed with magnetic foreign materials to obtain spherical fused silica powder without magnetic foreign materials.

S5: Take 100 grams of spherical fused silica powder without magnetic foreign matter, add 900 grams of pure water and ultrasonically form a third dispersed slurry. A 12,000 Gaussian-coated magnetic rod was inserted into the third slurry, and the magnetic rod was stirred for 15 minutes. Remove the magnetic rod from the sleeve, remove the magnetic rod from the copper sleeve, and wash the magnetic foreign matter from the copper sleeve with pure water. The washed magnetic foreign matter was observed with a microscope, and the number of magnetic foreign matter with different particle diameters (d) was counted.

Comparative Example 2

Comparative Example 2 includes the following steps:

P1, to provide the powder to be treated. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, which is composed of a spherical fused silica grade with an average particle diameter of 25 μm, 5 μm, and 2 μm, that is, 25 μm spherical fused The stacked voids of silica are filled by adding 5 μm spherical fused silica, and the filled voids are then filled by 2 μm spherical fused silica. Among them, the weight ratio of each component is 0.7: 0.25: 0.05, deionized water is added, and the mixture is uniformly mixed to prepare a first slurry. The first slurry has a solid content of 60%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

P2: The first slurry is spray-dried and granulated into a dry granulated powder having an average particle diameter of 300 μm.

Table 2: Magnetic foreign object detection results in Example 2 and Comparative Example 2

Example 3

S1. Provide the powder to be treated. In this embodiment, the inorganic filler powder is spherical fused silica with an average particle diameter of 5 μm. Deionized water is added and mixed uniformly to prepare a first slurry. The solids content was 50%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

S2: After passing the first slurry through a 10 μm sieve, the magnetic foreign matter is removed with a 6000 Gauss strong magnetic rod to form a second slurry. In this process, a 6000 gauss copper-coated magnetic rod was inserted into the solution after the first slurry was sieved, and stirred with the magnetic rod for 15 minutes. In this way, the magnetic foreign matter was absorbed by the magnetic rod and separated from the second slurry.

S3: The second slurry is spray-dried and granulated into a dry granulated powder having an average particle diameter of 150 μm.

S4: Use a 6000 Gauss strong magnetic rod to remove magnetic foreign matter from the dried granulated powder before packaging, to obtain a spherical fused silica powder without magnetic foreign matter. In this process, the dry granulated powder with a particle size of 150 μm will not adhere to the magnetic rod and will not wrap magnetic foreign matter. Therefore, the magnetic foreign matter is adsorbed by the magnetic rod, separated from the dry granulated powder, and removed. S3 may be mixed with magnetic foreign materials to obtain spherical fused silica powder without magnetic foreign materials.

Comparative Example 3

Comparative Example 3 includes the following steps:

P1, providing the powder to be treated. In this embodiment, the inorganic filler powder is a spherical fused silica with an average particle diameter of 5 μm. Deionized water is added and mixed uniformly to make a first slurry. The solids content was 50%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

P2: The first slurry is spray-dried and granulated into a dry granulated powder having an average particle diameter of 150 μm.

Table 3: Magnetic foreign object detection results in Example 3 and Comparative Example 3

Example 4

S1, providing the powder to be treated. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, and is composed of a spherical fused silica gradation with an average particle diameter of 10 μm and 2 μm, of which, 10 μm fused spherical The stacked voids of silica were filled by adding 2 μm fused spherical silica. The weight ratio of each component is 0.8: 0.2, deionized water is added, and the mixture is uniformly mixed to prepare a first slurry. The solid content of the first slurry is 60%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

S2: After passing the first slurry through a 20 μm sieve, the magnetic foreign matter is removed with a 6000 Gauss strong magnetic rod to form a second slurry. In this process, a 6000 Gaussian copper-coated magnetic rod was inserted into the solution after the first slurry was sieved, and stirred with the magnetic rod for 15 minutes. In this way, the magnetic foreign matter was adsorbed by the magnetic rod and separated from the second slurry.

Comparative Example 4

Comparative Example 4 includes the following steps:

P1, to provide the powder to be processed. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, which is composed of a spherical fused silica grade with an average particle diameter of 10 μm and 2 μm, that is, 10 μm spherical fused dioxide The stacked voids of silicon were filled by adding 2 μm spherical fused silica. Wherein, the weight ratio of each component is 0.8: 0.2, deionized water is added, and the mixture is uniformly mixed to prepare a first slurry. The first slurry has a solid content of 60%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

Table 4: Magnetic foreign object detection results in Example 4 and Comparative Example 4

Example 5

S1, providing the powder to be processed. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, and is composed of a spherical fused silica grade with an average particle diameter of 5 μm and 2 μm, that is, 5 μm fused silica. The stacked voids were filled by adding 2 μm spherical fused silica. Wherein, the weight ratio of each component is 0.7: 0.3, deionized water is added, and the mixture is uniformly mixed to prepare a first slurry. The first slurry has a solid content of 50%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

S2: After passing the first slurry through a 10 μm sieve, the magnetic foreign matter is removed with a 6000 Gauss strong magnetic rod to form a second slurry. In this process, a 6000 Gaussian copper-coated magnetic rod was inserted into the solution after the first slurry was sieved, and stirred with the magnetic rod for 15 minutes. In this way, the magnetic foreign matter was adsorbed by the magnetic rod and separated from the second slurry.

S3: A coupling agent is added to the second slurry for surface treatment. In this embodiment, the coupling agent is methacryloxypropyltrimethoxysilane, and the weight ratio thereof is 0.8. : 100; then spray-dried and granulated to make a dry granulated powder having an average particle diameter of 150 μm. In step S3, adding a coupling agent to the second slurry for surface treatment can improve the hardness of the dried granulated powder, thereby facilitating the dispersion of the dried granulated powder in a packaging material such as an epoxy resin.

Comparative Example 5

Comparative Example 5 includes the following steps:

P1, to provide the powder to be treated. In this embodiment, the inorganic filler powder is a spherical fused silica powder raw material, which is composed of a spherical fused silica grade with an average particle diameter of 5 μm and 2 μm, that is, 5 μm spherical fused dioxide The stacked voids of silicon were filled by adding 2 μm spherical fused silica. Wherein, the weight ratio of each component is 0.7: 0.3, deionized water is added, and the mixture is uniformly mixed to prepare a first slurry. The first slurry has a solid content of 50%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

Table 5: Detection results of magnetic foreign objects in Example 5 and Comparative Example 5

Example 6

S1. Provide the powder to be treated. In this embodiment, the inorganic filler powder is a spherical fused silica with an average particle diameter of 2 μm. Deionized water is added and mixed uniformly to prepare a first slurry. The solids content was 40%. In this way, the spherical fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign bodies.

S2: After passing the first slurry through a 5 μm sieve, the magnetic foreign matter is removed with a 6000 Gauss strong magnetic rod to form a second slurry. In this process, a 6000 Gauss copper-coated magnetic rod was inserted into the solution after the first slurry was sieved, and the magnetic rod was stirred for 15 minutes. In this way, the magnetic foreign matter was adsorbed by the magnetic rod and separated from the second slurry.

S3: Add a coupling agent to the second slurry for surface treatment. In this embodiment, the coupling agent is vinyltrimethoxysilane, and the weight ratio of the weight to the powder to be processed is 1: 100; then spraying is performed. Dry and granulate to make dry granulated powder with an average particle size of 100 μm.

S4: Use a 6000 Gauss strong magnetic rod to remove magnetic foreign matter from the dried granulated powder before packaging, to obtain a spherical fused silica powder without magnetic foreign matter. In this process, the dry granulated powder with a particle size of 100 μm will not adhere to the magnetic rod and will not wrap magnetic foreign objects. Therefore, the magnetic foreign materials are adsorbed by the magnetic rod, separated from the dried granulated powder, and removed. S3 may be mixed with magnetic foreign materials to obtain spherical fused silica powder without magnetic foreign materials.

Comparative Example 6

Comparative Example 6 includes the following steps:

P1, providing the powder to be treated. In this embodiment, the inorganic filler powder is spherical fused silica with an average particle diameter of 2 μm. Deionized water is added and mixed uniformly to make a first slurry. The solids content was 40%. In this way, the angular fused silica powder raw material is uniformly dispersed in deionized water to prevent it from enclosing magnetic foreign matter.

P2: The first slurry is spray-dried, and granulated into a dry granulated powder having an average particle diameter of 100 μm.

Table 6: Detection results of magnetic foreign objects in Example 6 and Comparative Example 6

The above are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. The above embodiments of the present invention can also make various changes, such as an inorganic non-magnetic foreign matter provided by the present invention. The method for preparing the filler powder may repeat steps S3 or S4, but at least once includes steps S3 and S4. That is, any simple and equivalent changes and modifications made according to the claims of the present application and the contents of the description fall within the scope of protection of the claims of the present patent. What is not described in detail in the present invention is conventional technical content.

Claims

A method for preparing inorganic filler powder without magnetic foreign matter, which is characterized in that the method includes the following steps:

S1, providing the powder to be treated, adding water to make a first slurry;

S2. The magnetic slurry removes the first slurry with a magnetic iron remover to form a second slurry.

S3, drying and granulating the second slurry to make a dry granulated powder;

S4. A magnetic iron removing device is used to remove magnetic foreign matter in the dried granulated powder to obtain an inorganic filler powder without magnetic foreign matter.
The method according to claim 1, wherein the step S2 is specifically sieving the first slurry, removing the magnetic foreign matter with a magnetic iron removing device, and forming a second slurry.
The method according to claim 1, wherein the powder to be treated in S1 is fused silica powder.
The preparation method according to claim 3, wherein the powder to be treated is prepared by using a fused silica powder grade, and the fused silica powder has a particle diameter between 2 μm and 25 μm.
The preparation method according to claim 1, wherein the particle size of the dry granulated powder is between 100 μm and 1000 μm.
The preparation method according to claim 1, wherein the magnetic induction strength of the magnetic iron removing device is greater than or equal to 6000 Gauss.
The preparation method according to claim 1, wherein the magnetic iron removing device comprises any one of a magnetic rod, a magnetic plate, a magnetic roller, a magnetic grid, or a magnetically conductive mesh.
The preparation method according to claim 1, wherein the magnetic iron removing device is a permanent magnet device or an electromagnetic device.
An inorganic filler powder without magnetic foreign matter prepared by the preparation method according to any one of claims 1-8.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 75 micrometers or more.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 55 micrometers or more.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 45 micrometers or more.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 20 microns or more.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 10 micrometers or more.
The inorganic filler powder according to claim 9, wherein the inorganic filler powder does not contain magnetic foreign matter having an average particle diameter of 5 micrometers or more.
The use of the inorganic filler powder according to claim 9 in a chip packaging material for an integrated circuit.
The application of the inorganic filler powder without magnetic foreign matter according to claim 16, wherein the preparation process of the inorganic filler powder comprises adding a coupling agent to the second slurry, followed by spray drying and granulation Made into dry granulated powder.