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Grinding wheel used for QFN packaging chip cutting and preparing method of grinding wheel

A technology for mounting chips and grinding wheels, used in grinding devices, manufacturing tools, metal processing equipment, etc., can solve the problems of poor cutting accuracy of metal-based diamond saw blades, insufficient smooth and tidy cutting surfaces, and reduced production efficiency of grinding wheels. The sintering process is carried out, the difficulty of chip removal is solved, and the effect of strong holding force

Active Publication Date: 2017-11-24
ZHENGZHOU RES INST FOR ABRASIVES & GRINDING CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, resin bond cutting grinding wheels also have prominent disadvantages: due to the poor wear resistance of the bond, the overall life of the grinding wheel is short, which not only increases user costs, but also reduces production efficiency due to frequent replacement of grinding wheels; the rigidity and strength of the grinding wheel are low. When cutting at high speed, it is easy to break the knife because it cannot withstand the large load caused by high-speed cutting, so the cutting speed of resin bonded grinding wheel is often low, usually below 40mm / s
Although the strength of the metal-based diamond saw blade is enhanced to a certain extent through the multi-layer design, the cutting accuracy of the metal-based diamond saw blade is poor, for example, it will cause burrs and tin melting during the cutting process, and the cutting surface is not enough Smooth and tidy, cannot meet higher processing precision, affect the performance of the chip, and have application defects

Method used

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  • Grinding wheel used for QFN packaging chip cutting and preparing method of grinding wheel
  • Grinding wheel used for QFN packaging chip cutting and preparing method of grinding wheel
  • Grinding wheel used for QFN packaging chip cutting and preparing method of grinding wheel

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Effect test

Embodiment 1

[0054] The grinding wheel used for cutting QFN packaged chips in this embodiment consists of a core layer 5 and surface layers 1 symmetrically arranged on both surfaces of the core layer. The structure is as follows figure 1 , figure 2 As shown, the composition of the surface layers on both sides of the core layer is the same. The thickness of the core layer is 0.2±0.002mm, and the thickness of the core layer accounts for 1 / 3 of the total thickness of the grinding wheel. There are pores 3 formed by microporous structure in the core layer, and the porosity of the core layer is 25%;

[0055] The surface layer is composed of 65 parts by mass of phenolic resin powder, 15 parts of tungsten carbide powder, 6 parts of cubic boron nitride micropowder and diamond, wherein the mass fraction of diamond in the surface layer is 55%, and the particle size of diamond is 200 / 230 mesh, the particle size of tungsten carbide powder is 38μm-45μm; the particle size of cubic boron nitride powde...

Embodiment 2

[0076] The grinding wheel used for cutting QFN packaged chips in this embodiment is composed of a core layer and surface layers symmetrically arranged on both surfaces of the core layer, and the composition of the surface layers on both sides of the core layer is the same. The thickness of the core layer is 0.2±0.002mm, and the thickness of the core layer accounts for 1 / 4 of the total thickness of the grinding wheel. The porosity of the core layer is 15%;

[0077] The surface layer is composed of 55 parts by mass of phenolic resin powder, 10 parts of tungsten carbide powder, 6 parts of cubic boron nitride micropowder and diamond, wherein the mass fraction of diamond in the surface layer is 50%, and the particle size of diamond is 230 / 270 mesh, the particle size of tungsten carbide powder is 38μm-45μm; the particle size of cubic boron nitride powder is 10μm-20μm;

[0078] The core layer is made up of the above-mentioned metal bond and diamond of 57 parts by mass, wherein the ...

Embodiment 3

[0098] The grinding wheel used for cutting QFN packaged chips in this embodiment is composed of a core layer and surface layers symmetrically arranged on both surfaces of the core layer, and the composition of the surface layers on both sides of the core layer is the same. The thickness of the core layer is 0.2±0.002mm, and the thickness of the core layer accounts for 1 / 2 of the total thickness of the grinding wheel. The porosity of the core layer is 20%;

[0099] The surface layer is composed of 60 parts by mass of phenolic resin powder, 12 parts of tungsten carbide powder, 5 parts of cubic boron nitride micropowder and diamond, wherein the mass fraction of diamond in the surface layer is 60%, and the particle size of diamond is 270 / 325 mesh, the particle size of tungsten carbide powder is 38-45μm; the particle size of cubic boron nitride powder is 10-20μm;

[0100] The core layer is made up of the above-mentioned metal bond and diamond of 76 parts by mass, wherein the mass...

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Abstract

The invention relates to a grinding wheel used for QFN packaging chip cutting and a preparing method of the grinding wheel, and belongs to the technical field of grinding apparatuses. The grinding wheel used for QFN packaging chip cutting comprises a core layer and surface layers arranged on the surfaces of the two sides of the core layer; each surface layer comprises surface layer diamond and components, and the components comprise, by weight, 55-65 parts of phenolic resin or epoxy resin, 10-15 parts of tungsten carbide and 3-6 parts of cubic boron nitride. The grinding wheel has the beneficial effects of a resin binder and a metallic binder, and has the beneficial effects of being excellent in cutting quality, good in grinding wheel rigidity, suitable for high-speed cutting, good in grinding wheel self-sharpening performance and long in service life. During QFN packaging chip cutting, copper lead galling and cutting collapsing openings are small, melting tin and core sheet layering phenomena are avoided, the grinding wheel cutting speed can reach 200 mm / s or above, and QFN high-speed cutting requirements can be met; and in addition, the service life of the grinding wheel is obviously prolonged, the core layer and surface layer abrasion rates are matched, and the grinding wheel cutting edge shape keeping performance is good.

Description

technical field [0001] The invention relates to a grinding wheel used for cutting QFN packaged chips and a preparation method thereof, belonging to the technical field of grinding tools. Background technique [0002] The pursuit of lighter, thinner, smaller, high reliability, and low power consumption of terminal electronic products continues to promote the development of semiconductor packaging technology. For example, one of the chip packages, QFN (Quad Flat No-Leal) package, is a square flat no-lead package, which is a new type of high-end package widely used in terminal products such as mobile phones and digital cameras in recent years. As a packaged product, QFN packaged chips are generally composed of an internal copper lead frame and an external plastic-pressed resin-based coating, which is a composite material structure. In modern large-scale industrial production, multiple chips are packaged at the same time during the manufacture of QFN packaged chips, and the chi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B24D3/10B24D3/28B24D18/00
CPCB24D3/10B24D3/28B24D18/0009B24D18/009
Inventor 赵炯赵延军吴晓磊
Owner ZHENGZHOU RES INST FOR ABRASIVES & GRINDING CO LTD
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