Semiconductor, Electronics ／ LT ・ GaN ・ Sapphire
砥石成形工具 （ダイヤモンドドレッサー） Semiconductor, Electronics
ＬＴ/ＬＮ
For LT/LN Wafers / VitaNova Masspower
・High porosity abrasive layer for long sharpness retention. ・Newly developed body shape to uniformly supply grinding fluid to grinding points. ・Highly efficient and high quality grinding. ■Features Because fragile LT wafers used as the SAW filter tend to get broken in processing, improving the processed surface roughness is required. "VitaNova Masspower", having a high porosity abrasive layer with excellent durability of sharpness, provides low-damage processing enabled by the added body shape with a function of efficiently feeding to the grinding point. Low-Damage Grinding of LT/LN Wafers
SiC For Rough Grinding SiC Wafers / VitaNova MasspowerⅠA
・Minimize the self-sharpening units to achieve long tool life and low-load processing ・Achieves less wear ratio of grinding wheel in both 6-inch and 8-inch compared with conventional spec. ・Continuous machining at a feed rate of 1 µm/sec is achieved for both 6-inch and 8-inch machines. ■Features As diameter of SiC wafers become larger, a demand for lower cost wheels for rough machining of wafer thickness will be required more. The vitrified bond wheel “VitaNova Masspower I A” fulfills the market requirement of longer wheel life and a significant reduction in production costs by “increased retention” of the abrasive grain layer. Contributes to Lower Machining Costs and Higher Machining Efficiency
・Precision surface grinding of LT/LN wafers ■Applications
■LT Wafer Grinding Problem Solving Thermal expansion coefficient varies significantly according to the crystal orientation. When it is exposed to thermal change, stress distortion occurs inside, breaking it instantaneously. Conventional Body
The Jetstorm shape body minimizes wafer cracks by supplying grinding fluid to the grinding point uniformly to minimize thermal change.
・Precision surface grinding of SiC wafers ■Applications
Example of SiC Wafer Processing: #2000 (Abrasive Grain Size 7 µm) Comparison with Conventional Products (Wheel Wear Rate and Spindle Load Current)
Jetstorm Shape Body
6-inch
8-inch
Grinding Wheel
8
10 15 20 25 35 30
10 12
100 80 120 140
Grinding Wheel
7
0 2 4 6 8
6
0 20 40 60
Water
Mist
5
0 5
LT Wafer
Grinding Water Supplied to Grinding Point Uniformly
4
Jetstorm Shape
Masspower ⅠA Feed Rate 0.6 µm/s
Masspower ⅠA Feed Rate 1.0 µm/s
Masspower ⅠA Feed Rate 0.6 µm/s
Masspower ⅠA Feed Rate 1.0 µm/s
Conventional Wheel Feed Rate 0.6 µm/s
Conventional Wheel Feed Rate 0.6 µm/s
GaN / Sapphire
For Finishing SiC Wafers / VitaNova Masspower ⅡB
・Both 6-inch and 8-inch models have approximately 2.8 times longer tool life than conventional products. ・Achieves better grinding with less load in both 6-inch and 8-inch compared with conventional spec. ・Low-damage processing equivalent to lapped surfaces is achieved. ■Features As SiC wafers become larger in diameter, further cost reduction and lower grinding resistance are required for wheels for wafer thickness processing. The vitrified bond wheel “VitaNova Masspower II B” achieves the market requirements of long life and low grinding resistance by adopting a bond with high porosity and high grain retention. This will contribute to the further spread of SiC power devices. Contributes to Improved Machining Efficiency Through Low-Load, Low-Wear Machining
For GaN / Sapphire Wafers / VitaNova Masspower
The adjustment of the binding grade and bond has enabled grinding of difficult-to-grind materials with fine grains that have been difficult to grind with conventional wheels. This wheel ensures high-speed and mirror finishing of GaN wafers. Reduces Grinding Time
・Grinding of difficult-to-machine materials. ・High-speed and near mirror finishing. ■Features
・Precision surface grinding of GaN / Sapphire wafers ■Applications
・Ultra-precision surface grinding of SiC wafers ■Applications
Example of SiC Wafer Processing: #8000 (Abrasive Grain Size 0.5 µm) Comparison with Conventional Products (Wheel Wear Rate and Spindle Load Current)
■Results from Grinding Single-Crystal GaN Wafers
■GaN Wafer
■Sapphire Wafer
6-inch
8-inch
100 120
400
GaN Wafer (Ga Surface)
2-inch
4-inch
6
6
Grinding Process
Rough ♯2000 (7 µm) 50-100
Finish ♯6000 (1 µm）
Rough ♯2000 (7 µm) 50-100
Finish ♯6000 (1 µm)
300
0 20 40 60 80
Grit Size
(Grain Dia.)
4
4
200
Stock Removal
（µm）
10
10
2
2
Feed Rate Wear Rate
（µm/min） 30 60 90
30 60 90 12 20 35
20
20
100
Grain Size 1 µm
Grain Size 0.5 µm
（%） 7 15 27
100
100
0
0
0
Masspower ⅡB Focus on Wear Resistance
Masspower ⅡB Focus on Sharpness
Masspower ⅡB Focus on Wear Resistance
Masspower ⅡB Focus on Sharpness
Conventional Wheel
Conventional Wheel
Surface Quality Ra （nm） 90
100
-
-
1-2
-
-
2
Measured by :
FOV:450 µm
045
046
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