Rotary Dressers. Diamond Tools. Rotary Dressers

Transcription

1 Rotary Dressers Diamond Tools Rotary Dressers Super-fine diamond grit and super-fine ceramics technology result in an innovative A.L.M.T. grinding wheel. Application of both acquired material technology and production technology provides super-fine grinding capabilities. Its effectiveness is enough to reduce a grinding damaged layer of brittle material such as polish-reduction of ø3mm silicon wafer and prevent cracks on thin layer device wafer. 35

2 RZ Type Advanced technology in high precision electro-deposition and machining, any kind of pro le can be produced. The high concentration of diamond grit is arranged randomly and made by the reverse plating method, so it is also suitable for longer life applications. Various optional speci cations are also available. SZ Type A rotary dresser with diamond grit arranged regularly made by the reverse plating method. Concentration of the diamond can be controlled according to requirements. The SZ Type provides ef cient plunge dressing of large size rotary dressers. Z Type The Z Type rotary dresser has diamond xed directly to the surface of the body by plating method. This type can be made relatively easily and is suitable for small lot production and trial production. SX Type A rotary dresser with diamond grit arranged regularly made by the reverse powder metallurgy method. This type works very ef ciently in grinding applications that require sharp cut of grinding wheels. It can also be effective in traverse dressing and contour dressing. X Type X Type rotary dresser is a metal bond interfused with diamond particles. High performance is made possible by free selection of concentration and uniform distribution of diamond grit. This type is suitable for transverse dressing of our VITMATE and EG Wheel. 36

3 Rotary Dressers Diamond Tools Manufacturing Details & Ranges for Rotary Dressers RZ SZ Z SX X Manufacturing Method Diamond Grit Distribution Applicable Grit Size Dress Method Major Applications Geometrical Accuracy Surface Roughness Dressing Force Major Features RZ Type SZ Type Z Type SX Type X Type 37

4 Outline of Production Processes for Rotary Dressers Electro-deposition Method RZ SZ Type Electro-plating Method Z Type Sintered Method SX Type Reverse Plating Method As the product is proccessed under room temperature, the accuracy is not changed by thermal expansion. Diamond is fixed directly on the body and finished by lapping on the surface. Powdered Metallurgy Method Surface of the diamond layer is lapped in the final process to achieve specified accuracy. Diamond Setting Machining Body Diamond Setting Plating 25 C Sintering 1 C + Diamond Body Setting Body Machining Body.3mm Machining Body Control Grinding Control Grinding.2mm 38

5 Rotary Dressers Diamond Tools Tolerances on Rotary Dresser Designs U U Value (mm) RZ Type 1 SZ Type 1 SX Type 3 Z Type 3 X Type 3 W Z W Value RZ Type.5Z (mm) SZ Type.5Z SX Type 4Z Z Type 4Z X Type 2Z M Y Value (mm) M Value (mm) L RZ Type 1 RZ Type L SZ Type 1 SZ Type L Y SX Type 4 SX Type.5L Z Type 4 Z Type.5L X Type 4 X Type.5L Convex R Concave R Convex R Concave R * Convex R Value RZ Type SZ Type.2 SX Type.2 Z Type.3 * (mm) Concave R Value.1 RZ Type.3 SZ Type.15 SX Type.15 Z Type.3 (mm) *Value depending on diamond grain sizes. P P P P Value (mm) RZ Type.3 39

6 Accuracy of Rotary Dressers Item Factor Symbol Accuracy (mm) Illustration Runout.2.5 A L L Width L ±.5 S Radius R ±.2.2 Step S ±.1 R R R Outline.2.2 Angle ± 2 Straightness.2 np P P P Pitch P ±.2 Accumulative Pitch np ±.4 Bore H.5.2 Body Parallelism.2.2 Control.2 A Squareness.2 Runout.2 A H Other tolerances available upon request 4

7 Rotary Dressers Diamond Tools Optional Specifications of Rotary Dressers Optional Specifications for RZ Type (reverse plating) 1. Improved Dressing Ability (for fast dressing) GB Type (controlled diamond concentration) Sharp Type (controlled diamond projection) Cross Ditch (controlled diamond concentration) 12 Grinding (exponential) Standard GB Sharp Cross Groove 2. Improved Wear Resistance (for longer life) Strong Type 41

8 Optional Specifications for SX Type 3. For Improving Wear Resistance High Concentration Type Strong Type Optional Specifications for Vitrified cbn Wheels (SP Type) 4. For stable performance and longer lasting sharpness SP Dress Ratio Standard S P Polycryastalline Prism Diamond Dressing Example Target Dresser Monocrystalline Polycrystalline Dressing Conditions Wheel specs: CBN23G125V3 ø min -1 RD specs:.4 2L 25pcs ø min -1 Testing Instrument: TOOLMEX Feed Rate: 24mm/min Dressing Amount:.2mm/pass (Total 1. mm in 5 dressing cycles) Results Wear Volume 1 5 Mono-crystalline Polycrystalline 42

9 Rotary Dressers Diamond Tools Inspection of Rotary Dressers For higher accuracy... Required accuracy of rotary dressers is becoming more strict, ranging from microns to submicrons. To ensure required accuracy, we have established a perfect inspection system with the most up-to-date equipment. Description of Inspection Rotary Dresser Inner diameter Air micrometer Coupon (Plate) Coupon (Cylindrical) Runout-reference surface Roundness measuring equipment Tool microscope Runout-profile Roundness measuring equipment measuring equipment Projector Surface roughness Surface roughness meter Tool microscope measuring equipment Projector Surface roughness Surface roughness meter 43

10 Recommended Dressing Conditions Feed Rate Vr (RD peripheral speed) = RD revolution (min-1) RD O.D. π *RD= Rotary Dresser Down Dress Up Dress Vs (grinding wheel peripheral speed) = grinding wheel revolution (min-1) O.D. π peripheral speed ratio = Vr Vs Feed rate = C RD width grinding wheel revolution Operation C Standard.25~.1 Efficient grinding.125~.2 Centerless.5~.1 44

11 Rotary Dressers Diamond Tools Technical Data In dressing, the surface roughness of grinding wheels is in uenced by elements such as: Peripheral speed ratio (Vr/Vs), and dress out (Na). infeed per revolution of wheel (Ar), Peripheral Speed Ratio I Influence of Peripheral Speed Ratio on Grinding Wheel Surface Roughness Control of the grinding surface accuracy by up-dress is easier than by down-dress Higher feed rate creates more open grinding surface (grinding ability increases). Surface Roughness of Grinding Wheel (μm) Down Dress Up Dress Peripheral Speed Ratio (Vr/Vs) Grinding Wheel Rotary Dresser Test Conditions Grinding Wheel Peripheral Speed Dress Out Infeed per rev. of grinding wheel Ar=.18μm/rev =.36μm/rev =.54μm/rev =.72μm/rev WA6K #2/3 Vs=29m/s Na= Influence of Peripheral Speed Ratio on Dressing Force Larger peripheral speed ratio allows higher normal force (increase in grinding ability). 8 Tangential force shows the same tendency as normal force, but the value is much smaller..6 Normal Force (N/mm) Normal Force (N/mm) Peripheral Speed Ratio (Vr/Vs) Peripheral Speed Ratio (Vr/Vs) 45

12 Infeed Rate Influence of Infeed Rate of Grinding Wheel Surface Roughness (Na= Dress out wheel rotation frequency) Higher feed rate creates more open grinding surface (grinding ability increases). Longer dress-out time diminishes sharpness of the grinding surface Surface Roughness of Grinding Wheel (μm) Infeed Rate (μm/rev) Down Dress Na= Up Dress Na= Down Dress Na=8 Up Dress Na=8 Influence of Infeed Rate on Dressing Force Larger feed rate increases normal force (grinding ability increases). Tangential force shows the same tendency as normal force, but the value is much smaller Normal Force (N/mm) ,min-1 1,min-1 5,min-1 Vr =.81 Vs Vr =.16 Vs Vr =.81 Vs Tangential Force (N/mm) Infeed Rate (μm/rev) Infeed Rate (μm/rev) Dress Out Influences of Dress out on Grinding Wheel Surface Roughness Longer dress out time increases roundness of the grinding surface, but reduces sharpness. Surface Roughness of Grinding Wheel (μm) Down Dress Up Dress Grinding Wheel Revolution During Dress Out (rev/sec) 46

13 Grinding Rotary Dresser Small Size/High Performance Straight Type Straight Type Model Number S4-N S4-C S Diamond Grit Size Concentration Natural Diamond CVD Prism (Crown) Synthetic Diamond 4SPC.4.4 SD#4 6 pcs/circumference 9 pcs/circumference 3.3ct/cm 3 Cup Type Model Number Cup Type C4-N C4-C C Diamond Grit Size Concentration Natural Diamond CVD Prism (Crown) Synthetic Diamond 4SPC.4.4 SD/4 4 pcs/circumference 9 pcs/circumference 3.3ct/cm 3 47 Other sizes and specifications available upon request.

14 CO.5 Crown Dresser Crown Dresser Features Straight Type 1. Binderless CVD coated diamond is capable of high resistance, like monocrystal diamond. 2. Constant and stable active area with diamond column. 3. Cost effective with no reworking. 4. Optimized dressing performance is a result of diamond column size and distribution. T Size CVD Size Pitch D H T ø35~18 ø8~3 6~2.2,.4,.6,.8.8~2mm H D Cup Type Size CVD Size Pitch D D H T ø4~8 ø1~2 15~2.2,.4,.6,.8.8~2mm Please contact us for special sizes. H CVD Ace Dresser L L1 1.8 W D T 45L (mm) 4 T L L1 D W T Please contact us for special sizes. Diamond Disc Dresser Worm wheel gear grinding with high accuracy 48