Diamond, Silicon Carbide and Alumina Lapping Films

[ Process Description ] [ Recommended Procedures ] [ Trouble Shooting ] [ Diamond Films ] [ SiC Films ] [ Alumina Films ]

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LAPPING FILMS

The applications for lapping films range from polishing fiber optics, optical components, ceramic capacitors, computer hard drive read-write heads, ceramic seals, etc. The main characteristic of lapping films is that they produce very flat surfaces, especially across a materials having a wide range in hardness.

Lapping films consist of a mylar backing (typically 3 mils) on which the abrasive is rigidly fixed with an epoxy binder. The most common abrasives used for lapping films include diamond, silicon carbide, alumina and to a lesser extent ceria.

Optical Interferometer Profile of a 3 micron Diamond Lapping Film

Diamond lapping films are precision coated abrasives using precisely graded diamond. A very flexible adhesive bonding agent is used which tenaciously hold the abrasive particles to the backing. These adhesive resists cracking or peeling to a tough, durable, tear-resistant plastic film which is waterproof and resistant to many solvents.

Diamond lapping films provide less polishing relief than intermediate rough polishing cloths and provide a fixed diamond grinding mode. Diamond lapping films are exceptional abrasives for preparing microelectronic materials for SEM and TEM analysis.

Silicon carbide lapping films are bonded or coated abrasive films of SiC designed so that the abrasive will have a large number of cutting points (negative abrasive rank angle). This is achieved by aligning the abrasive particles approximately normal to the backing. Note that coated abrasives are not quite coplanar, thus SiC papers produce the maximum efficiency (cut rate, stock removal and minimal damage) because new abrasive is exposed as the old abrasive breaks down.

Alumina lapping films consist of an aluminum oxide, which is a naturally occurring material (Bauxite). It exits in either the softer gamma (mohs 8) or harder alpha (mohs 9, 2000 HV) phase. Alumina abrasives are used primarily as a final polishing abrasive because of its high hardness and durability

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RECOMMENDED PROCEDURES (Lapping Films) For plain backed diamond lapping films

• Wet the flat lap plate with water or a water/ surfactant solution
• Place the plain backed lapping film on the surface
• Roll out or press out any entraped air bubbles
• Apply necessary lubricant
• Begin polishing with lower force to avoid tearing film
• Clean specimen and film for final 10-15 seconds of polishing cycle
• Clean and dry specimens

For PSA backed diamond lapping films

• Place the PSA backed lapping film on the surface
• Apply necessary lubricant
• Begin polishing with lower force to avoid tearing film
• Clean specimen and film for final 10-15 seconds of polishing cycle
• Clean and dry specimens

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TROUBLE SHOOTING for LAPPING FILMS POLISHING

Symptom	Cause	Action
Coarse scratching	Swarf build-up on the lapping film	Use a lubricant with an appropriate surfactant
Tearing of pad	Sharp specimen edges	Reduce intitial applied load so that the specimen edge does not cut the film. Gradually increase pressure during the lapping operation. Dispense lubricant more frequently
Excessive relief or edge rounding	PSA backing providing to much flexibility (resiliency) Lapping backing plate surface is not flat	Use a plain backed diamond lapping film Use a flat lapping surface

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Diamond LAPPING FILMS

Type A DIAMOND LAPPING FILMS (Plain-backed, 3 mil)
Description	Size (inches)	Catalog Number (Plain-backed)	Catalog Number (PSA backed)
0.10 um Diamond Lapping Film	Up to 24-inch	DA-01	DAA-01
0.25 um Diamond Lapping Film	Up to 24-inch	DA-025	DAA-025
0.50 um Diamond Lapping Film	Up to 24-inch	DA-052	DAA-05
1 um Diamond Lapping Film	Up to 24-inch	DA-1	DAA-1
3 um Diamond Lapping Film	Up to 24-inch	DA-3	DAA-3
6 um Diamond Lapping Film	Up to 24-inch	DA-6	DAA-6
9 um Diamond Lapping Film	Up to 24-inch	DA-9	DAA-9
12 um Diamond Lapping Film	Up to 24-inch	DA-12	DAA-12
15 um Diamond Lapping Film	Up to 24-inch	DA-15	DAA-15
30 um Diamond Lapping Film	Up to 24-inch	DA-30	DAA-30

DIAMOND LAPPING FILM LUBRICANTS
Description	Quanitiy (oz)	Part Number
32 oz Diamond Lapping Film Lube	32	LFL-032
1 gallon Diamond Lapping Film Lube	128	LFL-128

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Silicon Carbide LAPPING FILMS

Silicon Carbide Grinding Films (3 mil)
Description	Size	Catalog Number (Plain-backed)	Catalog Number (PSA backed)
1.0 um silicon carbide	Up to 32-inch	SIC-001PB-3	SIC-001PSA-3
3.0 um silicon carbide	Up to 32-inch	SIC-003PB-3	SIC-003PSA-3
5.0 um silicon carbide	Up to 32-inch	SIC-005PB-3	SIC-005PSA-3
9.0 um silicon carbide	Up to 32-inch	SIC-009PB-3	SIC-009PSA-3
12 um silicon carbide	Up to 32-inch	SIC-012PB-3	SIC-012PSA-3
20 um silicon carbide	Up to 32-inch	SIC-020PB-3	SIC-020PSA-3
30 um silicon carbide	Up to 32-inch	SIC-030PB-3	SIC-030PSA-3

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Alumina LAPPING FILMS

Alumina Lapping Films (3 mil)
Description	Size	Catalog Number (Plain-backed)	Catalog Number (PSA backed)
0.05 um alumina (ALO)	Up to 32-inch	ALO-105PB-3	ALO-105PSA-3
0.30 um alumina (ALO)	Up to 32-inch	ALO-103PB-3	ALO-103PSA-3
1.0 um alumina (ALO)	Up to 32-inch	ALO-001PB-3	ALO-001PSA-3
3.0 um alumina (ALO)	Up to 32-inch	ALO-003PB-3	ALO-003PSA-3
5.0 um alumina (ALO)	Up to 32-inch	ALO-005PB-3	ALO-005PSA-3
9.0 um alumina (ALO)	Up to 32-inch	ALO-009PB-3	ALO-009PSA-3
12 um alumina (ALO)	Up to 32-inch	ALO-012PB-3	ALO-012PSA-3
15 um alumina (ALO)	Up to 32-inch	ALO-015PB-3	ALO-015PSA-3
30 um alumina (ALO)	Up to 32-inch	ALO-030PB-3	ALO-030PSA-3

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