SILICON WAFERS

 




ROD GRINDING & SLICING


SILCOOL® GRINDING COOLANT
PRODUCT DESCRIPTION
SILCOOL is a highly concentrated I.D. Slicing Coolant also used for cropping, rod grinding, edge profiling and slicing. SILCOOL is designed to work at very low concentrations in de-ionized water. SILCOOL keeps machines clean, blades and wheels free of debris and kerf.

PRODUCT BENEFITS/FEATURES:
•Very high dilution capabilities up to 500:1 (0.2%) Edge Grinding and 300:1 for I.D. Slicing.
•Reduces warp and saw marks.
•Produces solutions of very low interfacial tension.
•Low foaming versions for Edge grinding.
•Good wetting of graphite and mounting media.
•Excellent corrosion protection.

Products are also available to meet customers’ special needs.

Silcool products are supplied both with and without dye.
 





WIRE SAWING


The ingot is sliced into thin wafers using a 10-tonne wire saw. The basic principle of wire sawing is to feed the ingot into a web of ultra-thin, fast moving wire. The cutting action of the wire is created by dispensing an abrasive slurry over the web while the wire is transported in a rapid, back and forth lateral motion. The wire web is, in effect, a single wire being fed from one large spool to another. Depending on the wire diameter, each spool can hold hundreds of kilometers of wire. The wire saw technology allows for the entire ingot to be sliced simultaneously, thus, lowering cycle time and minimizing "kerf" loss.

SILCUT

The above technology has enabled PRP to use suspension technology developed over many years to formulate “Silcut” wire saw carrier fluids. “Silcut” wire saw vehicles are available in a wide range of viscosities both in oil and glycol. Silcut fluids are suitable for wire sawing silicon wafers when made into a slurry using silicon carbide abrasive.
OIL-BASED WIRE SAW SLICING FLUID
PRODUCT DESCRIPTION
PROCESS RESEARCH PRODUCTS has successfully developed a series of oil based wire saw slicing fluids for slicing silicon, silicon carbide, quartz, sapphire, and other electronic semiconductor materials. All products have been designed with excellent suspension properties. SILCUT products are designed is for use on NTC, Hauser, Meyer & Berger saws, and Themis.
PRODUCT BENEFITS/FEATURES:
•Excellent thermal stability.
•Excellent suspension stability with GC 1000, 1200 & 1500 abrasive.
•Stable viscosity during use.
•Long slurry life and low replenishment.
•Easily cleaned.
GLYCOL BASED SILCUT
SYNTHETIC FLUID FOR WIRE SAWING
PRODUCT DESCRIPTION
PROCESS RESEARCH PRODUCTS has developed a range of proven synthetic wire saw slicing fluids for the cutting of silicon wafers. These products are developed specifically for each brand of wire saws. Various abrasives can be mixed with SILCUT to form a slurry. Typical abrasives are silicon carbide (GC). SILCUT is used in conjunction with Silicon Carbide typically GC 1000, 1200 or GC 1500. SILCUT, when mixed thoroughly with silicon carbide, produces a soft-settling glycol based slurry.
PRODUCT BENEFITS/FEATURES

•Excellent thermal stability
•Minimal viscosity increase during use
•Excellent thermal stability.

•Good lubricity
•Water soluble
•Easily cleaned (non-staining)
•Biodegradable and easy to dispose





EDGE PROFILING / GRINDING


After the sawing process, the individual slices have sharp, fragile edges. These edges must be rounded or "profiled" in order to provide strength to the wafer. Profiling will ultimately prevent chipping or breakage in subsequent internal processing and during device fabrication. Without edge profiling, the wafer is susceptible to edge fractures.

PRP PRODUCTS FOR EDGE GRINDING

SILCOOL range of products are highly concentrated for Edge grinding and profiling. SILCOOL was designed to function at very low concentrations in de-ionized water. SILCOOL keeps machines and wheels free of debris and kerf.

PRODUCT BENEFITS/FEATURES
•Very high dilution capabilities 500 to 1 in D.I. Water.
•Produces solutions of very low interfacial tension
•Special low foaming version for Edge grinding.
•Excellent corrosion protection.

Products are also available to meet customers’ needs.

SILCOOL products are supplied both with and without dye.





SURFACE GRINDING


Double sided grinding of individual wafers. The spindles contra rotate & grind both wafers surfaces at the same time.

This process is often used prior to lapping.

DISCOCOOL products are designed to be used at very low concentrations in de-ionized water.

DISCOCOOL keeps the machine clean and grinding wheels free of debris and kerf.

DISCOCOOL’s key function and benefit is to keep the vacuum chuck clean in order to provide a flatter wafer.





LAPPING


Lapping removes controlled amounts of silicon from a wafer by use of a slurry. This process removes saw damage and positively impacts the wafer flatness.

Aqualap®
Process Research Products’ range of water-based Aqualaps synthetic chemical gels are used with abrasive to make slurry.

•Aqualap is used on silicon wafers up to 300mm in diameter.
•Aqualap reduces the percentage of abrasive used in the lapping process for “cost down”.
•Aqualap overcomes the batch-to-batch variation of the abrasive when made into a slurry, improving process capability.
•Long-term suspension of abrasive slurries when using Aqualap is superior to all other products on the market.
•Aqualaps are designed especially for use on grooved plates.
•The latest series of Aqualaps can be recirculated for cost minimization.
•Aqualaps may be used for the lapping of quartz crystals, sapphire and ceramics such as Lithium Tantalate.
•Aqualaps may also be used in the texturing of memory discs and the lapping of recording heads.
•Aqualap gels should be used with calcined aluminum oxide, PWA type & “FO” powder.

GROOVED LAPPING PLATES

Unlike competitive plates, which are sand cast, all PRP plates for lapping silicon wafers are gravity die cast in specially designed molds that control the cooling rate and structure throughout the working depth. Graphite nodule size and distribution is uniform thus providing a consistent matrix throughout the plate.

FEATURES/BENEFITS OF PRP LAPPING PLATES
•Provides lower scratch rates due to homogenous structure and uniform nodules.
•Improved process capability and better yield.
•Average nodule size 20µ with a matrix of 250 nodules/square mm.
•Available in different hardnesses and 3 main chemistries according to customer requirements:

-Martensite for long life & “cost down”
-Mini Martensite for better TTV and lower scratch rate
-Gray/Flake iron for flat lapping.

PRP INNOVATIONS
•Webbed top plates for added rigidity & lighter weight for machines without head pressure. (C)
•Plastic inserts for slurry holes to prevent corrosion (A)
•Partial block segments removed to prevent scratching ( B )
•Radius bottom grooves for easier cleaning and improved plate rigidity ( B)

Recommendations
•PRPHK15 iron is recommended for machines without head pressure.
•PRPHK30 iron is recommended for larger and thicker plates.

Custom Plates or “Copy Exact”

PRP offers custom designed, specially machined grooves, grid patterns & edge chamfers to meet our customer’s unique requirements. To retain the highest structural rigidity, groove depth should not exceed 1/3 of the plate thickness. The depth to width ratio of the grooves should be 10 to 1. However, we are able to, in special circumstances to groove plates either deeper or at narrow pitch as dictated by customer need.




WAFER RINSING

After lapping, but before ultrasonic cleaning, PRP recommends rinsing the wafers and cast iron plates by feeding a water-based alkaline rinsing agent through the slurry feed lines.
These ”rinse aids” contain surfactants and corrosion inhibitors.

BENEFITS/FEATURES

PRP Ultraclean rinse aids

•Prevent corrosion on the plates.
•Prevent drying of the slurry on the wafers.
•Eliminate wafers sticking to the plates.
•Prevents ‘grid marks’ on the wafer.
•Makes the wafers easier to clean.

PRODUCT DESCRIPTION:

RP TEAM® is a liquid, mildly alkaline, organic rust preventative designed for direct application to lapping plates or similar surfaces. The product is recommended to be used undiluted, but is water-soluble. RP-TEAM® may also be added to most aqueous lapping vehicles to increase rust protection properties. RP TEAM® finds wide applications in silicon wafer lapping operations. It is effective in the prevention of the inevitable dark grid lines that sometimes form in wafers in the lapping process due to the elements iron and carbon present in cast iron lapping plates.




CLEANING

A complete and proven range of water-based cleaners from low pH to high pH for the cleaning of MOS wafers and many other electronic and ceramic parts. Ultraclean is especially designed for use in ultrasonic baths. Some Ultracleans are also suitable for spray applications. All Ultraclean is manufactured to semiconductor standards.

PRODUCT BENEFITS/FEATURES

•Ultraclean is typically used at 4% in water.
•Ultraclean works more effectively when used in ultrasonic cleaning baths.
•Ultrasonic baths should be heated to 60 degrees Celsius as a starting point.
•Ultraclean products are biodegradable.
•Ultraclean products have excellent rinsing characteristics.
•Ultralcean products have high reserve alkalinity for long shelf life.


For more detailed information about our products,
please visit our Technical Sales Information Database.

 

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Aqualap™  |   Silcool™   |   Silcut™   |   Ultraclean™