Wafer Lapping


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


Process Research Products’ range of water-based AQUALAP synthetic chemical gels are used with D.I. water and abrasive to make lapping slurries. AQUALAP offers the following benefits:
  • Can be used on silicon wafers up to 300mm in diameter.
  • Reduces the percentage of abrasive used in the lapping process for "cost down".
  • Overcomes the batch-to-batch variation of the abrasive when made into a slurry, improving process capability.
  • Long-term suspension of abrasive slurries is superior to all other products on the market.
  • May be used for the lapping of quartz crystals, sapphire and ceramics such as SiC.

Note: AQUALAP gels should be used with calcined aluminum oxide abrasive, either PWA type or "FO" powder.


Unlike competitive plates, which are sand cast, all Process Research 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.

  • Provides lower scratch rates due to homogenous structure and uniform nodule size
  • Improved process capability and better yield
  • Average nodule size 20µ with a matrix of 250 nodules/square nm
  • Available in different hardnesses and different 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
  • Webbed top plates for added rigidity & lighter weight for machines without head pressure
  • Plastic inserts for slurry holes to prevent corrosion
  • Partial block segments removed to prevent scratching
  • Radius bottom grooves for easier cleaning
  • PRPHK15 iron is recommended for machines without head pressure
  • PRPHK30 is recommended for larger and thicker plates

Process Research 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 groove plates either deeper or at narrow pitch as dictated by customer need.