The Hot Air Solder Leveling (HASL) process has been the preferred coating procedure utilized by the Printed Circuit Board (PCB) Industry for the past 20 years. With new regulations on the elimination of lead from solder, the HASL process has not lost its popularity or feasibility and still remains the preferred coating of PCB manufactures worldwide.

Nihon Superior Co., Ltd. ( Osaka , Japan ) has developed the patented SN100CL Sn-Ni-Cu HASL alloy. This alloy has been specially designed as an alternative to Sn-Pb alloy and provides a high quality surface finish for use in the HASL process. In addition, Lantronic (Wijchen, The Netherlands) manufacturer of HASL systems has completed the necessary modifications to their Model TT30 so that this system is compatible with the process parameters required by lead-free alloys. 

The newly designed Solder Pot has been designed specifically to handle lead-free solder. The Solder Pot generates a significant amount of solder flow which eliminates the need to double cycle every PCB’s, which is the case for one competitive lead-free HASL systems. Another huge advantage with the Lantronic Solder Pot is the ability to dross from the top of the Solder Pot. Competitive systems must drain their Solder Pot due to the fact that the dross settles at the bottom of their Solder Pot. Solder Pot exchange is very expensive and time consuming. In addition, the Solder Pot of the Model TT30 has been fitted with additional strip-heaters to ensure that the required Solder Pot temperature of 495º F is maintained. Lantronic has specially designed the “LanTroFlow” heating system which provides a steady flow of heated air to the Air Knives. The “LanTroFlow” system temperature is adjustable and maintains the recommended lead-free Air Knife temperature of 510° to 540° F.  

As previously mentioned, with the lead-free deadline now in place, PCB manufactures must embark on the necessary steps to convert their existing HASL systems which currently operate with traditional eutectic 63% - 37% Sn-Pb HASL alloy, to the new lead-free Sn-Ni-Cu HASL alloy.  ACS Technologies, Corp. ( Farmington , AR ), North American Distributor for Lantronic currently has begun installing Model TT30 HASL lead-free systems. These systems are successfully running the new Sn-Ni-Cu HASL lead-free alloy.  In addition, ACS is working closely with the HASL alloy Nihon Superior SN100CL lead-free alloy, in an attempt to provide direction, support, and service to the PCB industry. Our expertise and experience with the lead-free alloy provides a smooth and trouble-free transition when converting over to the new lead-free Sn-Ni-Cu HASL alloy.

ACS has experienced the following advantages when using the SN100CL Sn-Ni-Cu lead-free alloy in the Lantronic Model TT30:

• Superior uniformity and flatness on pads compared to Sn-Pb alloy

• A smooth bright finish on the surface of pads and through-holes

• Excellent through-hole clearance

• Exceptional solder-ability in assembly

As we move ahead into the next generation of HASL finishes, be confident in knowing that the transition is brief and undisruptive. Your current pre-clean and fluxing applications need no modifications. ACS is available to assist you with this procedure. Time is of the essence, and procrastinating until the last minute can lead to playing catch up or even lose of work to your competition. In addition, it is possible that you will need to make modifications in other processes due to the higher processing temperatures, so now is the time to get all the bugs worked out.  ACS can be reached at (479) 846-2403 or visit our web-site at www.acs-tech.com.