Automatic solder paste transfer and quick change squeegee deliver more efficiency

ASMPT adds two new features to its proven DEK printing platforms that automate solder paste transfers and simplify squeegee changes.

With its extensive product portfolio, the company covers almost the entire SMT manufacturing process and continuously works to further automate and simplify the various workflows.

“Solder paste printing, which is already the most error-prone process in SMT production, still has many steps that must be done by hand,” explains Rick Goldsmith, director of product management at ASMPT. “Finding suitable people for these activities is becoming increasingly difficult, which is why our customers are asking for solutions that reduce personnel and material costs as well as error rates.”

When the printer setup needs to be changed, the solder paste on the old stencil must be transferred to the new one. “Until now, this was done manually with a spatula,” explains Goldsmith. “In most cases, some of the paste remained on the old stencil and was not fully transferred to the new one. In addition, there was always the risk that the paste would get contaminated or wind up in the wrong place, leading to short circuits and malfunctions.”

The new paste transfer unit for the DEK TQ simplifies this process. The paste is automatically transferred through each stencil change, provided the process parameters permit this. To do this, the squeegee pushes the paste to a transfer unit, from which it is applied to the new stencil. Next, the system uses the under-stamp cleaning system to clean off any paste residue.

“This fully automatic paste transfer relieves the already scarce operators,” says Goldsmith. “It works faster, more precisely and more efficiently than would be possible by hand. With the manual process, up to 10% of the paste remains on the stencil. Our automated paste transfer system reduces this to 5%. This will represent a significant cost saving in solder paste, reducing manufacturing cost per PCB.”

The new paste transfer system can be easily installed on all DEK TQ-series solder paste printers.

The company has also improved the squeegee changeover process on its solder paste printers. “Previously, the squeegee was affixed with two thumbscrews,” explains Goldsmith. “To change the squeegee, the operator had to loosen and then tighten them again – a time-consuming process that often caused problems, for example, when someone tightened the thumbscrews too firmly, and another operator was unable to loosen them. The time factor was also significant because 20 changeovers over a 24-hour period are not uncommon.”

A new holder makes these changeovers considerably easier because the squeegee is automatically unlocked when removed from the machine. It can then be switched out in a single step before the bracket locks automatically as the squeegee is retracted. This reduces the changeover time by up to 50%. Also, a mechanical coding system stops the incorrect insertion of squeegees. The squeegee can be retrofitted in a few hours and is available for the DEK TQ and the NeoHorizon platforms.

“Competition is getting tougher all the time in SMT manufacturing,” says Goldsmith. “To be successful in this field, you must continuously automate and streamline your operations. At ASMPT, we understand the challenges SMT manufacturers face and are able to offer our customers interesting solutions that provide them with tangible competitive advantages.”