What pressure is recommended to clean AMT boards after reflow

Wut-chuw talkin' 'bout Carol?

Are you talking about an aqueous wash machine to clean your boards? Well then, I've always liked Electroverts machines. They're modular and seem to do the job well. It all depends on your boards and your process.

reply »

Hi Carol,

Pressure requirements have changed over the past few years. In the recent past, aqueous cleaning systems relied on high flow, low pressure �flooding� techniques. 20 � 30 PSI pumped through large orifice nozzles. With ever increasing board densities, decreasing component standoff heights, and aggressive �no-clean� profiles, the need for wider, finer nozzle diffusion (requiring higher pressures) has never been greater.

Modern aqueous cleaning systems utilize higher pressure spray systems with lower flow rates. Exact pressure is somewhat brand dependent. Batch-format aqueous cleaners (dishwasher type) range from 30 PSI to 90 PSI. Inline cleaners utilize higher pressures (due to their limited contact time with a board). Inline pressures, also brand and model dependent, range from 50 PSI to 120 PSI. Stoelting seems to be the king of pressure (and price).

Forgive the duplication of a recent posting, but some of the manufacturers of aqueous cleaning systems include:

Aqueous Technologies (batch and inline): http://www.aqueoustech.com Unit Design (batch): http://www.unitdesign.com Technical Devices: (inline): http://www.technicaldev.com EMC (batch and inline): http://www.emcgti.com Speedline (batch and inline): http://www.speedlinetechnologies.com Austin America (batch and inline): http://www.aat-corp.com Trek Industries (inline): http://www.trekindustries.com Stoelting (inline): http://www.stoelting.com

Hope this helps!

Michael Konrad Aqueous Technologies

reply »

Hello Everyone,

Speedline Technologies' Electrovert Division does offer a number of batch and in-line systems for your cleaning application. A good contact for you to reach to discuss the details of your application would be Bill Boyde at the factory. The Electrovert factory also has a demo/test lab which you could visit to discuss and test your process. The main phone number for the Electrovert Facility is 573-346-3341. You can also find more information at http://www.speedlinetechnologies.com

As a representative of Speedline, I would be happy to assist you in locating your local representative. Please feel free to contact me if there are any questions or concerns.

Best Regards, Sean D. 480-829-8170 ext.14

reply »

Watt tiepoo? [Cereally, you can usually fix typos after you post by using the P yellow �edit� button that shows when you are looking at your posting.]

We�re had people on SMTnet that were washing their boards with a brush attached to the end of a garden hose. We have used to use a Sears dish washer. You choice of type of cleaner is based on your ability to spend money and throughput requirements. The two primary types of cleaners are: 1 Batch 2 In-line

Many would argue that you should use a cleaner that is designed to wash PCA. Washer sales types are the most exuberant adherents of that perspective. Excellent suppliers are: * Batch: Accel, Aqueous Technologies, Austin American, EMC, Hotpack, Unit Design, Raygo [Some of these people are acquiring each other and are being acquired by others.] * In-line: Electrovert [ugly looking, but good cleaning], Trek, H2O/EMC

Recognize that: * Helium welding plastic is NOT rocket science. So, the supplier should bring something else to the party. In some cases, what else they bring is unclear. * Water pressure is not the issue. For years the plastic welders have upped pump pressure with that idea in mind. You should not be trying to blast the residue from the board. * Getting a clean board is the issue. Generally, this means getting as much water as possible in contact with water soluble res, so that it can get into solution.

Finally when you think about cleaners, also consider: * Quality requirements and consistency of your in-bound water. If you�re going to treat your in-bound water, how does that fit with your purchase decision? * Waste disposal plan. If you�re going direct to drain, does your water PTO approve? If you�re going to treat your waste, how does that fit with your purchase decision? * Machine maintenance. Cleaning these hogs is NOT fun. * Process control. If you�re going to clean boards, how do you check your process to be sure they�re clean? * Future cleaning needs. How will you clean no-clean? How will you clean whatever flux you end-up with for no-lead? etc. * Personal investment plans. Consider buying stock in your local electricity suppier.

reply »

We have two batch systems installed from Aqueous Technologies and have been very please with there performance and reliability. One machine is utilizing a 5hp pump and generates 60psi the other is a 3hp version and is about 40psi. I think the most important element is chemistry and positioning of your boards in the machine.

In line machines possibly would give a greater degree of pressure but I am not sure this means you necessarily get a cleaner product in the end especially if other variables having a greater impact are not optimized. The batch cleaners are great for low to medium volume. We have designs with FP QFP's and BGA's and feel very confident in our ability to clean the product.

Only comment I have is the need for a cleaner to brighten up the stainless steel in these systems.....they get dull in appearance......anyone have a suggestion?

Good luck and let me know if I can help,

Kevin

reply »