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IPC-5704
Bare Board Cleanliness
The cleanliness of a completed PCB is crucial because a circuit board with high levels of ionic contamination deteriorates insulation resistance and dielectric strength. This can result in dendrite growth, reducing the field life of the product.
IPC Cleanliness Requirement Standards
IPC-5704 provides industry guidance on cleanliness testing for both product acceptance and process control, ensuring reliable equipment and chemistries.
"The cleanliness of a printed board can directly impact the
effectiveness or quality of an assembled printed board," explains
John Perry, IPC technical project manager. "Residues increase the risk of field failures or can
electrically impede a printed board's function, so having acceptance
criteria for various levels of testing as well as direction on how many
samples should be tested is extremely important."
C-7000 for Unpopulated Circuit Boards
The cleanliness provisions for IPC-5704 have been adapted from Delphi's C-7000. A bare board specification based on ion chromatography, C-7000 has been successfully used for 10-15 years and is consistent with recommended cleanliness levels from CSL/Foresite, PAL, and Rockwell Collins.
Ion Chromatography
Like the industry standard Ionograph, Ion Chromatography measures total ionic contamination. However, and unlike an Ionograph, Ion Chromatography provides a breakdown of the levels of each individual component of ionic contamination.
Process Solutions
Accommodating this enhanced specification required us to employ a multi-step process adjustment.
Fluxing Things Up
A primary contributor to high ionic contamination levels is the flux used in the HASL process, which can become entrapped in soldermask pores.
UV Bumping
To close these pores, Saturn installed a UV oven in line with our soldermask developing and baking line. The UV "bumping" completes the soldermask cross-linking process to close the pores--ensuring the flux remains free on the PCB surface and no longer entrapped within the soldermask.
Custom Post-HASL Cleaning Line...On Steroids!
Saturn designed and built a custom post-HASL cleaning line for the sole purpose of removing the flux from the board's surface.
Simply put, it's an industry-standard post-cleaner on steroids.
Comparison Chart Provides Breakdown...Even if Industry Doesn't
Below is a chart comparing the industry-standard to Saturn's custom-built post-HASL cleaner.
Click here for more information on Saturn's High Reliability Applications
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Real Time With...Yash Sutariya
Check out Yash as he made the rounds at the recent IPC Apex show in Las Vegas.
The Plan for Success-It's No Secret!  Saturn Electronics has bounced back
from a significant sales hit having been immersed primarily in the automotive
market. They are a successful board fabricator, and are positioned for strong
growth with innovative technology and a commitment to investment.
Click here to view this Interview
Dispersing Heat With Graphite  Yash Sutariya, VP of Saturn
Electronics, and Mark Breloff, technical sales manager for Minteq, discuss a
thermal packaging solution that combines the heat dissipation benefits of a
graphite material with the mechanical benefits of FR-4, resulting in a
cost-effective mounting material.
Click here to view this Interview
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