-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueThe Growing Industry
In this issue of PCB007 Magazine, we talk with leading economic experts, advocacy specialists in Washington, D.C., and PCB company leadership to get a well-rounded picture of what’s happening in the industry today. Don’t miss it.
The Sustainability Issue
Sustainability is one of the most widely used terms in business today, especially for electronics and manufacturing but what does it mean to you? We explore the environmental, business, and economic impacts.
The Fabricator’s Guide to IPC APEX EXPO
This issue previews many of the important events taking place at this year's show and highlights some changes and opportunities. So, buckle up. We are counting down to IPC APEX EXPO 2024.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - pcb007 Magazine
Solder Mask Tack Dry
November 8, 2019 | Nikolaus SchubkegelEstimated reading time: 1 minute
Tack drying is a key process step, as it makes the solder mask surface suitable for exposure. Tack drying happens after coating the board surface with a solder mask, but before exposure. If the tack drying process is done correctly, the solder mask surface will not adhere to the base plate or the artwork.
The tack drying process is controlled through three parameters: temperature, dwell time, and airflow.
Practically speaking, in a factory environment, two of the three parameters—temperature and dwell time—are easily controlled. Generally, there is little opportunity to change the airflow. Let’s look at temperature and dwell time more in detail.
Temperature
As a general rule, the tack-dry temperature should be as low as possible; in other words, it should only be as high as necessary. If the temperature is too low, the evaporation rate for the solvent will be to slow, and the solder mask will not dry in a reasonable amount of time. If the temperature is too high, however, the dry time certainly will be excellent, but it could create a solder mask lock-in with repercussions by the developing time.
These repercussions manifest themselves in the necessity of longer dwell times in the developer and potential solder mask residues on pads and in holes.
For example, the LPI solder mask for rigid products from Taiyo recommends temperature range for tack dry between 65–80°C (150– 176°F) at the surface of the PCB. The elevated temperature leads to a higher vapor pressure of the solvent in the diffusion interface on the immediate solder mask surface. Air circulation then takes the solvent vapor away. Also, as a general rule, increasing the temperature by 20°C will double the evaporating speed of the solvent (valid in the range of 20–100°C).
To read this entire article, which appeared in the October 2019 issue of PCB007 Magazine, click here.
Suggested Items
AIM to Highlight NC259FPA Ultrafine No Clean Solder Paste at SMTA Wisconsin Expo & Tech Forum
04/18/2024 | AIMAIM Solder, a leading global manufacturer of solder assembly materials for the electronics industry, is pleased to announce its participation in the upcoming SMTA Wisconsin Expo & Tech Forum taking place on May 7 at the Four Points by Sheraton | Milwaukee Airport, in Milwaukee, Wisconsin.
Hentec/RPS Publishes an Essential Guide to Selective Soldering Processing Tech Paper
04/17/2024 | Hentec Industries/RPS AutomationHentec Industries/RPS Automation, a leading manufacturer of selective soldering, lead tinning and solderability test equipment, announces that it has published a technical paper describing the critical process parameters that need to be optimized to ensure optimal results and guarantee the utmost in end-product quality.
Empowering Electronics Assembly: Introducing ALPHA Innolot MXE Alloy
04/16/2024 | MacDermid Alpha Electronics SolutionsIn the rapidly evolving electronics industry, where innovation drives progress, MacDermid Alpha Electronics Solutions is committed to setting a new standard. Today, we are pleased to introduce ALPHA Innolot MXE, a revolutionary alloy meticulously engineered to address the critical needs of enhanced reliability and performance in modern electronic assemblies.
New Book on Low-temperature Soldering Now Available
04/17/2024 | I-Connect007I-Connect007 is pleased to announce that The Printed Circuit Assembler’s Guide to… Low-temperature Soldering, Vol. 2, by subject matter experts at MacDermid Alpha Electronics Solutions, is now available for download.
Inkjet Solder Mask ‘Has Arrived’
04/10/2024 | Pete Starkey, I-Connect007I was delighted to be invited to attend an interactive webinar entitled “Solder Mask Coating Made Easy with Additive Manufacturing,” hosted by SUSS MicroTec Netherlands in Eindhoven. The webinar was introduced and moderated by André Bodegom, managing director at Adeon Technologies, and the speakers were Mariana Van Dam, senior product manager PCB imaging solutions at AGFA in Belgium; Ashley Steers, sales manager at Electra Polymers in the UK; and Dr. Luca Gautero, product manager at SUSS MicroTec Netherlands.