Future-Proof Product Performance. With Automated Conformal ...

Future-Proof Product Performance.With Automated Conformal Coating.

Conformal coating contributes to long-term product quality and performance. But it’s often viewed as a process

that tolerates sufficient results – or “good enough.” That view is changing. More and more electronic products are

coming to market each year that require safe, reliable performance in diverse physical environments. That means

conformal coating applications need to evolve and scale. Comprehensive coating, curing, and inspection solutions

deliver rugged, reliable product protection and the traceable, day-to-day, and batch-to-batch results you need for an

efficient process.

Coating Consistency: The Roll of Automated Conformal Coating InspectionAutomation continues to be a driving force behind high-quality electronics manufacturing, and for good reason. It makes outcomes more predictable. Quality, consistency, and operator safety are all improved.

In a manual process, operators inspect coated boards for adherence to keep out zones, accurate coating thicknesses, the existence of bubbles, and consistent coverage. This requires a high-level of skill and experience that’s honed over time. How much skill? Let’s look at one example.

When verifying coating thickness, operators must learn to visually assess the level of light or “glow” emitted from the coating material under UV light. Although an operator can achieve an acceptable level of qualitative accuracy, it would not be possible to match the accuracy of automated inspection. Like any manual process it’s difficult to achieve repeatability. Results vary from operator to operator and human error is unavoidable.

Other common concerns include over exposure to chemicals and fumes affecting operator safety and damaged boards due to frequent handling.

More and more production processes are benefiting from

automation, including conformal coating.

If you’re trying to manage any of these concerns, automation is the solution.

The ASYMTEK FX-940UV Series automates the conformal coating inspection process – working together with the Select Coat® SL-940 Conformal Coating system to deliver ongoing coating quality and consistency. Programming and operations methods can be combined to create an efficient coating line that maintains repeatability across batches. The system is SMEMA compatible and available in batch and inline configurations to accommodate varied manufacturing floor space needs. How does it work? There are two powerful modes.

Large Area Grid Inspection Mode (Auto-Tune)

In Auto-Tune mode, the system scans known good boards and the software “learns” the variations across coated areas to capture the passing criteria. This method is excellent for quick inspection recipe development. The system’s automatic learning capabilities enable the inspection of coated and non-coated areas within minutes of scanning the first article.

Individual Part Inspection Mode

In this mode, the system analyzes critical areas for coverage, non-coverage, and coating thickness. Areas around filets can be inspected and selective bubble detection can be performed. When paired with optional side cameras, the sides of components can also be inspected.

The FX-940UV Series makes inspection of conformal coatings simple and convenient – providing complete inspection coverage at unmatched low false-failure rates. Advanced High-Power UV Lighting and image processing technology support coverage inspection, color inspection, normalized correlation, and rule-based algorithms.

Selective bubble

detection

Data-Driven: Process Control and Development

Every coating process has critical parameters that must remain within defined limits. Thankfully, there are enhanced methods that you can employ to meet those requirements – such as statistical process control (SPC). When combined in an automated coating line, the ASYMTEK Select Coat SL-940 Conformal Coating system and FX-940UV Series can monitor a wide range of conformal coating process parameters through SPC. Let’s take a look at the data-driven inspection features on the FX-940UV Series.

Create Recipes and Capture Inspection Data

The FX-940UV Series includes NYTVision automated optical inspection software. Create coating inspection recipes, define coated and non-coated areas, and refine recipes with the Auto-Tune feature.

This can be done completely offline, and programming time is typically less than 30 minutes.

A variety of details are logged during inspection to ensure traceability – machine name, login user name, inspection recipe, work order number, board serial number, inspection date and time, yield, parts failed per board, and more. User defined custom fields can also be added.

The FX-940UV can be fully integrated with your FIS/MES system to capture up-to-the-minute process data. Single-page quick feedback reports provide an overall view of the inspected board and allow you to zoom in on specific areas of interest – around keep out zones and critical components.

Analyze Historical and Real-Time Data

After you’ve collected data, it’s time for deeper analysis. The VuData Statistical Process Analyzer creates customizable charts and reports to identify clear process improvement opportunities. Reports are organized in a hierarchy that reveals additional data down to the individual defect level. Data can be searched, grouped, ordered, and formatted depending on your needs.

Continually Improve Your Process

Manufacturing relies on process improvement and quality control. Data analysis provides solid insight to help you sustain continuous improvement – enabling you to take specific, focused actions exactly where they’re needed. When developing a new recipe, you can use the inspection system feedback to optimize a program for complete coverage. And after a program is set up and verified, the ACI system will continue to validate the coating performance.

With process changes backed by data you can make accurate decisions to rapidly improve your conformal coating process – avoiding waste, rework, and scrap.

Inspection Results and Report with Individual Part

Detail

Real-Time Inspection Data –

Status View and False

Call Status Screens

Curing: The Final Step to Coating SuccessYou’ve automated your conformal coating and inspection processes. Masking is substantially reduced or eliminated and you’re getting consistent, high-quality coating results. That’s great progress, but what’s next? The final step in conformal coating automation, is to ensure the applied coating doesn’t migrate and that it remains unblemished. Damage can be introduced through handling. And failures such as shrinkage, solvent entrapment, orange peel, and bubbles can occur if the coating material isn’t appropriately cured. Curing, however, takes time and can impact operator safety. These concerns can be addressed by introducing ovens that “dry” boards, safely vent VOCs, block UV light, and support high production throughput.

Selecting the appropriate oven for your process involves several important considerations. The actual selection process is complex and requires expert guidance.

Curing vs. Drying – What’s the Difference?

Chemical curing involves hours or days at ambient temperature or in heated conditions to achieve the optimum properties for full protection and ruggedization. Drying, in contrast, can occur within minutes after the coating and inspection process allowing production operators to handle coated boards – without introducing fingerprints, pulling coating material off the board, or causing coating to migrate into keep-out-zones when boards are tipped. In other words, drying preserves the high-quality coating results that are achieved through an automated coating and inspection process without disrupting the ongoing flow of your production process.

Safety First – Protect Operators and Improve Compliance

Reflow ovens can dry conformal coatings, but the top-ventilation design used in reflow ovens emits VOCs directly into the work environment. ASYMTEK in-line IR/Convection Ovens feature a unique down-draft exhaust design for safe VOC removal.

And the ASYMTEK Select Cure® UV-9 Oven features shutters to protect operators from UV light exposure.

Choosing an Oven – Understanding the Basics

Each manufacturer will take a different path depending on the type of board and application, the desired cycle rate, and coating material curing profile. These factors determine the type of oven that’s needed. Use the following checklist to explore the basic considerations.

1. What is the desired cycle rate? This will determine the oven length requirements.

2. What are the temperature constraints for the board or part?Multi-zoned top and bottom heat sources can be used to control temperature settings. The top and bottom of a board can be dried at the same time. Horizontal ovens with an infrared heat source can also be used.

3. What curing mechanism is needed?Ovens with a modified inside atmosphere that control the amount of humidity, CO2, or nitrogen are available. ASYMTEK also offers specialized UV A, B, and C range Arc lamps doped with iron or mercury to enhance UV wave length.

This is a general checklist to help you understand the basic considerations. When you’re ready, contact us and we can help you navigate the decision-making process to ensure that you select the right oven for your application.

CHECKLIST

+1.760.431.1919www.nordsonasymtek.comemail: [email protected]

2747 Loker Avenue WestCarlsbad, CA USA 92010-6603

Prepare for the FutureThe electronic components that power next-generation products require high-quality conformal coating protection to ensure safe, reliable performance in a variety of physical environments. To keep pace with these requirements and maintain yield and throughput goals, modern coating applications must embrace a comprehensive process that combines coating, curing, and inspection along with process controls that provide traceability and consistent, day-to-day, and batch-to-batch coating performance.

Conformal coating inspection, especially when it is combined with a conformal coating system and the appropriate oven for your process, gives greater control over conformal coating outcomes.

The result is improved throughput, increased yield, maintained reliability, and process insights.

Panorama Line SolutionsIf you’re transitioning to automation or replacing depreciated or outdated equipment, our skilled technicians can design a Panorama™ coating line solution to meet your specifications.

Every Panorama Line Solution delivers a full range of equipment options; minimal operator interaction; closed-loop controls, parameter limits and inspection across the line; process data for improved productivity; and stability and consistency at every step.

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