Creative Flex Circuit Design and Manufacturing

MicroConnex has the engineering know-how and tools to manufacture flex circuits with very tight registrations, down to a 1 mil trace and space. We have also exceeded the specifications of our three lasers and can work with very small – sub +/- 5μm – tolerances with some select materials. Plus, our ability to create highly accurate, high-aspect microvias and 10μm spot drilling has put our laser drilling and laser micromachining in high demand.

Thus, we are often called upon to solve complex flex circuit design issues and are well known in the industry for our R&D capabilities.

The following creative applications are representative of our flex circuit design, laser micromachining, laser drilling, and our lean manufacturing capabilities.

Short lead times, flexible plans, on-time delivery, and quality products has helped to make our products more competitive in a global market.”

~ Jason Wang, Purchasing Manager, Shenzhen Mindray Bio-Medical Electronics Co., LTD.

Flex Circuit’s Ability to Withstand High Operating Temperatures

This customer had tried and failed to create a circuit that could continuously operate at +125C.

When we first spoke with our customer they hadn’t even considered flex circuits as a possibility because the application didn’t specifically call for flexibility. However, because we are accustomed to working with tight tolerances on a variety of surfaces, we accepted the challenge.

We knew that the inherent capabilities of flex, along with the ultra-tight tolerances of our laser micromachining, we’d figure out a way to improve the design of their circuit, and even offer process improvements that would reduce assembly time during manufacturing.

Our engineering team put their heads together to propose a stack-up.  We knew it would work, but because we anticipated customer skepticism, we expedited a small manufacturing run of the circuits.

The Results

Try as they might, our customer could not get the circuit to fail… at any temperature.  We were able to maintain a continuous operating temperature of 150C+ and offer suggestions on reducing manufacturing expenses.

Ultra-Fast Turnaround and Short Lead Times

“Quite honestly,” they told us, “We’re tired of waiting.”

This particular customer has a steady stream of designs cooking in their back kitchen, so they weren’t particularly happy with the six weeks or more it took for other flex circuit vendors to turn the prototypes.

Fast prototype turnaround has never been a problem for MicroConnex.  We’re able to turn two designs per week and deliver 2-4 panels in just 10 to 15 working days.

The Results

We’re their go-to company for flex circuit prototypes.  Plus, as an added bonus, we can do the manufacturing in house. There’s no need for our customer to go elsewhere, either for the design or the manufacturing of the circuits.

Ultra Tight Tolerances in 3 Layers with Flying Leads

They required a 25μm circuit with 27μm copper in 3 layers with flying leads, tight via/pad registration and ultra-tight spacing. This particular circuit would cut hours off their assembly process, saving them thousands of dollars.

Although we understood from our customer that other vendors had tried and failed to build their circuit, we knew that our team engineering approach would come up with a solution.

We poured over the sample board another vendor had created. We then went through four or five iterations of our engineering run to get it right. It was the purest of team efforts, as no one engineer could have possibly seen the ultimate solution.

But, solve it we did…

The Results

In the end we did cut 8 full hours off the assembly time for their ultrasound transducer, saving the company thousands of dollars.

MicroConnex’ Process Design capabilities enable companies to reduce production costs, while enabling advanced use of current technologies.

Tight Registration Caused all Other Vendors to “No-Bid”

Because we were already working with this company, their DARPA grant required them to seek other vendors for their circuit.

They put out an honest RFP, but every other company they approached returned a no-bid response.

They needed a fine line – under 2 mil, and very tight registration. They also needed a considerable amount of support from our design team to design the circuit for manufacturability.

It actually took us a number of small run iterations in which we worked closely with the customer to evaluate each run and provide recommendations on changes until they had a product they could use.

The combination of the < 2 mil trace and space and tight registration, along with the high number of traces and thin total stackup and required flexibility made it extremely hard to manufacture.

The Results

We kept at it until we exceeded their specifications. Our success hinged on our ability to find and use the best materials. The Dupont material we used was an ultra-thin copper, and as it turns out, we were told that we were the only vendor to successfully use this material. That’s exactly how we’re able to succeed with fine line circuits where other vendors fail.

Complex Flex Circuit Allows Advances in Sensor Development

The challenge was to produce a flexible circuit that allowed vias to be drilled through the top and bottom trace layers with an accuracy of plus or minus 3 microns across the part.

This would require extremely tight laser drilling registration of vias and fine line patterning.

The Results

MicroConnex’ capabilities enabled the customer to complete their design and prototype of an advanced sensor application. Prior to MicroConnex’ success, six (6) flex circuit manufacturers tried and failed to produce the same part.

Unique Flexible Circuit Design Solves a High-Current Transformer Design Challenge

A military and defense contractor wanted to use flexible circuit technology to build a planar transformer comprised of primary and secondary windings, with very high current carrying capability.

Our challenge was to build a circuit with 50μm line and space and 27μm traces.  We also needed to solve persistent problems associated with the design requirements:

• Very thick copper traces on the surface of thin polymers
• Thick bonding layers are required to conform to the traces and also provide insulation between layers
• High layer count – ultimately 54 layers
• Through Hole problems resulting from thick dielectric and thick conductor layers requires unusual solutions

The Results

MicroConnex was able to overcome all of the problems caused by the combination of design parameters and deliver the circuit to our customer quickly and reliably.

Elegant Flexible Circuit Enables Biometric Interface

A local researcher needed to attach a sensor with an inductor coil to a mouse’s eyeball. Solder terminations at the sensor had proven to be very difficult.

The MicroConnex design replaced the hand wound coil with a flexible circuit which included an integral lead. This allowed solder terminations to be made at a safe distance away from the eye.

The Results

The MicroConnex sensor included an inductor that was smaller and lighter than the wire-based device which allowed more windings to be put into the small space. Using MicroConnex’ unique laser direct-write capabilities, this project was completed in a very short amount of time, allowing the customer to pursue additional research funding.

Design, Qualification and Test of 3-layer Flexible Circuit.

Customer: U.S. Designer of Handheld Electronics

A U.S. designer of handheld electronics needed MicroConnex to design, qualify and test a multi-layer flex circuit as a shielded 50 ohm transmission line that can withstand a large number of flex cycles.

We evaluated and re-designed (if necessary) seven different flex circuits and developed a unique test device to qualify each component.

The Results

The customer was able to successfully introduce a new consumer electronics product that met or exceeded all of their complex requirements.