The rise of flex and rigid-flex PCBA: OptimaTech

 

Flex and rigid-flex PCBA (printed circuit board assembly) are rapidly gaining in popularity for their ability to provide greater functionality within a smaller footprint and withstand vibration, bending and repetitive motion. From wearables to aerospace systems, manufacturers are switching from rigid boards and wiring harnesses to flexible and rigid-flex boards for ever-smaller devices and increased reliability.

You've already enjoyed the benefits of flex and rigid-flex PCBA technology if you've ever worn a smartwatch, used a wireless earbud or relied on a pacemaker to keep functioning smoothly! Silently changing the way electronics are being designed these boards and seriously, it's time some recognition.

So, What is Flex and Rigid-Flex PCBA?

Flexible printed circuit boards (flex PCBs) are manufactured on a flexible substrate that will bend, fold and flex without breaking. Rigid-flex PCBA integrates these flexible components along with conventional rigid-board pieces into a single application. Imagine the best of both worlds: A rigid board for structure where you need it, and a flex circuit for space or movement where you need it.

Rigid boards are perfect for many uses, but there are limitations to their effectiveness. They are flat, inflexible (literally), and when you need to join more than one rigid board of the type you'll need connectors, cables, or wire harnesses. Each of those additions will be one more thing that can go wrong, will be one more thing that has to be carried, and will be one more area of no space.

What has all the buzz about Flex and Rigid-Flex PCBA?

The Technology is getting Smaller (and Smarter)

Every consumer electronics company engages in a constant struggle to make their products thinner, lighter and more capable – at the same time. This is achieved with flex PCBs because they eliminate the need for connectors and cables that occupy precious internal space. A flex circuit can easily bend around corners and curved enclosures where a hard board would not fit.

When it comes to wearables, hearing aids and foldable phones, every cubic millimeter is important. Consider flex PCBA for products that must fit into a curved or space-constrained enclosure, and rigid-flex for products that require solid mounting points for connectors or heavier components, as well.

Reliability under stress is a must!

The following is something that isn't discussed enough: connectors and solder joints are easily points of failure in electronics, particularly in environments where vibration and/or movement is constant. Rigid-flex PCBA can help minimize the interconnects used in an assembly, making it easier to avoid failures.

That is why rigid-flex has become so popular in the aerospace, defense, and medical devices fields. If it is in the body or on a plane flying through turbulence at 30,000 feet, “it might work” just doesn't suffice. Reliability must be inbuilt from the beginning and rigid-flex is built for that.

The need for lighter weight but effective impact

In the aerospace and automotive industry, weight can significantly impact fuel efficiency and performance, making every gram count. Flex and flex-flex assemblies offer the added advantage of cutting weight compared to a rigid-board/harness assembly by eliminating the use of bulky connectors, additional cabling and redundant board materials.

This weight savings can mean either more flight time or more payload for drone manufacturers and satellite designers. That's a pretty interesting compromise, and one of the most obvious motivators for engineers to continue to be drawn to flexible solutions.

Design freedom that reaches to the very root of the problem

Rigid-flex PCBA allows designers to route circuits in 3D rather than 2D, as opposed to rigid or rigid-flex circuits. Looking for a board that folds down into an origami style to fit into a cylinder? Rigid-flex can do that. Looking to create an articulation between two solid parts that opens and closes with each use, such as a laptop hinge or a door hinge? With each cycle, flex circuits take that motion in stride without cracking.

This three dimensional flexibility presents completely new form factors that would not have been possible with flat boards. No longer are designers working on new solutions to old problems, they are now envisioning products that didn't exist before.

Demand is being driven by the automotive and medical industries

Whether it's sophisticated driver assistance or infotainment systems, or battery management systems in electric-powered vehicles, today's vehicles have more electronics onboard than ever before. Due to these requirements these systems must be able to endure the constant vibration, temperature changes and close packaging requirements, making flex and rigid flex PCBA a perfect match.

Likewise, flex circuits are used in medical devices ranging from diagnostic imaging to implantable devices, where biocompatibility, reliability and miniaturization are all critical. The electronic industry and the rigid-flex industry are growing at the same rate and demand for flex and rigid-flex assembly is increasing with both of these industries.

Before making a selection between flexible or rigid-flex PCBA, what factors should be taken into account?

Price is one of the primary considerations. The cost of flex and rigid-flex boards is generally more expensive initially than rigid (conventional) PCBs, as the materials used are different and the process of manufacturing is more complicated. For applications where space is not necessarily limited, cost is important, and the solution is not dynamic, opt for traditional rigid boards. If your design will require movement or need to save a lot of space, or you need to save weight for a design that you're willing to pay more for, choose the Flex or Rigid-Flex.

Another factor to consider is manufacturing complexity. Flex and Flex-Rigid Assemblies involve unique processes, tooling and expertise beyond rigid PCB manufacturing. Working with a manufacturer who is knowledgeable in flex materials, lamination processes, and controlled impedance routing can have an impact on yield and long term reliability.

Conclusion

Flex and rigid-flex PCBA is not limited to trend, but it's a revolutionary change in electronics design. With devices shrinking ever further, industries increasingly looking for reliability and applications constantly pushing the envelope of 3-D solutions, flex and rigid-flex technology will continue to play an ever more significant role.

When you're designing the next product and space, or weight, or durability are in the top of your list of concerns, you may want to consider flex or rigid-flex PCBA as a possible solution that can only be approached with a rigid board. It has been proven in some of the most challenging applications from the imagination and it can only get better from there!

If you are looking for a fine PCBA provider, look no further than Optima Technology.

Sustainable PCBA practices: OptimaTech

 

Printed Circuit Board Assemblies (PCBA) are playing a crucial role in the push for sustainability in the electronics industry, making them a key contributor to lowering environmental impact. PCBA (printed circuit board assembly) practices are significantly contributing to the efforts of making electronics industry sustainable by implementing lead-free soldering, energy-efficient equipment, minimizing material waste, recycling water, and responsible end-of-life management. These techniques reduce emissions and costs and assist manufacturers in meeting regulations such as RoHS and WEEE.

The manufacture of electronics is associated with a significant environmental impact. At the heart of that footprint is printed circuit board assembly, the art of attaching components to bare boards to produce functioning electronics. It uses energy, water and raw materials and produces hazardous waste when mismanaged.

The good news? There are ways for manufacturers to make significant improvements without compromising quality or profitability. Whether it's replacing potentially dangerous substances or refining energy use to ensure facilities operate more efficiently, there are effective ways to implement sustainable PCBA practices. In this post, I'm going to give you with you the crucial strategies and tell you why they're important for the planet and your wallet.

The significance of sustainability in PCBA

The electronics industry generates a high proportion of e-waste and much of this can be attributed to the way in which boards are being manufactured and assembled. These and other regulations, including the EU's RoHS (Restriction of Hazardous Substances) and WEEE (Waste Electrical and Electronic Equipment) directives, now drive the industry to reduce the amount of harmful substances and accept responsibility for products once they have served their purpose.

Sustainability not only meets regulatory standards, it is also good business. Utilizing energy-efficient processes reduces utility costs. The cost of inputs is reduced with material recovery. And a believable green image is becoming more and more important to buyers – particularly to large OEMs who assess suppliers based on their environmental performance.

These are the key sustainable PCBA practices:

It doesn't have to be a dramatic change to be "green" in the assembly. It is derived from the usage of many practical changes throughout the production line.

Use lead free and halogen free materials

The traditional solders used lead, a harmful metal that can be dangerous to workers and the environment. Solder alloys with lead-free content are commonly used in compliance with RoHS, and are normally a tin-silver-copper alloy. Halogen-free laminates and halogen-free flux means even less harmful compound is emitted during soldering and during the disposal procedure.

Improve energy efficiency

Reflow ovens, wave soldering machines and testing equipment suck up a significant amount of power. Manufacturers can reduce energy consumption by:

Modern reflow ovens are made with improved insulation and heat recovery, which can cut energy use by as much as 50%. Modern reflow ovens are insulated and have improved heat recovery to reduce energy consumption by up to 50%.

·         Maximizing machine utilization by scheduling production runs to reduce idleness.

·         Installing LED lights and smart controls throughout the premises

·         Purchasing renewable energy if available

As a whole, small efficiencies accumulate over thousands of hours of production.

Reduce material waste

Reduce waste from design. The panels are designed in an efficient manner and reduce the scrap. Minimizing excess of solder paste and recovering unused solder/paste or unused metal components keeps valuable materials in circulation. Systematic material control also helps avoid the use of obsolete materials.

Recycle water; control chemicals

Chemical solvents and water are used in the PCB assembly and cleaning processes. Closed loop water systems include water collection, filtration and water reuse, rather than water discharge. Use of less toxic aqueous or bio-based cleaners instead of aggressive solvents reduces the hazard of wastewater and the risk to worker health and safety.

Plan for end of life recovery

Sustainable thinking doesn't end at the factory door. Easier disassembly of these boards makes it easier to recover metals such as gold, copper and silver at end of life. By using certified e-waste recyclers, you can be sure that your electronics are being recycled properly and not into landfill.

How to begin to make greener PCBA

If manufacturers are ready to take action, a phased approach is best. Start by conducting an energy audit of existing energy consumption, waste streams and material inputs to determine where the main opportunities lie. Look for first actions, such as lighting or recovery of paste to implement before investing in bigger equipment overhauls. Make sure to use metrics to track results, whether it's measuring kilowatt-hours per board or waste diverted from landfill. These can be used to measure progress and ensure your investment pays off.

In situations where you have to comply with regulations first, select lead-free materials first. If cost of operation is the key factor, then emphasize energy efficiency. Both routes will take you towards a more sustainable operation.

A fine PCBA provider you can choose is Optima Technology.

Conclusion

Sustainable PCBA practices show that there can be a symbiosis between environmental responsibility and good business. Manufacturers use lead-free materials, reduce energy and water usage, reduce waste, plan for recycling, and improve their competitiveness while decreasing their impact. It will not be an instant change, but one improvement at a time, towards cleaner, smarter electronics production.

Looking to “go green” on your assembly line? Get started with one audit this quarter, one high impact change and go from there.

Frequently asked questions

What does PCBA stand for?

Printed circuit board assembly is known as PCBA. It is the technology of soldering and attaching electronic components to a blank printed circuit board to make a working circuit board.

Is there evidence that lead-free soldering is as effective as leaded soldering?

The modern solder alloys that contain no lead, like the tin-silver-copper solder alloys, provide a reliable joint for most applications. They are processed at slightly higher temperatures but improvements in equipment and flux formulation have closed the performance gap except for a large majority of products.

How does sustainable PCBA save cash?

Sustainable PCBA can reduce costs due to the extra savings in energy costs, material waste, water recycling and the recovery of valuable metals. With these savings, it is possible to recoup your investment in efficient equipment or process improvements over time.

What are the laws and standards that apply to sustainable electronics production?

The EU RoHS and WEEE directives are two important directives that limit the use of hazardous materials in electronics and regulate the collection and recycling of e-waste. Similar standards have been adopted in many different regions.

How thermal management is done by a PCB assembly manufacturer - OptimaTech

 

A PCB assembly manufacturer handles heat in various ways that involve smart design elements and effective production methods: thermal vias, copper planes, heat sinks, thermal interface materials and careful placement of components. These techniques remove heat from vulnerable applications, provide thermal stability and extend the life of electronic products.

Electronics are the victims of heat. Each time that the circuit board turns on, it produces heat and when it cannot dissipate it, performance is affected, parts are damaged and product life becomes shorter. That is where thermal management is crucial in today's PCB assembly.

If you are designing or sourcing electronic products, you need to know how heat is managed by manufacturers, to avoid expensive redesigns and failures in the field. A well-managed board operates cooler, more predictably and with safety headroom.

The significance of Thermal Management in PCB Assembly

Electronic components have limits on their temperature ranges. If you goad them, you're likely to lose their efficiency, their temper, or they may fail altogether. The high temperatures also accelerate degradation of the materials, reducing the life of the board as a whole.

Some of the actual consequences of inadequate thermal management are:

·         Failure of components: If one component fails, such as capacitors, processors, and power regulators, it can cease to function.

·         Low reliability: After repeated heat cycling, solder joints become more unreliable and develop micro-cracks over time.

·         Performance throttling: Some chips throttle back in performance when they get too hot, which diminishes product performance.

·         Safety hazards: Excess heat will make boards warp or can even pose fire risks in extreme cases.

Due to these risks, thermal management is not an after-thought. It is integrated throughout the whole assembly.

How a PCB Assembly Manufacturer Handles Thermal Management

A combination of design, material selection and assembly methods are employed by manufacturers to help boards maintain cool temperatures. These are the basic techniques.

Strategic Component Placement

The position of a component on a board is as important as the component. High power components are spaced out so heat doesn't build up in one area. Components that are sensitive to temperature are separated from the primary heat source, and airflow routes are taken into account when designing layouts. This straightforward planning measure can help keep hot spots from developing.

Thermal Vias

Thermal vias are small plated holes which transfer heat between layers of the board. Manufacturers place groups of vias under hot components to provide a way for the heat to pass from the top layer to an internal copper plane or the bottom layer to spread out and dissipate.

Thicker Copper Layers and Copper Planes

Copper has a great heat conductivity. Large copper planes and pours are used by the manufacturers to distribute heat over a larger area instead of a small area. In higher power designs they might be able to identify thicker copper layers (measured in ounces), which can handle more current and more heat.

Heat Sinks

A heat sink is a metal body that is typically made of aluminum or copper and is attached to a hot component in order to increase the surface area of the hot component to transfer heat away from it. Greater surface area results in more heat going to the ambient air. Different components in the computer, such as processor or power transistors, have different load magnitudes, and manufacturers choose and attach the heat sink according to this.

Thermal Interface Materials (TIMs)

The reason that the air is a poor conductor of heat is that any small space between a component and a heat sink will reduce the rate at which heat is transferred. The space between the heat source and the heat sink is filled with a thermal interface material, such as thermal pastes, pads and gap fillers, which forms a continuous thermal pathway. The selection of the right TIM can make a significant impact in terms of the cooling performance.

Substrate and Material Selection

Heat response depends on the type of board material. Most uses require standard FR-4 but some high-heat uses require higher thermal conductivity materials like metal-core PCBs (MCPCBs) with an aluminum core. The substrate matches the thermal needs of the product.

Active Cooling Integration

Passive methods might not be sufficient for boards that operate at high temperatures. In such instances, the manufacturers engineer the board to be cooled with fans, blowers or even liquid cooling. The assembly process takes into account the mounting points, connectors and clearances these systems require.

Thermal Testing and Simulation

Many manufacturers conduct thermal simulations before a design is ever in full production, these can be used to predict where heat is likely to be generated. They then test them in the real world using thermal imaging cameras afterwards. An effective cooling strategy is confirmed with this testing and issues are identified at an early stage.

Selecting the appropriate thermal solution for your product

Not every board requires a hot rod cooling system! This will vary depending on the power that your product can achieve, the environment in which it operates and your budget.

·         For designs that are used at moderate power levels and a cost-effective, reliable solution, no moving parts, consider passive methods (copper planes, thermal vias, heat sinks).

·         Use active cooling (fans, liquid cooling) when components produce a lot of heat, and passive cooling is insufficient to maintain safe temperatures.

·         If you have LED lighting, power electronics or other high-heat applications, select metal-core PCBs.

An excellent PCB assembly manufacturer won't take a cookie-cutter method of doing things, but will consider all of these factors and more in relation to your design.

Conclusion

Thermal management is the key factor that distinguishes between a board that fails early and one that can run for years. Smart placement of components, conductive materials such as copper, thermal vias, heat sinks and appropriate interface materials help a PCB assembly manufacturer maintain control of heat throughout the life of a product.

Communicate with your manufacturer about thermal management as early as possible in the design process if you're designing your next electronic product. It's much simpler and cheaper to deal with heat at the beginning of the process than after it has been manufactured. Discuss thermal simulation, materials and cooling options that can be exploited for your particular application, it's a matter of reliability!

A fine manufacturer you can pick is Optima Technology.