Solving Electronics Requirements from the Inside Out
NexLogic recently completed a Class 10,000 clean room that is key to the company’s ability to take on PCB microelectronics work. Photo courtesy of NexLogic Technologies, Inc.
As research points the way to innovations, electronics engineering and manufacturing firms provide the nuts-and-bolts expertise to bring a range of finished electronic products to market.
By Mark Shortt
The electronics industry is fertile ground for innovation these days, powering the creation of intriguing new products across sectors like the internet of things (IoT), autonomous vehicles, wearable devices, and microelectronics for implantable medical devices. In one instance, research engineers at Purdue have reportedly come up with a powerful transistor that can perform double duty: By processing and storing information, it shows potential to make computing faster and more efficient.
At the same time, it’s becoming more and more common to integrate artificial intelligence (AI) into integrated circuits, or ICs. Often, the goal is to enable predictions of human behavior that can help people make their routines faster or more efficient.
“Artificial intelligence is coming into everything,” said Zulki Khan, president of NexLogic Technologies, Inc., an electronics manufacturing services provider in San Jose, California, in an interview with Design-2-Part Magazine. “There are startups making hardware chips that will predict how people are going to behave in a certain way in an industrial or commercial application.”
As research points the way to further innovations, OEMs and product manufacturers are looking to electronics engineering and manufacturing firms to provide the nuts-and-bolts expertise necessary to bring a range of finished electronic products to market. A company with an established track record in this area is TBR Electronics, an electronics engineering firm in Romeoville, Illinois that offers electronic design capabilities in hardware, software, embedded firmware, and IoT, as well as web- and PC-based applications.
“We focus primarily on the electronics, designing to fit inside the footprint that’s provided by the mechanical engineer,” said Paul Lynch, president of TBR Electronics, in an interview. “It’s shaped the way he wants it to look.”
TBR Electronics began as The Board Room, Inc., in Tinley Park, Illinois, in 1990. Today, it works mostly in industrial applications, serving a mix of clients from relatively large companies to startups and other smaller firms. The company has designed products like power charging systems, battery-operated hair clippers, access control systems for medical carts, and lubrication control systems for overhead conveyors. Its design capabilities include development of ultra-low-power embedded systems and embedded Wi-Fi.
TBR Electronics’ relatively small size allows the firm to be nimble in responding to clients’ needs. As customers moved towards battery-operated devices over the past 15 years, TBR developed expertise in conserving battery life. “We’re very good at milking every ounce of energy out of batteries because it’s been a focus of our clientele,” Lynch said.
Implantable Medical Devices Spur Interest in Microelectronics Assembly
Another key trend in printed circuit board (PCB) technology today is hybrid assembly, which combines surface mount technology with microelectronics. It’s quickly taking hold in the production of implantable medical devices, which require tiny parts made with exacting precision.
According to NexLogic Technologies President Zulki Khan, the company has been preparing to enter the market for some time, investing in a PCB microelectronics assembly and manufacturing line that includes a high-performance wire bonder for gold and silver alloy wire bonding, and a Nordson EFD precision fluid dispenser system.
Multi-tier wire bonding is one of NexLogic’s specialties. Photo courtesy of NexLogic Technologies, Inc.
The precision fluid dispenser is critical, Khan said, because when dispensing glues, pastes, or adhesives on the microelectronics level, the tolerances must be extremely precise. Unlike conventional parts, microelectronic devices require extremely fine-grained solder pastes.
“The finest grain that you use in SMT is maybe type 4, maybe 4 and a half,” Khan said in an interview. “If it’s traditional BGA, you might be okay with type 3 solder paste; a finer BGA, maybe 4, or 4.5. But when it comes to microelectronics, you’re talking about either type 5 or even type 6, which means smaller, tinier solder balls inside the paste so that you can place them very consistently, very reliably, and in extremely repeatable format when it comes to dispensing it under the chip or during the glob top. The application can vary, but the consistency, the tolerance, the precision has to be there.”
NexLogic is certified to the ISO 13485 quality management system standard for medical devices, and completed construction of a Class 10,000 clean room for microelectronics manufacturing in 2018. The company’s array of equipment includes multiple Hesse Bondjet 820 fully automatic fine wire bonders and MRSI 705 auto die placement devices; a Janome JR3303 Robotic level flux and epoxy dispenser; a TPT-HB16 Wire/Ball Bonder; a Royce 620 Multi-test Bond Tester and sheer strength puller; and a Keyence VK-X1000 Profile Measurement Microscope for wire bond inspection and verification.
A Different Kind of ‘Beast’
In addition to making significant investments in research and capital equipment, Khan said that NexLogic has bolstered its microelectronics process engineering know-how by acquiring a small local company and bringing its team in house. Leveraging its new capabilities, NexLogic has begun working with some prominent OEM customers that are making implantable medical devices. This new line of work– medical microelectronics– is quite different from the more conventional type of PCB manufacturing.
To explain just how different it is, Khan began by saying that traditional PCB manufacturing is divided into three classes: IPC Class 1, for items like small toys and devices; IPC Class 2, for industrial and commercial items; and IPC Class 3, which includes very stringent requirements for the manufacturing of medical devices and aerospace parts.
“But when we are talking about implantable devices, we are really talking about a brand new beast,” Khan said. “At that level, the challenge is not only that the product that you’re making has to be a specific biodegradable type of product that’s going inside the body. It should also have a certain combination of the right fluxes that you’re using, the right paste, the right sensors, the right cameras, and so on. And to make implantable devices, the number one thing you have to make sure of is that the manufacturing product specifications and instructions have to be well thought out.”
Khan said manufacturing will depend on the type of material that’s selected for making the device. That means not only the base material– the substrate or a PCB– but also the material to be used for components, like passive diodes, capacitors, cameras, sensors, and MEMS. “Some of them might be able to work compatibly with the human body and fluids, but some of them might not be.”
Documentation is extremely important throughout the process. As an ISO 13485 certified manufacturing firm, NexLogic is accustomed to following rigorously defined requirements for medical devices. But PCB microelectronics manufacturing for implantable and ingestible medical devices takes these requirements to the next level.
A conformal coating is applied over a component to protect it from contamination or the elements. Photo courtesy of BTW, Inc.
“You have to follow the steps anyway, for any kind of medical devices, but, especially for ingestible and implantable devices, you have to follow it to the T,” Khan said. “There are no shortcuts, there are no taking any chances. Every minute step that you have defined in your documentation, you have to follow through on, you have to implement that. And you have to have records because if there’s a recall in the industry, then you have to make sure that you are able to provide proof of who manufactured a component that went inside the board, what sensors were made, what MEMS were made, by which manufacturer, which years, lot codes, date codes, and everything. So, it’s held to very, very high standards of manufacturing, record keeping, and traceability.”
A profound challenge facing the electronics industry, Khan said, is that the real estate on the boards is shrinking.
“This makes it a lot more difficult to manufacture on the fabrication level. Designs are becoming a lot more compact. The footprint for components is becoming smaller and smaller. And to add one more layer of complexity: It used to be rigid board, but now we are seeing the combination of rigid with flex, or flex alone. If it’s flex, it has its own challenges in terms of keeping the coplanarity, and stiffener sizes and shapes, and temperature concentrations for reflowing, and so on. But these are the types of challenges we are facing in industry right now because everything has to be lighter, everything has to be smaller, and everything has to have all kinds of functionality in the product.”
Khan said that NexLogic has one of the top imaging systems available in the industry, a Keyence profile measurement microscope for wire bond inspection. It’s used to check the size and shape of wire bond pads. Khan said that it can show the inconsistencies of pad sizes and shapes, as well as corrosion, at such a high level of magnification that there is no question of any ambiguities.
“If you have a high magnifying digital tool, like Keyence, it will measure and take a picture and show you that a sub-mil, say, seven tenths (0.7) of a mil of board or aluminum wire, cannot be bonded properly because the pad size is off by 10 percent. In SMT, you can live with 10 percent all day long, no big deal. But when it comes to microelectronics, 10 percent is a big deal because we are talking about a few mils, like 3 mils or 2 mils, 50 microns, and if you’re off by 10 percent, there’s not enough room.
“So, a device like Keyence is extremely important. If you are doing an underfill underneath the die, it will even show what the height of that underfill is, and what the consistency is. Is it across the whole chip or does it have some kind of voids? It gives details in so extremely small a format that nobody can dispute it– you have those images right in front of you, where you don’t question it. So that’s the importance of a tool like Keyence.”
Software Provides Paperless Route to Higher Quality
Some electronics manufacturing services companies are using another technology– manufacturing execution systems (MES) software– to boost their efforts to achieve better visibility and quality of their production operations. BTW Inc., an EMS provider in Coon Rapids, Minnesota, uses Aegis MES Software to enhance its process control, traceability, and quality analytics.
According to BTW Director of Manufacturing Support Dan Juelich, the Aegis software controls all assets of the company’s production, tracking everything from kitting to shipment. All of BTW’s boards and assemblies have bar codes on them at every point on the production floor.
The pr0t0n™ robot arm, designed and manufactured by e1ectr0n Inc., can be used for repeatable tasks like dispensing material, precision pick-and-place, and soldering. Photo courtesy of e1ectr0n Inc.
“It (the software) gives us traceability, control, visual aids– everything they need to manufacture the product and for us to track the product to the production floor,” said Juelich in an interview. “No longer does our account manager have to run out on the floor and go, ‘Where’s all my stuff?’ It’s all right at their desk. They know exactly where their stuff is and when it will be done. It also gives us defect tracking, which gives us the quality metrics behind areas we’re having issues with.”
Design and Testing Capabilities
When designing an electronic product, it’s important to keep in mind the importance of design for manufacturability (DFM) and design for test (DFT). NexLogic has the built-in benefit of doing its manufacturing and testing in the same building as the design. That allows its test engineers and design engineers to interact with each other and make sure that what’s been designed can easily be manufactured, as well as tested.
“Since we do everything in one building, then our interaction can be real-time,” Khan said. “When a design engineer has finished a product and is doing a debug in the lab, and it’s not checking out to the specs, he can go to the test engineer and say, ‘Hey, it’s not giving me the results. What could be the possible cause?’ And they can look at the practical aspects of making a product, versus the theoretical, which is the design side. That is very, very important.”
NexLogic has embedded testing into its manufacturing capability within its flow charts for manufacturing. That enables its team to take a look at the manufacturing and testing aspects as the product is being designed, Khan said.
Once the product is completed, how is it tested? NexLogic has three different ways of testing it.
The first is a flying probe test, which is a fixtureless test typically used for newer products that are not completely time tested. It’s a relatively slow test but it doesn’t require a big expenditure, like making a fixture or toolset or a jig, Khan said.
But once the product matures and the customer knows it’s going to last for a year or two or more, they can opt for an in-circuit test, or ICT.
“This makes a very expensive fixture and it can test the board almost in the high 80s or low 90s, percentage wise,” he said. “It can test the whole board in terms of functionality, and it can mimic the environment in which the board is going to be operating. It gives us the results without having to go into the field. It gives us the results in our lab, enabling us to see if the board is working optimally or not.”
The third method is functional testing.
“That’s where the customer gives us their own testing system, their own operating system, their own firmware, where we are plugging in every single board and making sure it is going through this rigorous programming cycle, or repeatability of different aspects of current or voltage cycles, to make sure that it performs the way it’s supposed to perform. And all of these, or a combination of these, are used in today’s technologies that we are focused on– IoT devices, wearable devices, portable devices, and now, medically insertable and ingestible devices.”
A Robot Arm for High-Mix, Low-Volume Electronics Manufacturing
Can automation help keep small manufacturing companies in business?
While high-volume electronics manufacturers typically operate numerous production automation machines, smaller, low-volume manufacturers often depend on trained assemblers. The problem is that many assemblers are aging out of a workforce that doesn’t have sufficient numbers of younger assemblers to replace them. This gap in the skills required for manufacturing jobs has many small manufacturers looking to robotics as a possible solution to their dilemma.
One technology, a new robot arm designed and manufactured by e1ectr0n, Inc., is intended to help electronics manufacturing services (EMS) companies and other small manufacturers meet demanding high-mix, low volume production requirements. Designed to work with skilled assemblers on their workbench, the pr0t0n™ robot arm assists workers with high precision tasks and works autonomously to complete repetitive tasks.
According to e1ectr0n, the pr0t0n robot arm can handle repetitive tasks quickly, moving fast from one task setup to the next. By doing so, it allows skilled workers “to manage one or more robots or address more difficult portions of the production process,” the company said in a release.
The manufacturer said that the robot arm can be used for tasks like dispensing material, applying peelable mask or conformal coat mask, torque- driving screws and bolts, and soldering. It can also be used for parts binning, precision pick-and-place, product packaging, and small product assembly. The need for specialized programming is reduced, e1ectr0n said, because its programming is simplified.
“Skilled assemblers train the pr0t0n robot arm using a familiar game controller, keyboard, and CAD files for precision tasks,” the company said in the release. “Training can be shared among a number of local robots, or transmitted to remote locations, or saved for future use.”
The robot arm was initially designed to meet the high-mix requirements of Axiom Electronics (www.axiomsmt.com), an EMS company that specializes in low volume manufacturing. Today, e1ectr0n designs and manufactures the robot in a building co-located with Axiom in Hillsboro, Oregon, where it focuses on developing automated assistants for small businesses and high-mix, low-volume manufacturing.
They’ll Build a Box for It, Too
A view of the assembled electronics enclosure built by Continental Industries. Photo courtesy of Continental Industries.
When you think about the electronics manufacturing services (EMS) supply chain, what type of company comes to mind? If you’re like most people, it’s typically the electronics contract manufacturers (ECMs) that design, manufacture, and test electronic components, printed circuit boards (PCBs), and assemblies for original equipment manufacturers (OEMs).
But while ECMs play a critical role in the EMS supply chain, they aren’t the only suppliers that help create finished electronic products. Sheet metal fabricators, for instance, use processes like metal cutting, punching, bending, and welding to build the boxes and enclosures that are used to house and protect printed circuit board assemblies and wiring harnesses.
“Most of the products they (ECMs) manufacture– printed circuit assemblies, PCBs, wiring harnesses, et cetera– go on the inside of the finished product. We build what’s on the outside– box builds, enclosures, chassis, up to full mechanical assemblies,” said Mike Moss, director of sales at Continental Industries (www.continental-ind.com), a sheet metal fabrication company in Anaheim, California, in an emailed response.
To “build what’s on the outside,” Continental Industries uses a mix of traditional sheet metal fabrication equipment– five turret punch presses and eight press brakes for CNC punching and bending, respectively– and leading-edge cutting and inspection machinery. Complementing the punching and bending workhorses is a high-speed laser cutter, an Amada LC-3015 that enables the firm to cut precision parts faster for customers. Continental also uses a laser inspection machine that performs automated first-article and in-process inspections, and generates statistical process control (SPC) reports that can be emailed to customers.
Moss said the level of automation Continental uses in its inspection processes allows its personnel to run customers’ parts “in the most efficient manner possible.”
“The inspection machine has reduced our first-article inspection time, while increasing the accuracy of the inspection by eliminating human error. What might have taken hours in the past will now take minutes to complete,” he said.
Component parts and assemblies produced by Continental Industries include electronic chassis; rackmount, Hoffman style, and medical device enclosures; radio frequency (RF) systems; data storage racks; and flight simulation, ground support, and electronic test and measurement equipment. The company makes these products for customers in the government, aircraft/aerospace, medical, and commercial sectors, among others.
The 4,000-watt Amada LC-3015 laser is the centerpiece of Continental’s cutting technology. It provides precision cutting, holding tolerances within 0.002 inch, yet requires no special tooling. Capable of cutting complex geometries and intricate shapes with clean edges, it also minimizes wasted material through use of part nesting. The laser is equipped with a 3-axis linear motor drive system, cut process monitoring, and twin-adaptive optics; it also features an Amada tuned oscillator. Moss called the Amada LC-3015 “an ultra-fast, ultra-precise, full range laser cutting system.”
An exploded view of the electronics enclosure. Photo courtesy of Continental Industries.
Moss said that although Continental’s pricing is competitive and its facility is very well equipped, its customer service sets it apart. Communication is critical to its relationship with customers.
“We acknowledge the receipt of RFQs, we send order acknowledgements with due dates, we respond quickly to inquiries and open order reports. This responsiveness gives our customers a feeling that they are connected with us and, as a result, gives them a feeling of comfort. This is not something we can put on a quote or on our facilities list, but it is definitely one of our biggest strengths and a large part of the success we have with our customers.”
A Better Quality Panel
Continental recently worked with a customer to improve the quality of a panel that the customer had been sourcing to another fabricator. Although the panel generally met the dimensional tolerances called out on the print, Moss said the end user was not satisfied with the overall quality and aesthetics of the part.
The application presented some interesting challenges for Continental. The large (approximately 2 feet by 7 feet) panels were part of an assembled unit, with a series of formed cutouts that provided airflow to cool electrical components. Because each tab on the panels was formed one at a time on a press, Continental’s team knew it needed to automate the process to be competitive.
The print called for a bend angle on the tabs of 90 degrees +/- 0.5 degrees. The tab cutout was trapezoidal, Moss said, and dimensionally critical for providing airflow. And because the assembled unit contained various electronic components and wiring, the edge condition around the cutouts, formed tabs, and perimeter of the part needed to be free of all sharp edges and burrs.
“The design of the part included formed hat sections near the outside edge of the panel, with tight height and width tolerances,” Moss said. “Normally, you can hold the hat section dimensions and work with your tolerances on the outside edge. But in this case, there was also a 90 degree flange at the edge of the part, so there was no room for error.”
It was challenging to achieve these results because the fabrication process required the panels to be run through various machines, Moss said. Another challenge was the aesthetics of the part. Surface finish was critical because when the unit was assembled, the panels were visible. “The print did not call for any line graining, jitter bugging, plating or painting, which created another engineering challenge,” Moss said.
To meet the application requirements, Continental’s engineers designed and purchased special tooling so that its machines could perform the trapezoidal cutout and form the tab opening for the airflow. Once the tooling was in house, it was modified to produce the parts with the degree of accuracy specified by the customer. With the aid of this tooling, Continental was able to automate the fabrication process to achieve greater efficiency and faster throughput, Moss said.
“We also worked with our material supplier so we could get the greatest yield for our material, and had them address the aesthetic requirements of the part. In the end, we were able to offer a part that met [our customer’s] dimensional tolerances, offered significantly shorter lead time, and exceeded their expectations by offering a 40 percent reduction in part cost.”
|Home | About Us | Back To Technical Library | Contact Us|
Copyright © 1996-2010 JobShop.com. All Rights Reserved.
General or Technical Questions? E-mail support@JobShop.com