No matter what brand or board type you’re working with, it’s impossible to escape the reality that PCBs are inherently failure-prone. Planning for when, rather than if, your circuit boards will malfunction is an approach that reduces costs and relieves future headaches.
Shipping out your faulty PCBA for service can be stressful when you’re on a tight production schedule and board failure has already led to downtime, but it pays to have practiced technicians discover the root cause of a circuit board’s failure and analyze the extent of its damage.
In addition to physical damage to the circuit card, like cracks and corrosion, discrete and power components can deteriorate for a wide range reasons, including extreme heat, over/under voltage surges and sags, and age; contaminants like grime and dust are also frequent sources of trace damage. Contacting a repair provider is the best way to ensure that your circuit board assembly functions properly once it’s reinstalled, and—more importantly—that your industrial electronics won’t fail again a few weeks down the road.
Even though factories save millions every year by repairing and/or reworking circuit boards, the guesswork associated with choosing a repair shop and anxiety about the quality of the craftsmanship they offer convinces many plant managers to purchase brand new replacement boards instead. This is a costly decision in the short and long-term: in addition to spending an arm and a leg for new boards, OEMs don’t provide preventive and corrective repair recommendations and actions to help your electronics equipment (not just the circuit board part that needs to be replaced) exceed its performance expectations.
What criteria should guide your selection of a service provider if you've decided to repair or rework your circuit board? We recommend focusing on “Three E’s”—Expertise, Equipment, and Economies of scale.
I. Expertise
Circuit board repair remains a labor-intensive process at its core, demanding highly-skilled handiwork and technical knowledge.
One of the benefits of working with service-centric repair companies, as opposed to OEMs, is that their profitability depends on the capabilities and customer service of their engineers and technicians. Their ability (or inability) to deliver high-quality and reliable repairs before deadline—especially when large or complex projects are on the line—powers (or stunts) their growth.
Subsequently, longevity is an important factor to consider when choosing a repair company—there’s a reason why some repair providers have been operating and growing for several decades and others stagnate after a few years in business.
Certifications are another obvious factor to bear in mind: if a company’s technicians aren’t qualified in Electro Static Discharge (ESD) and Institute for Interconnecting and Packaging Electronic Circuits (IPC) repair and rework standards, you shouldn’t trust them to handle advanced microprocessors and digital signal processor circuits.
Similar to this, while not advertised publically, ongoing specialized training for technicians is a sign of a competent independent service provider (ISP) committed to competing on a global stage. Technicians should be able to operate the latest diagnostic technology and also develop world-class programs for handling and testing parts.
In addition to having the ability to quickly diagnose a failing circuit board component, execute its repair, test its performance, and provide an aggressive warranty, repair companies should also be eager to offer value-added technical services. These might include: removing and replacing stressed parts, improving inefficient design with stronger, more reliable technology, remanufacturing unsalvageable or obsolete components, manufacturing custom-designed products and implementing End-of-Life (EOL) strategies, among others.
II. Equipment
Everything else held equal, up-to-date diagnostic and testing instruments can make the difference between a 1-day turnaround and a 3-day turnaround on an urgent project. For this reason alone, ISPs invest millions to equip their facilities with the most state-of-the-art equipment available.
Specifically, ISPs need a mixture of equipment in order to address the digital, analog, and power sections of circuit cards. A properly outfitted PCB repair facility will incorporate the following equipment into their production process:
1. In-Circuit Testers perform both a powered, in-circuit logical test of digital and many analog ICs, as well as signature analysis of the chips. These tests check for the Boolean functions from digital chips, and also provide a signature analysis of dynamic operation. Unknown chips can be identified by its Boolean output. The Diagnosys PinPoint System also contains libraries of digital chip pinouts to assist the technician in troubleshooting, and can determine wiring patterns of the circuits.
2. Data I/O Programmers read, verify and store data in programmable logic devices, such as PROMs, microprocessors and memory devices. A master database of all programmable devices are stored for current and future repairs.
3. Hot Air IC Installation & Removal Systems – with this equipment, surface mount ICs are subjected to temperature-controlled hot air to reflow solder. A vacuum pickup tool is used to remove or install the chip with the help of a magnifying CCD camera.
4. Signature Analysis is the primary diagnostic tool for PCB repair activity. It works by applying a current-limited AC signal across two points of a semiconductor junction. The current flow causes a vertical deflection of the CRT trace, while the applied voltage causes a horizontal deflection. Together, they form a unique V/I signature that represents the overall health of the junction under test. Analyzing the deflection signature tells us whether the component is good, bad or marginal. Many units also have the internal ability to fire gate-triggered devices while viewing the V/I curves.
5. Oscilloscopes – various bandwidth analog and digital oscilloscopes are used to analyze voltage waveforms under power.
6. Function Generations are used to simulate square, sinusoidal or triangle wave input and trigger signals.
7. Digital Volt Meters (DVMs) – 3 ½ to 6 ½ digit meters measure voltages down to 6 ½ digit precision at the selected measurement range.
8. Sencore Cap & Inductance Meters are used to analyze capacitors for capacitance, equivalent series resistance (ESR), dielectric leakage and frequency response. Inductance meters are used for measuring similar attributes in coils.
9. Power Supply Load Boxes – dynamic load banks for testing power supplies capacities, hold-up time, and spike sensitivity.
10. Calibrators are reference systems traceable back to NIST standards for final adjustment of temperature, flow and pressure related products.
11. Mings are hand-held testers for identifying and checking various integrated circuits.
12. System or Simulation Testers provide a means to test assemblies from the connectors to determine entire functionality.
Furthermore, all equipment should be identified as either used for diagnostic work or for final repair (calibrated). All calibrated equipment should be on a scheduled gage program.
III. Economies of Scale
The best repair, rework, and overhaul options at the lowest price points are only sustainable if an ISP is highly scalable.
For example, larger repair shops can offer more agility by leveraging their inventory of new and refurbished circuit board assembly parts. This is especially important as it relates to emergency/rush repair services when customers are experiencing production downtime.
In addition to cost-effectively replacing defective circuit boards components with new and/or more reliable parts, plant managers, owners and operators want a full-service partner that can improve their equipment performance and operating efficiency as a whole.
Most repair shops, however, do not have the manpower, experience, and technology necessary to provide value-added PCB redesign and manufacturing services, for example—these are simply cost-prohibitive for small and medium-sized ISPs.
Bottom Line
When your circuit board repair project is complete, the remanufactured, like-new condition board(s) should always meet the same industry specifications for performance as new PCBs. If you found a quality shop, you should expect that the parts will easily exceed the expected lifetime of the original board.
And when it’s all said and done, choosing the right ISP can save you up to 70% versus the cost of buying replacement PCBs from the OEM.
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