Modern Printed Circuits: August 2014 by EEWeb Magazines

AUGUST â&#x20AC;&#x2DC;14

Interview with John Yacoub President of Advanced Circuits

Advanced Circuits

Delivers

CIRCUIT BOARDS with Made-in-America Pride The Wide World of Regulatory Testing and Certifications

PCB Surface Finishes Find Favor

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Modern Printed Circuits The next step is to print the solder paste over the BGA ball locations of the cleaned substrate and then install the balls by using a fixture. Once all the balls are installed, a microscope reinspection is conducted to assure the balls are properly populated and then, reflow is applied based on the designated temperature stated in the spec sheet of the BGA manufacturer, keeping in mind the accurate thermal profile of the BGA package. MOISTURE SENSITIVITY Besides the actual reballing steps, emphasis must be placed on the BGA substrate moisturesensitivity levels or MSL. There are two aspects involved here—relative humidity and ambient temperature. These two factors must be kept in mind during reballing. Relative humidity should be less than 50 percent in the atmosphere and ambient temperature less than 80°F.

If these levels aren’t maintained, then certain airborne chemicals such as sulfur, ammonia, or acetic chloride will reduce chances of proper BGA balling since these airborne chemicals reduce the probability of the balls wetting process occurring during the reflow process.

Special considerations should go toward ball size and type, whether it is eutectic or lead free. Sphere or ball size can vary from 0.3 to 0.76 millimeters and require specific solder paste. Careful evaluations are demanded to match alloys and ball sizes with the correct solder paste and reflow temperatures, along with the appropriate flux types.

A veteran and experienced EMS provider measures the temperature and humidity at different parts of the floor and keeps a log of both to assure tight manufacturing controls.

As for plastic BGAs, moisture absorbency must be taken into account. JEDEC calls for a standard atmosphere of 30°C at 60 percent relative humidity to develop the time limit exposure. If the plastic BGA is exposed to more humidity or a higher temperature, then less than optimal results are achieved, creating less than optimal solder joints at BGA’s.

Other major considerations include flux types used during reballing process, the types of balls involved, stencil design, and avoiding costly shortcuts. The flux type is important because solder alloys are exposed to the oxygen in the atmosphere, which, at an elevated temperature of 125°C or above, evaporates, and flux rapidly oxidizes. The main function of any flux is to

TECH ARTICLE

PCB Surface Finishes Find Favor

However, exposing the BGA substrate to more humidity or temperature doesn’t mean it isn’t

protect the alloy and reduce surface tension to solder the joint properly.

acceptable for reballing. The main requirement is to bake it according to the Joint Electron Device Engineering Council (JEDEC) standard—24 hours at 125°C. Baking takes the moisture out of the package before soldering. Once baked, the substrate needs to be reballed within a few hours. On the other hand, if the substrate is baked and not used, it must be immediately vacuum sealed using Desiccant, a drying agent,

Figure 1. Close up photo of a tiny passive device.

CUT COST, MINIMIZE CONCERNS One of those demands is to cut cost. Historically, OEMs have closely watched product development costs, as the price of goods continue rising. There’s no question about it, gold is not getting any less expensive. OEMs have closely monitored gold prices and the increasing cost of the popular surface finish, electroless nickel immersion gold (ENIG). The gold associated with ENIG is a very thin layer of the precious metal, yet is still costly.

Stencil quality plays an important part as well in reballing to ensure solder properly adheres to the site. An effective solder joint ensures good ball collapse. When the right stencil design is used and an adequate amount of solder paste is dispensed, the result is a good solder joint. Stencil design includes the aperture opening and sizes in relation to the surface-mount technology (SMT) pads along with the thickness of the stencil foils. Correct stencil design ensures that enough paste is dispensed on the SMT pads, especially if these are fine pitch devices. If too much paste is dispensed on the SMT pads, they create a chance of shorting between the BGA balls, and if not enough paste is dispensed there could be the probability of voids and opens.

“If strong mechanical stress to remove additional moisture. Repairing Ball-Grid-Array Defects Reduces Costs is applied to the Solder with Finesse to Salvage Surface-Mount Packages board, there’s a chance of damaging or cracking the substrate.”

TECH ARTICLE

“Black pad” is closely related to highly stressed ball-grid array (BGA) package solder joints. Among the reasons it’s getting so much attention is the fact that BGAs are today the most popular type

of device packaging being placed on PCBs of all sizes. In particular, with some PCBs shrinking in size, highly functional devices housed in micro BGA packages are being used to populate those small boards. Black pad is particularly prevalent with fine and ultrafine pitch packaging that has extremely tight distances between the leads or the tiny ball connections on a BGA.

Developers coming up with the newer finishes try to keep the desirable characteristics of traditional finishes such as ENIG, but at the same time substitute newer innovations to pare down the cost and improve performance. Electroless nickel immersion silver (ENImAg) recently

Electroless nickel–electroless palladium– immersion gold or ENEPIG for short, is another

introduced by Macdermid, is an example. Using silver rather than gold reduces the cost. In addition, the company maintains that its

That’s because the electroless-nickel layer is not compromised thanks to the palladium

COVER INTERVIEW

contender to protect a PCB from ENIG’s solderability issues. ENEPIG proponents say the black pad failure problem no longer exists.

Advanced Circuits Delivers Circuit Boards with Made-in-America Pride

ENImAg is also a solution to concerns associated with solder joint-defects and failures on ENIG

that’s plated onto it using chemical reduction. Plus, the ENEPIG process is less expensive than bondable gold. Some savings estimates run as

surfaces known as “black pad” or “black-line nickel” (BLN) .

high as 80 percent for total final finishing cost when ENEPIG replaces nickel-gold processes.

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TECH ARTICLE The Wide World of Regulatory Testing and Certifications

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dvanced Circuits is one of the largest U.S.-based

printed circuit board manufacturers. A leader in quick turn around time, they specialize in both prototype and production quantities. With divisions in Colorado, Arizona and Minnesota, Advanced Circuits serves over 10,000 active customers who find the company extremely reliable. EEWeb spoke with John Yacoub, president of Advanced Circuits, about being one of the few, large printed circuit board manufacturers in the U.S. and how they continue strong in the face of competition from overseas manufacturers. Yacoub also discussed the company’s support of engineering students and free design

Modern Printed Circuits

PCB

Surface Finishes Find Favor By Will Morrissey, Contributing Writer

TECH ARTICLE

New product requirements cast doubt on conventional finishes while innovation promises more effective solutions

ome original equipment manufacturers (OEMs) may not be familiar with printed circuit board

(PCB) surface finish. However, most veteran PCB designers, fabricators, and assembly engineers are well acquainted with the various coatings applied to circuit boards. Surface finish is applied to a PCB to assure solderability of the metal underplate and is the outermost layer that dissolves into the solder paste when the PCB goes through the reflow oven during assembly.

Modern Printed Circuits

Several major, new advances in the PCB world in the last few years have affected these finishes. This includes the introduction of the industry-wide restrictions of hazardous

PCB manufacturing equipment has been used to assemble those larger boards.

substances (RoHS), prohibiting the use of lead in electronics equipment. Also, more recently, OEMs have made an even greater push toward portable products, which significantly impacts PCB sizes and technologies. These and other

and other smaller, portable gear, PCBs have shrunk, device packaging has become extremely small, and in some cases, has undergone a metamorphosis to the point you can barely see these devices (figure 1). Only the newer assembly

advancements have a direct bearing on the types of surface finishes used in a variety of different applications. So it’s worth taking a new look at these finishes to determine where they fit best.

high-magnification vision machines can effectively view them for verification purposes.

The PCB business has long embraced five traditional surface finishes (see chart). Most

are still requiring the larger boards and use the conventional board surface finishes.

experts would agree those finishes have longevity because the PCB technology has been rather staid for a number of years. Staid

However, PCB surface finish technologists and suppliers are closely monitoring the technology trends associated with PCBs. As they do,

in this sense means that, generally speaking, the average circuit size of a PCB has been about that of a legal pad; packaging has been rather

they are targeting certain PCB application characteristics and are coming forward with their versions of the right surface finish to meet

conventional, and basically, the same generation

the newer OEM demands.

However, with the advent of smartphones, iPads,

Meanwhile, the older PCB surface finishes remain popular in most cases. Many OEMs

Leaded HASL

Lead-Free HASL

ENIG

OSP

Immersion Silver

Immersion Tin

Co-Planarity

Poor

Good

Excellent

RoHS Compliant

Yes

Solder Joint Integrity

Best/Excellent

Good

Excellent

Good

Fabrication Cost

Low

Medium

Low

Medium

Reflows

Mulitple

Multiple

2 to 3

Shelf Life

12 months

9-12 months

“Black pad is particularly prevalent with fine and ultrafine pitch packaging.” 6

TECH ARTICLE

Figure 1. Close up photo of a tiny passive device.

CUT COST, MINIMIZE CONCERNS One of those demands is to cut cost.

“Black pad” is closely related to highly stressed ball-grid array (BGA) package solder joints. Among

Historically, OEMs have closely watched product development costs, as the price of goods continue rising. There’s no question about it,

the reasons it’s getting so much attention is the fact that BGAs are today the most popular type of device packaging being placed on PCBs of all

gold is not getting any less expensive. OEMs have closely monitored gold prices and the increasing cost of the popular surface finish,

sizes. In particular, with some PCBs shrinking in size, highly functional devices housed in micro

electroless nickel immersion gold (ENIG). The gold associated with ENIG is a very thin layer of the precious metal, yet is still costly. Developers coming up with the newer finishes try to keep the desirable characteristics of traditional finishes such as ENIG, but at the same time substitute newer innovations to pare down the cost and improve performance. Electroless nickel immersion silver (ENImAg) recently introduced by Macdermid, is an example. Using silver rather than gold reduces the cost. In addition, the company maintains that its ENImAg is also a solution to concerns associated with solder joint-defects and failures on ENIG surfaces known as “black pad” or “black-line nickel” (BLN) .

BGA packages are being used to populate those small boards. Black pad is particularly prevalent with fine and ultrafine pitch packaging that has extremely tight distances between the leads or the tiny ball connections on a BGA. Electroless nickel–electroless palladium– immersion gold or ENEPIG for short, is another contender to protect a PCB from ENIG’s solderability issues. ENEPIG proponents say the black pad failure problem no longer exists. That’s because the electroless-nickel layer is not compromised thanks to the palladium that’s plated onto it using chemical reduction. Plus, the ENEPIG process is less expensive than bondable gold. Some savings estimates run as high as 80 percent for total final finishing cost when ENEPIG replaces nickel-gold processes.

Modern Printed Circuits

Although ENEPIG is popular, it’s not really a new development, but rather a finish that is now cost effective. A decade ago, ENEPIG was not exactly a welcomed finish with PCB fabricators

HASL is the granddaddy of them all. In some circles, veterans claim it was the finish used on the original circuit board. It has a number of attributes PCB fabricators and assembly houses

since palladium was priced out of the reach of cost-conscious PCB fabricators, assembly houses, and the OEM. However, today, it is less expensive than gold and is sought after for wire bond applications, RoHS or lead-free, and

like. On the plus side, both leaded and lead-free are available; however, cost of the lead-free version is high, yet the leaded one remains low cost. Fabricators claim this is the best finish as far as solder joint integrity. That trait alone

leaded PCB assembly. ENEPIG is described as ideal for high-reliability military, aerospace, and medical electronics systems.

speaks volumes for the high reliability of solder joints. The PCB assembly people like HASL because it can withstand multiple reflow cycles.

REVISIT THE BIG FIVE

Among the downsides to HASL is poor co-

The big five surface finishes that have withstood the test of time with PCB fabricators

planarity for the leaded version. But on the upside, lead-free HASL co-planarity is good. Co-

and assembly houses continue to be used extensively. The five traditional surface finishes have associated positive and negative

planarity, which is synonymous with warpage, or bow and twist, on the board is a growing concern among OEMs and contract manufacturers and

characteristics: • Hot-air solder leveling (HASL) for leaded

EMS Providers. Warpage adversely affects solder bond integrity. Maintaining that integrity is becoming more difficult due to greater use of

PCBs and lead-free HASL • Organic solderability protectants (OSP) • Electroless-nickel immersion gold (ENIG)

finer-pitch devices like micro BGAs. The solder bond in these instances is at greater risk since solder paste volumes are considerably smaller.

• Immersion tin • Immersion silver Figure 2. PCB with ENIG finish.

TECH ARTICLE “The gold associated with ENIG is a very thin layer of the precious metal, yet is still costly.”

Immersion tin comes in second as far as popularity. It has excellent co-planarity, meaning it provides a consistently flat surface and is a good match for fine-pitch devices. Fabricator cost is acceptable, but the product has a limited shelf life. The more conservative fabricators say immersion tin should be used within three to six months. But some assemblers give it a nine-to-twelve month shelf life. However, the phenomenon called “tin whiskers” has historically plagued immersion tin. These electrically conductive, wispy-looking, hairlike formations can cause short circuits and subsequent system failure. Despite the extra cost gold incurs, ENIG continues to be a well-accepted surface finish. It has high marks in all the key categories, in particular excellent co-planarity and medium fabrication cost. Immersion silver also comes in among the top surface finishes. Its co-planarity and solder joint integrity are excellent. It is RoHS compliant, which in this day and age, is very important. It can sustain multiple reflows and has a good shelf life. OSP’s downside is it can only sustain a couple of reflow cycles. Any more than that, the PCB incurs thermal damage. Otherwise, its characteristics closely mirror those of immersion silver.

Battle Against

Black Pad Black pad failure problem stems from a fragile bond where the solder and nickel come together. Consequently, at this juncture the joint becomes weak and highly unreliable. Any stress or shock applied to that connection easily breaks the joint resulting in a defect or open-circuit failure. It’s called black pad because once the affected BGA packaged component is removed, a dark or black pad with virtually no solder is seen. Researchers checked into this problem. Their initial findings showed that the problem surfaced as a result of too much phosphorus co-deposition during the electroless nickel plating process. Later on and based on further research findings, it was determined that the extra amounts of phosphorous came about because the nickel was being corroded, leaving excessive amounts. Therefore, those researchers contend that the best protection against black pad is to use higher phosphorus content in the ENIG process so that it is less sensitive to process fluctuations. However, other groups of researchers focusing not only on the problem, but also the growing gold cost came up with the idea of substituting gold with a silver, tin, or palladium coating on the nickel base. That solved the cost issue and provided improved performance in terms of black pad failures. These findings triggered the move to the newer PCB surface finishes.

Modern Printed Circuits

REPAIRING

Ball-Grid-Array Defects

Reduces Costs Solder with Finesse to Salvage Surface-Mount Packages By Joe Batey, Contributing Writer

TECH ARTICLE

imple and inexpensive semiconductor devices in earlier generations of

electronic systems were easily discarded or recycled when they were damaged either before or during the printed circuit board (PCB) assembly process. Not much engineering, purchasing concern, or thought went into that decision over devices which cost under a dollar each.

Modern Printed Circuits

That’s not the case today with highly complex semiconductor devices such as the extraordinarily expensive and complex microprocessor (MP), the field-programmable

When BGAs are soldered on the PCB, it’s highly probable that some may have partially collapsed balls, meaning those spheres haven’t effectively been soldered onto the board. Other soldering

gate array (FPGA), the custom applicationspecific IC (ASIC), and the system-on-a-chip (SoC). A majority of these highly sophisticated semiconductors are packaged in advanced ballgrid-array (BGA) packages.

defects include voids, opens, or shorts between the different balls. Also, there can be excessive solder paste applied. This causes bridging between BGA balls, also known as ball shorts.

There are a variety of BGA types. The plastic one is the most popular and cost-effective. Other main variations include ceramic and nonceramic materials. The more advanced

X-ray and automated optical inspection (AOI) are used to locate BGA defects. Assembly personnel may try to correct these problems though certain methods, for example placing those defective BGAs again on the PCB and

the BGA and circuitry inside it, the higher the costs. Some cost in the hundreds; others cost

then reflowing that board, hoping it’ll pass a second inspection. However, if those steps don’t

upwards of several thousand dollars. In some cases, there can be limited availability or long lead times for obtaining new devices to replace

produce the expected results, then BGA reballing is next, especially if BGA balls are damaged during assembly.

the damaged ones. Because of cost and time constraints, it’s unlikely that a company would discard a device when finding a problem with the BGA package. The likelihood of finding BGA soldering defects is relatively high since many PCBs today are heavily populated with BGAs. A single defective ball or sphere can cause device failure and make that device unusable. BGA SOLDERING DEFECTS The process of reballing can salvage a BGA device and put it back into a PCB subassembly. The number of tiny balls or spheres that today’s BGAs have ranges from several hundred to over a thousand. These tiny balls connect the device to the PCB surface. There can be several potential problems on any one or several of those balls during PCB assembly.

“A single defective ball or sphere can cause device failure and make that device unusable.”

TECH ARTICLE REBALLING PROCEDURES As a first step, the contract manufacturer (CM), electronics maunfacturing services provider

It’s important to note that the BGA reballing process is highly controlled. Expertise and careful steps must be applied simply because

(EMS), or PCB assembly house should get a good understanding of a given component’s BGA package specifications. Included here are maximum thermal limits for that component’s materials, eutecticity, alloy type, ball size, moisture sensitivity level, and of critical importance is the component manufacturer’s

it deals with a number of potentially damaging mechanical, thermal, and stress-related problems. There are a number of tools needed to do the job, but the most prevalent are flux, solder wick, isopropyl alcohol wipes, and a fume extractor system.

suggestions for the maximum number of reflow cycles that particular a component can handle. BGA rework falls into four categories. They

Flux is initially applied to all the balls. Care must be taken to assure the flux does not evaporate, which makes ball removal more difficult. Balls are then removed from the pads,

are removal, site preparation, flux or solder paste application, and replacement or reflow.

using a soldering braid or iron, placing it on top of the flux, and then tracing the solder iron on

However, initially, the BGA devices must be prebaked to make sure there’s no moisture on or in the device when the rework begins.

top of the braid. The solder iron heats the braid and melts the solder ball so that they are desoldered from the package.

Sometimes a hot gas tool fitted with a custom head is used to remove the BGA package from the PCB. That custom head is designed to

Once the balls are removed, the package is cleaned with an isopropyl alcohol wipe. It’s

comply with the size of the BGA package. A vacuum nozzle, which is a part of the hot gas head, performs the actual removal of the BGA

important to make sure flux residues are removed by rubbing the complete surface of the package and making them entirely

component from the board.

clean. Caution must be used here to make sure too much pressure isn’t applied. If strong mechanical stress is applied to the board, there’s a chance of damaging or cracking the substrate within the package, itself. Also, it’s worth noting that flux can be corrosive. That means extra cleaning is sometimes required if the package is left idle for a period of time before reballing it. The package is then closely inspected under a microscope to see that pads are clean, there is no damage, and all the unremoved balls have no flux or paste residue.

Modern Printed Circuits

The next step is to print the solder paste over the BGA ball locations of the cleaned substrate and then install the balls by using a fixture. Once all the balls are installed, a microscope

If these levels aren’t maintained, then certain airborne chemicals such as sulfur, ammonia, or acetic chloride will reduce chances of proper BGA balling since these airborne chemicals reduce

reinspection is conducted to assure the balls are properly populated and then, reflow is applied based on the designated temperature stated in the spec sheet of the BGA manufacturer, keeping in mind the accurate thermal profile of

the probability of the balls wetting process occurring during the reflow process.

the BGA package.

different parts of the floor and keeps a log of both to assure tight manufacturing controls.

A veteran and experienced EMS provider measures the temperature and humidity at

MOISTURE SENSITIVITY Besides the actual reballing steps, emphasis must be placed on the BGA substrate moisture-

Other major considerations include flux types used during reballing process, the types of balls

sensitivity levels or MSL. There are two aspects involved here—relative humidity and ambient

involved, stencil design, and avoiding costly shortcuts. The flux type is important because

temperature. These two factors must be kept in mind during reballing. Relative humidity should be less than 50 percent in the atmosphere and

solder alloys are exposed to the oxygen in the atmosphere, which, at an elevated temperature of 125°C or above, evaporates, and flux rapidly

ambient temperature less than 80°F.

oxidizes. The main function of any flux is to protect the alloy and reduce surface tension to solder the joint properly.

TECH ARTICLE Special considerations should go toward ball size and type, whether it is eutectic or lead free. Sphere or ball size can vary from 0.3 to 0.76 millimeters and require specific solder paste.

Stencil quality plays an important part as well in reballing to ensure solder properly adheres to the site. An effective solder joint ensures good ball collapse. When the right stencil design is

Careful evaluations are demanded to match alloys and ball sizes with the correct solder paste and reflow temperatures, along with the appropriate flux types.

used and an adequate amount of solder paste is dispensed, the result is a good solder joint.

technology (SMT) pads along with the thickness of the stencil foils. Correct stencil design ensures that enough paste is dispensed on the SMT pads, especially if these are fine pitch devices. If too much paste is dispensed on the SMT pads, they

humidity or a higher temperature, then less than optimal results are achieved, creating less

create a chance of shorting between the BGA balls, and if not enough paste is dispensed there

than optimal solder joints at BGA’s.

could be the probability of voids and opens.

Stencil design includes the aperture opening and sizes in relation to the surface-mount

However, exposing the BGA substrate to more humidity or temperature doesn’t mean it isn’t acceptable for reballing. The main requirement is to bake it according to the Joint Electron Device Engineering Council (JEDEC) standard—24 hours at 125°C. Baking takes the moisture out of the package before soldering. Once baked, the substrate needs to be reballed within a few hours. On the other hand, if the substrate is baked and not used, it must be immediately vacuum sealed using Desiccant, a drying agent, to remove additional moisture.

“If strong mechanical stress is applied to the board, there’s a chance of damaging or cracking the substrate.”

Modern Printed Circuits

Interview with John Yacoub President of Advanced Circuits

Advanced Circuits

Delivers

CIRCUIT

BOARDS

with Made-in-America Pride 18

COVER INTERVIEW

Drilled panels being processed through automated Desmear and electroless copperdeposition line prior to outer-layer resist and image application.

dvanced Circuits is one of the largest U.S.-based printed circuit board manufacturers. A leader in quick turn around time, they specialize in both prototype and production quantities. With divisions in Colorado, Arizona and Minnesota, Advanced Circuits serves over 10,000 active customers who find the company extremely reliable. EEWeb spoke with John Yacoub, president of Advanced Circuits, about being one of the few, large printed circuit board manufacturers in the U.S. and how they continue strong in the face of competition from overseas manufacturers. Yacoub also discussed the companyâ&#x20AC;&#x2122;s support of engineering students and free design for manufacturing.

Modern Printed Circuits

What are some of the advantages of being a U.S.-based board manufacturer? The first advantage is pride. Advanced Circuits is one of the few large-board manufacturers left that is 100 percent based in the U.S. We have 550 employees, and we are doing everything we can to not migrate any part of our business overseas. Here in the U.S. the quality is fantastic, the reliability is good, and the communication between customer and board manufacturer is good. You hear many stories from customers who leave for a cheaper product overseas, and then they come back because the quality or delivery has not been what it should be. As manufacturers here in the U.S., we have pride and are saving American jobs.

What sets you apart from your U.S.-based competition? Advanced Circuits’ stability sets us apart, especially our financial resources. We’ve been in business for 25 years, and in the last three years, we have invested over $10 million in infrastructure and equipment. We have advanced equipment, such as laser direct imaging in every location. We have extensive automation in our Aurora, Colorado facility with 1,000-panel capacity. We don’t buy second-grade products or the cheapest chemicals in the marketplace. We buy quality materials from reputable companies with great product reputations—we go to Kodak for

film and Isola for laminate. Others may use cheaper materials because they are trying to stay in business by cutting costs. There are less than 300 shops left in the U.S., and a good number are struggling. It’s not an easy time to be a printed circuit-board manufacturer. Advanced Circuits has a broad base of over 12,000 customers. So if one segment of the business is weak, another is strong. We are very consistent in our daily bookings and our quality. We don’t take short cuts when things get tough—we would not reduce staff or make other changes that aren’t quality oriented. We are ISO 9001 in all facilities. At our facility in Aurora, we are committed to our customers’ best experience—if the delivery from our Aurora facility isn’t on time, it’s free. And we stand behind that. We have buying power derived from close to $100 million in revenue. Because of this, we buy better quality materials than other companies, and we buy these materials at a lower cost.

Have you ever had to honor the if-it’s-not-on-time-it’s-free policy? Yes, but we don’t have more than 10 instances a year, if that. Our on-time delivery rate is 99.85 percent. We ship over 7,000 orders a month, and we have less than 8 lates per month. In our Aurora facility, we have a redundancy of every piece of equipment. We are running 24 hours a day, five-and-a-half days a week. We have a maintenance department working around the clock.

COVER INTERVIEW To our customers, we are known for our reliability and dependability. Factoring in cost, if you look at our total package, we are somewhere in the middle of the road. We are not most expensive, and we are not the cheapest—but we give the customer an excellent product for a fair price.

Considering challenges in the printed circuit-board (PCB) market, what are you doing or what have you been doing to stay ahead of the curve? Advanced Circuits has a lot to offer to our customers such as free design for manufacturing (DFM), free layout software, and PCB file check. In addition, we have student programs. We are working with the top fifty engineering colleges in the U.S. Students use our PCB Artist software program. We support the software program so that at graduation, there is hardly an engineer that doesn’t know about Advanced Circuits. We are one of

“At our facility in Aurora, we are committed to our customers’ best experience—if the delivery from our Aurora facility isn’t on time, it’s free. However, our on-time delivery rate is 99.85 percent.”

A solder masked panel being inspected for complete coverage after applying a final finish of leaded solder using hot air solder levelers.

Modern Printed Circuits

the few circuit board manufacturers who continuously support students. We work with them by supporting the software program, sponsoring their final project, and giving them free boards. We are really trying to take care of customers and build a brand name.

“To our customers, we are known for our reliability and dependability.”

Pattern-plated, outer-layer panels being prepared for processing through the combined resist strip, copper etch, and tin strip line prior to solder mask application.

Also, we are in a specialized assembly niche that is similar to what we did with the PCB 15 years ago. As a total PCB solution, we can do your PCB and your assembly under one roof, but we are not competing with our contract electronics manufacturer (CEM). We are not an assembler in the traditional sense, but we assemble our boards only and take care of our customers. Our engineering can help a customer who is trying to build a board. So instead of a small customer working at home in his garage or in his lab, we can provide service with quality at a reasonable price.

COVER INTERVIEW What are some of the challenges that are unique to working with defense and aerospace industries? The military and aerospace industries are changing. The budget cuts and some programs are being frozen or scrapped. Also, the buyers in the defense industry need things for less money. They’re asking for the same product you used to build, but they want it faster and a little bit cheaper.

In the next two to five years, what do you think some of the challenges or opportunities will be in the PCB world? I think the opportunities are going to be great for whoever is going to survive. Things have to turn around. The industry’s been flat and weak with no

growth in the last three or four years. I think the last good year we had was 2011. Things need to come back. Having the economy growing at a better pace will be a good sign of improvement. We are dealing with companies that are doing great, and we are dealing with companies who are seeing their business go backwards.

Any final words? The most important thing is product reliability. Just because something is cheap doesn’t mean it’s good. Advanced Circuits is U.S. based and has much to offer. We would like U.S. companies to support each other. This makes a big difference.

“Our engineering manager can help a customer who is trying to build a board. So instead of a small customer working at home in his garage or in his lab, we can provide service with quality at a reasonable price.”

Modern Printed Circuits

The Wide World of

REGULATORY

TESTING and

CERTIFICATIONS Article contributed by Advanced Assembly

he average consumer product today has a dozen safety and certification marks, stamps, or seals that most consumers do not understand. These marks, when appropriately used, can indicate a great deal about the quality and safety of the product; they show that the product has been independently tested to verify its conformance to industry standards and regulations. Some markings are voluntary while others, in certain cases, are mandatory. Even if they are not mandatory, they can make the difference between acceptance and rejection when going through customs. A great deal of the success of your product can be contingent on the certifications it has. However, knowing which of the certifications you need and the process to receive them is imposing and can seem overwhelming at first.

TECH ARTICLE

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During product design, one of the first steps should be researching and working toward compliance with these certifications. It is much simpler to start from the ground up while keeping certain criteria in mind than it is to try and change or retrofit the project after the fact. Once the product has been defined with an established objective in mind, you should already be working with the appropriate agencies to start the process. This article will elaborate on some of the more well-known certifications, what they represent, and in what countries they are accepted.

Underwriter Laboratories One of the most widely known and respected marks is that of Underwriter Laboratories, or UL. UL was established in 1894 to test products that were being developed to find out if they were safe, which remains their primary goal to this day. They have expanded into many different fields, ranging from consumer products to construction, but their focus is still safety in each of those fields. UL can certify products at the component level, which is given the “Recognized Component Mark” and indicates that the component is UL certified but not necessarily the end product. This is important as PCB manufacturers are often UL certified and will stamp their PCBs with the “Recognized Component Mark,” but this does not mean that the overall project is UL listed. Near any UL mark is a number which is searchable in the UL database.

Before working with UL, review the different fields and decide which one fits your product best. This may change once you start the process, but it will help you get a better idea of how they divide their fields and helps give a feel of what UL will be looking for. After contacting UL, you will be assigned an account manager who will help you step through the process. One of the first questions that a UL account manager will ask is where the product will be marketed. UL has collaborated with similar safety certifications around the world and can provide special markings to indicate that your product has been certified in the U.S., Canada, or China, as well as a variety of countries in Europe and South America. Once the market has been established, the account manager will discuss the product with you to create an overview of the process and what will come next. At this stage, you are provided a cost estimate for the process and the decision is made whether or not to continue in the certification process. Once you commit to the process, you will be helped every step of the way to make sure that your product reaches the standards set forth by UL. You can expect to have at least one physical visit from a UL representative to view your facilities to make sure that the entire process is being followed according

TECH ARTICLE to their requirements. In the end, you will receive certification as well as a number that end users can find on the UL website to confirm that your end product is legitimately UL certified. While UL is a nonprofit organization and a Nationally Recognized Testing Laboratory (NRTL) by OSHA, it is not a government agency, which means that certification is not mandatory. Although this testing is not mandatory in general, there are certain markets, organizations, and even municipalities that require a UL mark on selected product categories to be installed in homes or businesses. If your product deals with hazardous energy in any way—whether it is electricity, gas, or steam—it is more likely that a UL listing will be required or strongly recommended.

Conformité Européenne The CE mark, or mark of the Conformité Européenne, is not an organization but simply a mark that indicates conformance to European Union (EU) standards and limits. Depending on the type of product, these standards could be for safety, environment, or even health related certifications. Perhaps the most famous directive, “Restriction of Hazardous Substances” (RoHS) is one of the many directives that fall under CE. If a product falls under one of the CE directives, it is required to meet the EU standards before it can be distributed within the European Economic area, which includes the European Union and other countries, such as Turkey and Norway, that have adopted the CE mark and made it a requirement for certain imports.

Many products do not need external review but can bear the CE mark after internal processes confirm conformance. As there is no independent review and no way to verify the legitimacy of the self-certified marks, CE cannot be depended on as a mark of safety like UL. The products that do require external review will have a “notified body” which will independently test and decide whether or not it conforms. It should be noted that UL is one among many testing agencies considered one of these notified bodies. If the product passes, then the notified body will provide an identification number that will accompany the mark that can be verified online. With either the internal or external review, manufacturers and distributors need to maintain the paperwork that indicates that due diligence was taken. This needs to be provided upon demand, and if it is found that the product does not actually qualify, the penalties can include civil and criminal charges against the company and its officers. With the CE mark, the first steps are the simplest. Search for the different directives, and note if your product fits under any of the categories. For electronics manufacturers, it is guaranteed that at least the RoHS 2 directive will be applicable, with the lowvoltage directive and the electromagnetic compatibility (EMC) directive most likely being applicable as well. Once all of the applicable directives have been identified, you will then look to see if a notified body must be involved in the certification or if you can self-certify. Even if you are permitted to selfcertify, you can use a notified body to perform an external certification. If self-certifying, the next step is to confirm that your product conforms to the applicable directives, and if not, then make the appropriate changes. Once

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the product is in conformance, you will then document the conformance using the EC Declaration of Conformity along with any technical reports to support the declaration. Once these steps have been completed, you can place the CE marking on the product itself or its packaging. It is in your best interests to make the marking as visible as possible in order to reduce the amount of packaging that customs will need to remove in their inspections. Once approved, it is recommended to put the marking on both the final product and the packaging.

Restriction of Hazardous Substances “Restriction of Hazardous Substances 2” (RoHS 2)— the 2011 update of the original 2003 Reduction of Hazardous Substances— sets limits on the amount of certain substances in electronics. RoHS is frequently referred to as the “leadfree directive” as the move to lead-free solder is the most apparent change in the certification. However, this is inaccurate as the directive covers several other hazardous materials as well. Besides lead, RoHS limits the amount of mercury, cadmium, hexavalent chromium (to enhance corrosion protection of solder), polybrominated biphenyls (a flame retardant used in PCBs), and polybrominated diphenyl ether (another flame retardant used in PCBs). There are a multitude of exceptions to this directive, the largest being lead-acid batteries. Fluorescent bulbs are also exempt since they require mercury. All medical devices were originally exempt, but with RoHS 2, the exemption has narrowed, and now only

certain types of medical devices are exempt. It is a good idea to check to see if your product fits under one of these exemptions, and if it doesn’t, you must take care to properly conform as breaking the threshold of any of these substances will close off practically the entire European market. Oddly enough, if your product qualifies as an exemption, it can still bear the RoHS mark as it is technically in compliance. When the RoHS directive was implemented, many engineers and designers simply switched to RoHS-compliant equivalent parts without changing their designs. However, all of these hazardous substances were included in printed circuit boards (PCBs) and solder to improve performance, and their removal has, in most cases, reduced that performance. When planning on RoHS compliance, it is necessary to use not only RoHS-compliant parts and manufacturing processes but to also analyze the effects of these changes in performances and temperatures. There may be more subtle changes in component selection and mounting to ensure that the PCBs are still structurally and electrically robust.

“In general, an ETL mark can be accepted as equivalent to a UL mark, but its comparative renown can be debated.”

TECH ARTICLE Electrical Testing Laboratories

Canadian Standards Association

The ETL listed mark was originally a mark of the Electrical Testing Laboratories, founded in part by Thomas LISTED Edison in 1896. Over the years, it has absorbed many different testing laboratories and is now called the Intertek Group, a worldwide testing company based out of London. Also a Nationally Recognized Testing Laboratory by OSHA, Intertek specializes in testing consumer goods and performs a wide variety of tests. These tests are not mandatory but are performed to ensure the highest quality and safety of a product. In general, an ETL mark can be accepted as equivalent to a UL mark, but its comparative renown can be debated.

The Canadian Standards Association (CSA) is similar in setup to UL and Intertek Group in that it performs tests and certifies that products meet those tests. Created originally to define standards after World War I due to interoperability issues among different systems used in the war, CSA still fills this role. Like other certifiers, CSA has expanded in its scope beyond its original wartime-specific goals and now covers a variety of fields from consumer products, to industrial equipment, to environmental standards. CSA has also expanded out of Canada and is recognized in several countries in the Americas, Europe, and Asia.

The steps to ETL certification are extremely similar to UL. Upon contacting Intertek Group, you will work with an account manager who will help you through the process of certification. There are variations of the ETL mark dependent on the anticipated country in which your product will be marketed. As mentioned previously, the CE mark is not a guarantee of safety or quality, whereas the ETL-EU mark verifies that a product has been officially tested and deemed safe and in conformance with EU laws. The serial number associated with the mark can be verified either online or via a telephone hotline that Intertek has set up. Intertek can also be used as a notified body for the CE mark.

While preeminently focused on safety, CSA also tests product quality and even electromagnetic interference. As with UL and ETL, CSA serializes its products, and a product can be verified as truly CSA certified via an online form.

Federal Communications Commission Besides the large quantity of safety or health certifications, there are also several certifications specific to the emissions of electromagnetic energy. Foremost is the Federal Communications Commission, a government organization dedicated to making wired and wireless communication available to all those living in the U.S. As a small part of this overall goal, they organize the wireless spectrums

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to reduce overlap and make sure that unauthorized devices are not creating too much spurious radio frequency energy in the wrong spectrum bands. To ensure this, the FCC requires electromagnetic compatibility (EMC) testing. For certain items, such as cell phones, the FCC mark is required before they are able to hit the market. However, any item that has communication lines or traces that go above 9kHz are expected to be tested, though this is not enforced unless the product is causing electromagnetic interference issues and is reported to the FCC. The inspections for compliance are done by accredited third-party vendors who will perform tests on the devices under a variety of different settings to make sure that maximum thresholds are not exceeded. If the device passes these tests, the device can bear the FCC mark and will be listed as compliant. If the device surpasses the maximum threshold, then you will need to have discussions with the testing agency to devise a way to reduce emissions.

Voluntary Control Council for Interference by Technology Equipment Japan has a voluntary EMC testing and compliance mark called the VCCI, which is similar in intent to the U.S. FCC mark. While legally and technically voluntary, it has become a de facto requirement for entrance into the Japanese market. The VCCI mark is unique in that it is required to work for both voltages and frequencies that are used in Japan. As Japan is divided with 100VAC/50Hz on the eastern half of the country and 110VAC/60Hz on the western half, certification has to be completed with both inputs to receive certification.

C-Tick Australia’s and New Zealand’s equivalent to the FCC emissions standards is the C-Tick, a mandatory requirement for all products covered by Australia’s EMC regulatory arrangements. The C-Tick is only authorized for manufacturers who are based out of Australia or New Zealand or who use authorized agents. Testing under C-Tick is also run at the standard voltages that are operated in Australia and New Zealand, namely 230VAC/50Hz.

Bureau of Standards, Metrology, and Inspection Taiwan’s Bureau of Standards, Metrology, and Inspection sets the EMC standards for Taiwan, which are similar to the FCC’s, in part due to the similar voltages of the U.S. and Taiwan. Taiwan accepts the results of testing facilities outside of the country, making it considerably easier for you to perform the testing. Due to Taiwan’s rising prominence in the high tech industry, this mark is becoming more prevalent and necessary.

“Japan is divided with 100VAC/50Hz on the eastern half of the country and 110VAC/60Hz on the western half.”

TECH ARTICLE Korean Certification The Korean Certification (KC) mark was changed as of January 2011 from the Korean Communications Commission mark. The requirements for this certification are very similar to those in Europe but are performed at 220VAC/60Hz in accordance with South Korea’s electrical infrastructure. Previously, the KC or KCC marks required in-country testing, but it has expanded to allow testing centers outside of Korea to certify products. This is merely a small sample of the very large world of regulatory testing and certifications. While there is a great deal of overlap between many of the certifications, it is still imperative to anticipate the market of your product. Whether you anticipate your products in the Americas, Europe, Australia, or Asia, you must make certain that you both design and certify for that market. You will save yourself time, money, and many headaches by starting early instead of retroactively trying to incorporate the standards. Finally, the value of being able to easily and legally spread your end product across the globe could make the difference between success and failure of your product and your company.

“Whether you anticipate your products in the Americas, Europe, Australia, or Asia, you must make certain that you both design and certify for that market.”

Advanced Assembly specializes in quick-turn, PCB assembly. For more information on the company, visit www.aa-pcbassembly.com.

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