By Thomas Blaha
President, Memory Protection Devices

While breakthrough technologies continue to grab headlines, components like the humble coin cell battery holder often get overlooked, despite playing a major role in support of their glamorous cousins. However, as electronic devices become increasingly feature-rich, power-hungry, and miniaturized, coin cell holders can become an unanticipated failure mode, as harsh manufacturing and operating environments take their toll.

Design engineers face growing challenges developing power management solutions that are capable of handling real-world environmental issues related to vibration, heat, shock, humidity and corrosion. These environmental conditions can jeopardize electrical connectivity, leading to product failure, service calls, and possible breakage caused when untrained end users attempt to replace a battery.

Facing ongoing challenges related to contradictory design requirements, optimal solutions often require a careful balancing act to ensure that cost targets can be achieved without compromising quality or customer satisfaction. By focusing on these product criteria, design engineers can achieve product reliability at the best possible cost.

Coin Cell Retention and Removal:

A well-designed coin cell holder must be resistant to shock and vibration while remaining flexible enough to allow for easy battery replacements, a requirement that can vary depending on whether the typical end user is a child, elderly or disabled.  Unfortunately these two criteria are often in conflict, as better retention equals tougher removal.  Look for holders that have special features that are designed to ease removal, or better yet, get samples and try them out for yourself.

It is particularly important to test the holder in situ.  It is often a lot easier to remove a battery when the coin cell holder is in your hands than when it is soldered to a PC board and surrounded by other components and a housing.

Durability:

This is an especially critical requirement for applications where frequent battery replacement may be required over the expected lifespan of the product. These problems can be exacerbated if the battery holder has high grip due to increased wear and tear during battery insertion and removal.  If your application will require relatively frequent cell changes, find out the cycle count the holder has been tested for.

Also, all battery holders should have polarity protection, so they will not make contact if the battery is inserted improperly.  This becomes more important when a large number of battery replacements is anticipated.

Conductivity and Corrosion Resistance:

Products exposed to excessive heat and humidity, caustic chemicals, or airborne pollutants can often have problems associated with corrosion build-up, which can negatively impact electrical performance. To minimize these effects, locate holders that are constructed from corrosion-resistant materials. Corrosion problems can be further increased by the presence of electrochemically dissimilar metals, resulting in galvanic corrosion, which can be minimized through the use of insulators or gold-plating.

Highly conductive metals, such as gold, can have an unanticipated additional benefit.  These materials can also have lower friction, resulting in decreased insertion forces.  While housing and contact geometries are the primary contributors to insertion forces, all other things being equal, gold and similar materials will reduce the force over tin and copper.

Required Tolerances:

Competitive batteries can differ substantially in terms of dimensional specifications. For example, according to industry standards, a CR2032 coin cell can vary in height by +/-0.3 mm, or 10% of its total height. Therefore, it is critical that a coin cell holder be adaptable to normal height variances without accepting incompatible batteries. Remember, too loose a connection is unacceptable, as it compromises electrical performance.

This is less of an issue if cells are installed at the factory and you have control over the battery that is used, but if the end user can purchase a replacement you should make sure that the full range of battery sizes is supported.

Solderability Requirements:

Soldering processes affect the choice of coin cell holder. For example, a coin cell holder requiring SMT soldering should be made of high quality LCP plastic that offers exceptional dielectric strength at high temperatures, and is capable of withstanding 300ºC lead-free reflow process temperatures. By contrast, wave soldering processes require less rugged materials, which allowing the use of PBT/Nylon plastic insulator material. This material offers a dielectric strength of 560 volts/mil at 25ºC for 5 seconds, as well as resistance to chemicals and solvents, excellent toughness and strength, a broad service temperature range with excellent thermal cycling performance, and insulator resistance of 5000 M Ω min.

An incorrect material selection for the manufacturing process can lead to a high level of line rejects.

Manufacturing Integration:

When designing products for high volume manufacturing, coin cell holders should be supplied on standardized tape and reel packaging for pick and place assembly. In addition, you need to factor in applicable government or industry regulatory compliance requirements such as RoHS lead-free.

Conclusion

As so many different styles and manufacturers of battery holders continually flood the market, it is important to evaluate potential suppliers to ensure that the coin cell holder you purchase performs as promised. Carefully balancing performance requirements against potential cost savings will increase the likelihood that the coin cell holder specified will be ideally matched to the intended application. As part of your due diligence process, make it a policy to request comprehensive product test data to ensure that the quality of all raw materials is superior and that the coin cell holder meets or exceeds ANSI/EIA-5405000 standards. These basic quality assurance procedures will serve to ensure that you receive years of trouble-free battery performance.

By Thomas Blaha
President, Memory Protection Devices

During the design of a handheld medical device, the battery holder selection is often left to the very end. We could warn that significant issues such as shorter run times, excessive weight, or unusual shapes can lead to end user dissatisfaction, leaving your company at a competitive disadvantage. We could also promise that early considerations of existing battery holder technology would eliminate compromises, redesigns, tooling changes, expensive customized parts, and delays. Instead, we have broadened the range of battery holder options, to allow the designers increased flexibility to fit them into even the most challenging designs. New battery holder designs have lower profiles, smaller footprints, and resist shocks, vibrations, and drops like never before. The following are just a few ways that battery holder designs have begun to satisfy the unique, and necessarily strict, conditions of medical device manufacturing.

For decades now, coin cell batteries have sat flatly among the various components of many PCBs. However, in increasingly miniaturized handheld devices, a cell with a large diameter can begin to take up a disproportionately large surface area. Vertical coin cell holders were introduced to address this issue, and at least it gave designers a choice between a wide or thick device. Radical rethinking was needed – not of how a battery should sit ona PCB, but of where a battery should sit in a PCB. To minimize the height of vertical coin cell holders, new designs may call for a small hole to be drilled in the surface of the PCB. This allows for the battery holder to sit not on, but partially through the PCB. Thus, the choice between a fat or wide device can be mitigated. The same concept is also applied to the newest horizontal coin cell holders. This new style of battery holder design works brilliantly as both a through-hole and surface mount component, meaning it can be utilized to clear up space on all types of PCBs.

To make stronger and more resilient medical grade battery holders, it was necessary to examine new materials beyond simple polypropylene. Liquid crystal polymers have been widely selected for many new coin cell holders for a variety of reasons. LCP can withstand the brutal peak temperatures of 260°C that reflow ovens often operate at, and it also boasts excellent chemical and humidity resistance that can withstand multiple applications of most sterilization methods. Even while having walls that are 1 mm or thinner, LCP is rigid enough to eliminate the weight shifting that causes intermittent contact, plastic fractures, crushed contacts, and a host of other common problems with less strong plastics. Finally, LCP flows so well during molding that it can meet the tight quality control tolerances required by medical devices, all while maintaining the cost savings associated with making a part with the very thin walls that LCP has become known for.

Of course, a strong housing for the holder means nothing if the contacts aren’t maintaining a constant connection with the battery. Over time, battery contacts have developed from simple tin-plated steel to combinations are complicated as gold over nickel over copper over a phosphor bronze base. The nonreactive nature of gold makes the contacts resilient like the LCP body for sterilizations, and can also keep the contacts safe from forms of corrosion associated with shipping and storing. New contacts can also have features such as an anti-wicking shape for more consistent and stronger solder joints on the board, or recurved positive contacts that increase durability, enhance battery retention, and reduce connection failures.

These are just some of the recent ways in which the battery holder community has enhanced our designs with the medical community in mind. However, it is a two way process – we need the feedback from medical device design engineers who use battery holders in order to know what works and doesn’t. And although nobody knows what the next big battery holder design breakthrough will be, we certainly hope to work with you on developing it.

In today’s world, a wide array of automotive 12 volt plug-in cord sets, 12v-plugs and 12v-sockets are presented to designers of electronic systems and products. Some are hardly up to the challenges presented by the ever-increasing multitude of electronic devices like cell phones, iPods and portable navigation devices that have become as commonplace as tires on a vehicle.

Market Outlook: Automotive 12 volt cord sets are normally made with twin copper wires and in lengths typically from three to fifteen feet. Some use heavy gage copper wire in longer lengths and are greatly affected by changes in the market. Copper prices have been predicted to rise 34% this year by economists, and long lengths of heavy gage wires suffer twice because of higher freight costs. Freight prices have already risen by 4-6% this year, and are expected to continue rising along with the economic recovery. Our expectation is leaning towards a mid-year mild price rise for products containing copper wire or phosphor bronze contacts.       

Vibration.  Heat.  Shock.  Humidity.  Corrosion.  Pressure.  These real-world conditions cause device failures and higher support costs for suppliers.  Without a reliable and continuous supply of current, an electronic device’s operation will be interrupted and the system might be damaged.  Repeated, forceful insertions and removals by consumers could cause stress fractures of plastic or metal components and wires.  

Automotive plug-in cord set designs are traditionally full of trade-offs: size and weight constraints versus durability, ease of insertion and removal versus ability to retain the plug under rigorous conditions, and durability of materials versus component cost, to name a few.  The increasing demand for ruggedness of portable devices has made the balancing act of 12v-plug design even trickier.

Retention: An automotive 12v-plug needs to be able to retain itself into the socket even under significant vibration, shock, and torque.  Failure to properly hold the connection, even for a matter of microseconds, can result in an interruption of power and device malfunction.  A well-designed 12v-plug will resist shock and vibration, while remaining easy to remove without tools.

Durability: Depending on the use, a device could have its 12v-plug inserted hundreds or even thousands of times throughout its lifespan.  Because of the retention issues described above, an automotive plug must hold its connection securely.  However, this results in extra wear upon the contacts  as the same high grip which secured the 12v-plug causes increased wear under the stresses of removal and insertion.  Thus, it is important to insure that 12v-plug materials be durable enough to withstand stresses that could cause dangerous fractures.

Corrosion Resistance: When components are exposed to humidity, airborne pollutants, extreme temperatures, and other environmental conditions, corrosion can result. Over time, this corrosive build-up can cause loss of electrical contact. The use of corrosion resistant contacts is particularly necessary for portable devices, where protection from the elements cannot be guaranteed.

Contact Conductivity: The choice of metals in 12v-plug sets determine how easily electricity will flow from the automobile to the device. Some types of platings are subject to oxidation and thus the resulting increase in electrical resistance. More conductive metals that resist oxidation, such as gold, allow high conductivity, meaning lower resistance, which allows for slightly quicker charging during short trips. 

Fuses: A safety item that every automotive cord set should have but frequently do not. Many assume that the current in automobiles is not subject to voltage changes.  An automobiles electrical system can have very high voltage spikes, for instance when the starter stops a minus 200 volt spike can occur, and large positive spikes can also occur. The battery does a good job as a filter because it acts like a large capacitor to absorb these spikes, but a fuse is an inexpensive insurance, especially in a product having worldwide distribution and use. 

Big changes for large automotive cord sets are already occurring as plug-in hybrids and pure electric vehicles enter the market. Product categories include new plugs, sockets, flexible power cords, charging stations and vehicle connectors. Product safety testing will have to address connectors, stationary and portable electric vehicle cables and personal protection circuitry. 

Adopting responsible practices that reduce the e-waste stream while making economic sense can positively influence consumer brand preferences

By Thomas Blaha
President, Memory Protection Devices

Product designers and procurement professionals need to be mindful that successful brands demonstrate a strong commitment to environmental protection and sustainability.

This commitment starts by addressing the growing problem of used alkaline batteries, as Americans purchase nearly 3.3 billion alkaline cells annually: a staggering amount that can be cut significantly by substituting rechargeable batteries and battery holders.

This environmentally-conscious approach also makes good business sense. For example, equipping a device with four (4) AA rechargeable Lithium-ion (Li-ion) batteries could cost up to $50 but provides 5+ years of service with 500+ recharge cycles. Conversely, having to replace a set of four (4) alkaline batteries multiple times over the life of the device could add up to as much as $1,000, nearly 20 times more expensive. If properly educated, consumers will certainly consider paying more initially to save money in the long run.

Increasing regulation for e-waste recycling

Increased regulatory controls have transformed battery manufacturing, recycling, and shipping. In 1996, Congress passed the Mercury-Containing and Rechargeable Battery Act to address the collection and recycling of NiCd cells along with certain small sealed lead-acid batteries intended for “personal or household use” in cellular phones, laptops and personal computers, cordless power tools, video cameras, and uninterruptible power supplies (UPS).

The Battery Act required proper battery labeling that indicates consumer responsibility for proper recycling/disposal, and requires easy battery access for removable at end-of-life. In addition, certain mercury-based chemistries were phased out, including most alkaline-manganese, zinc-carbon, and mercuric oxide batteries.

Since improperly packaged batteries can pose a fire hazard, the USDoT introduced Call2Recycle regulations that require all batteries to be individually bagged or taped prior to shipping. Li-ion batteries must be sorted separately from other recyclable batteries, including individually bagged (or terminals taped) to ensure safe storage and shipping. If the shipping package is damaged, the batteries must be quarantined, inspected, and repackaged. Also, any package containing Li-ion batteries with a gross weight of 30 kg (66 lb) or more must be marked “LITHIUM BATTERY, UN 3090”, carry the Class 9 miscellaneous hazard label, and be handled by specially trained shippers in accordance with U.S. hazmat regulations.

Dozens of states have also passed some form of e-waste legislation, including mandatory electronics recycling and recovery programs for computers, peripherals, and other electronic devices. Battery manufacturers have independently funded the Rechargeable Battery Recycling Corporation (RBRC), a nonprofit public service organization dedicated to educating manufacturers, retailers and consumers about the benefits of rechargeable battery recycling. The RBRC established a national cadmium recovery facility in Ellwood City, PA

Thinking forward

Approximately 73% of municipal solid waste is sent to landfills or incinerated. Intelligent prctices are needed to ensure that batteries and other e-waste is properly disposed of or recycled to limit the amount of heavy metals and harmful chemicals that enter the food chain, including many known carcinogens.

Fortunately, rechargeable batteries are becoming less toxic and less expensive, making them a cost viable alternative for consumer and industrial electronics. Battery holders offer additional benefits at minimal cost by firmly securing the cells and by enabling fast battery removal at end-of-life.

As the cost of rechargeable Li-ion batteries continues to drop, they are becoming an increasingly wise investment for OEMs based on the merits of adopting a more consumer-focused approach that values environmental protection and a lower total cost of ownership over short-term profits. This is a winning strategy, as embracing corporate responsibility towards environmental protection and sustainability serves to positively influence consumer brand preferences.

By Thomas Blaha
President, Memory Protection Devices

Certain electronic devices require additional protection in the form of a fuse, a sacrificial device that provides increased protection against electric overcurrent or surges.

Patented by Thomas Edison in 1890 to provide circuit protection for his municipal electric distribution system, fuses are now commonplace, available in all shapes and sizes, including fuses for electronic circuitry.

The essential component of a fuse is a metal wire or strip that melts when too much current flows, thus interrupting the circuit to help protect sensitive circuitry against overcurrent damage as well as to help prevent excessive heat build-up that can potentially lead to electrical fires.

Fuses are designed with varying current and voltage ratings to meet application-specific and/or regulatory requirements. At the same time, fuses should be carefully selected so as to avoid needless interruptions caused by blown fuses. The fuse is typically constructed with a metal strip or wire fuse element mounted between a pair of electric terminals, which are enclosed within a non-combustible housing. The size and construction of the element allows for a certain maximum temperature that, if exceeded, causes the element itself or a solder joint to melt, thus opening the circuit. Certain types of fuses allow for short-term overload and are self-reset to restore the circuit after the overload has cleared.

Fuses are attached to electronic devices using a variety of mounting methods. For example, 2AG and 3AG cylindrical glass fuses, which are commonly used in consumer electronics and high fidelity audio equipment, can be off-board mounted, with the fuse inserted into an inline fuse holder. These fuses can also be on-board mounted, with the fuse resting in a clip or cradle. Fuse clips are very economical to produce, and allow for a high degree of interchangeability between fuse brands. Fuse clips are typically made of nickel-plated brass with pins inserted through the pc board that are soldered.

Multiple 2AG and 3AG fuse clips can be combined to create a fuse block, which allows multiple fuses to be connected to one common ground to save valuable pc board real estate. Fuse blocks are commonly available in 2-position, 4-position, 6-position, 8-position, 10-position and 12-position configurations.

In certain situations, the fuse may need to be panel mounted, where a hole is punched in a chassis and a fuse holder is hard mounted to the outside of the case for easy access and wired discretely. This form of attachment typically involves the use of a wiring harness, plastic body, screw-on cap and a spring that ensures the electrical connection. As a result, these systems are far more expensive to manufacture than standard fuse clips, which limits their overall demand.

Blade-type fuses are highly popular for automotive systems. Available in both standard and a mini-blade sizes, blade-type fuses are extremely rugged, color coded for easy identification, and allow for easy insertion and extraction in challenging environments with an inexpensive extraction tool. Blade-type fuse holders are usually mounted vertically with pins inserted into the pc board, allowing the fuses to stand straight up for easy replacement by the consumer. Multiple blade fuse holders can be combined in a plastic frame to create a fuse block that takes the guesswork out of component spacing and makes insertion into the pc board virtually goof-proof.

The pricing outlook for fuse holders appears to be relatively stable over the next 18 months, as resins and metals such as copper, brass and steel are currently trading in a relatively narrow band on the futures markets.

By Thomas Blaha
President, Memory Protection Devices

Some key criteria should be considered before including one of these devices in a design

By Thomas Blaha
President, Memory Protection Devices

Rechargeable and replaceable battery technologies offer important long-term environmental benefits

Growing concerns about such issues as peak oil, climate change, carbon emissions, ozone layer depletion and industrial pollution have raised alarms among consumers, business owners and policymakers worldwide.
As more information becomes available about the long-term effects of environmental degradation caused by ou industrialized society, governments and industry associations worldwide will be forced to start taking increasingly pro-active measures to help protect the future of our planet and its inhabitants. However, arguments surrounding how far and how fast we need to move in order to effectively counteract man’s impact on the environment can digress into complex discussions about the validity and possible biases of available data as well as cost vs. benefit considerations that are difficult to quantify. Meanwhile, these arguments fail to negate our common obligation to serve as environmental stewards by incorporating simple and sensible steps into our daily lives that benefit the environment without causing undue cost. The electronics industry must play a critical role in transforming our society into a more environmentally conscious global community by incorporating common sense solutions that reduce the e-waste stream, starting with the disposal and recycling of cell phones, smart phones, PDAs and similar hand held devices.
With more than 1.1 billion mobile cell phones sold worldwide each year, the potential environmental benefits of a coordinated approach to re-use and recycling could be enormous, especially if all consumer batteries became replaceable, and, wherever possible, disposable alkaline dry-cell batteries were replaced with rechargeable battery chemistries. Through the use of low cost reliable battery holders rather than soldered-in connections, the vast majority of batteries found in consumer products could become easily replaceable, providing additional benefits by extending the service
life of consumer products, which further reduces the e-waste stream.
According to the EPA, Americans purchase nearly 3.3 billion alkaline batteries each year – a number that could be substantially reduced if consumer products were redesigned to operate on rechargeable batteries.
Rechargeable batteries often carry a significantly higher initial cost compared to alkaline cells. However over the expected service life of the device, the switch to rechargeable batteries can result in significant long-term savings. For example, a pack of four AA rechargeable batteries may cost the consumer approximately $50 initially but provide years of service life with up to 500 recharges. Continually replacing sets of disposable AA-size alkaline batteries over the same time period could end up costing the consumer approximately $1,000 over the life of the product.

Lithium-ion chemistry is rapidly emerging as the prevailing choice among rechargeable technologies used in cell phones, computers, hybrid-electric cars and electric cars, to short term power storage devices for wind and solar generated power. Lithium-ion batteries deliver top of the line performance and are far more environmentally friendly than NiCd rechargeable batteries.

Increasing regulation for recycling

With an eye towards greater environmental protection, municipal, state, federal and international policymakers have significantly expanded regulatory controls over the manufacturing, recycling and transport of batteries.

In 1996, the U.S. Congress passed the Mercury-Containing and Rechargeable Battery Act, which makes it easier for rechargeable battery and product manufacturers to collect and recycle NiCd batteries as well as certain small sealed lead-acid batteries. The Battery Act requires that the batteries intended for “personal or household use” in cellular phones, laptop computers, cordless power tools, personal computers, video cameras and uninterruptible power source (UPS) devices must be easily removable, with labels that indicate the battery chemistry, show the “three chasing arrows” symbol, and contain phrases that indicate consumer responsibility for proper battery recycling or disposal.

The Battery Act further stipulates that regulated batteries must be properly labeled and easily detachable or removable from a rechargeable consumer product at the “end-of-life” using common household tools. The Battery Act also phases out the use of Alkalinemanganese batteries that intentionally contain mercury (except for button cells containing less that 25 mg of mercury), Zinc-carbon batteries that intentionally contain mercury, button cell mercuricoxide batteries, and certain other mercuric oxide batteries.
The U. S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration also recently enacted Call2Recycle regulations that require all batteries to be individually bagged or taped prior to shipping starting January 10, 2010, as improperly packaged batteries can short
circuit and pose a fire hazard.


The USDOT regulations call for lithium-ion batteries to be sorted separately from other recyclable batteries, including individually bagged (or terminals taped) to ensure safe storage and shipping. These regulations also require packaging instructions that expressly forbid the shipping of these batteries by aircraft and vessel. Furthermore, if the shipping package is damaged, the batteries must be quarantined, inspected and repackaged. Also, any package containing lithium-ion batteries with a gross weight of more than 30kg (66 lbs) must be marked “LITHIUM BATTERY, UN 3090,” as well as carry the Class 9 Miscellaneous hazard label, be accompanied by hazardous material shipping papers, and handled exclusively by shippers trained in accordance with U.S. hazardous material regulations.

Dozens of states have also joined in the “green” movement by passing various forms of e-waste legislation, establishing mandatory electronics recycling and recovery programs for computers, peripherals and other electronic devices on a state-by-state basis.


Battery manufacturers have been highly supportive of this “green movement by independently funding the Rechargeable Battery Recycling Corporation (RBRC), a nonprofit public service organization dedicated to educating manufacturers, retailers and consumers about the benefits of rechargeable battery recycling. A key initiative of the RBRC has been to establish a national cadmium recovery facility in Ellwood City, PA


Looking to the future

The need for greater regulation and self-policing by the electronic industry is clearly indicated by the fact that approximately 73% of municipal solid waste is either land filled or incinerated. Neither of these methods is well suited for the disposal of rechargeable batteries or other forms of e-waste. In landfills, heavy metals from discarded batteries and circuit boards can leach into the soil, ground water, or surface water. When incinerated, the heavy metals contained in batteries and electronic devices can enter the atmosphere through smokestack emissions or incinerator ash. Once introduced into the environment through landfill disposal or incineration, these heavy metals can then make their way into the food chain, presenting very serious health risks to humans and animals, as cadmium
and other heavy metals are known carcinogens.

As rechargeable batteries become less toxic and increasingly ubiquitous in everyday use, the cost of rechargeable cells may come down so as long as raw material prices remain stable. Making lithium rechargeable batteries more affordable could provide leading manufacturers of consumer electronic products with further impetus to incorporate rechargeable battery technologies, allowing them to promote their corporate efforts to reduce the e-waste stream.


Ongoing advancements in battery holder design and adaptability to pick-and-place assembly is also making it easier for OEMs and contract manufacturers to integrate battery replacement solutions into high speed production and board assembly operations. The composite effect of these efforts will ultimately make the “green” movement less costly and thus more palatable to electronic device manufacturers.
The public is realizing the importance of the green movement in greater and greater numbers, and it is becoming ever more vital to address these concerns in the electronics industry. Simply reacting to new government regulations will no longer be enough; consumers are beginning to discriminate which manufacturers are adding value to their products through the utilization of modern technologies that reduce our impact on the world. Batteries and battery holders have improved over the last few years, just as all products have, and are now more reliable and better engineered. The use of modern, reliable battery holders and rechargeable, replaceable battery technologies is just one of the few new ways we can continue to enjoy the benefits of electronics without causing more environmental damage than we have to. In the end, latent market forces will favor forward thinking companies, which will adapt and survive, and those that don’t will become obsolete.

The battery holder design plays a critical role in handheld medical device performance and reliability, helping minimize its size and weight to make it smaller and more streamlined

By Thomas Blaha
President, Memory Protection Devices

Handheld medical devices face numerous hurdles on the way to market. First, they need to obtain FDA 510(K) pre-marketing approval for safety and effectiveness.Then, they must be manufactured to the highest quality standards using superior grade components to ensure long term reliability and greater customer satisfaction. All phases of product design are critical, including the selectio of the battery holder. Often considered an afterthought, the battery holder plays a central role in product performance and reliability. For example, the choice of battery holder can help minimize size and weight to make the device more streamlined and miniaturized. The ideal battery holder can also enhance product ruggedness to better survive normal wear-and-tear as well as the extreme abuse of being dropped and manhandled, all the while maintaining a strong electrical connection that serves as the lifeblood of the device.

For decades, coin cell batteries primarily sat flat on the PCB along with the other various components. However, as handheld devices have become increasingly miniaturized, a large diameter battery begins to take up a disproportionately large surface area. Radical rethinking was needed – not of how a battery should sit on a PCB, but of where a battery should sit in a PCB. As a result, vertically-oriented coin cell holders were introduced, giving product designers a choice between making the medical device wider or thicker. To further minimize the height of vertically-oriented coin cell holders, a new option emerged, whereby a small hole was drilled in the surface of the PCB, thus allowing the battery holder to sit partially through instead of on the PCB, helping to reduce overall height. The same concept is now being applied to horizontal coin cell holders. This new style of battery holder works as both structed with gold plating over nickel over copper plating over a phosphor bronze base. The nonreactive nature of gold makes gold-plated contacts more resilient to the corrosive effects of multiple sterilization cycles. Use of gold plating also helps prevent corrosion problems associated with bi-metallic contact, as well as temperature and humidity during shipping and storage.