Owing to the increasingly complex designs of today’s technology, printed circuit boards have evolved into increasingly complex electronic structures. A printed circuit board today may consist of multiple layers or substrates.

This article will simplify a PCB into three types.

Single-sided Board

pcb-assemblyThe simplest of printed circuit board designs is the single-sided board. This type of circuit board has only one layer of substrate. This means the design of the printed circuit board is simplified into two sides. The first side is where the printed circuit boards’ components are soldered on. The components are connected to the circuit board through their terminals which are soldered onto the substrate. This is to provide permanent connection between the transistors and the copper tracks of the circuit board. But in a single-sided board, the copper tracks are printed on the other side. To establish a connection with the transistors on the other side, there are vias or holes that are drilled through the circuit board. The vias allow the transistors to pass through the board and make direct contact with the copper tracks.

Double-sided Board

Another design type of printed circuit board is the double-sided board. This design still only has a single layer of substrate. However, instead of having a component side and copper track side, both sides of the single substrate are printed with copper tracks. Both sides can also house different components. The copper tracks printed on each side may or may not be connected to each other, depending on the intended design of the electronic circuit. Should the design require electric current to flow on both sides of the single substrate, vias can be integrated into the design of the circuit board.

Multi-sided Board

Finally, the third type of printed circuit board is the multi-sided board. These circuit boards are used for more advanced and complex circuit designs wherein a number of electronic components are required. Because it is multi-layered, this design can accommodate a significantly higher component density. A multi-sided board has three or more sides with printed copper tracks. To achieve this, double-sided board designs are usually connected together to form multiple substrates. If the design requires the different sides of copper tracks to be connected together, vias may be integrated into the design. However, since some substrates and layers are not readily accessible because they are sandwiched between other substrates, microvias are used to form electronic connections.

Typical vias form a straight hole through all of the substrates. Microvias are not full vias though they allow connections between substrates. A blind via is a microvia that is accessible to the outermost substrate but terminates in-between substrates. On the other hand, a buried via is not accessible and cannot be seen as it is embedded between substrates and allows sandwiched copper sides to connect with each other.

Flexible and Flexi-Rigid Boards

Common printed circuit boards are usually made of glass with reinforced plastic or FR-4 glass epoxy. However, innovations in design and development have led to the creation of flexible and semi-flexible boards to suit a wide range of applications, like non-traditional and non-conventional product designs.
Basically, instead of being made with the rigid FR-4 glass epoxy, these new variations of printed circuit boards are made of conductor layers printed on dielectric film and or coverlay’s/semi flexible liquid photo imageable solder resist.


Without a doubt, these types of boards hold many advantages over rigid designs like lighter construction, smaller space, and reduced interconnecting problems. In addition, flexible and flexi-rigid designs are also cheaper to produce and can be molded to suit all sorts of designs.

Essential Information About Challenge Coins According to

The practice of giving and receiving challenge coins has long been held in high regard in organizations, particularly branches of the military.  These days, the practice of giving challenge coins as a significant piece of memorabilia or memento has also been picked up by top corporations.

If you are new to the concept of challenge coins and you’re looking for more information,, a leading manufacturer of customized challenge coins, is here to break it down for you. is trusted not only by every branch of the United States Armed Services, but also by leading companies such as Colt, UPS, American Airlines, United Nations Development Fund (UNDP) and Symantec.

The Meaning Behind Challenge Coins

The practice of giving challenge coins can be traced back to the military campaigns of the mighty Roman Empire.  Legends say that they are given to the soldier who did exemplary work.

The history of challenge coins has always been connected to military service, but these days, its significance extends beyond the military.

Military Coins

If you are part of an organization, having a challenge coin means a lot of things.
First, it means loyalty and pride.  Owning a specially customized challenge coin means that you are a committed member of a certain group.  Aside from military branches and units, these items can also be made for fire and police departments, and sports teams. works with organizations in customizing their logos and adding special touches, such as texts or important images.  This creates a detailed piece that you can carry with pride.

Challenge coins also signify camaraderie and teamwork.  Owning a challenge coin creates a special bond with teammates and other members of the group.  In social situations, some members bring out their coins to validate membership to the group. It is used to build good relationships and strengthen bonds among group members.
Challenge coins are also used to celebrate personal accomplishments.  Bearing in mind their military past, these items are still given as incentives to people who do exemplary work for the organization, which they are a part of.  It is a reward given to honor hard work and dedication.

Challenge coins can also encourage members of the group and boost their morale.  Sports teams benefit from owning these items.  Team members who own these coins are reminded of holding on to their team spirit, which causes them to strive hard to be successful.

Many organizations also use challenge coins to raise awareness to certain important issues.  They serve as means to communicate important messages to the public.
If you own a challenge coin, it also means that you value being part of a certain group of people.  It serves as a valuable keepsake and memorabilia. Owning this significant memento means a whole lot to people.



Types of Challenge Coins

Challenge coins may be created for Federal Government agencies, military branches or even smaller military units, local police and fire departments, sports teams, academic institutions, interest groups, fraternities, civic clubs and corporations.
Challenge coins come in various sizes. Typically, they come in 1.5 inches in diameter to 3 inches in diameter.  You can choose from various design options offered by companies.

Military coins usually include the logo, and the name of the branch or unit.  They are typically given to members to symbolize the camaraderie and teamwork of the group, and celebrate their shared experiences. For some unit members, owning a challenge coin is like a badge of identification.  We, at, create coins for all branches of the United States military.  Check out the beautiful samples of coins that they helped design and manufacture for the Air Force, Coast Guard, Marine, Navy, and Army units.

Police challenge coins symbolize membership to certain elite units such as SWAT teams, bomb disposal teams, special detectives, or even major crime units. Firefighter coins, on the other hand, signify membership to a certain fire department.  Most fire departments opt to put the symbol of St. Florian on their coins.  Police and fire departments also use challenge coins to give out to the public for their fundraising events.  Those from renowned police forces and fire brigades fetch for hundreds of dollars when sold to collectors.

Corporate challenge coins usually have their company name or logo on display, and are typically given as incentives or keepsakes to employees.