The Basics of PCB Assembly Process

The assembly of printed circuit boards is a multi-step process. It begins with the manufacturing of the substrate, followed by drilling and plating holes on the substrate surface, and then printing the circuit pattern on the substrate. After these first 3 basic steps, the contact fingers are attached then fused using a tin-lead coating. The panels are then sealed, stenciled and cut before the components are mounted on the PCB.

PCB assembly- Preparing the Substrate  

Electronic circuit boardThe substrate refers to the baseboard through which the rest of the PCB will be made. Substrates are often made from woven glass fiber. The glass fiber is impregnated with epoxy resin. The substrate is either sprayed or dipped in a vat of resin.
After impregnation, the glass fiber is passed through rollers to flatten it into the desired thickness. Excess resin is also removed as the substrate passes through the rollers.

The substrate is placed in an oven to semi-cure. After which, the substrate is cut into large panels. The panels are then stacked in layers. In between each glass fiber layer is a layer of copper foil with adhesive backings. The stacked panels are placed in presses under high temperature (340˚F/170˚C) and pressure (1500 psi) for at least about an hour. The resin is fully cured in this process and the copper adhesives are tightly bound to the substrate.

Quick Turn PCB Assembly– Drilling, plating, printing

Several substrate panels are piled and pinned together for stability. The panel is then laid out to sketch a pattern. The panel stacks are placed inside a CNC machine where designated holes are to be drilled. After drilling, the holes are de-burred in order to remove any excess from the edges of the holes. Copper plating is placed on the inside surface of the holes, which will serve as conductive circuits. The non-conductive surfaces are plugged to prevent them from getting plated.

The circuit pattern is printed on the substrate either through a substractive or through additive process. In the subtractive process, the entire substrate surface is plated with copper. The pattern is then etched on the copper plating, removing copper on areas that are not part of the circuit design.

In the additive process, the surface is covered in foil, revealing only the areas where the copper plating is supposed to go in. The copper plating is only placed in the desired pattern and the rest of the substrate surface is left unplated.

PCB assembly- contact fingers

Contact fingers are responsible for the conduction in between the layers of glass fiber substrates. These are fastened to the substrate edge and connected to the printed circuit. These are then masked off for plating, using three kinds of metals, namely, tin-lead, nickel, and then gold.

The entire PCB surface with the circuit pattern printed with copper is coated with tin-lead. This coating material is very porous and easily oxidized. To protect the PCB from oxidation (rusting), the entire circuit board is passed through a hot oil bath or a “reflow” oven. The tin-lead coating is melted and allowed to reflow on the shiny surface of the PCB.

Quick Turn PCB Assembly- Seal, Stencil and Cut

Circute bordThe panels are then sealed with epoxy. This will protect the printed circuit patterns from damage when the PCB components are being attached. Then, other instructions and markings are stenciled on the circuit boards.

After which, the panels are cut into the desired size of individual boards. After cutting, the edges are smoothed out.

Quick Turn PCB Assembly- Mounting

Electronic components of the PCB are then mounted as the boards are passed through several machines. The panels are passed through an automatic solder paster if surface mount technology is used to mount the components.
After all the components are placed, the boards are packaged for storage and shipping.

Carry your Seal with Pride with the Help from www.ChallengeCoins4Less.com

We believe that every person needs to become a part of a group. During our childhood years, we had our first group that is called family, and later on, we became playmates with a group of children to whom we share our common interests with. Various clubs and organizations had popped up upon our entrance to schools that we ended up becoming a part of. Even until we had our own professions, there was always a group where we belong to.

There is one special thing, which is common in groups and organizations, whether it be the high school sports team, college fraternity, volunteer group, or the department where we work in. Each of them has their own seal or logo, which symbolizes and represents the group’s identity and at times, their motto or vision statements. Just seeing it sewn in flags and shirts, printed in mugs and notebooks and displayed in establishments make us feel proud and honoured as members of the group.

Have you ever had the thought of wanting your seals to be not only sewn in thin cloth or printed in souvenirs, but at the same time not as big as the logo you use in your building’s lobby? Here in www.ChallengeCoins4Less.com, we give you the opportunity to obtain just what you deserve to have – challenge coins. Imagine having a gathering with your frat bros and just having to simply pick in your pocket and show everyone how proud you are of becoming a part of the group, or telling your children how proud you are of your department and show them the coin you have as a proof of becoming a member of it and see your kids in admiration.

Custom Coins

Here in our site, www.ChallengeCoins4Less.com , having the coin carrying your seal is not as complicated as you think it is

It is a fast and simple process. Customers can send their ideas and we take it from there and do the work. You send us your ideas at our site and with the help of our best artists, we will develop it just the way you like it. Your ideas may come in photos, sketches or simple words describing your desired outcome. You then choose the shape you want your coin to be. Any shape, which enters your mind, is acceptable.

Not fond of round coins? Then maybe you would love to have your coin shaped rectangular, like the sun, or like an animal perhaps. We just have your seal embedded on a round coin and remove the excess part just to match your desired shape with no added fees. After deciding the design and shape, you can choose which metal/metals you like your coins to be made of.

Whether you want your coin to be in gold, silver, black nickel, or brass, or a mixture of any of those in polished or antique style, we can provide it to you just to match the way you want.

Lastly, you pick from a wide range of options. You may choose if you want your coin to be in diamond cut edges, keychains, bottle openers, or velvet boxes. For the full set of options, visit our website ChallengeCoins4Less. With just a few clicks, you can have your own challenge coin ready for work. You will also have it on your doorstep then in your palms in no time.

Challengecoins4less

www.ChallengeCoins4Less.com will truly satisfy you. What you see is what you get and what you want is what you receive at a very reasonable price. Pricing varies depending on the size of the coin and no additional fees are made for customized shapes. Revisions don’t charge extra as well. Shipment fee varies but for people who reside in the continental U.S.A., it is totally free. You can actually have your own customized challenge coin for a price of $5.

What a great feeling it would be to carry the seal of your own sport teams, academic organizations, volunteer groups, fraternities and sororities, and workplace anywhere you go with pride. Just looking at it, a coin designed, shaped and made just the way you want makes you remember all the good memories you had with your groups and recall the motto, vision and mission statements you had promised to live by until the end.