Process

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The process starts once your files and specifications have been sent to KAZ Circuits. Our engineers review each order to ensure design for manufacturability and proper selection of materials and technologies before manufacturing begins.


Patterning | Etching

The majority of printed circuit boards are manufactured by applying a layer of copper over the entire surface of the circuit board substrate either on one side or both sides. This creates what is referred to as a blank printed circuit board, meaning the copper is everywhere on the surface. From here the unwanted areas are removed, this is called a subtractive method, the most common subtractive method is known as photoengraving.


Photoengraving

The photoengraving process uses a mask or photomask combined with chemical etching to subtract the copper areas from the circuit board substrate The photomask is created with a photoplotter which takes the design from a CAD PCB software program. Lower resolution photomasks are sometimes created with the use of a laser printer using a transparency.


Lamination

Many printed circuit boards are made up of multiple layers, these are referred to as multi-layer printed circuit boards. They consist of several thin etched boards or trace layers and are bonded together through the process of


Drilling

Each layer of the printed circuit board requires the ability of one layer to connect to another, this is achieved through drilling small holes called "VIAS". These drilled holes require precision placement and are most commonly done with the use of an automated drilling machine. Theses machines are driven by computer programs and files called numerically controlled drill or (NCD) files also referred to as excellon files. These files determine the position and size of each file in the design.

Some files require very small vias to be drilled which results in heavy wear and tear of the drill bit itself. Drilling through different substrates may require the drill bit to be made of tungsten carbide and are costlier than other materials but required to provide a proper hole.

Controlled depth drilling can be used to drill just one layer of the circuit board rather than drilling through all the layers. This can be accomplished by drilling the individual sheets or layers of the PCB prior to lamination.

Blind Vias : Is when the holes connect a layer to the outside surface

Buried Vias : Is when the holes only connect interior layers and not to the outside surface.

The walls of each hole (for multi-layer boards) are copper plated to form plated-through holes that connect the conductive layers of the printed circuit board.


Solder Plating | Solder Resist

Pads and lands which will require components to be mounted on are plated to allow solderability of the components. Bare copper is not readily solderable and requires the surface to be plated with a material that facilitates soldering. In the past a lead based tin was used to plate the surfaces, but with RoHS compliance enacted newer materials are being used such as nickel and gold to both offer solderability and comply with RoHS standards. Areas that should not be solderable are covered with a material to resist soldering. Solder resist refers the a polymer coating that acts as a mask and prevents solder from bridging traces and possibly creating short circuits to nearby component leads.