Printed Circuit Board Manufacturer
Printed circuit boards have a variety of finishes that make them a viable option for electronic devices. Typically, these finishes cover the copper PCB traces and help prevent them from oxidation and corrosion.
Technicians begin the process by imaging and etching the inner layer of the board. They then use registration holes to align the two layers before undergoing automated optical inspection (AOI). This step eliminates any defects that could prevent the board from functioning as intended.
Layout
Printed circuit boards are found in almost all electronic devices and serve as the foundation for their functionality. However, they didn’t just magically appear out of thin air – their design and production is an enormous engineering undertaking.
The first step in creating a printed circuit board is the layout, which requires using PCB schematic capture and PCB layout software. During this process, the circuitry is defined through routing traces on the circuit board. It is a complex procedure that must be done accurately for the board to perform properly. Depending on the complexity of the board, it may take up to 20 or more steps.
In the early days of electronic circuitry, components were connected point-to-point on a chassis by copper wire. This was a labor-intensive and time-consuming process. Fortunately, the invention of the PCB made it possible to downsize and simplify electronic equipment.
A bare PCB is then populated with electronic components to create a functional PCA. This is usually accomplished by using through-hole technology or surface-mount technology. During the through-hole assembly, component leads are inserted into holes that are surrounded by conductive pads on the PCB. They are then soldered into place.
During this phase, it is important for the designer to consult with the fabricator about available components that are compatible with the PCB layout. This is called “design for manufacturing” (DFM) and ensures that the board can be fabricated in the fastest and most cost-effective way.
Fabrication
Printed circuit boards consist of alternating layers of copper and electrically insulating material. During printed circuit board manufacturer fabrication, the inner copper layer is etched leaving only the intended traces of copper for connecting components. The etching process can be either additive or subtractive. Additive processes involve depositing copper onto a pre-preg (filler material) laminate and then using laser direct imaging to expose areas that will become the conductive pads or metal ground of the PCB. A dry film solder mask is then applied to the exposed areas. This is what gives a PCB its characteristic green color and is commonly called LPI.
After the copper is deposited and the mask removed, the board is prepared for etching and plating. A brief etching step removes the dry film solder mask and bare original copper laminate, isolating the copper traces. After etching, the copper may be plated to the desired weight. A tin-lead coating is usually added for good conductivity and corrosion resistance.
After the copper is plated, the board is ready for lamination and assembly. The prepreg filler material is bonded to the copper with heat and pressure, creating a “PCB sandwich.” Different dielectrics are available for the insulated layer. Common ones include FR-2, FR-4, FR-5, UPILEX, and Kapton. These materials provide various insulating values and strength levels at high temperatures.
Testing
Whether it’s the latest video game or high-performance aircraft, most electronic products will contain at least one Printed Circuit Board (PCB). The PCB is comprised of a conductive material such as copper deposited onto non-conductive substrate and upon which components are soldered. PCBs are manufactured in a variety of sizes and styles, ranging from single-sided to multi-layered and from small to large.
To ensure that the PCBs are fabricated to the original design specifications, a manufacturer must employ various testing procedures. A key step in this process Printed Circuit Board Manufacturer Supplier is burn-in testing, which simulates extreme operating conditions to identify early failure points. This helps manufacturers detect defects and understand why they occur so that they can improve their manufacturing process and avoid such problems in the future.
Before moving on to the assembly stage, a PCB must be coated with a solder mask. This coating, which is printed using a similar UV exposure to the photoresist, protects the copper on the board from damage caused by oxidation. It also prevents solder bridges, which are unintentional connections that can render a circuit board useless.
Once a bare board has been coated with solder mask, engineers will use an AOI machine to inspect it for defects such as short circuits or missing or incorrect parts. The AOI machine compares images of the PCB with those of a template, or it can be programmed to recognize certain types of defects by recognizing patterns in the traces. This test can be done on single or dual grid testers that verify isolation between conductors and power to ground separation, as well as through hole and wider pitch component pads.
Packaging
A printed circuit board (PCB) can be found in almost every electronic device we use, from mobile phones to appliances. This is due to their ability to shrink electronic equipment and make them more efficient. PCBs also have a high demand globally, which is expected to reach $69.4 billion by 2024. Because of this, manufacturers are investing heavily in their facilities and research and development. They are also making efforts to protect the environment and ensure a smooth supply chain, even during COVID-19.
The final step in the process of manufacturing a printed circuit board is packaging it for shipping and delivery. This is a highly specialized job and must be done carefully to prevent any damage during transit. A damaged board can cause hefty losses, both in material and opportunity costs. Choosing the right type of packaging for your PCBs is crucial.
The outer packing of a PCB must be able to prevent dust and dirt from entering the box. It should also be able to hold the board in place during handling and shipping. It should also be able to resist punctures, tears, opening of seams, and corners. The inner packing should be made from anti-static foam or bubble wrap. This is especially important if the board is to be shipped in a harsh environment. The PCB may also be labelled with legends that contain the component designators, switch settings, test points and other indications. These can be printed using various methods, including silkscreen printing epoxy ink or liquid photo imaging.