Every printed circuit board has a unique function. Therefore, PCB production is always different and includes many complex steps. First and foremost, PCB designers should be satisfied with their design and make sure Gerber files are complete before sending them to the manufacturer. The application engineer should make a checklist for every design step, and Gerber file generation should be created when sure of perfection. Following is a quick overview of a complete and satisfactory design.
1.PCB Production—Stages Of PCB Production
The schematic design is error-free, with proper connections and supplies. Components placed for the PCB layout have a correct footprint, drilling size of pads, and proper orientation. The routing is appropriate between the right parts with relevant trace width. Cross-checking every detail, along with their reference designator and nets, and run design rules check often.
Now comes the PCB production phase. For this, it is advisable to first develop a PCB prototype before going for total production. This gives designers to test their circuit and the actual layout in physical form, and then once satisfied, they can order the total output of that PCB.
The main stages of PCB Production are:
Step 1: Selecting PCB material
The popular PCB substrate materials belong to the FR series, among which the most common is FR4. FR4 material-based PCB is a glass, fiber-based board. It is yellowish-green in color and offers good mechanical and reasonable stability under various temperature ranges. And the best part, it is not excessively expensive. Other materials are available at low costs like FR2, FR3, FR-5, CEM1, CEM3, and PTFE.
Now to make a printed circuit board, the copper clad board is obtained. This is done by a copper cladding that bonds a thin layer of copper on both sides of the substrate.
Step 2: Tracking on PCB
The next step is creating tracks onboard. For gaining correct channels on the board, a photographic process is used. The photo-resist material covered the copper on the PCB, which is then exposed to light through a photomask or a photographic film. These details required tracks onto the photo-resist fabric. After completing this process, the photoresist is placed in a developer to cover that area where ways are needed.
Step 3: Etching PCB
The next stage involves etching those areas where copper isn’t required. This is usually done by a chemical etching process, most commonly using ferric chloride solution. The board is placed for a certain amount of time in the etching agent according to the concentration of ferric chloride solution and thickness of the copper.
Step 4: Creating vias and holes
In complex PCB, small holes or vias are created to ensure electrical connection between different layers. There are three types of vias: blind vias, buried vias, and through-hole vias.
Furthermore, holes may also need to add to the PCB for mounting leaded components. For these holes, drilling is done using drill files from the Gerber files. The drill file data is supplied to PCB CAD design software which controls drilling machines to make holes. Make sure that the sizes of the holes are not much different. The lesser the number of different hole sizes, the cheaper the PCB cost will be.
Step 5: Solder plating of PCB
To protect areas on the PCB that don’t need to be solder, a polymer layer is applied to those areas called solder resist. In addition, this deep green or red layer also prevents short circuits that can cause by solder during soldering and from contamination.
The mounting areas are platted or tinned with solder for soldering leaded components or mounting SMT components. Occasionally, these exposed areas may be gold plated.
Step 6: PCB SilkScreen
Often, the text is printed on PCB for marking components or identifying the board. For this, PCB design software generates a silkscreen for these markings. These markings are added onto the PCB when the manufacturing mentioned above process has been completed.
2.PCB Production—Multi-Layer PCB Production
Manufacturing a multi-layer PCB required similar stages that a single-layer PCB needed. However, these stages need to be performed with a greater degree of accuracy and manufacturing process control. Multi-layer PCBs are made using individual boards, one for each layer, that are much thinner. These individual boards are bonded together to produce an overall printed circuit board. Therefore, the individual panels must be lighter to prevent a thick finished multi-layer PCB.
3.PCB Production—Materials For Printed Circuit Boards
PCB can be made from a variety of circuit boards materials.
FR or fire retardant material is one of the most standard glass laminated materials made from glass-epoxy compounds. Resin binder gives this composite material its flame-retardant qualities. The FR-4 material is used to design a highly dense or multi-layer PCB. Its ambient temperature is between 120 degrees to 130 degrees C, according to the thickness of the substrate.
This material has the following properties:
- Good mechanical strength
- Low moisture absorption
- High electrical insulation
- Good fabrication capabilities
- PCB layers: 1 to multi-layer
This glass fabric reinforced material is perfect for high temperature and humidity applications. This is due to the presence of epoxy resin binder in this substrate. FR-5 exhibits:
- Excellent mechanical properties
- Good dielectric constant
- Low moisture absorption
- High chemical resistance
- PCB layers: 1 or double layer
This fire retardant material makes use of stiff paper and epoxy resin binder for its composition.
• It is cheap and, therefore, an excellent choice to use for consumer electronics.
• PCB layers: 1 or double layer.
► FR-2 and FR-1:
FR-1 and FR-2 feature the composition of the stiff paper and a phenol compound. Both are the same substrate materials, having similar characteristics. However, there is one difference which is the glass transition temperature. FR1 has a higher glass transition temperature of 130 degrees C instead of 105 degrees C for the FR-2 substrate material.
► CEM materials:
Composite Epoxy materials, CEM, feature the composition of epoxy synthetic resins and materials produced from woven glass fabric and non-woven glass fabric. There are five types of CEM materials. CEM-1 is an FR, flame retardant, material featuring a composition of two layers of woven glass fabric, phenol compounds, and cellulose paper laminate.
CEM-2 features a composition of single-layer woven glass fabric and cellulose paper core. It is a good choice for the single-sided printed circuit board. CEM-3 and CEM-4 have similar characteristics.
It is commonly used in double-layer printed circuit boards and is a good choice for the FR-4 substrate. CEM-5 features material of polyester woven glass core and is not flame retardant.
Among all mentioned circuit boards materials, FR4 is the best selection for PCB production. Other materials are suitable and come at a low price.
However, they can only be used to make a single-layer printed circuit board. In addition, the reliability of these boards is not good. Therefore, FR-4 is best suited to make a quality superficial one layer to the multi-layer board.
4.PCB Production—Factors Effecting PCB Cost:
Always consider these factors for estimating the cost of PCB production.
1.Number of boards: Smaller printed boards are quickly processed in more significant numbers on the production panel, thus decreasing the cost per board.
2.PCB thickness and number of layers: The layers in PCB also affect the price. More layers in a PCB means more thickness of thickness along with complex WellPCB. We will provide you with a one-stop service and high-quality products. You can send us the documents you need to make and get a quote immediately! What are we waiting for? We have ten years of PCB manufacturing process, which is expensive. Therefore, design PCB with a minimum number of layers and thickness. The specification also affects the thickness of the PCB. For these boards, expensive materials increase the price. Furthermore, copper weight also increases the cost of the PCB.
3.PCB size: Most of the time, the price of PCB exceed due to its large size. The reason is that larger PCBs require more substrate material and holes of different sizes that increase the overall cost. On the other hand, smaller PCBs are quickly processed in more significant numbers on the production panels, thus decreasing the cost per board.
4.Impedance control and routing: Routing and impedance control in PCB add the extra price to the overall cost of the final PCB.
5.Solder mask and silkscreen: These are additional that tend to increase the cost of PCB. Therefore, if these features are not included in PCB, the price gets decreased significantly.
When you order PCBs from wellpcb.com, you are paying a reasonable cost for the high-quality production of your PCB. We have WellPCB. We will provide you with a one-stop service and high-quality products. You can send us the documents you need to make and get a quote immediately! What are we waiting for? We have ten years of PCB manufacturing equipment and facilities that drive us completely capable of producing 2 to 32 layers of PCB. We made PCBs from Gerber 274-X data and drill files. It is used to make one layer in a physical board, and then multiple layers are then bond to form a multi-layer PCB.
Our expert team ensures that the PCB delivers what we promise. Representatives are available 24 by 7 hours to help consumers decide the best package that suits their budget without compromising the quality of PCB. Our team guide for appropriate options selection of competitive prices by giving reasonable suggestions for a considerable reduction in total costs.
We always try our best to deliver PCBs at an economical rate so that customers can focus on their core purpose rather than worrying about the cost. For more information, please get in touch with our support team through [email protected].