The total cost of an electronic product prototype usually includes the cost of the printed circuit board (PCB), component cost, assembly cost, and housing cost. The cost of product prototype mainly includes two parts: “engineering cost” and “processing cost”. For most product prototypes, engineering costs will dominate, especially as product complexity has a large impact on engineering costs. The engineering cost of a simple product may be only tens of thousands of RMB, while the engineering cost of a truly complex product may be as high as hundreds of thousands or even millions of RMB. Therefore, the best way to reduce prototyping costs is to simplify the product as early as possible, and seemingly “simple” features often greatly increase the complexity and cost of development.
PCB Prototyping Cost Factors
What you will pay for a prototype of a printed circuit board PCB depends on many variables. It may contains the cost of circuit board, pcb components, pcb assembling, pcb manufacturing, and engineers.
Circuit Board Cost
Generally, the three most influential factors that affect the cost of manufacturing a PCB are the type of material used, the size of the board, and the number of layers,.
Material of PCB
The type of material used to manufacture a Printed Circuit Board (PCB) can have a significant impact on the cost of PCB prototyping. There are several different materials available for PCB production, each with its unique properties and cost implications.
The most commonly used material for PCB production is FR-4, which is a type of fiberglass-reinforced epoxy laminate. FR-4 is a cost-effective material that is suitable for most applications, making it a popular choice for PCB prototyping.
Ceramic PCBs, for example, are used for high-temperature applications and require specialized manufacturing processes, which can increase the cost of production. Polyimide PCBs are used for flexible and high-temperature applications and require specialized equipment and handling during production, which can also increase the cost.
Metal-core PCBs, on the other hand, are used for applications that require high thermal conductivity, such as LED lighting and power electronics. These PCBs are more expensive to manufacture than FR-4 PCBs because they require specialized materials such as aluminum and copper, as well as additional processing steps.
Size of PCB
The size of a Printed Circuit Board (PCB) is a critical factor that affects the cost of PCB prototyping. This is because the size of the PCB determines the amount of material needed for its production, as well as the time and effort required to assemble and test it.
In general, larger PCBs require more material and take longer to produce, resulting in higher prototyping fees. This is because larger PCBs require more raw materials, such as copper, substrate, and solder mask, to manufacture. Additionally, the production process for larger PCBs may require more steps, such as additional drilling and routing, which can increase the production time and labor costs.
Furthermore, the size of the PCB can also impact the cost of shipping and handling. Larger PCBs may require special packaging or shipping arrangements, which can add to the overall cost of prototyping.
Layers of PCB
Although board cost increases with board size, the number of layers has a greater impact on cost. Most PCBs need to be made of four layers, of course adding more layers can help reduce board size, but it will increase the cost of the board.
Electronic Components Cost
In addition to the cost of production and assembly of circuit boards, there is also the cost of electronic components. But for most products, the cost of these components is the lowest, and the total cost of several boards is usually less than one hundred 20 dollars.
The PCBA manufacturer purchases the components you need according to the BOM list you provide. When purchasing components, due to the loss of materials such as resistors and capacitors and the loss of SMT, it is necessary to cover about 5% of the material loss. Usually PCBA assembly and processing manufacturers have long-term cooperation with component suppliers, so the price will be lower.
PCB Manufacturing Cost
Material selection for PCBs:
A typical PCB is laminated with FR4 material, but this is not sufficient for high-strength applications. For example, in the fuel or aerospace industries.
The actual size of the PCB itself:
The size of the PCB affects its final cost, which is the second key factor that affects the overall price of the PCB.
Number of layers in a PCB design:
The more layers, the higher the cost. Of course, this is also one of the factors that determine the price. The logic here is that the more layers there are, the more the number of production steps (lamination process) needs to be increased, and the more time and resources it takes to complete the manufacturing process.
Types of PCB Finishes:
The finish chosen for the PCB design affects cost, although this is a secondary factor, but some higher grade finishes can increase the shelf life of the PCB.
The size of the holes on the PCB:
The size and quantity of the holes on the PCB will affect the final production cost, and the size (design) of the holes on the PCB is the key determining factor affecting the cost.
Minimum Trace Width and Spacing:
Regardless of board size, there is often a correlation between trace width and current-carrying capability. The need for wider (thicker) traces will require more material and work, although other factors can affect current carrying capacity.
PCB Thickness and Aspect Ratio:
There is a fairly direct correlation between price and board thickness. In more detail, thicker materials can lead to higher costs for sourcing, laminating, and forming the PCB.
Custom or Special Specifications: Custom or unique specifications can also add cost. So, use simulation to better understand your likely board costs and subsequent design requirements before making any final design decisions.
PCBA Cost
PCBA circuit board assembly and processing requires you to provide PCB files and BOM lists. The PCBA assembly and processing factory will make PCB bare boards according to the PCB files, and determine the cost of PCB circuit boards according to the difficulty of the process. The price factors that affect PCBA circuit boards mainly include: component procurement, PCB manufacturing, SMT chip processing, DIP plug-ins and PCBA testing.
- SMT/DIP welding cost;
- PCBA testing fee;
- Assembly engineering fee;
- Special packaging and logistics fee.
SMD chip + DIP plug-in:
To calculate the SMT chip processing cost, it depends on your processing volume. Small batches usually require additional engineering fees.
Next, multiply the points by the point unit price. The unit price of the patch point is between 0.01-0.015 yuan. The number of points is calculated according to 2 feet of SMT patch material and 1 point of 1 foot of DIP plug-in, and the two can be multiplied.
The price of SMT chip processing is currently almost in the transparent stage, and the algorithm of how much a point is very simple.
For example, a quotation from a factory:
2 feet of SMD patch material is 1 point; 0402 components are calculated at RMB 0.018 per point, and 0603-1206 components are calculated at RMB 0.015 per point;
1 foot of the plug-in material is 1 point; each point is calculated as RMB 0.015;
4 pins of socket type are 1 point; each point is calculated as RMB 0.015;
Ordinary IC, 4 pins are 1 point; each point is calculated as RMB 0.015;
For dense pin IC, 2 pins are 1 point; each point is calculated as RMB 0.015;
2 feet of BGA is 1 point; each point is calculated as RMB 0.02;
Machine-mounted large materials are calculated according to the volume of the components doubled;
The additional fee is calculated at RMB 20 per hour.
The information required for SMT chip processing quotation includes BOM list, PDF patch image, sample image, etc., which can provide a more accurate quotation.
The main purpose of SMT chip processing is to mount SMD components on the pads of the PCB. Some companies count one pad as one point, but there are also cases where two pads are counted as one point.
In the simplest mode, if a pad is calculated as a point, customers only need to multiply the unit price according to the number of pads on their own PCB.
The next step is to determine the unit price of the solder joint, if you need to know the SMT processing cost.
SMT processing cost:
Materials: solder paste, flux, glue, cleaning agent, etc.;
Man-hours: PCB layout, number of patches, etc.;
Labor: SMT does not need a lot of people, about 3-4 people per line;
Equipment: The investment depends on the complexity of the product, which requires electricity and inert gas;
Others: The workshop needs anti-static, installation of air conditioners, ventilation and gas exchange, etc.
SMT chip processing cost: points X unit price of one point + solder paste, AOI inspection fee + download calibration fee + composite board cutting fee + stencil fee.
In SMT placement, charge by point + stencil + solder paste cost + download calibration + cutting board cost is a very classic algorithm.
PCBA testing fee and assembly fee:
The cost of PCBA testing mainly includes testing labor cost + fixture + auxiliary materials.
The cost of testing labor is calculated on an hourly basis. The cost of making test fixtures mainly depends on market conditions. The auxiliary materials are mainly oscilloscopes and computers.
Adding them together can get the PCBA test cost, and adding the above 4 parts together is the PCBA circuit board processing cost.
Labor Cost (Engineers)
Design engineers are generally charged by the hour, which is also affected by the location, work experience and years, education level, field of expertise, and the success of previous projects.
Good engineers may work twice as fast and produce higher quality work, both of which will lower your overall cost.
Regardless of their location or level of experience, if you don’t have the experience to judge the quality of their work, you’ll have to have other independent engineers review their work.
For most products, you will need at least one electrical engineer, one programmer and one structural engineer.
