With the development of technology, the manufacturing process of electronic products has become increasingly complex, requiring highly automated SMT processing technology. PCBA SMT processing is a crucial step in this process. However, for many customers who are new to PCBA SMT processing, understanding the components of SMT processing costs can be a challenge. This article focuses on analyzing the cost structure of PCBA.
When designing electronic products, it is necessary to evaluate hardware costs. What are the main components of hardware costs? They mainly consist of components, PCB circuit boards, and the prices of SMT + DIP, which is the cost of PCBA SMT processing. In other words, calculating hardware costs mainly involves calculating the costs of PCBA SMT processing.
01
PCBA SMT Processing Flow
PCBA SMT processing is the process of applying SMT technology to circuit board assembly. The processing mainly includes the following steps: component procurement, stencil production, placement, soldering, and soldering inspection. Among these steps, placement is the core link of the entire processing.
Generally understood, the costs of PCBA SMT processing consist of the following parts
- PCB board fee (no charge if provided by the customer)
- Component procurement fee (no charge if provided by the customer)
- SMT processing fee (SMD placement + DIP soldering)
- PCBA testing and assembly fee
Next, let’s learn about the calculation method for PCBA SMT processing costs.
02
PCB Board Fee
Provide the PCB files designed for R&D, open the PCB schematic, and export the corresponding BOM (Bill of Materials).
The PCBA processing service provider will make the PCB bare board based on the PCB files, which will incur the first part of the cost, the PCB board fee. The cost of the PCB board depends on the difficulty of the board’s process, such as the number of layers: 4-layer board, 8-layer board; types of materials like FR4, aluminum substrate, carbon ink board, FPC, etc., brand and standards of materials like Shengyi TG135, Jante TG150, etc., and processes like gold immersion, tin spraying, bare copper, via cover oil, resin plug hole, etc. The prices of these boards vary. If you have a long-term cooperation with a one-stop PCBA SMT processing service provider, the price will be more advantageous, as besides the PCB board, BOM and SMT are also arranged together, leading to better prices and delivery times.
To calculate the cost of the PCB, first, you need to know the price per square meter of the PCB, then calculate how many PCBs can be made from the PCB material per square meter. Finally, divide the price per square meter of PCB by the number of PCBs that can be made per square meter to get the unit price of the PCB.
03
Component Procurement Fee
After parsing the BOM from the hardware design files, organize the components in the BOM, categorize the same components, and count the quantity of each category. This facilitates the subsequent calculation of component costs and SMT placement costs based on the BOM.
Next, we discuss the second part of the PCBA SMT processing costs—component procurement fees. The processing factory procures the required components based on the BOM. When procuring components, it is important to note that due to the nature of components like resistors and capacitors, as well as SMT placement losses (such as misplacing components, not clearing the tape in time, etc.), a material loss of about 5% should be included; generally, processing factories have long-term partnerships with component suppliers, which can lead to lower prices.
04
SMT Processing Fee (SMD Placement + DIP Soldering)
The specific costs of placement processing vary due to various factors, such as the type and quantity of components, process difficulty, equipment performance, etc. Generally, the SMT processing fee mainly includes: labor costs, equipment costs, material costs, etc. Making an accurate cost estimate requires a comprehensive consideration of these factors and in-depth communication with the placement processing factory.
When calculating the SMT processing fee, first check the processing batch size; if it exceeds 2000 pieces, no engineering fee is charged; otherwise, an engineering fee will be added. Next, calculate the number of points multiplied by the unit price per point.
SMT Production Process and Each Procedure Content
Loading -> Printing solder paste -> Placing components -> Visual inspection -> Passing through the reflow oven -> Ultrasonic cleaning -> Cutting the board -> Appearance inspection -> Packaging (some products require IC programming and PCBA functional testing).
Calculating the Number of Placement Components
SMT processing fees are generally calculated based on the number of component points, where each SMD component with 2 pins counts as one point, and each DIP component with 1 pin counts as one point. For example, a surface mount resistor, capacitor, or diode counts as one point, a transistor counts as 1.5 points, and an IC with four pins counts as one point. The total number of placement points on the board can be calculated from the BOM list.
Calculating Placement Processing Costs
Placement processing cost = number of points * unit price per point (the processing fee includes: red glue, solder paste, cleaning solution, etc.), with the unit price per placement point generally ranging from 0.01 to 0.025 yuan.
Other Costs
PCBA test fixtures, stencils, startup fees, fixtures, programming, conformal coating, glue dispensing, and other mutually agreed costs need to be calculated separately.
To reasonably calculate PCBA SMT processing costs, the following methods can also be used:1. Understand the pricing strategies of processing manufacturers: Different manufacturers have different pricing strategies. By researching multiple manufacturers, you can understand the average price level in the industry and reasonably assess processing costs.2. Consider the benefits of mass production: Generally, the unit cost of mass production is lower than that of small batch production, so when calculating costs, consider the expected sales volume of the product to choose an appropriate production batch.3. Communicate thoroughly with manufacturers: When communicating with placement processing manufacturers, clearly convey the detailed requirements and specifications of the product, and inquire about the specific pricing methods and cost components to better calculate costs.4. Accurately estimate material costs: Material costs are an important component of PCBA SMT processing costs and need to be accurately estimated based on the types, brands, and quantities of components required to ensure the accuracy of cost calculations. When calculating PCBA SMT processing costs, it is essential to fully consider the above factors and conduct a scientific cost estimate. By comparing multiple manufacturers, you can choose a placement processing manufacturer that fits your budget and can provide good service quality. In summary, understanding PCBA SMT processing costs and calculation methods helps in formulating a reasonable budget and project plan. When carrying out PCBA SMT processing, by thoroughly understanding the processing flow, communicating effectively with manufacturers, and conducting effective cost calculations, you can provide strong assurance for the smooth progress of the project. If you need PCBA SMT processing services, it is recommended to choose a reliable manufacturer and calculate costs based on actual needs and budget.
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