In PCB assembly processing, BOM needs to list the components that make up the PCBA, as well as detailed descriptions and quantities of each component. For example, the following are some common components:

Serial number. (Based on this information, you can see how many components there are on this PCB.)

The part number of the component. (Usually refers to the manufacturer's part number.)

Part name. (Refers to what component this part is, some BOM lists may not have this, but you can also know what part it is based on the indicator.)

Specifications/Description. (This item will describe the details of the component, such as its value, size, color, etc.)

Packaging/Pin Position (Packaging is divided into DIP dual in-line and SMD surface mount packaging, such as SMT capacitor packaging: 0603, 1005, 2012, 3216, etc. Some BOM lists do not have this item and need to be checked based on the part number. Some BOM lists will include this item in the specifications/instructions.)

Brand/Manufacturer. (Some components may be branded, such as certain ICs, while some functions may not be branded. You can use common brands, such as certain capacitors and resistors.)

quantity (This item will display how many parts are used in a PCB. For example, 2 R1s indicate that a PCB must use two R1 components.)

'R' represents a resistor.

C "represents a capacitor.

D "represents a diode.

U "represents IC chip.

SW "means switch.

'F' represents a fuse.

JP/CN "stands for connector.

Alternative parts. (This item will display alternative parts.)

Comment/Explanation (This item will raise some special requirements or explanations for the parts.)

PCB manufacturing involves various raw materials. So how to determine the raw material requirements for PCB? The answer is the BOM list. A suitable PCB component material list can help you understand the required components and materials, their brands, quantities, sizes, and other detailed information. Usually, in PCB assembly, the BOM list includes cables, PCB boards, surface mount components, and circuit requirement lists.

From PCB design, production to assembly, PCB is a very complex and lengthy process. Therefore, you must accurately fill out the list. Any mistake is a huge loss. The following are some reasons why BOM lists are crucial for PCB assembly.

The BOM list is very convenient, allowing you to intuitively understand all the parts required for assembly, such as quantity, part numbers, etc.

The BOM list will help you estimate the number of employees required for a specific assembly based on the purchased components and difficulty level.

BOM list is beneficial for correct procurement, production planning, and stable operation.

All details need to be reviewed before actual production. At that time, BOM helped track purchased parts and inventory parts.

Accurately obtaining the parts you need or the parts produced by a specific manufacturer is crucial, and a BOM list can effectively solve this problem.

If the parts cannot be used in the PCB, you can discuss and immediately provide other options based on the specifications in the BOM list.

The BOM list is very important. The quality of the BOM list determines the operational quality of the product, so the production of the BOM list is crucial. The production requirements are very strict, as follows: coverage rate: All PCBA products in production need to have a BOM list, so the coverage rate needs to reach 99% or more. So without a BOM list, it is impossible to calculate the procurement demand plan and production plan for PCBA assembly, and it is also impossible to control the quantity of component procurement. Timeliness: BOM production and engineering changes require very timely response, and any changes will affect the procurement plan. Therefore, the BOM list must be completed before MRP, and engineering changes must be completed before the parts are released to the production department. There are two meanings: A. Timely production. B. Timely updates. Accuracy: The BOM list accuracy should reach over 98%, preferably 100%. The assessment requirements are: compared with the bill of materials, the actual assembled parts randomly disassembled shall be counted according to a single-layer structure. If there is any discrepancy, the accuracy of that layer structure shall be calculated as 0. From the above three points, it can be seen that the production requirements of the Bill of Materials (BOM) are strict and clear on paper, but BOM is not just a universal framework. The establishment of BOM directly affects the operation of the ERP system. Without a good BOM, there can be no good ERP.

What should you do when you receive an order for 50 PCB components from a customer? In addition to arranging PCB production, the following points need to be considered when creating a BOM list: considering the total quantity required (50 PCB components at a time) is not a good idea. On the contrary, consider one PCB component project at a time, identify the type of PCB and the required components, list the detailed information of only one PCB component's parts, and perform the same operation on the next project. Assign tasks to your engineering team and identify all necessary components. Organize and send the list to your clients for verification.

After final discussions with your team and clients, determine the BOM list for each project.

The BOM must display the "when", "what", and "how" questions related to the project.

Therefore, do not hastily create a BOM list, as it is easy to miss certain components or obtain incorrect quantities. This will require a lot of round-trip emails and waste a significant amount of production time. But most companies provide a BOM list format, making it easy to fill out. However, in addition to the BOM list, your PCB components must be accurate and fully functional, so it is crucial to collaborate with reliable PCB assembly manufacturers and service providers.

Some customers have PCBA samples but do not have PCB Gerber files and BOM lists, but they want to make that PCBA so that the customer can send the samples to the manufacturer, who can copy the Gerber files and BOM lists. The BOM production steps are as follows:

Check if the components of the sample provided by the customer are damaged or if there are worn chips. If there are worn chips, do not rush to disassemble the components on the PCB, but carefully examine the circuit of the PCB and analyze the chip principle.

Remove the components from the PCB and test the values of each component using a bridge.

Some components may have silk screen printing to display their model, which can be copied and included in the BOM. Some components, such as transistors, have code, and during later debugging, it is necessary to search for the manufacturer and model based on the code; If there are uncertain components, their circuits and principles can be analyzed.

Organize and archive all components. And create an EXCEL spreadsheet to facilitate later production.

The difficulty of PCBA can be roughly judged based on the quantity of materials in the BOM table.

After receiving the BOM list, check if the BOM is complete. A general BOM list should include part numbers, brands, tag numbers, quantities, packaging, and part descriptions. The essential components include part number, quantity, and tag number. Without a part number, you don't know what part it is. Without a tag number, you don't know where the parts should be soldered onto the PCB. Without quantity, you don't know how many parts should be soldered on the PCB.

If pursuing cost-effective FPC manufacturing services, choosing a Chinese manufacturer is the best choice. As a manufacturing powerhouse, China has abundant resources, cheap labor, and a large number of technical personnel. We recommend Haibo, a Chinese FPC assembly service provider with over 10 years of experience, who has performed outstandingly in various aspects

Efficient and reasonable quotation:There is an efficient quotation process to assist you in making decisions, providing reasonable prices and highly competitive quotes in China.
High quality and reliable products:Produce high standard printed circuit boards, manufacture and test according to specifications, international standards, and internal controls, and conduct pre production inspections to ensure robust processes.
Quick and on-time delivery:The assembly equipment is in good condition, with high productivity, minimal downtime, short delivery time, and also provides urgent services.
Timely and effective response:Always respond to customer needs, provide accurate information, answer questions through multiple channels, and offer one-stop services.
Strong technical strength:China's FPC manufacturing technology is leading, and Haibo has a complete SMT solution that covers assembly, inspection, and other capabilities. It also provides prototype production and customization services.