02
Factors Affecting PCB Prices
Every procurement personnel in electronics factories has experienced headaches due to fluctuating PCB prices. Even seasoned buyers may not fully understand the reasons behind these price changes.
To assist buyers in calculating PCB costs and confirming quotations, the following factors affecting PCB prices have been summarized.
1. Materials
Taking ordinary double-sided boards as an example, the materials typically include FR-4, CEM-3, etc. The board thickness ranges from 0.6mm to 3.0mm, and the copper thickness varies from ½Oz to 3 Oz. All these factors contribute to significant price differences in materials; regarding solder mask inks, there are also price differences between ordinary thermosetting inks and photosensitive green inks, leading to diverse pricing based on material differences.
2. Production Processes
Different production processes incur different costs. For instance, gold-plated boards versus tin-sprayed boards, the milling boards for shaping versus punching boards, and the use of screen-printed circuits versus dry film circuits all result in varying costs, leading to price diversity.
3. Manufacturing Difficulty
Even with the same materials and processes, the inherent difficulty of the PCB can lead to different costs. For example, if two circuit boards each have 1000 holes, but one board has all holes larger than 0.6mm while the other has all holes smaller than 0.6mm, the drilling costs will differ. Similarly, if two circuit boards are otherwise identical but have different line widths and spacings, one being greater than 0.2mm and the other less than 0.2mm, this will also result in different production costs, as boards with higher difficulty have higher scrap rates, thus increasing costs and leading to price diversity.
4. Customer Requirements
The level of customer requirements directly affects the yield of the board factory. For instance, a board meeting IPC-A-600E, class 1 requirements may have a 98% pass rate, while class 3 requirements might only yield a 90% pass rate, resulting in different costs for the board factory and ultimately leading to variable product prices.
5. Manufacturers
Even for the same product, different manufacturers may have varying costs due to differences in process equipment and technical levels. Currently, many manufacturers prefer to produce gold-plated boards due to simpler processes and lower costs, while some manufacturers producing gold-plated boards may see increased scrap rates, raising costs, leading them to prefer producing tin-sprayed boards, resulting in lower quotations for their tin-sprayed boards compared to gold-plated ones.
6. Payment Methods
Currently, PCB manufacturers generally adjust PCB prices based on different payment methods, with variations ranging from 5% to 10%, thus contributing to price differences.
7. Regions
Geographically, prices in China tend to increase from south to north, with certain regional price differences contributing to overall price variations.
03
How PCB Quotations Are Calculated
1) Material costs (different materials have different costs);
2) Drilling costs (the number and size of holes affect drilling costs);
3) Process costs (different process requirements lead to varying process difficulties and thus different prices);
4) Labor, utilities, and management costs (these costs depend on each factory’s cost control, with Taiwanese-funded factories generally being much lower).
Regarding materials:the main factors affecting prices include:
1) Material type: FR-4, CEM-3 are common materials for double-sided and multilayer boards, and their prices are also related to board thickness and copper foil thickness. FR-1, CEM-1 are common materials for single-sided boards, and their prices differ significantly from those of double-sided and multilayer boards;
2) Board thickness: Common thicknesses include 0.4, 0.6, 0.8, 1.0, 1.2, 1.5, 1.6, 2.0, 2.4, 3.0, 3.4, and the price differences for standard thicknesses are not very large;
3) Copper foil thickness: Generally categorized as 18 (2/1 OZ), 35 (1 OZ), 70 (2 OZ), 105 (3 OZ), 140 (4 OZ), etc.;
Process costs:
1) The PCB’s circuit density and fineness (if below 4/4mm, the price will be calculated separately);
2) If the board has BGA, the costs will also increase, with some places charging extra per BGA;
3) The type of surface treatment process matters; common methods include lead-tin spraying (hot air leveling), OSP (environmentally friendly boards), pure tin spraying, tin plating, silver plating, gold plating, etc. Different surface treatments lead to different prices;
4) The process standards also matter; we commonly use IPC Level 2, but some customers may require higher standards (e.g., Japanese companies) such as IPC2, IPC3, enterprise standards, military standards, etc. Naturally, higher standards lead to higher prices.
Every PCB sold in the industry is custom-made for the customer, so PCB quotations require initial cost calculations, while also considering PCB computer-aided layout calculations to provide a comprehensive quotation based on material utilization on standard-sized copper-clad boards.
Cost calculations in the PCB industry are among the most unique and complex across all industries. From material cutting, pressing, forming, to FQC, packaging, and finished goods storage, each step requires detailed accounting of material costs, labor costs, manufacturing costs, etc., and then cumulative costs based on order product numbers.Moreover, different product types have different standard rates for processes. For certain products like blind buried hole boards, gold-plated boards, and copper base boards, due to their unique processes or materials, special calculation methods must be employed. Similarly, the size of drill bits used in drilling processes also affects product costs, directly impacting WIP costs and scrap cost calculations and evaluations.
Additionally, PCB factories primarily operate as OEMs, with each customer’s products being unique, and there are very few shared products. On the other hand, due to quality considerations, some customers may specify the use of certain manufacturers’ substrates or inks to meet their quality and cost control requirements.
04
Only Quick Response to Changes Can Ensure Survival
ECN (Engineering Change Notification) Changes:
In the PCB industry, ECN engineering changes frequently occur during product production, often involving both internal ECNs and external ECNs (customer engineering document changes). Frequent ECN changes in product design, if not managed properly, can lead to significant scrap inventory. Therefore, how to plan ECN product design changes in ERP systems is a critical and significant task.If ECNs, whether major or minor, are immediately changed in product and semi-finished product part numbers, it will confuse personnel in various departments about whether each different version of the product is compatible, and whether different part numbers can be delivered. This will lead to unnecessary scrap of inventory or work-in-progress during ECN product design changes.
05
Planning and Establishing BOM Data
Planning and establishing basic BOM data is as crucial for the PCB industry as laying a foundation for a building; if the foundation is poorly constructed, the building will inevitably fail.
Basic engineering data includes two parts: material basic data management and product structure BOM management.
The PCB industry is rapidly evolving, with material usage and processes changing due to technological advancements. Some materials and processes may become obsolete after one or two years, while others may increase due to advancements in production and R&D technologies. Therefore, there will be many changes in basic data within the PCB industry.
Another characteristic of the PCB industry is that, due to quality considerations, some customers may explicitly specify that they will only accept materials produced by certain manufacturers.
06
How to Ensure PCB Delivery Times
The PCB industry has short delivery cycles, requiring production management to control the entire process from order placement to production completion. This necessitates that ERP systems provide production scheduling plans and work-in-progress management to ensure production delivery times and customer response speeds. Therefore, the key competitive advantage in PCB lies in the management of engineering R&D, production, material control, manufacturing, outsourcing, etc., especially in the on-site production management of WIP (work-in-progress). If WIP management is inadequate, it can lead to many issues such as mixed batches, losses, stagnation, inaccurate WIP counts, delayed material replenishment, increased line changeovers, and unclear delivery times.
PCB products come in various types, generally categorized by the number of layers, including single-sided, double-sided, four-layer, eight-layer, and ten-layer boards. The processing materials, process flows, process parameters, testing methods, and quality requirements for PCB products are all communicated to the production department and external units through the issuance of manufacturing instructions (MI).
For products with four layers or fewer, the process flow is relatively simple, and the production flow card can be followed from start to finish without needing to change processes or replace flow cards. However, for blind buried hole products with six layers or more, different inner and outer layers have different circuit diagrams, process flows, or process parameters, and require different molds, films, and other auxiliary equipment, necessitating the use of different manufacturing instructions and related documents. Different production flow cards will also be created during the production process to control the manufacturing process and quantity of different inner and outer layers.
In the production process, multilayer boards will have different inner layer codes, which must be distinguished through different codes and controlled by different production flow cards to manage production progress. PCBs are assisted by production batch cards (Lot Cards) for product transfer, commonly referred to as passing numbers. Due to the large number and variety of products produced online, operations for passing numbers, scrap operations, and rework operations must be simple, quick, and error-tolerant. In the implementation process, I have found that generic ERP products are generally unable to handle the business of separately coding, passing numbers, scrapping, and replenishing materials for inner and outer layers.
Generally, the more detailed the production operation plan, the richer and more valuable the information it provides, making calculations more complex. Conversely, a rough production operation plan provides less information and is less valuable. The processes involved in PCB manufacturing are often quite complex, and the engineering data and MI creation for a complex PCB multilayer board often take a long time to complete, while customer delivery deadlines are often very tight. The production management operations in the PCB manufacturing industry belong to process-oriented manufacturing, so small scheduling (Run Card scheduling) management techniques are employed.
Therefore, when scheduling, attention must be paid to the following characteristics of PCB production processes.
07
Key Production Process Characteristics to Note
Reflow Processing:
PCB processing is a representative process-oriented manufacturing, unlike mechanical assembly processing modes. It primarily involves one main raw material input, with subsequent auxiliary material inputs and processing techniques revolving around that main raw material. Additionally, with the advent of multilayer board technology, reflow production (i.e., repeating a specific processing step) has become increasingly common in the PCB industry.
Cutting and Laminating:
Whether in the front-end substrate processing or the back-end PCB board output, a crucial step is continuous cutting. The initial input consists of large sheets of raw material, which are cut down to appropriate sizes for subsequent processing. Another process is laminating, where two pieces of the same area and shape are pressed together, particularly evident in multilayer boards.
Regarding the characteristics of cutting and laminating, the number of finished products required determines how much raw material is needed, converting large board quantities into smaller board quantities, thus calculating raw material input. However, when waste occurs, combined with the parent-child work order material ratios, it can sometimes lead to increased workloads and disrupted processing flows in PCB factories.
Single Piece Scrap:
Unlike assembly industry scrap, PCB scrap also includes what is known as single piece scrap (removing defective products). This is because the laminating process typically targets large boards, which generally yield varying numbers of final single-piece products. When defects occur in the pre-laminating process, affecting a specific point on single-sided board A or B, production personnel cannot simply discard the entire large board but must continue using the material while recording a single piece scrap count for that single-sided board.
For example, if a large board A can ultimately be cut into 16 small PCB pieces, but due to process issues, a specific point on the board is damaged, the result for that batch of processing would be a large board scrap count of 0 (no entire board scrapped), while the single piece scrap count would be 1. This number will accumulate as the process flows forward for production statistics and final product output. It should be noted that the single piece scrap count will be inherited by the double-sided board after the laminating operation. Since single-sided boards A and B are laminated together, any defects on board A will project onto board B, resulting in the same number of single piece scrap for the double-sided board.
08
PCB Changes
Finally, the PCB industry is an OEM industry, and product design changes are very frequent, often involving version changes. Once a customer changes a version, manufacturing instructions and process flow cards must also be updated accordingly, and there may even be cases of partial changes and partial unchanged situations.
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