How does PCB calculate cost and quote?

Author: Release time:2019-12-12 Source: Font: Big Middle Small View count:351

PCB price is composed of the following factors: ­

1.Different materials used in PCBs cause price diversity

Taking ordinary double-sided board as an example, the sheet material generally includes FR-4, CEM-3, etc. The sheet thickness varies from 0.6mm to 3.0mm, and the copper thickness varies from ½Oz to 3 Oz. There is a huge price difference; in terms of solder resist inks, there is also a certain price difference between ordinary thermosetting oils and photosensitive green oils, so different materials have caused price diversity.

2.Different prices caused by different production processes used by PCBs ­

Different production processes cause different costs. For example, gold-plated plates and tin-sprayed plates, the production of gong (milling) plates and beer (punching) plates, and the use of silk screen lines and dry film lines will cause different costs, leading to price diversity.

3. Price diversity caused by different difficulties of the PCB itself ­

Even if the materials are the same and the process is the same, the PCB itself will cause different costs due to different difficulties. For example, if there are 1000 holes on both circuit boards, the hole diameter of one board is greater than 0.6mm and the hole diameter of the other board is less than 0.6mm, different drilling costs will be formed; if the other two kinds of circuit boards are the same, but the line width and space are Different, one is more than 0.2mm, and one is less than 0.2mm, it will also cause different production costs, because the scrap rate of difficult boards is high, the cost will inevitably increase, which will cause the price diversity.

PCB

4.Different customer requirements will cause different prices

The level of customer requirements will directly affect the yield of the board factory. For example, a board according to IPC-A-600E, class1 requires a 98% pass rate, but according to class3 requirements, it may only have a 90% pass rate, resulting in different costs for the board factory , And finally lead to changeable product prices.

5. Price diversity caused by different PCB manufacturers ­

Even for the same product, because different manufacturers have different process equipment and technology levels, they will also have different costs. Many manufacturers nowadays like to produce gold-plated plates because of the simple process and low cost, but some manufacturers also produce gold-plated plates. As a result of the increase in cost, they would rather produce tin-plated plates, and their quotes for tin-plated plates are lower than gold-plated plates.

6. Price differences caused by different payment methods ­

At present, PCB board manufacturers generally adjust PCB prices according to different payment methods, ranging from 5% to 10%, which also causes price differences.

7.Diversity of prices caused by different regions ­

At present, in terms of geographical location, prices are increasing from south to north, and prices vary from region to region, so different regions also cause price diversity.

How to calculate PCB quote?

1. Plate cost (different plate cost is different) ­

2.Drilling costs (the number of holes and the size of the holes affect the drilling costs) ­

3. Process cost (different process requirements of the board lead to different process difficulties and even price differences)

4, artificial hydropower plus management costs (this cost depends on the cost control of each factory, relatively speaking, Taiwan-funded factories are low in many countries) ­

This is the basic structure. As for the price of raw materials, it has basically stabilized now, and the possibility of price increases is unlikely.

Let's add another point. As far as the plate is concerned, the main factors affecting the price are as follows: ­

1. Plate material: FR-4, CEM-3. This is our common double-sided and multi-layer plate. Its price is also related to the thickness of the plate and the thickness of copper and platinum in the middle of the plate. FR-I, CEM-1 It is our common single board material, and the price of this material is much different from the double-sided and multi-layer boards above.

2. It is the thickness of the plate, which is common to us: 0.4, 0.6, 0.8, 1.0, 1.2, 1.5, 1.6, 2.0, 2.4, 3.0, 3.4, and the thickness and price of our conventional plates are not very different.

3. The thickness of copper and platinum will affect the price. The thickness of copper and platinum is generally divided into: 18 (2 / 1OZ), 35 (1OZ) 70 (2OZ), 105 (3OZ), 140 (4OZ), etc. ­

4. Suppliers of raw materials, which are common and commonly used by everyone: Shengyi, Jiantao, International, etc.

Process cost: ­

1. It depends on the circuit on the PCB. If the wire density is thin (below 4 / 4mm), the price will be calculated separately.

2. There is also a BGA on the board, so the cost will increase relatively, and in some places, how much is BGA.

3. Depending on the surface treatment process, we commonly have: sprayed lead tin (hot air leveling), OSP (environmental protection board), sprayed pure tin, tin, silver, gold, etc. Of course, the surface process is different, Prices will also vary.

4. It also depends on the process standard; we usually use: IPC2 level, but some customers will have higher requirements (such as Japanese capital) we commonly have: IPC2, IPC3, corporate standards, military standards, etc., of course, the higher the standard , The price will also be higher.

Each PCB sold in the PCB industry is customized by the customer. Therefore, the quotation of the PCB board needs to be costed first. At the same time, it is necessary to refer to the PCB computer for automatic imposition calculation. Comprehensive quote.

The cost calculation of the PCB industry is the most special and complicated in all industries. From material opening, pressing, forming, to FQC, packaging, completion and storage, the cost of materials, labor, and manufacturing costs need to be based on each process. Perform step-by-step accounting, and then accumulate costs in batches according to the order product number.

And different types of products, the standard rate of their processes will be different. For some products, such as blind buried plates, immersion gold plates, and copper base plates, due to the speciality of their processes or all materials, some special calculation methods must be adopted for this. In the same way, the size of the drill used in the drilling process will also affect the cost of the product, which directly affects the calculation and evaluation of WIP cost and scrap cost.

In addition, PCB factories are all products manufactured by OEM customers. The products customized by different customers are different, and there are rarely shared products.

On the other hand, due to quality considerations, some customers may also specify the use of substrates or inks from a certain manufacturer to meet their quality and cost control requirements.

How to ensure delivery? ­

The short delivery cycle of the PCB industry requires production management to control the entire production process from order placement to production completion. This requires the ERP system to provide production scheduling and work in progress management to ensure production delivery and customer response speed.

Therefore, the most critical competitive advantage of PCB lies in the links of engineering research and development, production management, material control, manufacturing, outsourcing processing, etc., especially WIP (work in process) control of on-site production management. If WIP is not properly controlled, many mixed editions will occur, such as loss, stagnation and rotation, inaccurate WIP quantity, delayed replenishment, increased number of line changes, and unknown delivery time.

There are many types of products in the PCB industry. Generally, they are differentiated according to the number of layers, including single panel, double panel, four-layer board, eight-layer board, and ten-layer board. The processing materials, process flow, process parameters, testing methods, quality requirements, etc. of PCB products will be issued to the production department and subcontracting units through the preparation of production instructions (MI).

For products with four-layer boards and below, the process flow is relatively simple, and the production process card can be completed from the beginning to the end. There is no need to change the process or replace the process card. As for blind buried plate products with more than six layers, because different inner and outer layers have different circuit diagrams, process flows or process parameters, and different auxiliary equipment such as molds and films are used, different productions are required. Instructions and related documents will also make different production process cards during the production process to control the production process and quantity of its different inner and outer layers.

PCB

In the production process, multilayer boards will have different inner layer codes. In the production process, they must be distinguished by different codes, and their production progress is controlled by different production process cards. PCB is the transfer of auxiliary products through the production of lotcards (LotCard), commonly known as overcounting. Due to the large number of production online products and miscellaneous models, it is required that the operations of counting, scrapping and repairing should be simple, fast and fault-tolerant.

In the implementation process, general-purpose ERP products are basically unable to deal with such inner and outer layer separately coding, separately counting, scrapping, and replenishing.

In general, the more detailed the production operation plan, the richer and more valuable the information it gives, and the more difficult it is to calculate accordingly. The rougher the production plan, the less information and the lower the value. The process flow involved in PCB is often complicated. The engineering data and MI production of a PCB with complex process often takes a long time to complete, and the delivery time required by customers is often very urgent.

For the PCB manufacturing industry's production management operations, which belong to the process flow manufacturing method, a small schedule (Run Card schedule) management technology will be used. Therefore, you must pay attention to the following PCB production process characteristics when scheduling: ­

Reflow processing ­

PCB processing is a representative process flow, which is different from the mechanical assembly processing mode. It is mainly based on the input of a raw material, and the subsequent auxiliary material input and processing technology are processed around the main raw material. And due to the emergence of multilayer board technology, reflow production (ie, repeating a certain process or a certain process) in the PCB industry is becoming more and more common.

Crop and press

Whether it is the front-end substrate processing or the rear-end PCB board output, one link that must go through is continuous cutting. In the previous stage, large original fabrics are used. In continuous processing, in order to meet the needs of subsequent processing, it will be continuously cut to a reasonable size for subsequent processing. The other process is lamination. No matter it is the front-end processing of the substrate or the back-end processing of the multi-layer board, the lamination process is required. That is, two plates with the same area and shape are laminated into one. .

For the characteristics of cutting and pressing, that is, how many raw materials are required to process a certain number of finished products, the number of large plates is converted to the number of small plates, and the number of raw material inputs is calculated. However, when there are waste products / wastes, combined with the parent-child work order material ratio, sometimes it will cause an increase in the workload of the PCB factory and the process is not smooth and inconsistent.

Single piece scrapped ­

Unlike scrapping in the assembly industry, PCB scrapping has so-called single-chip scrapping in addition to scrapping (removing scrapped products). The reason is that the lamination process is usually performed on large plates, and a large plate usually produces a final amount of single-chip products of varying amounts. When a defect occurs in the pre-pressing process, causing a point on the single panel A or B to be of poor quality, the production staff cannot simply discard the large panel and continue to use the material, but will record for the single panel Scrap quantity of a single piece.

For example, a large board A can be finally cut into 16 small PCB boards, and due to process problems in the current processing process, a certain point on the board is damaged. Therefore, the batch processing result is 0 No whole piece is scrapped), and single piece scrapped to 1. This quantity will accumulate backwards as the process flows, for production statistics and final product output. At this time, it should be noted that the scrap quantity of a single piece will be inherited by the double-layer board after passing through the press industry. Because the single panel A and the single panel B are pressed together, the projection of the bad point on the A plate onto the B will also cause the bad point. The resulting double-layer board will also be unusable at that point, forming the same number of single sheets Number of scraps.

Finally, the PCB industry is a foundry industry. Product design changes are very frequent, and versions are often changed. Once the customer changes the version, the manufacturing instruction and process card must also cooperate with the change, and there may even be some changes, and some do not change.

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