PCB Assembly

Low-volume PCB assembly

Publish Date:2020-10-15

With the PCB becoming an indispensable part of more and more equipment, PCB prototype design is at the highest level in history. As the company continues to innovate, small PCB assembly is needed in hours, which can provide high turnover time without letting the manufacturer fall into high inventory that he cannot use.
There are some obvious advantages here that are of great value to manufacturers: low volume PCB assembly:

Low-volume PCB assembly


Cost advantage – although the traditional scale economy has known large production, it has a significant cost advantage in the changing technology scheme low capacity PCB production. First, you won’t get more production boards than you need. In addition, the board will not become redundant as technology changes.

Low-volume PCB assembly


In the prototype phase, you often improvise your product in terms of design and functionality. Low volume PCB assembly means you will not encounter defective products. In addition, because you can outsource small batch PCB assembly, this means lower management costs for your own business. You can also save valuable time available in other production areas. For lower batches, you can also save storage costs, in case you encounter a large inventory load, and if the prototype fails, it can also lead to excess inventory. Therefore, low volume PCB assembly can provide low-cost testing methods Turnover time – low yield also has a rapid turnaround time. Therefore, you can quickly assess whether there are any design changes. This in turn shortens the time to market and can be a source of significant competitive advantage in the world today.

Low-volume PCB assembly


Agility – the agility of an enterprise to respond to changes if there is an attribute between business success and failure. Low volume PCB assembly itself provides the enterprise with this advantage because the enterprise will not encounter a large number of products and has the advantage of rapid turnover time. By better understanding whether there are any defects in the product, no matter whether the design needs to make any changes, the enterprise can combine the product with the customer requirements very quickly. There is no doubt that the chances of success are increasing.

Low-volume PCB assembly


The quality end product – PCB’s ability to turn around time fast prototyping and early detection of defects, your advantage is to improve the product and enter the market with high-quality products. This has a long way to go in terms of improving credibility because the product has been successful in the market and has brought a reputation to the manufacturer.
It’s also possible for startups and amateurs – businesses are no longer just big business companies. Through the low volume PCB assembly and low cost related to the test idea, the business has become a fair competition environment. For small businesses and amateurs, it’s easy to test their ideas without having to invest a lot of money. For startups that want investors, it is easy to get proof of concept in addition to the paper business plan.

Low-volume PCB assembly


In a word, low volume PCB assembly has many advantages, which saves management costs from outsourcing. Small order size can automatically shorten the turnover time. In addition, it is a simple and low-cost method to test product design concepts without a lot of costs.
Thank you very much for coming to our Shenzhen IDEASPCBb technology. We are a professional PCB  manufacturer, which specializes in fast proofing, large, low volume PCB assembly. The whole production process is controlled by computer and barcode tracking. Only a few factories in China have this production technology. At the same time, we also provide SMT patch, plug-in machine, PCBA finished product assembly one-stop service. Quality assurance, punctuality of delivery, affordable price, welcome to consult quotation!

Printed circuit board mound, also known as "fill" or "fill bare printed circuit board," is a process that involves many different stages.

For low volume PCB assembly, to maximize production and minimize cost, What should consider some restrictions. Also, What should consider human factors before designing. Here are some of the factors that IDEANSPCB summarizes:

Low-volume PCB assembly

1) If the wire spacing is less than 0.1 mm, the etching process can not be carried out because if the etching solution can not effectively diffuse in the narrow space, part of the metal will not be etched out.
2) If the wire width is less than 0.1 mm, it will break and damage during the etching process.
3) The pad size should be at least 0.6 mm larger than the hole size.
The following constraints determine the design method of the panel:
1) The size performance of the reproduction camera used for the original film of the product;
2) Tabulated dimensions of original drawings;
3) The smallest or largest operating size of the circuit board;
4) Drilling accuracy;
5) Excellent linear etching equipment.
In the design, from the perspective of low volume PCB assembly, the following parameters should be considered:
1) The diameter of the hole depends on the maximum material condition (MMC) and minimum material condition (LMC). Who should select the diameter of the hole of an unsupported component in such a way that the MMC of the pin is subtracted from the MMC of the hole, and the difference is between 0.15-0.5mm. Moreover, for the band pin, the difference between the pin’s nominal diagonal and the inner diameter of the unsupported hole will not exceed 0.5mm, and not less than 0.15mm.
2) Place smaller components reasonably so that larger components will not cover them.
3) The thickness of solder resist shall not be greater than 0.05mm.
4) The screen-printed logo cannot intersect with any pad.
5) The top half of the circuit board should be the same as the bottom half to achieve structural symmetry because asymmetric circuit boards can bend.
From the perspective of quality control of low volume PCB assembly, an important factor to be considered is that IT should pay special attention to the possible short circuit problem caused by the inclination between the inserted components and their theoretical positions before welding. According to experience, What should keep the maximum allowable inclination of component pins at 15 degrees from the theoretical position. Within the corner. When the diameter difference between the hole and pin is large, the inclination can be up to 20 degrees. For vertically mounted components, the inclination can reach 25. Or 30 degrees, but this will lead to a reduction in package density. Figure 3-13 shows the package of the TO-18 transistor with different pin inclination. In the figure, the installation position of the to-i8 transistor is 2mm away from the printed circuit board. If the aperture is IMM, the inclination can reach 20 degrees. Of course, the pin itself does not have any inclination.
The assembly mode of multiple circuit boards usually makes the field maintenance as easy as pulling out the circuit board for the replacement. Of course, the precondition is that each independent circuit board can exercise its unique function. There will not be much disassembly for replacing circuit boards, and the minimum number of soldering / desoldering is ensured. Therefore, the design of PCB must consider its maintainability.
In the production of low volume PCB assembly, the required welding technology and equipment also add many limitations to the circuit board’s design and layout. For example, in wave soldering, the groove’s maximum size, the distance between the edges, and the operating space are all important factors. Simultaneously, designers must be aware of what the final product should look like as much as possible and try their best to protect its most sensitive parts.
There are four main steps in the assembly process of low volume PCB assembly.

  1. Application of solder paste: similar to T-shirt shielding, the solder paste template uses a thin stainless steel template to apply solder paste on the components, and What will install the components on the printed circuit board. When using solder, a chemical called flux is used to help melt the solder paste and bond it to the circuit board’s surface.
  2. Pick and place components: after applying solder paste, the next step in the circuit board assembly process is to pick and place the machine. This is where the surface mount components are placed on the printed circuit board. This process was done manually by the circuit board assembler, who will use a pair of tweezers to pick up and place components. However, with the advent of robotics, this step has been automated to achieve greater consistency and accuracy.
  3. Soldering: after all components are installed, place the printed circuit board on the conveyor belt and move the conveyor belt to the reflux furnace. Inside the oven, the circuit board is heated to melt the solder paste and permanently bond the components to the circuit board itself. Where the circuit board includes components other than SMD, it may be necessary to insert through-hole components. However, in these cases, more professional welding methods are needed.
  4. Testing and quality control: in some cases, the movement of the printed circuit board during the reflow process may cause component dislocation, resulting in poor connection, no connection at all, or incorrect component connection. That’s why it’s important to check and do some testing to ensure the board’s functionality. Even if all the above steps are carefully completed, the circuit board may fail the function test. The failed PCB can be scrapped or recycled, and the process will start again until the final result is a fully functional PCB.
    Once the finished product of low volume PCB assembly passes the function test, we can confirm the design, put it into production in large quantities, assemble the shell, and put the finished product online.