China Printed circuit board supplier: (Best Guide in 2020)2020-11-19
China Printed circuit board supplier: (Best Guide to choose Pcb manufacturing company)
So, you are going to order printed circuit boards (PCBA) from China. You sent requests and gerber files to suppliers, received offers. Moreover, you are ready to sign a contract with printed circuit board supplier. Do I need to visit the factory before starting work?
Definitely yes! There should be no doubt about this. If we are talking about a large order (from 500 pcs.), do not place it before a visit to the plant. The cost of a mistake can be very high!
This article is a perfect guide who are looking for professional printed circuit board supplier
The article will be useful to those who are going to personally visit factories for the production and assembly of boards in China. Especially in order to select a printed circuit board supplier. Hence in this guide you ill find very accurate information before starting your new project.
I have combined the critical requirements for quality assurance into a “minimum package”. If some of them are not here, you should seriously think about working with the manufacturer. Other factors are important, but not so fundamental. Similarly, I will cite as “additional benefits”. Their absence is not critical, but their presence will add a few points to the factory.
Our goal is to select a factory that can provide consistently high quality products. If we talk about the production of printed circuit boards, then to the common enemies of good quality for China. We will go through all areas of skills that a printed circuit board supplier should have.
I must say right away that an experienced electronic engineer is unlikely to find something new or interesting here. The material is more important for managers and business owners.
What is printed circuit board supplier actually?
All the PCB factories I have visited in China are organized in roughly the same way. Depending on the size of the business, the plots can be visible in one room or several buildings, but the technological process remains unchanged and includes:
- workshop for surface-mounted components (SMD);
- workshop for the installation of outlet components;
- testing, assembly, packaging;
- Component storage warehouses are not really a process, but an important place in terms of quality assurance.
Generally, your tour of the workshops of the plant will take place in this order.
Surface-mounted components workshop (SMD)
This is the heart of every printed circuit board supplier plant. This is where surface mounted devices (SMD) are automatically available. The main strength lies in automation. Robotic machines position miniature devices with astonishing speed and pinpoint accuracy. Moreover, the fast movements of the manipulators and the flashes of optical recognition are mesmerizing!
The technological process includes:
- the application of solder paste
- the installation of SMD components of different sizes
- a baking oven and final control.
Checking the dust protection at printed circuit board supplier factory
The printed circuit board supplier workshop must carry air conditioning and protection from dust and dirt. The indoor air must be cool and dry. If you are not with shoe covers at the entrance, you can turn around and not waste time. Similarly, look at the floor, in a decent factory it literally shines from the anti-dust polymer coating. Step back to a corner and do the simplest dust test – finger on the surface. Your finger should stay clean.
The entrance to the workshop goes through a special blowing chamber. In which you need to spin under the air jets. Just don’t be surprised if next to such a camera you find a rusty fan and a gaping hole right into the street. This is China!
The force of the discharge “biting” you upon contact is enough to damage delicate electronic components. Therefore, in the factory, the issue of “statics” must be important at the system level. Try to touch any machine in full view of your companions.
Ideally, printed circuit board supplier may ask not to touch anything. Similarly, they can provide you special gloves. All conveyor workers need to wear earthed antistatic wrist straps . Just keep in mind that some shots prefer to wear it over the ankle.
Antistatic protection of printed circuit board supplier SMD workshop
Aerobatics is a special “column” that removes static at the entrance to each workshop. The incoming person puts his hand on him and waits for a few seconds until the signal sounds.
Quality control of component installation
The third and final critical point is intermediate quality control. As well as the issue of combating “static”, this aspect is important at all stages of production. Hence, there is never too much quality control!
The minimum package should include visual inspection and at least one automated optical inspection (AOI) at the exit. These machines sequentially scan the surface of the board. Moreover, it reveals missing or incorrect component installation, distortions, soldering defects, etc. No inspector can match them in speed and reliability! I would not recommend working with a plant that does not have an AOI site capable of 100% in-line inspection.
Workshop for installation of outlet (THT) components
Unlike SMD, lead-out printed circuit board supplier does not solder components, but installed through holes in the board. The organization of this site will tell a lot about the factory!
Generally, small factories use exclusively manual labor. This is not bad in itself, but the productivity of manual soldering is lower, plus there is a human factor in the appearance of defects.
Good factories come with a Wave soldering oven that can automatically seal installed components. Here, too, there is a conveyor and manual operations. But the workers only “bait” the component by inserting its “legs” into the corresponding holes, and then remove the “tails”. It’s much faster and more reliable!
- installation of input components on a PCB before wave soldering
- installation of input components on the board before sending to the wave soldering oven
- The minimum package is the same.
Some important instructions before choosing printed circuit board supplier
For added benefits, a printed circuit board supplier should pay attention to job organization. Convenient positioning of the tool, conveyor belts, extraction and good lighting of the workshop are significant factors in the quality of printed circuit boards. Stop and observe the workers a little: in what rhythm they work, in a hurry, whether they carry out all the prescribed operations with each workpiece.
I saw a factory where the duties of each (!) Worker on the conveyor included checking the received workpiece. He carefully examined the board, checked the soldering of individual elements, and only then proceeded to his operation.
Testing and printed circuit board supplier assembly workshop
Testing of finished printed circuit boards takes place at least in 2 stages:
Electrical control is carried out on a special stand. He checks the board for an open circuit or, conversely, the presence of unwanted contacts.
Functional control involves checking a partially assembled product for the performance of the main functions laid down in it. For example, if you order a board with a GSM module, then a functional test will include:
- inserting a SIM card
- connecting the power supply and
- Running a series of tests on a computer.
Make sure all 100% PCBs are electrically and functionally tested before leaving production! To choose 2020 best printed circuit board supplier in china, you can visit here.