Before looking for a manufacturer to proofread a large number of PCBs, it is necessary to check whether the quality and design of PCBs meet the standards. It is necessary to proofread 5 to 10 PCBs in small batches quickly. This provides a great opportunity for the development of small-batch proofing PCB factories. So what are the key points for customers to choose PCB small-batch proofing fastboard factory? There are three aspects.
It takes a look at speed. Now many customers often have urgent proofing needs, which puts forward higher requirements for the production efficiency and quality of PCB manufacturers. Only when production efficiency is up to par can you provide PCB emergency services for a wide range of products on a timely basis. Huaqiang Express PCB Factory, for example, has a single, double, multi-layer panel and small batch of emergency services to ensure delivery on time.
Second, look at quality. It depends on whether the copper thickness of PCB meets the standards, whether the line spacing is smooth, whether the surface treatment of the board is smooth and tidy, whether the adhesion of copper foil is good enough, and so on. These are important factors to inspect the quality of PCB. Only if the product quality is guaranteed can it be explained that the Allegro factory is worth your choice.
Third, look at services. The service level mainly depends on the speed of order auditing, customer requirements and the speed of solving customer problems. If the service attitude is good, and has a rich number of orders, then the quality of service is guaranteed.
The above three aspects are the key points for customers to choose PCB to accelerate the small-batch proofing production of accelerated plate manufacturers. These three aspects can help you form strategic thinking, so as to select a suitable small-batch proofing PCB manufacturers, and promote the development of their own business requirements.
The notices of PCB Allegro proofing and the following two points
Plate Thickness: 0.6, 0.8, 1.0, 1.2, 1.6, 2.0 This is a commonly used specification, if there is no special requirement, routine selection of 1.6 mm plate thickness.
Resistant color: green, black, red, white, this is the conventional use of green, no requirements on the use of green, if it is their own proofing should be used more green, because this green board circuit can be seen most clearly
Copper foil thickness: 0.5, 1.0, 2.0 This is a common specification, if the power is not very large board can not be manufacturers will generally use 0.5 oz board to do, if the power is around 100 W power board will use more than 1.0.
Silk printing color: white, black is the conventional color, if it is green, then generally choose white words, this is mainly to see clearly, choose the color contrast of the heel board is big enough, if it is white solder resistance, then choose black words.
Solder pad treatment: rosin, antioxidant, tin spray (divided into lead and lead-free), generally used in the latter two can be, spray tin storage time will be longer.
Plate selection: HB, 94V-0, FR-4 this is routine, HB is rarely used, it is not fireproof board, the general single panel on 94V-0, double panel on FR-4.
1. Short circuit caused by running tin
1, the plates that have been removed from the membrane stack together to cause running tin.
2. Improper operation in the withdrawal film syrup can cause running tin.
Improvement methods:
(1) High concentration of the film removing agent, long time of film removing, the anti-coating has already fallen off, but the plate is still immersed in strong alkali solution, part of the tin powder attached to the copper foil surface, etching with a very thin layer of metal tin to protect the copper surface, play a role in corrosion resistance, resulting in the removal of copper is not clean, resulting in short circuit. Therefore, we need to strictly control the concentration, temperature and time of film removal. At the same time, we need to insert the film removal with the insertion board rack, so that the board and the board can not be stacked together.
(2) The stripped sheets are stacked together before drying, so that the tin between the sheets is immersed in the undried stripping solution, and part of the tin layer will dissolve and adhere to the surface of the copper foil. When etching, a very thin layer of metal tin protects the copper surface, playing an anti-corrosion role, resulting in the removal of copper is not clean, resulting in short circuit.
Two. Short circuit caused by etching.
1. The quality of etching is directly affected by the control of the parameters of the etching solution. At present, the alkaline etching solution is used in our company.
1.1 PH value: control between 8.3 to 8.8, if the PH value is low, the solution will become viscous state, the color is white, the corrosion rate will decline, this situation is easy to cause side corrosion, mainly by adding ammonia to control the PH value.
1.2 Chloride: Controlled between 190 and 210g/L, mainly through the etching salt of chloride ion content control, etching salt is composed of ammonium chloride and supplements.
