Huaqiang fast
PCB rapid proofing production speed, good quality, reasonable price slightly lower than the market price
Designed circuit boards need to be manufactured by circuit board manufacturers, and then after proofing comes back, various components are welded, and finally assembled into the shell of the product to form a complete electronic product. So PCB proofing is an important link in the production process of electronic products. So what should we pay attention to if we want to get good quality PCB proofing?
Plate thickness: 0.8, 1.0, 1.2, 1.6, 2.0 are commonly used specifications. If there is no special requirement, choose 1.6 mm plate thickness.
Copper foil thickness: 0.5, 1.0, 2.0 is a common specification, if the power is not particularly large plate can not be , manufacturers will generally use 0.5 oz board to do, if the power of about 100 W power board will be used to more than 1.0.
Weld resistance color: green, black, red, white are commonly used, there is no requirement to use green, if it is used in their own experiments, it should use green, because the color of the board circuit can be seen most clearly.
Solder pad treatment: rosin, anti-oxidation, tin spraying (divided into lead and lead-free two), generally using the latter two can be, tin spraying will last longer.
Silk screen printing color: white, black is the commonly used color, if it is green, then generally choose white words, this is mainly to see clearly, the color contrast of the choosing heel plate is large, if it is white solder resistance, it is necessary to choose black words.
Plate selection: HB, 94V-0, FR-4 are commonly used, HB is rarely used, it is not fire-resistant board, generally single panel is 94V-0, double panel is FR-4.
I. Short Circuit Caused by Tin Running
1. The improper operation in the defilm dispenser can cause tin running.
2. The demembered plates are superimposed to cause tin runs.
Improvement methods:
(1) The concentration of the film-removing agent is high, the film-removing time is long, the anti-plating film has fallen off, but the board is still immersed in strong alkali solution, some tin powder is attached to the surface of copper foil, and a thin layer of metal tin protects the copper surface during etching, which plays an anti-corrosion role, causing the copper to be removed not clean, resulting in short circuit of the line. Therefore, we need to strictly control the concentration, temperature and time of the film-removing medicine. At the same time, when the film-removing is done, the inserting frame is used to insert the film-removing medicine, so that the plate and the plate can not be overlapped and collided.
(2) The stripped sheets are superimposed without drying, which makes the tin between the sheets immersed in the undried stripping solution, and part of the tin layer will dissolve and attach to the copper foil surface. During etching, a very thin layer of metal tin protects the copper surface and plays an anti-corrosion role, resulting in the copper to be removed is not clean, resulting in short circuit.
2. Short Circuit Caused by Imperfect Etching
1. The control of etching potion parameters directly affects the quality of etching. At present, our company uses alkaline etching solution. The detailed analysis is as follows:
(1) PH value: control between 8.3 and 8.8. If the PH value is low, the solution will become viscous, the color is white, and the corrosion rate will decrease. This situation is easy to cause side corrosion, mainly by adding ammonia to control the PH value.
(2) Chloride ion: Controlled between 190 and 210 g/L, the content of chloride ion is mainly controlled by etching salt, which is composed of ammonium chloride and supplement.
1. Attention should be paid to controlling the quantity of proofing
Because PCB proofing is usually carried out in small batches of production, so the cost of start-up is higher for proofing manufacturers, so it will cause the cost of enterprise proofing to increase. In order to better control the cost input, enterprises should calculate before PCB proofing, count the samples that need to be assembled and standby, and control the number of proofing. Quantity.
2. Pay attention to approving the proofing process
Because PCB proofing can also take a variety of different processes, so in addition to looking for professional PCB proofing manufacturers, special attention should be paid to the approval of the proofing process used by the manufacturers to ensure that the process configuration adopted by the manufacturers can meet the requirements of PCB design and manufacturing enterprises, in addition to flying needle testing after proofing.
3. Pay attention to the layout of proofing signals
Whether the signal layout of the proofing board is complete and reasonable will affect the quality of the whole proofing, so enterprises should pay attention to the signal layout of the proofing board to ensure integrity and rationality, and should check the electrical aspects comprehensively, so as to better improve the electrical performance and stability of the circuit board, and also reduce noise.
These are just a few things that should be paid attention to when PCB proofing, besides, enterprises should pay attention to good communication with designers and operators of PCB proofing manufacturers, and carefully check the packaging of relevant documents and components when delivering proofing materials, so as not to cause proofing failure or ineffectiveness due to negligence in some minor matters. Good.
