PCB proofing, small and medium batch production experts
We are specialized in manufacture and supplier of rubber Sealing Strip, which are used in mechanical seals, automobile and car door seals, door and window industry and other construction industry, with more than 20 years experience and steady development, we has become recognized leader company of the rubber extrusions products. These products are widely used in truck, car, shipping, railway, machinery, bridge, drilling industry, and other areas. The main materials are rubber, PU, PA, EPDM, PVC, silicon, NBR, BR, CR, TPE and ABS. Our company has already established good and cooperative relationships with many domestic and foreign automotive manufacturers, door and window manufacturers..--
PCB circuit board production process
Cutting - inner layer graphics - lamination - drilling - electroplating - outer layer - solder mask - surface treatment - forming - electrical testing - FQC - FQA - packaging - finished product
Opening
According to the size requirements of MI, the large-size copper clad plate is cut into manufacturing units - Panel (PNL).
(Sheet (Purchasing Unit) - Panel (Manufacturing Unit) - Set (to the external client unit) - Piece (using unit))
Production process
Incoming material inspection - shearing plate - grinding plate edge - rounded corner - washing plate - after baking - the next process
A, common plates and specifications
The plates are: FR-4 and CEM-3, and the bulk sizes are: 36×48, 40×48, 42×48, 41×49, 48×72.
B, material utilization rate
The billing utilization rate is the percentage of the finished product shipping area and the billing area in the billing area. Double panels are generally required to reach more than 85%, and multi-layer boards require more than 75%.
Inner layer graphics
After the material core is opened, the copper surface is microetched and roughened by pretreatment, and then the film is dried or printed with a wet film, and then the core plate coated with the photosensitive layer is exposed by the production film to make the required line portion. The photosensitive layer undergoes a polymerization crosslinking reaction, which remains after development by weak alkali, dissolves the unreacted photosensitive layer through the developing solution to expose the copper surface, and then etches away the exposed copper portion by acid etching to make the photosensitive layer cover the area. The copper remains and forms a line pattern. This process is the process of transferring the film graphics to the core graphics, also known as graphics transfer.
Production process:
Pre-treatment - dry film (wet film) - alignment exposure - development - etching - film removal - QC inspection (over AOI) - the next process
A, pre-treatment (chemical cleaning line)
The 3%-5% acidic solution is used to remove the copper oxide layer and the protective layer on the original copper substrate to prevent copper from being oxidized, and then subjected to micro-etching treatment to obtain a sufficiently roughened copper surface to increase dry film and copper. Adhesion properties of the face.
B, wet film or dry film
First, the polyethylene protective film is peeled off from the dry film, and then the dry film resist is pasted on the copper clad plate under heat and pressure, and the resist layer in the dry film becomes soft after being heated, and fluidity The film is added by means of the pressure of the hot press and the action of the binder in the resist.
C, dry film exposure principle:
Under the irradiation of ultraviolet light, the photoinitiator absorbs the light energy to decompose into a free radical, and the radical further initiates a polymerization crosslinking reaction of the photopolymerizable monomer, and forms a stereoscopic macromolecular structure insoluble in the weak base after the reaction.
D, development principle, etching and fading
The active group in the unexposed portion of the photosensitive film reacts with the weak alkali solution to form a soluble substance, and the unexposed photosensitive film is dissolved in the reaction solution, and the exposed photosensitive film is not reacted with the weak alkali solution to be retained. Thereby obtaining the desired line pattern.
Etching
Ejection
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