Monday, February 14, 2011

【 Weak current College 】 permeated, leaching welding low foaming, Peel strength and countermeasures 】

Rigid circuit board PCB and FPC flexible circuit board production process are often encounter the following issues:

A, line section appear dry or wet processed there in etching line, the lateral erosion corrosion, causing sunken line width or line unevenness. the reason for no and dry and wet film material choice inappropriate, improper, exposure parameters exposure machine performance side. sprayer developer, etching segment, related parameters adjustable unreasonable, inappropriate drug concentration range, transmission speed of improper series may be causing the problem, however we often found after checking the above parameters and related equipment performance is not an exception, however doing Board still appear line too erosion, corrosion, and other issues. alcove what?

Second, in making PCB pattern plating, PCB, FPC Terminal surface treatment such as immersion gold, gold, Tin, Tin of electro-technology, such as when we processed often found out of plates in the dry and wet film edge or solder mask layer edges appear permeated phenomenon, or the majority of the Board, or some part of the Board, in either case will cause unnecessary scrap or bad for the back section processing unnecessary trouble, and eventually scrapped, distressing! the reason analysis we usually think of is the dry and wet film parameters, material performance problems; solder mask as hard Board ink, soft Board covering film, or in print, press, curing, section problems. Indeed, where each may cause this problem to occur, then we also confused by checking the above procedure did not question or problem is solved, but it still appears that permeated. whether there is any reason didn't look it up?

Third, the circuit board in the shipment of Tin on do before trial, the customer, of course, in use at the Tin soldering components. possible two stages will occur, or in a certain stage occurs when the wicking or solder, solder blistering and peeling substrate. do tapetest ink peeling strength, tensile Tester soft plate cover film peeling strength when it appears clear ink can be split or overlay membrane Peel strength is insufficient or no problem. this kind of problem clients especially do precision SMT customer is absolutely unacceptable. solder mask layer once encountered the bubble welding peeling will cause you to lose precision placement primitives. caused a significant loss of client components and tardy. circuit board factory at the same time will face deduction, feeding, and even the loss of customers, and other great damage then we usually encountered such problems will begin in a few aspects? we usually go to analysis is not solder mask (inks, mulching) material; it is not the screen printing, laminating, curing stage; is it a problem of electroplating solution?, and so on ... so we usually order the engineers make sure these section a a find, and we will also improve the thought is not the cause of the recent weather?, humid? sheet moisture (substrate and solder mask are susceptible to moisture) after a bitter, how many can reap some effectiveness issues was temporarily under the surface of the solution, so inadvertently such problems took place, what causes the problem that can happen? ' section obviously has been checked in the improvement is what is not. Note?

For PCB, FPC above belong to a wide range of industry challenges we confused a lot of testing and research, finally found produces line, alloying, tiered, blistering, peeling strength shortage was an important reason is that the former treatment section. includes dry-wet membrane pre-treatment, solder plating before processing, such as section prior to the treatment of partial. here, perhaps, many people cannot help but to laugh industry. pre-treatment is the simplest, acid cleaning, degreasing, micro-etch. which drops, as before, parameters, and performance, the industry's many technicians are clearly. circuit board production process involves a large number of complex surface treatment solution, such as heavy electrical copper, electric power, Tin, gold, sink, OSP, etching, etc. these complex processes in most cases, the process engineer can choose to go in-depth research, analysis, and strive to master these techniques as upgrading their technological capacity breakthrough. While most factories also to pay standard as an engineer, performance assessment and treatment before the PCT standard piece basically little engineer staff to carefully study the. either directly from the vendor to purchase the finished product, except the oil, acid wash their own inhibitor with dilute sulfuric acid as pickling. and even many plant micro-etch also own distribution, either with a sodium, ammonium system (formula became known), or purchase a hydrogen peroxide stabilizers themselves with hydrogen peroxide-sulfuric acid system. except oil through the purchase of vendor products except purchasing oil or oil powder dilution. According to our survey found that many manufacturers do not know from the root up pretreatment of the liquid in the subtle effects, or is it a key role, focused only on the surface look if oil segment, you may have always thought that the plate surface grease, finger print can be dropped, invisible for degreasing OK, everyone knows except oil technology on board, not only will have on the copper surface depths with oil peeling, while more important drug to be split down to the molecular decomposition of oil so that parties can fall. on Board did not form a second pollution. market now for sale except oil, oil meal, usually only contain ingredients except oil, rust, and other components such as photoresist, surfactants, emulsifiers, and other important groups are divided into lower costs did not increase; even the vendors of prescription purchase from elsewhere, are not understanding the role of each component, let alone study, or in combination with the actual process of circuit board needs leveling joinedthe effective component. This effectively many PCB factory uses degreasing agent is not applicable to the printed circuit board industry-specific, and degreasing agents are generic to the hardware, the traditional mineral processing industry, except oil. how to achieve this product good oil effects, the pan with the naked eye watching degreasing effect is good, actually? we power microscope or oil film test can find a large number of small oil molecules attached to the plate surface. how effective such treatment cannot be guaranteed follow-up production corrosion layer, solder mask layer, Terminal surface treatment, good adhesion, Peel strength, solderability, etc. must be performance of efficacy and stability it is particularly serious. is our micro-etch this piece of PCB industry awareness. micro-etch technique actually remove copper 1.Surface rust, oxidation layer, and other foreign bodies; 2. uniform coarsening copper surface, the formation of micro-bump, the macro-level coarsening layer. achieve rate stable coarsening effect .3. activating the copper surface, and have a short period of resistance to corrosion in gas and liquid, ensure follow-up surface processing of operability .4, low peroxide and sulfuric acid content, prevent liquid Flash-boiling and forming polymer organic residues Board., actual production, that mixes or purchased most of the micro-etching fluid as the micro-etch Etchant. considers that only the Board surface rust stain removal of foreign bodies, revealing new copper surface is achieved the effect of micro-etch. fact? our micro-etch that mixes in peroxide as hydrogen peroxide, sodium persulfate, ammonium, strong acids such as sulphuric acid to achieve the effect of the content is high, such as peroxide content reaches 120 and 150 grams/liter, sulfuric acid content of more than 5 per cent, such high concentration is the micro-etch into a substantial copper etching, bite inhibition, and because no regulators, bite inhibition is not a superficial depth, the caused the plate surface treatment results are inconsistent, to the second rework that cause serious bite copper layer etching, after section processing cannot be done, resulting in scrap. many with hydrogen peroxide systems also make that added hydrogen peroxide stabilizers can achieve uniform-inhibition of common misconceptions. hydrogen peroxide stabilizers for Suppression of hydrogen peroxide decomposes into too quickly, and will not be able to play the role of uniformity are not actually used for circuit board £ ® professional micro-inhibitor it should with low foam surfactant, wetting agents, organic complexing agents, micro-set Agent to resist and so on many kinds of additives, thereby enabling peroxides, sulfuric acid, biting rate too high, the reaction products of higher primary components in minimizing, and make the liquid more stable, in addition to the more basic features of rust and can even stable coarsening of copper surface, forming a flat and smooth surface of macroscopic (favor Terminal surface appearance), no color difference, peculiar zone or point; at the same time, the micro to achieve uniform and consistent punch and coarsening layer (conducive to subsequent corrosion wet film, solder mask layer processing), actually rely on antioxidants and strong acids and cannot increase the ideals of copper surface roughening area, to be joined to the active agent, wetting agent, etc to achieve a good depth coarsening effect, increase the copper surface roughening area, after upgrading from surface processing of adhesion and peeling strength £ ® after perfecting and improving the circuit dedicated micro-etch liquid whole should achieve: liquid without Flash-boiling, the formation of by-products without polymer, good rust contamination, good appearance uniform flat, depth coarsening of copper surface, corrosion of copper in small plate surface appearance. achieve smooth solder or when combined with strong coating processing, etc.

With the circuit board to the ultra-thin copper type conversion, we increasingly need a corrosion of copper in smaller micro-etch liquid (while keeping the rust and coarsening effect).

With the circuit board line accuracy requirements are getting higher and higher, we increasingly need a pretreatment effect better oil, slightly altered fluid. to ensure that the corrosion layer (dry film) resistance to penetration.

As PCB Terminal surface treatment looks increasingly high demands, we need to introduce high-quality pretreatment.

As the surface welding to lead-free transition, circuit board need to withstand welding temperature higher and higher, on the surface of the solder mask layer of thermal shock capacity increasingly demanding, on Terminal surface treatment and solder mask layer (inks, film), Peel strength, and substrate binding force requirements of copper is getting higher and higher, we need a better effect of pretreatment for protection.

With the circuit board industry competition becoming increasingly fierce, we need to improve our processes so that product yield increase, in order to obtain profit growth point. quality of medicine will no doubt be low-cost help us a lot.

Printed circuit board industry front such as the United States, Japan, Korea, Taiwan has long been valued and enable next-generation pretreatment. make the products more competitive, performance stability brought up by small, formerly set out to ensure that the overall process for handling stability.

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