![]() In the manufacturing process,no additional process steps are required.It may be applied to single side (Type I-a) or both sides (Type I-b) of the via structure.Usually,the vias considered for tenting is done on vias less than or equal to 0.3 mm(diameter). Stretch the dry film mask to cover via and annual rings,no additional materials.That is create a tent-like shape over the opening to hide the vias.By far, via tenting is the most developed and common process in PCB manufacturing.Tented via means the via is only covered by solder mask ink. Finally, the PCB is placed in a copper sulfate solution to undergo chemical etching, which removes the uncovered copper and leaves behind protected copper, forming the desired circuitry. It is then exposed to ultraviolet light, which causes the photosensitive agent to harden the coating where it is exposed to the light, while the areas not exposed to light remain in liquid form. The liquid can be applied to the areas of the PCB that need protection by using methods such as printing or spraying. They are mixed together to form a viscous liquid during the manufacturing process. LPI solder mask typically consists of two main components: resin and photosensitive agent. It serves as a protective layer to shield the PCB from the chemical substances and thermal effects that occuring during soldering, cleaning and processing. It a special type of coating that is commonly used in surface mount process during manufacturing of PCB. Special Plugging Epoxy + Copper Plating to planarization The following is a summary of seven different types of via covering from the IPC-4761 "Design Guide for Protection of Printed Board Via Structures".ĭry film solder mask + LPI solder mask To make that clear, we recommend reading the IPC-4761document, which can help designers and manufacturers better understand the seven types of Via covering. Sometimes designers may not fully understand all the available types of via covering. Fully Filled: Via Filling or Filled Vias.Partially Filled: Via Plugging or Plugged Vias.Simple Covering: Via Tengting or Tented Vias.The condition in which the vias are not covered is called via opening. Via covering refers to the via being covered by solder mask or other chemistry material. To avoid the above situations, via covering is introduced. Dust and residues from any mechanical processes can also potentially enter vias, which may cause poor connections, signal attenuation, or even short circuits. We know that vias are plated with copper for conductivity, but if the remaining part of the hole is not covered, it is possible for solder paste to flow into it, which may ultimately result in a short circuit. ![]() So it is easy to add.Vias in the PCB are used to connect different layers. ![]() You can just create one zone over the whole PCB and assign it to NoNet. You will save your FeCl3 or whatever you use. If there is not too many of front side tracks then I etch only the back side.Įdit: And add fill zones if you etch at home. I put only straight tracks on the front side so that I can decide not to etch front side but just put Φ0.25 mm wire bridges instead. ![]() I typically design them as two sided and I put as much tracks as possible on the back side. If I would need to etch both sides I would probably prefer photo resist since it is easier to align. One sided PCBs with these limits are easy to do even using the most simple toner transfer method (and you can put there as many tracks as they fit). I etch at home and my experience is that it is easy to do if you have min track width 0.3 mm, min gap 0.25 mm, min via diameter 1 mm, min via drill 0.5 mm. I did not study your schematic but your PCBs looks very empty.
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