|
PermaCapTM is a proprietary process developed at TTM Technologies that utilizes a 2 step soldermask process.
The first process is to create a dry film vacuum lamination seal to both sides of the via holes using a thin dry film
soldermask. The second step is to use standard liquid photoimagable (LPI) soldermask over the remaining exposed
PWB. The combination of the dry film and liquid soldermask ensure both the tentability for plugging and the thinnest
soldermask available for dense surface mount technology.
Current Industry Problems and Solutions:
Disadvantage of Liquid Soldermask plugging: Solution with PermaCapTM
- Partial plugging of vias
- Potential corrosion of plated holes over time
- Inconsistent height of liquid via plugs
- Volcanic eruption of via plugs at assembly
- Poor via seal causing vacuum failure at assembly ICT
- 100% guaranteed plugging of vias
- No seepage of chemistry
- Consistent 1.6 mils average plug height
- Vacuum seal eliminates outgassing
- Preferred process for ICT vacuum
Key Advantages of PermaCapTM
- Flat Surface: PermaCapTM provides a consistent via plug height of 1.6 mils nominal as compared to 2.5 mils with
standard screened via plugs utilized by the industry. This eliminates solder paste planarization problems during
assembly.
- Via Hole Seal: PermaCapTM eliminates all possibility of entrapment of chemistry and or solder entrapment in the
holes that could cause corrosion over time. Also the seal will eliminate any dragout of chemistry that will affect
wetability of the surface mount pads at assembly.
- Thermal Resistant: PermaCapTM eliminates all entrapped air inside the vias thereby eliminating all possibilities of
plugs blowing out during assembly.
- Flexibility: PermaCapTM is recommended for all
via sizes up to .020" in size.
- Offering: PermaCapTM is offered at all divisions
within TTM Technologies.
Cost:
- PermaCapTM is price competitive with standard
LPI screened via plug.
|
