Process Condition

Process Conditions
Stir Mixing Main agent: 80/hardener: 20 (weight ratio) 20min
Hold time 15min
Coating 90~120 mesh 30~35mm(wet film)
Hold time 15min 10~20 min
Pre-cure One side each coating backing:
First side: hot air convection oven (70-75/15~20min.)
Back side: hot air convection oven(70-75/25~30 min.)
Both side simultaneous coating backing:
Hot air convection oven(70-75/30~45min.)
70-75/20+5 min
70-75/30+5 min
70-75/30~45 min
Exposure 400+50 mj/cm2(lightgreen, yellow)
550+50 mj/cm2(blue,red and dark green)
600+50 mj/cm2(white)
900 mj/cm2(black)
11 step~21 step (Kodak No. 2)
Hold time 10 min 10~20 min
Development Aqueous alkaline solution: 1 wt% Na2CO3
Temperature of developers:32
Spray pressure: 2.5 kg/cm2
Developing time: 60 seconds
2.0~30 kg/cm2
60~90 seconds
Rinsing and dry Temperature of rinsing water:25
Spray pressure:2.0 kg/cm2
Rinsing time:45 seconds
1.5~205 kg/cm2
45~60 seconds
Post cure Hot air convention oven:a. 150/60min

Attention on each process

  • As to the operation environment, it is desirable to deal with the ink under the yellow lamps in the clean room, Room temperature,20,25, Room humidity 60, RH Please avoid using it directly or indirectly under white fluorescent lamps or sun ligth.
  • The main agent and hardener must mix evently, then apply also the given hold time.less holding time possibly cause the low tackiness and may cause scum.
  • The adequate thickness is 20, 25 m(on the copper after curing). Thin coating possibly reduces its solder heat resistance. (the min thickness is 10mm) On the ither hand, thick coating possibly cause the under cut.
  • During the printing process, if the ink blocks the hole, this may cause scum.
  • Pre-cure ar 72 + 3. insufficient dryness causes tackiness and loss of gloss.
  • Exposure energy depends may increase development time or cause scum.
  • Regarding to the development process, please control the developer density, the temperature, the spray pressure and thre developing time etc. The inadequacy of the control causes the degradation of the ability to development.
  • Setting of the post cure condition for solder mask will vary with the curing condition of marking ink. Insufficient curing cause peeling and over curing may cause the degradation of properties with regard to electroless gold plating.
  • During electroless gold plating process, therd are two ways of printing mark ink after post curing.
  • 150/60 min electroless gold plating mark printed.
  • 150/30 min mark printed 150/30 min electroless gold plating.