IPC CID FINAL EXAM 2026 QUESTIONS
WITH ANSWERS GRADED A+ COMPLETE
SOLUTIONS
●● What are the 4 types of build-up multilayers?.
Answer: Piercing post, Sequentially built-up multilayer, Passive
substrate, Filled via sequential co-laminated substrate
●● The temperature at which anamorphous polymer changes from being
a hard and relatively-brittle condition to be in a viscous or rubbery state.
Answer: Glass transition temperature (Tg)
●● Affects dimensional stability and changes the electrical characteristic
in the material which can cause potential difficulties in assembly.
Answer: Moisture absorption
●● What are the 3 general methods of plating material on PCBs?.
Answer: Immersion, electroless, and electrolytic
●● What are the benefits of metallic coatings / final(surface) finish?.
Answer: Corrosion prevention, Improved long-term solderability
,●● Simplest of the wet processes; involves a simple galvanic
replacement reaction; the more noble metal in the solution picks up
electrons from the less noble metal immersed in the solution and plates
out.
Answer: Immersion Plating
●● Why would you use immersion plating?.
Answer: The thickness is limited to a very thin coating as it is a simple
replacement reaction
●● Why is Immersion finishes more beneficial than HASL?.
Answer: Immersion has a flatter base for attachment
●● What are the assembly challenges/problems with HASL process?.
Answer: Coplanarity / solder thickness varies, solder crowning, less
uniformity
●● Stencil fits flat on pad, opening is smaller than the land pattern in all
dimensions.
Answer: Gasketing
●● What is the problem with gasketing in HASL?.
Answer: Uneven surfaces cause leakage of paste underneath the stencil
, ●● What other surface finishes are better/flatter than HASL?.
Answer: Gray tin, nickel/gold, nickel/palladium gold, immersion
"white" tin, immersion silver, ENIG
●● What surface finish is good for BGAs and surface mount?.
Answer: ENIG
●● Why would you use a washable solder mask / what is the
advantage?.
Answer: Washable masks are removable; they come off in a cleaning
operation
●● What is plugging?.
Answer: Process to ensure that plated through holes are prevent from
being contaminated by the assembly cleaning and plating process
chemistries
●● For liquid photo imageable masks, what via process does IPC
recommend?.
Answer: Plugging
●● For dry film masks, what via process does IPC recommend?.
Answer: Tenting
WITH ANSWERS GRADED A+ COMPLETE
SOLUTIONS
●● What are the 4 types of build-up multilayers?.
Answer: Piercing post, Sequentially built-up multilayer, Passive
substrate, Filled via sequential co-laminated substrate
●● The temperature at which anamorphous polymer changes from being
a hard and relatively-brittle condition to be in a viscous or rubbery state.
Answer: Glass transition temperature (Tg)
●● Affects dimensional stability and changes the electrical characteristic
in the material which can cause potential difficulties in assembly.
Answer: Moisture absorption
●● What are the 3 general methods of plating material on PCBs?.
Answer: Immersion, electroless, and electrolytic
●● What are the benefits of metallic coatings / final(surface) finish?.
Answer: Corrosion prevention, Improved long-term solderability
,●● Simplest of the wet processes; involves a simple galvanic
replacement reaction; the more noble metal in the solution picks up
electrons from the less noble metal immersed in the solution and plates
out.
Answer: Immersion Plating
●● Why would you use immersion plating?.
Answer: The thickness is limited to a very thin coating as it is a simple
replacement reaction
●● Why is Immersion finishes more beneficial than HASL?.
Answer: Immersion has a flatter base for attachment
●● What are the assembly challenges/problems with HASL process?.
Answer: Coplanarity / solder thickness varies, solder crowning, less
uniformity
●● Stencil fits flat on pad, opening is smaller than the land pattern in all
dimensions.
Answer: Gasketing
●● What is the problem with gasketing in HASL?.
Answer: Uneven surfaces cause leakage of paste underneath the stencil
, ●● What other surface finishes are better/flatter than HASL?.
Answer: Gray tin, nickel/gold, nickel/palladium gold, immersion
"white" tin, immersion silver, ENIG
●● What surface finish is good for BGAs and surface mount?.
Answer: ENIG
●● Why would you use a washable solder mask / what is the
advantage?.
Answer: Washable masks are removable; they come off in a cleaning
operation
●● What is plugging?.
Answer: Process to ensure that plated through holes are prevent from
being contaminated by the assembly cleaning and plating process
chemistries
●● For liquid photo imageable masks, what via process does IPC
recommend?.
Answer: Plugging
●● For dry film masks, what via process does IPC recommend?.
Answer: Tenting
