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