1
IPC CID+ Questions with Answers (100% Correct
Answers)
dielectric constant and the loss tangent Answer: The board material has
significant influence on the electrical performance of the circuit from what two
effects?
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?
© 2025 All rights reserved
,2
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?
© 2025 All rights reserved
, 3
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?
Tenting Answer: For dry film masks, what via process does IPC recommend?
Manufacturers will mix and match the various prepreg products Answer: What
will manufacturers do to get proper flow characteristics of the prepreg material
and gain better performance of the multilayer structure?
Polyimide material can be used for the outer layers of a multilayer while inner
layers are standard epoxy-grade product Answer: For surface mount and for
the outer layers to be heat-resistant, what can the manufacturer do to help this?
Same material is used/only slight variations occur between different material
properties. Resin flow of the prepreg must be consistent between the layers
Answer: In terms of material performance capability, how do you achieve
homogenous construction?
Differences in overall resin content and the use of different styles of glass cloth;
more resin/glass content can produce the same external thickness Answer:
What variation in construction change the physical and electrical performance
of pcbs?
© 2025 All rights reserved
IPC CID+ Questions with Answers (100% Correct
Answers)
dielectric constant and the loss tangent Answer: The board material has
significant influence on the electrical performance of the circuit from what two
effects?
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?
© 2025 All rights reserved
,2
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?
© 2025 All rights reserved
, 3
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?
Tenting Answer: For dry film masks, what via process does IPC recommend?
Manufacturers will mix and match the various prepreg products Answer: What
will manufacturers do to get proper flow characteristics of the prepreg material
and gain better performance of the multilayer structure?
Polyimide material can be used for the outer layers of a multilayer while inner
layers are standard epoxy-grade product Answer: For surface mount and for
the outer layers to be heat-resistant, what can the manufacturer do to help this?
Same material is used/only slight variations occur between different material
properties. Resin flow of the prepreg must be consistent between the layers
Answer: In terms of material performance capability, how do you achieve
homogenous construction?
Differences in overall resin content and the use of different styles of glass cloth;
more resin/glass content can produce the same external thickness Answer:
What variation in construction change the physical and electrical performance
of pcbs?
© 2025 All rights reserved
