IPC CID
IPC CID EXAM STUDY GUIDE
QUESTIONS AND ANSWERS 2025
The board material has significant influence on the electrical performance of the circuit
from what two effects? -Correct Answer ✔dielectric constant and the loss tangent
What are the 4 types of build-up multilayers? -Correct 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 -Correct Answer ✔Glass
transition temperature (Tg)
Affects dimensional stability and changes the electrical characteristic in the material
which can cause potential difficulties in assembly -Correct Answer ✔Moisture
absorption
What are the 3 general methods of plating material on PCBs? -Correct Answer
✔Immersion, electroless, and electrolytic
What are the benefits of metallic coatings / final(surface) finish? -Correct 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 -Correct Answer ✔Immersion Plating
Why would you use immersion plating? -Correct 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? -Correct Answer ✔Immersion
has a flatter base for attachment
What are the assembly challenges/problems with HASL process? -Correct Answer
✔Coplanarity / solder thickness varies, solder crowning, less uniformity
Stencil fits flat on pad, opening is smaller than the land pattern in all dimensions -
Correct Answer ✔Gasketing
What is the problem with gasketing in HASL? -Correct Answer ✔Uneven surfaces
cause leakage of paste underneath the stencil
IPC CID
, IPC CID
What other surface finishes are better/flatter than HASL? -Correct Answer ✔Gray tin,
nickel/gold, nickel/palladium gold, immersion "white" tin, immersion silver, ENIG
What surface finish is good for BGAs and surface mount? -Correct Answer ✔ENIG
Why would you use a washable solder mask / what is the advantage? -Correct Answer
✔Washable masks are removable; they come off in a cleaning operation
What is plugging? -Correct 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? -Correct
Answer ✔Plugging
For dry film masks, what via process does IPC recommend? -Correct Answer ✔Tenting
What will manufacturers do to get proper flow characteristics of the prepreg material
and gain better performance of the multilayer structure? -Correct Answer
✔Manufacturers will mix and match the various prepreg products
For surface mount and for the outer layers to be heat-resistant, what can the
manufacturer do to help this? -Correct Answer ✔Polyimide material can be used for the
outer layers of a multilayer while inner layers are standard epoxy-grade product
In terms of material performance capability, how do you achieve homogenous
construction? -Correct Answer ✔Same material is used/only slight variations occur
between different material properties. Resin flow of the prepreg must be consistent
between the layers
What variation in construction change the physical and electrical performance of pcbs? -
Correct Answer ✔Differences in overall resin content and the use of different styles of
glass cloth; more resin/glass content can produce the same external thickness
Integral part of the manufacturing and testing process; considered in all aspects during
the manufaturing process and NOT confined to an evaluation at the end of the line -
Correct Answer ✔SPC (Statistical Process Control)
What is an example of an SPC? -Correct Answer ✔In-process coupon evaluation may
be cross-sectioned and evaluated; first article inspection may be performed to ensure
the remainder of the lot would be in conformance
These specimens are representative of a the product produced and must represent the
process -Correct Answer ✔Test coupons / specimens
IPC CID
IPC CID EXAM STUDY GUIDE
QUESTIONS AND ANSWERS 2025
The board material has significant influence on the electrical performance of the circuit
from what two effects? -Correct Answer ✔dielectric constant and the loss tangent
What are the 4 types of build-up multilayers? -Correct 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 -Correct Answer ✔Glass
transition temperature (Tg)
Affects dimensional stability and changes the electrical characteristic in the material
which can cause potential difficulties in assembly -Correct Answer ✔Moisture
absorption
What are the 3 general methods of plating material on PCBs? -Correct Answer
✔Immersion, electroless, and electrolytic
What are the benefits of metallic coatings / final(surface) finish? -Correct 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 -Correct Answer ✔Immersion Plating
Why would you use immersion plating? -Correct 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? -Correct Answer ✔Immersion
has a flatter base for attachment
What are the assembly challenges/problems with HASL process? -Correct Answer
✔Coplanarity / solder thickness varies, solder crowning, less uniformity
Stencil fits flat on pad, opening is smaller than the land pattern in all dimensions -
Correct Answer ✔Gasketing
What is the problem with gasketing in HASL? -Correct Answer ✔Uneven surfaces
cause leakage of paste underneath the stencil
IPC CID
, IPC CID
What other surface finishes are better/flatter than HASL? -Correct Answer ✔Gray tin,
nickel/gold, nickel/palladium gold, immersion "white" tin, immersion silver, ENIG
What surface finish is good for BGAs and surface mount? -Correct Answer ✔ENIG
Why would you use a washable solder mask / what is the advantage? -Correct Answer
✔Washable masks are removable; they come off in a cleaning operation
What is plugging? -Correct 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? -Correct
Answer ✔Plugging
For dry film masks, what via process does IPC recommend? -Correct Answer ✔Tenting
What will manufacturers do to get proper flow characteristics of the prepreg material
and gain better performance of the multilayer structure? -Correct Answer
✔Manufacturers will mix and match the various prepreg products
For surface mount and for the outer layers to be heat-resistant, what can the
manufacturer do to help this? -Correct Answer ✔Polyimide material can be used for the
outer layers of a multilayer while inner layers are standard epoxy-grade product
In terms of material performance capability, how do you achieve homogenous
construction? -Correct Answer ✔Same material is used/only slight variations occur
between different material properties. Resin flow of the prepreg must be consistent
between the layers
What variation in construction change the physical and electrical performance of pcbs? -
Correct Answer ✔Differences in overall resin content and the use of different styles of
glass cloth; more resin/glass content can produce the same external thickness
Integral part of the manufacturing and testing process; considered in all aspects during
the manufaturing process and NOT confined to an evaluation at the end of the line -
Correct Answer ✔SPC (Statistical Process Control)
What is an example of an SPC? -Correct Answer ✔In-process coupon evaluation may
be cross-sectioned and evaluated; first article inspection may be performed to ensure
the remainder of the lot would be in conformance
These specimens are representative of a the product produced and must represent the
process -Correct Answer ✔Test coupons / specimens
IPC CID
