IPC CID TEST QUESTIONS WITH 100%
CORRECT ANSWERS.
How do you measure annular ring on an external layer? - ✔✔Including the plating the hole.
How do you measure annular ring on an internal layer? - ✔✔Excluding the plating in
the hole.
What are minimum annular ring requirements defined by? - ✔✔Internal supported,
external supported and external unsupported holes.
What is the most important factor in determining the minimum land size for a hole? -
✔✔The max drill hole diameter
What are each of the following: a+2(b+c)+d - ✔✔Min land size=max drill hole+2(min
annular ring+etchback)+manufacturing
What is tolerance? - ✔✔The amount of variation allowed in a dimension or location
What is breakout? - ✔✔Drilled hole breaking out of the edge of the copper land
What is breakout acceptability? - ✔✔Varies among class, where different amounts
of breakout are allowed.
, What is the MMC and LMC? - ✔✔Can have dimensions given in a range, where MMC is
most material condition and LMC is least material condition
What is the recommended electrical spacing from board edge? - ✔✔16 mils PLUS
the electrical requirement
What is it called when a land is only present to balance the construction of the board? -
✔✔Nonfunctional lands
What is the clearance on nonfunctional lands? - ✔✔0.25 mm (10 mils)
What is thermal relief? - ✔✔Thermal relief is intended to remove sufficient copper to
avoid heatsinking during the soldering processes while still meeting minimum current carrying
requirements
How do you calculate thermal web size? - ✔✔0.6*(1/number of webs)*landsize
What does CTE stand for and what are its units? - ✔✔Coefficient of thermal expansion
and ppm/C
What is the CTE for copper, brass and aluminum? - ✔✔Copper: 17-18 ppm/C; brass: 19
ppm/C; aluminum: 24 ppm/C
What is special about thermal vias? - ✔✔They must be connected to board-level planes
What does MTBF mean? - ✔✔Mean time between failures; a higher mean time means
your board is more reliable
CORRECT ANSWERS.
How do you measure annular ring on an external layer? - ✔✔Including the plating the hole.
How do you measure annular ring on an internal layer? - ✔✔Excluding the plating in
the hole.
What are minimum annular ring requirements defined by? - ✔✔Internal supported,
external supported and external unsupported holes.
What is the most important factor in determining the minimum land size for a hole? -
✔✔The max drill hole diameter
What are each of the following: a+2(b+c)+d - ✔✔Min land size=max drill hole+2(min
annular ring+etchback)+manufacturing
What is tolerance? - ✔✔The amount of variation allowed in a dimension or location
What is breakout? - ✔✔Drilled hole breaking out of the edge of the copper land
What is breakout acceptability? - ✔✔Varies among class, where different amounts
of breakout are allowed.
, What is the MMC and LMC? - ✔✔Can have dimensions given in a range, where MMC is
most material condition and LMC is least material condition
What is the recommended electrical spacing from board edge? - ✔✔16 mils PLUS
the electrical requirement
What is it called when a land is only present to balance the construction of the board? -
✔✔Nonfunctional lands
What is the clearance on nonfunctional lands? - ✔✔0.25 mm (10 mils)
What is thermal relief? - ✔✔Thermal relief is intended to remove sufficient copper to
avoid heatsinking during the soldering processes while still meeting minimum current carrying
requirements
How do you calculate thermal web size? - ✔✔0.6*(1/number of webs)*landsize
What does CTE stand for and what are its units? - ✔✔Coefficient of thermal expansion
and ppm/C
What is the CTE for copper, brass and aluminum? - ✔✔Copper: 17-18 ppm/C; brass: 19
ppm/C; aluminum: 24 ppm/C
What is special about thermal vias? - ✔✔They must be connected to board-level planes
What does MTBF mean? - ✔✔Mean time between failures; a higher mean time means
your board is more reliable
