IPC A 610 MAIN FINALS ANSWERS AND QUESTIONS
SET A+
✔✔What is the purpose of an EPA? - ✔✔To control electrostatic charge when handling
ESD-sensitive items.
✔✔What is the basic goal of personnel grounding? - ✔✔Keep personnel and ESD-
sensitive items at controlled/equal electrical potential and safely dissipate charge.
✔✔What is the purpose of ESD protective packaging? - ✔✔Protect ESD-sensitive
hardware during transport and storage outside a controlled ESD area.
✔✔How should assemblies generally be handled when practical? - ✔✔By their edges or
other approved noncritical areas.
✔✔Why should solderable surfaces, contacts, and component leads not be touched
unnecessarily? - ✔✔Oils, salts, moisture, and contamination can affect solderability and
reliability.
✔✔Can fingerprints be a contamination issue? - ✔✔Yes.
✔✔What is an MSD? - ✔✔Moisture-Sensitive Device.
✔✔What can happen when a moisture-sensitive component absorbs moisture and is
then rapidly heated? - ✔✔The trapped moisture can vaporize and damage or
delaminate the package.
✔✔What is popcorning? - ✔✔Package cracking or delamination caused by rapidly
expanding absorbed moisture during heating.
✔✔Does visual inspection prove an assembly is chemically or ionically clean? - ✔✔No.
, ✔✔What determines the normal magnification used for inspection? - ✔✔The feature
being inspected and the applicable inspection requirements.
✔✔Should the highest possible magnification always be used? - ✔✔No.
✔✔Why shouldn't excessive magnification routinely be used? - ✔✔It reduces field of
view and can overemphasize conditions that are not intended to be evaluated at that
magnification.
✔✔What is higher/referee magnification used for? - ✔✔Clarifying a suspected condition
that cannot be resolved at normal inspection magnification.
✔✔Why is adequate lighting required during inspection? - ✔✔The condition being
evaluated must be clearly visible.
✔✔Does ugly appearance automatically mean Defect? - ✔✔No.
✔✔Does beautiful appearance automatically mean Acceptable? - ✔✔No.
✔✔What is wetting? - ✔✔Formation of a metallurgical bond where molten solder
spreads and adheres to the solderable surface.
✔✔What is nonwetting? - ✔✔Failure of solder to properly wet a required surface.
✔✔What is dewetting? - ✔✔Solder initially wets a surface and then recedes from
portions of it.
✔✔Nonwetting vs dewetting? - ✔✔Nonwetting never properly wets; dewetting wets and
then recedes.
✔✔What is a cold solder connection? - ✔✔A poorly formed connection characterized by
inadequate metallurgical bonding or wetting.
✔✔Does a dull solder joint automatically mean cold solder? - ✔✔No.
✔✔Can acceptable lead-free solder appear duller than tin-lead solder? - ✔✔Yes.
✔✔What is disturbed solder? - ✔✔A connection affected by movement while the solder
is solidifying.
✔✔What is fractured solder? - ✔✔A connection with an actual crack or physical
separation.
SET A+
✔✔What is the purpose of an EPA? - ✔✔To control electrostatic charge when handling
ESD-sensitive items.
✔✔What is the basic goal of personnel grounding? - ✔✔Keep personnel and ESD-
sensitive items at controlled/equal electrical potential and safely dissipate charge.
✔✔What is the purpose of ESD protective packaging? - ✔✔Protect ESD-sensitive
hardware during transport and storage outside a controlled ESD area.
✔✔How should assemblies generally be handled when practical? - ✔✔By their edges or
other approved noncritical areas.
✔✔Why should solderable surfaces, contacts, and component leads not be touched
unnecessarily? - ✔✔Oils, salts, moisture, and contamination can affect solderability and
reliability.
✔✔Can fingerprints be a contamination issue? - ✔✔Yes.
✔✔What is an MSD? - ✔✔Moisture-Sensitive Device.
✔✔What can happen when a moisture-sensitive component absorbs moisture and is
then rapidly heated? - ✔✔The trapped moisture can vaporize and damage or
delaminate the package.
✔✔What is popcorning? - ✔✔Package cracking or delamination caused by rapidly
expanding absorbed moisture during heating.
✔✔Does visual inspection prove an assembly is chemically or ionically clean? - ✔✔No.
, ✔✔What determines the normal magnification used for inspection? - ✔✔The feature
being inspected and the applicable inspection requirements.
✔✔Should the highest possible magnification always be used? - ✔✔No.
✔✔Why shouldn't excessive magnification routinely be used? - ✔✔It reduces field of
view and can overemphasize conditions that are not intended to be evaluated at that
magnification.
✔✔What is higher/referee magnification used for? - ✔✔Clarifying a suspected condition
that cannot be resolved at normal inspection magnification.
✔✔Why is adequate lighting required during inspection? - ✔✔The condition being
evaluated must be clearly visible.
✔✔Does ugly appearance automatically mean Defect? - ✔✔No.
✔✔Does beautiful appearance automatically mean Acceptable? - ✔✔No.
✔✔What is wetting? - ✔✔Formation of a metallurgical bond where molten solder
spreads and adheres to the solderable surface.
✔✔What is nonwetting? - ✔✔Failure of solder to properly wet a required surface.
✔✔What is dewetting? - ✔✔Solder initially wets a surface and then recedes from
portions of it.
✔✔Nonwetting vs dewetting? - ✔✔Nonwetting never properly wets; dewetting wets and
then recedes.
✔✔What is a cold solder connection? - ✔✔A poorly formed connection characterized by
inadequate metallurgical bonding or wetting.
✔✔Does a dull solder joint automatically mean cold solder? - ✔✔No.
✔✔Can acceptable lead-free solder appear duller than tin-lead solder? - ✔✔Yes.
✔✔What is disturbed solder? - ✔✔A connection affected by movement while the solder
is solidifying.
✔✔What is fractured solder? - ✔✔A connection with an actual crack or physical
separation.
