CIS Cheat Sheet 2026

The 30 highest-yield CIS facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the role of a conformal coating in PCB assembly? → To provide electrical insulation and environmental protection
2. Which condition would constitute a defect in conformal coating per IPC-A-610 for Class 2 and Class 3 assemblies? → Exposed conductors or solder connections that are required to be coated
3. During conformal coating application, which types of features MUST typically be masked to prevent coating? → Edge connectors, test points, and adjustable components
4. What is the proper method for removing excess solder from a joint? → Use a solder wick or desoldering pump
5. How can manufacturers reduce the risk of component damage during transport? → Using ESD-safe packaging and ensuring proper cushioning
6. What is a common method for testing PCB functionality after assembly? → Functional testing to verify performance
7. What is the maximum number of times a through-hole plated barrel may be thermally stressed during rework per IPC-7711? → Four times
8. What color are most standard ESD protective bags and packaging materials? → Pink or metallic shielding (silver/gray)
9. Why is it important to use the correct amount of solder in a joint? → To ensure a reliable connection without shorts or weak joints
10. What is the IPC-A-610 acceptability condition for a solder bridge between two conductors that should not be electrically connected? → A defect for all classes
11. Which packaging material provides BOTH electrostatic shielding AND dissipative properties for transporting ESD-sensitive assemblies? → Metalized shielding bags
12. What is the correct interpretation of a 'target condition' in IPC-A-610? → The ideal, preferred condition showing a high degree of workmanship
13. A wrist strap used for ESD protection should be tested: → Before each use or at the beginning of each shift
14. Which ESD model most closely simulates the discharge from a metal tool or conductive object touching a component pin? → Machine Model (MM)
15. Which IPC standard specifically addresses the qualification and performance requirements for conformal coating materials? → IPC-CC-830
16. What is the primary function of a component identifier (CID) number? → To ensure correct component usage in assembly
17. What is the best method for preventing ESD when handling sensitive components? → Using an ESD-safe workstation and wrist straps
18. Why is testing crucial in the PCB assembly process? → To verify that the PCB performs correctly and is free from defects
19. What is the primary purpose of proper component identification in electronics? → To ensure components are correctly used and avoid assembly errors
20. What is ESD and how does it affect electronic components? → It is the discharge of static electricity that can damage components
21. Which ESD control element provides the primary grounding path for operators working at a bench? → ESD wrist strap connected to a common point ground
22. Which of the following is NOT a typical source of ionic contamination on PCB assemblies? → Solder mask pigments
23. According to IPC-A-610, component skew for chip resistors and capacitors is acceptable for Class 2 when: → Both terminations remain on their respective pads within specified limits
24. What is the primary purpose of soldering in electronics? → To create a permanent electrical and mechanical connection
25. According to IPC-A-610, a 'process indicator' is best described as: → An anomaly that does not affect form, fit, or function but warrants monitoring
26. Why is it important to have an accurate stencil for solder paste application in PCB assembly? → To apply the correct amount of solder paste to the pads
27. What is the importance of a controlled environment during PCB assembly? → To maintain the quality and integrity of components and prevent defects
28. For IPC-A-610 Class 3, what is the acceptability status of a pinhole or blowhole in a solder joint? → Defect
29. What defect is described as solder that forms a sharp peak or spike projecting from a solder joint? → Solder icicle (solder spike)
30. What does 'impedance stack-up' refer to in multi-layer PCB design? → The arrangement of signal, plane, and dielectric layers to achieve target trace impedances