Part 5. Electrical Test (ICT, FCT, boundary scan)
Testing is the financial and technical firewall that stops bad product from shipping. This chapter covers the layered electrical test strategy required to achieve high coverage, speed, and reliability.
We detail the three main pillars of modern board testing:
- Structural Test (ICT): The fastest way to find common flaws like opens, shorts, and wrong component values, heavily dependent on fixture design and maintenance.
- Boundary Scan (JTAG): A mandatory technology for accessing fine-pitch and hidden BGA pins without physical probes, which also enables in-line programming.
- Functional Test (FCT): The final validation, confirming that the board actually performs its intended job, guided by the product's golden unit.
Get this right, and you maximize yield, secure quality, and ensure every failure is traceable for fast repair.
2.22 Strategy & Coverage
Electrical test is not an option; it is a financial and technical firewall. The goal of a well-de...
2.23 ICT & Fixture Design
In-Circuit Test (ICT) is the fastest, most effective way to eliminate 90% of all common structura...
2.24 Boundary Scan Essentials (JTAG)
Boundary Scan, formalized as IEEE 1149.1 (JTAG), is a mandatory technology for structural testing...
2.25 Functional Test Design
Functional Test (FCT) is the final stage of the electrical quality strategy, confirming that the ...
2.26 Data Logging & Repair Tickets
Data logging and the formal Repair Ticket system are the nervous system of modern electronics man...