Module 19: Soldering and Construction
Every circuit in this course eventually has to be built. Good construction is what turns a correct schematic into equipment that works first time, keeps working for years, and does not radiate or pick up interference. This module covers the practical skills: choosing and using a soldering iron, solder and flux, making and inspecting reliable joints, desoldering and rework, building with through-hole and surface-mount parts, prototyping on copper-clad board, laying out circuit boards for fast and mixed signals, decoupling and grounding, and sizing wire and fuses for the current it must carry.
- Choose a soldering iron, tip, solder and flux for each job
- Make reliable through-hole and surface-mount joints and recognize defective ones
- Desolder and replace parts without lifting pads
- Build RF and analog prototypes using Manhattan and ugly construction
- Apply layout rules for RF, high-speed digital, mixed-signal and switching circuits
- Decouple ICs and lay out ground planes correctly
- Size wire, PCB traces and fuses for current and voltage drop
Module Overview
The first five lessons are about soldering itself: the tools, the materials, the technique, how to tell a good joint from a cold or cracked one, and how to remove solder and parts cleanly when something has to be repaired or changed.
The next three lessons cover construction methods: through-hole assembly, surface-mount assembly by hand, and Manhattan and ugly construction on copper-clad board — the fastest way to build a high-performance prototype without waiting for a circuit board.
The final three lessons cover the physical design decisions that decide whether a circuit works as drawn: PCB layout rules for RF, fast digital, mixed-signal and switching circuits; decoupling and grounding on circuit boards; and choosing wire and trace sizes, voltage drop limits and fuses for projects, vehicles and solar systems.
Lessons
Soldering Iron Selection
Soldering Iron Selection
Iron types, wattage and thermal reserve, temperature control, hot-air stations, tip shapes, and a quick reference for common jobs.
Solder Types and Flux
Solder Types and Flux
Leaded and lead-free alloys, RoHS, specialty solders, flux types and activity, and choosing solder diameter.
Soldering Technique
Soldering Technique
The step-by-step method for reliable joints, temperature and timing, solder quantity, common mistakes, and difficult joints.
Good Joints vs Cold Joints
Good Joints vs Cold Joints
What a good joint looks like, IPC classes, cold and fractured joints, bridges, lifted pads, and inspection.
Desoldering
Desoldering
Braid, vacuum pumps, desoldering stations and hot air, removing ICs and SMD parts, and protecting nearby components.
Through-Hole Construction
Through-Hole Construction
Lead forming, assembly order, orientation and polarity, soldering and trimming, sockets and heat-sensitive parts.
Surface Mount Construction
Surface Mount Construction
SMD packages and codes, tools, chip components, SOT and SOIC parts, drag soldering, paste and hot air.
Manhattan and Ugly Construction
Manhattan and Ugly Construction
Copper-clad ground-plane construction, pad islands, dead-bug building, layout principles and an oscillator project.
High-Speed and Mixed-Signal Layout Rules
High-Speed and Mixed-Signal Layout Rules
Ground planes and return paths, placement, microstrip, vias, shielding, fast digital, mixed-signal and switching layout.
Decoupling and Grounding on PCB
Decoupling and Grounding on PCB
Bypass capacitors and their placement, self-resonance, bulk decoupling, ground planes and ferrite bead filtering.
Wire Gauge and Current Capacity
Wire Gauge and Current Capacity
AWG and metric sizes, ampacity, voltage drop, PCB trace width, fusing, DC connectors, and vehicle and solar wire.