# Brief Introduction to Integrated Circuits

As miniature electronic devices or components, integrated circuits (ICs) occupy a pivotal position in modern electronics. Via dedicated semiconductor processes, components including transistors, resistors, capacitors, inductors and interconnect wiring required for a complete circuit are fabricated onto one or multiple semiconductor wafers or dielectric substrates, before being encapsulated inside a package to form a compact microstructure with predefined circuit functions. All components are structurally integrated as a single unit, enabling groundbreaking miniaturization, lower power consumption, smarter functionality and superior reliability for electronic parts. IC is the standard abbreviation used in circuit schematics. The IC was co-invented by Jack Kilby, who developed the germanium (Ge)-based prototype, and Robert Noyce, creator of the silicon (Si)-based integrated circuit. Nowadays, silicon-based ICs dominate the global semiconductor industry.

From a technical perspective, IC fabrication involves sophisticated sequential processes: thermal oxidation, photolithography, impurity diffusion, epitaxy and aluminum evaporation. These steps integrate all semiconductor devices, passive components and connecting wires onto a tiny silicon die, followed by packaging. Common package formats include metal can, flat pack and dual in-line package (DIP) to accommodate diverse application requirements.

## Key Features of Integrated Circuits

Also referred to as microcircuits, microchips or simply chips, an IC miniaturizes electronic circuitry (predominantly semiconductor devices plus passive components) and is typically manufactured atop semiconductor wafers.

Circuits fabricated directly on wafer surfaces are categorized as thin-film ICs. By contrast, hybrid thick-film ICs are assembled from discrete semiconductors and passive components mounted onto substrates or printed circuit boards. This article focuses primarily on monolithic ICs, namely thin-film integrated circuits.

ICs boast prominent merits: compact size, light weight and fewer leads/solder joints, facilitating easy installation and space savings. They deliver long service life, high reliability and stable performance under harsh operating environments. Low production costs enable mass-volume manufacturing and outstanding cost-performance. Widely deployed in consumer electronics such as radios, TVs and computers, ICs are also indispensable for military equipment, communications and remote control systems. Adopting ICs boosts assembly density dozens to thousands of times compared with discrete transistor circuits and drastically improves equipment runtime stability.

Emerging in the late 1950s and 1960s, IC production relies on oxidation, photolithography, diffusion, epitaxy and aluminum metallization to integrate full circuitry onto silicon dies prior to encapsulation. The overall IC industry chain spans chip design, wafer fabrication, packaging and testing, underpinned by processing equipment, proprietary manufacturing techniques and iterative design innovation.

China’s integrated circuit industry originated in the 1960s and has evolved across three major development phases:

### 1965–1978

Centered on computing and defense procurement, the sector prioritized logic circuit development and laid initial industrial infrastructure alongside supporting equipment, instrumentation and raw material supply chains, building foundational domestic IC manufacturing capability.

### 1978–1990

Second-hand semiconductor equipment was imported from the US to upgrade production capacity amid industrial consolidation. Focus shifted toward consumer electronics, successfully realizing localized IC production for color television sets to satisfy domestic market demand.

### 1990–2000

Flagship national projects 908 and 909 prioritized EDA/CAD breakthroughs, key technical research and construction of northern R&D bases to serve the booming information industry, fueling substantial industrial and technological upgrades for domestic IC manufacturing.

The integrated circuit industry covers the full value chain, encompassing IP licensing, EDA software, wafer foundry, packaging & testing, semiconductor equipment and specialty materials markets. Driven by mobile internet, triple-play convergence, multi-screen interaction and smart hardware, the sector is no longer reliant solely on CPU and memory chips and enjoys diversified market opportunities fueled by innovative business models. Decades of accumulated technical expertise, market expansion experience and resource integration capabilities have laid solid groundwork for robust domestic industrial growth over the next five to ten years.

## Basic Guidelines for IC Testing

1. Master operating principles of target ICs and peripheral circuits before testing

Prior to maintenance and troubleshooting, technicians must fully grasp IC functionality, internal architecture, key electrical parameters, pin definitions, nominal pin voltage, waveform characteristics and peripheral circuit operation to accurately diagnose faults.

2. Prevent short-circuit between pins during measurement

When measuring voltage or probing waveforms with oscilloscope probes, avoid accidental pin shorting; take readings on connected peripheral PCB traces instead. Instant short-circuits can permanently damage ICs, especially static-sensitive CMOS chips housed in flat packages.

3. Ban grounded test instruments from direct contact with hot-chassis audio/TV equipment lacking isolation transformers

Never connect grounded test gear to televisions, audio players or video devices without power isolation transformers. Even devices with built-in power transformers require chassis voltage verification first; live chassis risks short-circuit and cascading IC damage.

4. Verify soldering iron insulation performance

Never solder with an electrically live iron. Ground the iron casing where possible; a low-voltage 6–8V soldering iron is strongly recommended for MOS chips susceptible to electrostatic damage.

5. Ensure high-quality soldering

Secure reliable joints free from solder accumulation or voids that cause cold solder joints. Limit each soldering operation to under three seconds using a 25W internal-heat iron. Post-soldering, check all pins with an ohmmeter for bridging before powering on the circuit. Poor solder contact leads to intermittent circuit failures.

6. Avoid premature confirmation of IC failure

Most ICs employ direct-coupled circuitry; abnormal component voltages do not always stem from defective ICs. Certain latent faults cause no DC voltage deviation even with functional degradation, requiring comprehensive multi-angle troubleshooting.

7. Use high-input-impedance multimeters for DC pin voltage measurement

Select multimeters with input impedance above 20 kΩ/V for DC pin measurement; low-impedance meters draw stray current and introduce significant reading inaccuracies.

8. Proper thermal management for power ICs

Power integrated circuits must be fitted with specified heat sinks and prohibited from running at full rated load without thermal dissipation to prevent overheating-induced performance degradation or premature breakdown.

9. Rational wiring for external repair components

When using discrete external parts to replace faulty internal IC circuitry, adopt compact components and optimized routing to minimize stray parasitic coupling; pay extra attention to grounding layout between audio power amplifiers and preamplifier stages to suppress electromagnetic interference.

As the core backbone of modern electronics, integrated circuits underpin all electronic engineering fields. Mastering IC fundamentals, industrial evolution and standardized testing practices is essential for electronics engineers, hobbyists and industry practitioners. With sustained technological advancement, China’s integrated circuit sector is poised to achieve remarkable milestones in the coming years.