Chip Resistors-Surface Mount

Part Number	Description / PDF	Quantity
WR12W3404FTL Walsin Technology	RES 3.40M OHM 1% 1/4W 1206	0
WR12X6190FTL Walsin Technology	RES 619 OHM 1% 1/4W 1206	0
WR04X223 JTL Walsin Technology	RES 22K OHM 5% 1/16W 0402	20000
WR02W6R98FAL Walsin Technology	RES 6.98 OHM 1% 1/20W 0201	0
WR12X6490FTL Walsin Technology	RES 649 OHM 1% 1/4W 1206	0
WR12X9092FTL Walsin Technology	RES 91K OHM 1% 1/4W 1206	0
WR12X2872FTL Walsin Technology	RES 28.7K OHM 1% 1/4W 1206	0
WR12X27R4FTL Walsin Technology	RES 27.4 OHM 1% 1/4W 1206	0
WR08X330 JTL Walsin Technology	RES 33 OHM 5% 1/8W 0805	10000
WR12X1910FTL Walsin Technology	RES 191 OHM 1% 1/4W 1206	0
WR02W3014FAL Walsin Technology	RES 3.01M OHM 1% 1/20W 0201	0
WR04X4700FTL Walsin Technology	RES 470 OHM 1% 1/16W 0402	8700
WR12X3010FTL Walsin Technology	RES 301 OHM 1% 1/4W 1206	0
WR12X4643FTL Walsin Technology	RES 464K OHM 1% 1/4W 1206	0
WR08W5R62FTL Walsin Technology	RES 5.62 OHM 1% 1/8W 0805	0
WR08X1503FTL Walsin Technology	RES 150K OHM 1% 1/8W 0805	9395
WR12X8663FTL Walsin Technology	RES 866K OHM 1% 1/4W 1206	0
WR12X153 JTL Walsin Technology	RES 15K OHM 5% 1/4W 1206	10000
WR12X4321FTL Walsin Technology	RES 4.32K OHM 1% 1/4W 1206	0
WR12X1960FTL Walsin Technology	RES 196 OHM 1% 1/4W 1206	0

Chip Resistors-Surface Mount

1. Overview

Surface Mount Chip Resistors (SMD Resistors) are passive electronic components designed to limit current flow and divide voltages in printed circuit boards (PCBs). As key elements in Surface Mount Technology (SMT), they enable high-density PCB layouts and automated manufacturing. Their miniaturized footprint and reliability make them essential for modern electronics, including smartphones, automotive systems, and industrial equipment.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Thick Film Resistors	Cost-effective, standard tolerance ( 1%-5%), power ratings up to 1W	Consumer electronics, power supplies
Thin Film Resistors	High precision ( 0.01%), low noise, stable temperature coefficients	Medical devices, precision instrumentation
Power Resistors	High power dissipation (up to 3W), robust thermal management	Motor drives, EV battery management systems
Network Resistors	Multiple resistors in single package, matched temperature coefficients	Digital circuits, memory modules
Wirewound Resistors	High inductance, precise low-resistance values	Audio amplifiers, industrial control systems

3. Structure and Composition

Typical SMD resistors consist of: - Ceramic substrate (Alumina, 96% Al₂O₃) - Resistive layer (Ruthenium oxide for thick film, Nichrome for thin film) - Termination electrodes (Ni/Sn or Ag/Pd metallization) - Protective coating (Epoxy or glass encapsulation) Standard packages follow EIA dimensions (e.g., 0402, 0603, 0805).

4. Key Technical Specifications

Parameter	Description	Importance
Resistance Range	1 to 10M (film), 0.1 to 100k (power)	Determines current control capability
Tolerance	0.01% (precision) to 5% (general)	Impacts circuit accuracy
Power Rating	0.05W to 3W @ 70 C	Defines thermal dissipation limits
TCR	5ppm/ C (thin film) to 200ppm/ C	Affects stability over temperature
Operating Temp	-55 C to +155 C	Defines environmental reliability
Voltage Coefficient	<0.1ppm/V	Ensures voltage stability

5. Application Fields

Consumer Electronics: Smartphones, wearables, IoT devices
Automotive: ADAS sensors, battery management systems, ECUs
Industrial: PLCs, motor drives, power converters
Telecom: 5G base stations, optical transceivers
Medical: Diagnostic equipment, implantable devices

6. Leading Manufacturers and Products

Manufacturer	Representative Series	Key Features
Yageo	CRCW Series	0.05W-1W, 0.1% tolerance
Vishay	CRCWE Series	Thin film, TCR 25ppm/ C
ROHM	MCR Series	Power resistors up to 2W
Ohmite	PWR Series	High-power 3W devices
Bourns	CRCU Series	Network resistors with 8-element arrays

7. Selection Recommendations

Consider: - Required resistance tolerance and power rating - Operating temperature range (automotive needs -40 C to +125 C) - Package size constraints (e.g., 0402 for mobile devices) - Long-term stability requirements (medical applications prefer thin film) - Cost vs. performance trade-offs (consumer vs. industrial use) Example: For smartphone power management, select 0603 thick film resistors with 1% tolerance and 125 C rating.

8. Industry Trends

Key trends include: - Miniaturization: Development of 0201 and 01005 packages - Higher precision: Sub-0.01% tolerance thin film resistors - Enhanced thermal management: New materials for power densities >1W/mm - Automotive growth: AEC-Q200 qualified parts for EVs - Smart manufacturing: AI-driven resistor selection tools - Sustainability: Lead-free and halogen-free material adoption