Chip Resistors-Surface Mount

Part Number	Description / PDF	Quantity
WR08W2R87FTL Walsin Technology	RES 2.87 OHM 1% 1/8W 0805	0
WR02W3R65FAL Walsin Technology	RES 3.65 OHM 1% 1/20W 0201	0
WR12W7R50FTL Walsin Technology	RES 7.5 OHM 1% 1/4W 1206	0
WR06X1004FTL Walsin Technology	RES 1M OHM 1% 1/10W 0603	7784
WR12X6650FTL Walsin Technology	RES 665 OHM 1% 1/4W 1206	0
WR02W1R69FAL Walsin Technology	RES 1.69 OHM 1% 1/20W 0201	0
WR02W2004FAL Walsin Technology	RES 2.00M OHM 1% 1/20W 0201	0
WR12X6800FTL Walsin Technology	RES 680 OHM 1% 1/4W 1206	9100
WR08W4R22FTL Walsin Technology	RES 4.22 OHM 1% 1/8W 0805	0
WR08W7R68FTL Walsin Technology	RES 7.68 OHM 1% 1/8W 0805	0
WR12W1R02FTL Walsin Technology	RES 1.02 OHM 1% 1/4W 1206	0
WR08X15R0FTL Walsin Technology	RES 15 OHM 1% 1/8W 0805	0
WR08W2744FTL Walsin Technology	RES 2.74M OHM 1% 1/8W 0805	0
WR12W9534FTL Walsin Technology	RES 9.53M OHM 1% 1/4W 1206	0
WR08W1214FTL Walsin Technology	RES 1.21M OHM 1% 1/8W 0805	0
WR12X2670FTL Walsin Technology	RES 267 OHM 1% 1/4W 1206	0
WR08W4754FTL Walsin Technology	RES 4.75M OHM 1% 1/8W 0805	0
WR12X1330FTL Walsin Technology	RES 133 OHM 1% 1/4W 1206	0
WR12W3R83FTL Walsin Technology	RES 3.83 OHM 1% 1/4W 1206	0
WR02W3R57FAL Walsin Technology	RES 3.57 OHM 1% 1/20W 0201	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