Chip Resistors-Surface Mount

Part Number	Description / PDF	Quantity
WR08X331 JTL Walsin Technology	RES 330 OHM 5% 1/8W 0805	3785
WR12X7152FTL Walsin Technology	RES 71.5K OHM 1% 1/4W 1206	0
WR12W4R32FTL Walsin Technology	RES 4.32 OHM 1% 1/4W 1206	0
WR08W8664FTL Walsin Technology	RES 8.66M OHM 1% 1/8W 0805	0
WR02W4R22FAL Walsin Technology	RES 4.22 OHM 1% 1/20W 0201	0
WR02W7154FAL Walsin Technology	RES 7.15M OHM 1% 1/20W 0201	0
WR12W1R58FTL Walsin Technology	RES 1.58 OHM 1% 1/4W 1206	0
WR12X1741FTL Walsin Technology	RES 1.74K OHM 1% 1/4W 1206	0
WR08W1054FTL Walsin Technology	RES 1.05M OHM 1% 1/8W 0805	0
WR02W3R01FAL Walsin Technology	RES 3.01 OHM 1% 1/20W 0201	0
WR08W2494FTL Walsin Technology	RES 2.49M OHM 1% 1/8W 0805	0
WR12X4990FTL Walsin Technology	RES 499 OHM 1% 1/4W 1206	0
WR02W1874FAL Walsin Technology	RES 1.87M OHM 1% 1/20W 0201	0
WR12X20R0FTL Walsin Technology	RES 20 OHM 1% 1/4W 1206	0
WR08X4702FTL Walsin Technology	RES 47K OHM 1% 1/8W 0805	4846
WR12X5493FTL Walsin Technology	RES 549K OHM 1% 1/4W 1206	0
WR08W2944FTL Walsin Technology	RES 2.94M OHM 1% 1/8W 0805	0
WR12W3R57FTL Walsin Technology	RES 3.57 OHM 1% 1/4W 1206	0
WR12X7320FTL Walsin Technology	RES 732 OHM 1% 1/4W 1206	0
WR12W6R34FTL Walsin Technology	RES 6.34 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