Resistors are one of the fundamental building blocks of electronic circuis.
Resistors are electronic components that resist the flow of electrical current in a circuit. They allow a controlled amount of current for a given voltage and prevent other components, such as transistors and LEDs, from drawing too much electricity and burning out.
Surface Mounted and Laser Trimmed
Z-AXIS works with resistors that come in many different styles, sizes, and wattages. Most are surface-mounted, which means we solder them directly to the surface of a printed circuit board. Often, these surface-mounted parts are made by applying a resistive slurry to a piece of ceramic that is then laser-trimmed.
Evidence of laser-trimming isn’t visible to the naked eye, but we can see it with our X-ray equipment. Resistor manufacturers use this finishing process to achieve tolerances of 1% or less. The tolerance percentage determines the maximum allowable variation in resistance, which is measured in Ohms.
Thin Film Resistors
Z-AXIS also works with thin film resistors that are made by depositing a very thin layer of metal onto a piece of ceramic or a silicon wafer under vacuum. The silicon wafers are extremely flat and can support nanometer-sized features,. They’re also laser-trimmed to achieve tight tolerances.
Thin film resistors are called thin because the thickness of their film is usually equivalent to the wavelength of green light. That’s about 500 nanometers. By contrast, thick film resistors have a film that is typically one or two-thousandths of an inch thick. That’s about half the thickness of a sheet of paper.
Large vs. Small Resistors
Large resistors that can handle 25 or 50 watts are wire wound. They consist of a ceramic insulator that’s wrapped in a resistive wire, often nichrome, and then painted to exclude moisture, dust, and contamination. Yet the trend is toward smaller resistors because electronics are getting smaller.
Today, the most popular resistor size is probably the 0603. They’re only about sixty thousandths by thirty thousandths of an inch. These resistors are shipped on 5,000-piece reels that we inventory and then load into our pick-and-place machines.
Printed Circuit Board (PCB) Assembly
During PCB assembly, it’s the resistor end caps that are soldered to the circuit board. Large 600-watt resistors are also bolted to an aluminum chassis for heat dissipation. These large components are considerably more expensive than low-wattage resistors that each cost a fraction of a cent.
From the cell phone you carry in your pocket to the power supplies that Z-AXIS manufacturers here in upstate New York, resistors are used in virtually all electronic devices. No matter their size, style, or wattage, resistors are one of the fundamental building blocks of circuits.
Electronic Design and Manufacturing
Are you looking for electronic design and manufacturing services all under one roof? From prototyping to production, we’re ready to help. Contact Z-AXIS.