Wondering what chip resistors are? Then you are in luck because this article will answer that question in detail. Not only that, but we’ll also reveal how they are made, how they work, and the types of technology these devices use. There’s a lot to cover, so let’s get started.
What They Are
Contents
Chip resistors aka surface mount devices (SMDs) are integrated circuit devices. They are either rectangular or square. These Resistors are designed to resist the flow of electric current. They are used to regulate, safeguard, and operate circuits.
SMDs can be found in all kinds of sizes. Some are too tiny to pick up with your hands. Values such as E192 and E3 are common values you can readily find.
Surface mount devices are found in most electronic products with advanced circuitry. SMDs are known as such because they are placed directly on the electronic product’s printer circuit board. Without these resistors, there’ll be nothing regulating the current flow within the product. In such a case, the electronic product is subject to damage that can destroy it.
How They Are Made
To manufacture a chip resistor, the end connection of electrode bases is attached to the substrate of a ceramic material. To ensure that the attachment is firm, the resistor is fired. The next step is the printing or depositing of the film of a resistive material. Again, the resistor is fired.
Afterward, several layers of protective coat are used to cover the resistor. You can click here to find out more about the protective coating. Before the application of the next coat, the previous one is allowed to dry first.
The addition of these protective coatings is beneficial to the SMD and the electronic product. First of all, the protective coating protects the resistor from mechanical damage. Secondly, it prevents contaminants and moisture from affecting these devices.
Chip resistors with large surfaces are designed with a marking. When packaged these devices resemble blister rolls. They can then be used on pick-and-place electronic machines.
How They Work
Chip resistors are designed to restrict the flow of circuit current. These chip resistors sometimes are designed with a definite resistance value. This type is known as a fixed resistor.
On the other hand, the resistance value of the second group isn’t definite but is designed to operate within a range. This type is known as a variable resistor or potentiometer. Because of its passive function, a resistor only decreases voltage or current signals.
The perfect resistor is linear. In this case, the instantaneous current that passes through the SMD is proportional to the instantaneous voltage being applied. Resistors that do not operate linearly include varistors and thermistors.
In electronic circuits, these SMDs are formed into several series based on resistance value and power. Surface mount devices act as voltage dividers and shunts to control and steady voltage and current in circuits. You can visit https://eepower.com/ to learn more about shunts in circuits. They also serve as circuit-matching loads.
Chip Resistor Technology
Manufacturers can choose from different technologies when manufacturing an SMD. These different technologies have their advantages and disadvantages. The following are the most commonly used chip resistor technologies:
Thin Film
Chip resistors manufactured with this technology are made by depositing a thin metallic coating on the upper part of a ceramic substrate. Due to this design, these devices have greater resistance for a certain area. As such, they are economical and space-efficient.
The downside is that they are prone to failure. The reason for this is that they can easily heat up or be affected by water vapor. Chemical contamination is another reason that can lead to the failure of these SMDs.
Thick Film
These are made by applying the paste of a restive metal onto a base. Because of this, the resistance they provide for a certain area is usually high. Furthermore, they are cheaper when you compare them to other resistor types such as wire-wound resistors.
The disadvantage of using this technology is it produces more noise compared to thin-film resistors. Although they have similar frequency response to thin films, they are still noisy. Despite this, they are still very used in circuit units that don’t require durability and accuracy.
Foil
This technology involves the use of a metallic foil applied to a ceramic substrate. It is then photo-etched via a restive pattern. The result is a resistor with enhanced stability, low capacitance, reduced noise, and non-inductance. All these benefits are achieved without losing precision and speed. As such, these surface mount devices are in high demand.
Reading a Chip Resistor Code
These devices are usually marked with a code known as SMD Resistor Codes. The code might be made of three or four digits. The purpose of this code is to reveal the device’s resistance value.
To interpret a code with three digits, take the first two digits as a standalone number and the third digit as a standalone number. The first two digits are the significant resistance number while the third digit is the multiplier. You use the third digit to multiply the first two to get the resistance value.
For a code with four digits, take the first three digits as a standalone number and the fourth digit as a standalone number. The first three digits are the significant resistance number while the fourth digit is the multiplier. You use the fourth digit to multiply the first three to get the resistance value.
Chip Resistor Advantages
They do not take up much space in a product. Having several connections for every single component is proof of their high component density. Also, they have a simpler automated assembly and are much faster.
Because of their structured design, the PCB has fewer holes bored into it. You can visit https://www.techtarget.com/ to learn more about the Printer Circuit Board. Also, they can be on either side of the PCB. Their mechanical performance is enhanced, and they have cheap parts.
Chip Resistor Disadvantages
Their solder components can be prone to damage which happens via thermal cycling that moves potted compounds. Also, the component packages they are designed with prevent them from being installed into sockets. Furthermore, when there is a need for reassembling or repair, an expert must handle it and extensive tools are required.
Conclusion
In this article, we’ve discussed what you need to know about chip resistors. We discussed what they are, how they are made, how they work, and the technologies used in making them. We also revealed the advantages and disadvantages of these devices.