What do you need to know about SMD resistors and resistor assemblies and where to buy them in Kiev and Ukraine?

Millions of SMD resistors are used to make electronic devices, from mobile phones to TVs and MP3 players. The small size allows them to be placed in a relatively small interior space. However, they have many disadvantages. Most importantly, is the high level of energy consumption.

Structure of chip resistor

The resistor chip is rectangular. There are metallized areas on both sides of the rectangle. This gives them the ability to touch the PCB after soldering.

The resistor itself consists of a ceramic substrate on which a film of metal oxide is deposited. The actual thickness and length of the film determine the resistance of the component. Since SMD resistors are made from metal oxides, they are very reliable and usually have low internal resistance.

The substrate consists of ceramic elements with a high alumina content. This provides very good insulation on which the resistive element is mounted.

Connections also play an important role. They must establish reliable contact between the resistive element and the resistor chip and provide a high level of conductivity. This is achieved by using a nickel-based interlayer and an outer tin layer to ensure good solderability.

SMD resistors are available in various standard sizes. Technology will not stand still, so the size of radio components is constantly decreasing. In 2014, the common size for SMD resistors was 0.05mm.

Characteristics of resistors and resistor assemblies

SMD resistors and resistor assemblies    are manufactured by many companies. Therefore, the characteristics of elements with the same rating can be very different. Pay attention to a few basic parameters.

Rated power requires special attention. For surface mount resistor designs, the power dissipation level is less than the wired assembly power level.

Because SMD resistors are made using metal oxide films, they have relatively close tolerances. In addition, the most common deviations are 5%, 2% and 1%. For special parts, the value can be 0.5 and 0.1%.

Chip resistors usually have a good temperature coefficient. The most common pulse modulation values are 25, 50 and 100 units at 1 C.