Inductor Guide

Anecdote of inductor development [No.1] Birth of the LQH and its peculiar shape

03/28/2012

This story is from way back. Thirty-some-odd years ago, we received our first request for full-on mass production of LQH wire wound chip inductors from a small affiliate company in Hokuriku, Japan. Today, many inductor manufacturers are producing the LQH series, but at the time, Murata was the only manufacturer to develop and produce inductors with this shape.

The archetypes of the current LQH were the first-generation 2010 size (5.0 mm × 2.5 mm) and second-generation 1210 size (3.2 mm × 2.5 mm) square-shaped wire wound chip inductor produced at the time. Normal ferrite cores in wire wound inductors were round-cut drum cores. Murata used a different strategy, developing our own unique product including our choice of material to create an inductor with a square exterior and square single-mold ferrite core. Not only that, but we eschewed the common electrode geometry that used metal frame terminals and built the electrodes directly into the ferrite core, employing our own unique method for connecting the wire wound terminal. Hence was born a chip inductor with a slightly different shape.

Interestingly, this slightly different inductor shape was its strength. From the first generation, we expanded the lineup to create a number of products that varied in size and performance, and developed it into the current LQH series. After that, Murata adopted the chip inductor design concept of "Simple is Best." At the beginning, Murata was only an emerging newcomer among inductor manufacturers. We knew that we had no chance competing with the then long, established inductor manufacturers if we made the exact same product with the exact same construction method. We trimmed off all the elements we felt were excess to make the absolutely simplest structure possible. That was the starting point of the LQH. We would often say to each other, "let's overtake those longtime manufacturers and leave them in our dust."

We later added many improvements. No, we did not continue making the exact same product for over 30 years. We periodically revised and improved the inductors to respond to customer demands and align with their applications. We produced ferrite cores with a number of different materials and shapes and developed various techniques for directly mounting electrodes. We were thus able to create many new products with new capabilities.

However, we never strayed from our basic design of a "Simple is Best" structure. If it's simple, it's easy to make. If it's simple, it's easy to mechanize. And if it's simple, it's easy to speed up. Perhaps Murata is the only company right now producing wire wound chip inductors that are "Made in Japan."