Product Introduction Videos

Welcome to SSM USA’s brief technical presentation on thin film chip resistors.

This presentation will provide an overview of Susumu’s thin film chip resistors, including a discussion of
the differences between thin film resistors and thick film resistors, the characteristics of thin film resistors
and a brief introduction of Sususmu’s two types of thin film chip resistors.

There are two types of chip resistors, thin film resistors and thick film resistors. While thick film is
composed of a screen printed metal particle resin composite, thin film is deposited by a vacuum process
such as sputtering or CVD. Due to this difference, thin film resistors are generally superior in performance
to thick film resistors. Thick film resistors are more popular and common as general purpose resistors.
Thin film resistors are used for more specialized areas that require higher performance.

Thin film resistors are very precise and boast very tight tolerances such as 0.02%. The temperature
coefficient of resistance, which can be as low as 5ppm, is also excellent. Thin film resistors also have
much less current noise than thick film resistors and excel in performance at high frequencies even those
over 1 GHz.

One of the reasons that thin film performs better is that, due to its thinness, the laser trimming trace is
much cleaner than in thick film materials. This provides advantages to thin film in resistor tolerance and
other characteristics. Thick film performance is affected by the unclear definition of laser trace, melted
composite residue and micro-cracks created by the laser.

Thin film is a continuous metal built atom by atom by using a vacuum deposition process, while thick film is
made of screen printed metal particles suspended in organic compounds. Naturally, electric current runs
smoothly and evenly through the thin film but is unable to do so through the thick film. This is the major
reason that thin film has much less current noise.

This illustrates one example of the noise data. The light blue line is the noise of the power supply itself. As
Susumu’s RR series thin film resistor (red line) stays close to the power supply noise level, the blue line,
the thick film resistor, demonstrates a much higher noise level. This difference is most prominent between
500Hz and 10KHz.

At higher frequencies, the electric current begins flowing only at the surface of the conductive materials
exhibiting the phenomenon known as skin effect. This changes the resistance of thick film materials or
bulk materials significantly while the thin film’s resistance remains the same because it has only “skin” to
begin with.

As previously discussed, thin film resistors excel in performance when compared to thick film resistors.
Susumu offers two types of thin film resistors. The conventional RR series has all the advantages of the
thin film resistors described so far. The latest RG series has been developed to provide enhanced
performance and to match the reliability of thick film resistors.

The major difference between the RR and the RG series is the passivation material. The RR series uses
organic compounds such as epoxy resin as the passivation material while the RG series uses inorganic
passivation material deposited by vacuum deposition. Another major difference is that in the RG,
trimming is done after the passivation film is deposited, making the contamination prone laser trimming
process a completely clean process.

Inorganic passivation is virtually a hermetic seal, providing the RG series with unsurpassed reliability even
when compared to our own RR series which is probably the most reliable conventional thin film chip
resistor in on the market. The new passivation technology also enhances electrical performance. The RG
series offers better tolerance, TCR, and operating temperature range when compared to the RR series.
The RR series is sufficient for regular application but if the application requires extra accuracy and strong
environmental protection, the RG series is the answer.

This chart illustrates one example of the RG series’ unprecedented reliability. When exposed to a
temperature of 155oC, even thick film resistors start drifting at 100 hours. The RG series does not show
any change at 3000 hours! This is the reason that the RG is the choice for automotive electronics
applications that require the higher temperature tolerance and a higher operating temperature.

This is a brief summary of the RG series characteristics. In our accelerated stress test using over 100
thousand products, the fit rate of the RG series is currently calculated as 0.011 fit, which means that only
11 pieces out of 1 trillion pieces may fail.

Susumu also offers resistor networks using the same technology as the RG series. Consider this package
as multiple RGs built into one chip. Because these multiple elements are processed side by side
simultaneously, the matching tolerance in resistance and TCR are unprecedented.

In summary, the material and technology used to create thin film chip resistors provide them with
characteristics such as tighter tolerance, lower TCR, low noise and better high frequency performance,
which are all significant advantages over thick film resistors.
Susumu offers two types of thin film resistors, the conventional RR series and the new RG series. The RG
series was created to target the industry segment that requires extreme accuracy and reliability. The RG
series offers this extreme reliability without compromising thin film performance. Resistor networks, the RM
series, using the same technology as the RG series are also available. This concludes this brief technical
presentation on Susumu’s thin film chip resistors. Thank you for your interest.