Vibration measurement for electronics and devices

Understanding and controlling the dynamic behavior of parts, components, circuit boards and assemblies is crucial for high-performance, high-quality, safe and robust products. In vibration tests, components excited by a shaker are examined with an Optomet laser Doppler vibrometer, for example. This enables manufacturers to identify potential weaknesses in the development process at an early stage and to increase the reliability of their products. However, natural vibrations can also be determined, for example, to identify disturbing sources of noise and then dampen or eliminate them constructively.

Every household has a variety of electrical devices such as electric hand mixers or power drills. In addition to a functionality and ease of use, the vibration or acoustic signature during use may influence consumer reviews and plays a major role in the final purchase decision. The customer’s poor subjective perception of the vibration and acoustic quality may even translate into poor perception of overall product quality.

Ergonomic and health criteria play a very important role, especially for professional users of rotating or striking hand machines. The machine vibrations are transmitted through the palm of the hand and the fingers into the hands and arms and cause hand-arm vibrations. With long-term exposure, these can lead to chronic complaints or illnesses, such as Raynaud's syndrome, also known as “white finger disease”.
Scanning laser Doppler vibrometers from Optomet are very well suited to record the frequencies and amplitudes of all relevant vibrations. Thanks to the advanced infrared laser technology (SWIR), meaningful vibration measurements are possible even on rough and rotating surfaces such as saw blades, cutting or grinding wheels. The investigations make the spread of vibrations on the tool visible and, in cooperation with model calculations, provide the necessary information for suitable structural changes, such as damping or decoupling, which can reduce the vibration levels experienced by the user.

In order to make electric shavers more effective and comfortable, contactless measurements are carried out on individual blades and on the handle. The influence of the battery charge level on the movement of the blades over the skin can also be determined. The manufacturer gains a deep insight into the operational behavior of his product, can increase the development processes efficiency and thus increase the competitiveness of its products.

OLED displays have a considerably simplified layer structure than LCD displays. Due to the elimination of background lighting, polarization films, filters etc., the actual display becomes thin enough to also serve as a speaker membrane, excited to vibrate by actuators installed behind it. This improves the listening experience with TVs and permits an enlargement of the display on smartphones because the earphone is eliminated. Optomet laser vibrometers are used to characterize display vibrations to improve designs and performance.

A printed-circuit board carries electronic components and interconnects them over multiple circuit levels in some cases. If the PCB is exposed to dynamic loads, e.g. in an engine control unit, this mechanical stress can result in damage on components, the PCB or the solder joints and may even cause a total failure of the electronics.

With scanning laser Doppler vibrometers from Optomet, the operating deflection shapes (ODS) of the PCB and also of the individual components can be measured directly. This provides manufacturers with deep insight into the behavior of their products and enables them to optimize the design to avoid critical failures.

Laser vibrometers can also be used for the final inspection. The non-contact measurement method of laser Doppler vibrometry can avoid application errors that can occur in contact test methods. For example, the inconsistent contact pressure of traditional sensors has an influence on the measurement. This affects the decision whether a test object meets the quality criteria, which are conservatively designed due to the measurement uncertainty, or not. As a result, the number of rejected parts can be reduced through better and more precise control procedure. The lasers used in the SWIR vibrometers from Optomet have a lifespan of more than ten years in continuous operation (24/7), which reduces the downtime of the production lines and maintenance costs. Several measuring heads can easily be connected to a single vibrometer and the individual channels can be read out separately.

Manufacturers of smartphones are systematically improving their products and are looking for new, innovative ideas. Laser vibrometers from Optomet help with the development of audio, camera or haptic solutions, with new ultrasonic fingerprint sensors or for using the display as a speaker. In manufacturing, Optomet laser vibrometers are permanently used to monitor ultrasonic welding and bonding processes or help with the set-up of machinery.

Optomet laser Doppler vibrometer are also essential for product testing. Before a product is qualified for mass production, potential structural weaknesses must be identified and eliminated. Laser Doppler vibrometers by Optomet enable the manufacturer to identify such weaknesses and take necessary actions in advance, minimizing potential rejects.

Further application areas

Electronics - Vibration of Components

Household Appliances and Power Tools

Practical Example

OLED Displays

Vibration Analysis of a Printed Circuit Board (PCB)

Quality Control

Smartphones

High frequency scanning measurement