Electronic Farts for Smartphones
High-Density Components Keep Pace with Innovation
PARTS MANUFACTURERS HAVE STEPPED UP IN REINFORCINGTECHNICAL FEATURES OF ELECTRIC COMPONENTSAND MOUNTINGPROCESS EMPLOYED TO MEET THE EVOLVING REQUIREMENTSOF SMARTPHONES, WHICH CONTINUE TO
ADVANCE IN TERMS OF TECHNOLOGIES AND FUNCTIONS.
In order to mount many functions in a small board area,high-density mounting of circuit components for smart-phones has been progressing. For this reason, in circuitcomponents incorporated in smartphones, the percentageof ultrasmall chip components has been increasing further.
Smartphones have been polarized into smaller models and relatively large products. The common trend for both models is the advancement of technologies for high functionalities. For this reason, mounting technology employs high density process, printed wiring boards (PWBs) have become finer, and onthe whole, downsizing of chip components that are mounted on PWBs advances.
Finer Circuits, High Density Mounting
At present, as PWBs, build-up multilayer boards are used. The number of layers of PWBs and specifications for achieving finer boards vary from low-cost models to high-function models. For high-functional models, PWBs with 10 or more layers and line-space of 50pm/50|im or finer have been supplied. In the future, for the formation ofcircuits,the modified semi-additive process (MSAP), a method to form circuits using plating, will be adopted, replacing the etching method, which has conventionally been used. With this, circuits will become dramatically finer,and components mounting technology will become high density.
As many as 800 multilayer ceramic capacitors (MLCCs) and around 400 chip resistors are used in a high-end model. These components come in various sizes depending on capacitance, resistance, rated power and rated voltage.
In order to promote high-density mounting, the use of small MLCCs with large capacitance values and small chip resistors with high voltages has been increasing. For this reason, the trend is to reduce the number of 1608-size to 1005-size coponents and to increase in the ratio of ultrasmall chips, such as 0603-size and 0402-size components. Reduced costs of ultrasmall chips also contribute to this trend.
photo 1: In smartphones, the ratio of 0402-size and 0603-size components
has been increasing.
Support High-Speed Transmission
Connection and conversion components manufacturers have been stepping up the development of new products, pursuing smaller and thinner products, support for high-speed transmission and rapid charging, and improved usability, for mobile devices, such as smartphones and wearable devices.
The development race of low-profile, narrow-pitch, and space-saving board-to-board connectors and connectors for flexible printed circuits (FPCs), which are used as internal connectors in smartphones, has intensified. The lineup of 0.35mm-pitch board-to-board connectors and FPC connectors with shield has been expanding.
Furthermore, recently, pursuing narrower pitch, mass production of 0.3mm-pitch board-to-board connectors for high-end smartphones is beginning on full scale.
With connectors for interface, manufacturers increasingly embark on the development of new standard USB Type-C-compliant connectors. USB lype-C connectors enable reversible mating, which enables insertion and extraction regardless of the plug's front and rear directions. They support high-speed transmission of up to lOGbps and confonn to USB Power Delivery (USB PD) standard.
With the growing trend of high-end smartphones to have waterproof properties, manufacturers have been earnestly developing jacks that have passed advanced waterproof technology as well as waterproof interface connectors.
Meanwhile, there has been a growing interest in developing slide switches and detection switches that are not only ultrasmall but are also highly reliable and possess longer life cycle. Aside from good operation feel, development of operation switches with full waterproof specification are also becoming active.
With conversion components, wireless headphones to be packed in smartphones have been developed, zeroing in on the
downsizing of microelectromechanical systems (MEMS) microphones and enhancing its sound quality.