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Transistor & diode suppliers shift upmarket to spur sales

Makers of transistors and diodes are emphasizing production of MOSFETs, IGBTs, and units with better performance and higher energy efficiency to attract more orders.

China suppliers of transistors and diodes are moving upscale to buffer slowing sales growth in the low-end and midrange sectors, and escape competition in the general-purpose category. Makers are currently directing efforts toward the development of MOSFETs and insulated gate bipolar transistors or IGBTs. Although these are still dominated by Japan, the US and Europe, local manufacturers have started mass production to increase market share.

High-voltage diode
Anshan Leadsun’s 2CL73 model is a high-voltage diode with 12kV peak repetitive reverse voltage and 5mA average forward current.

Enterprises are likewise emphasizing models with better heat dissipation, lower power consumption, elevated efficiency and voltage, and enhanced signal integrity. As the technology is mature, advanced chips and materials are adopted to achieve these characteristics.

Anshan Leadsun Electronics Co. Ltd is among those that have released versions for high-voltage applications. It offers diodes, rectifier blocks and bridge rectifiers used in electrostatic precipitators, powder coating and spraying, X-ray generators and RF welders.

In addition, suppliers are launching more SMD units to meet form factor requirements in latest electronics devices. In the months ahead, many are expected to boost output of this type. Yangzhou Ark Component Imp. & Exp. Co. Ltd, for instance, is planning to raise the share of such products to 70 percent from 60 in 2010.

Manufacturers are similarly taking advantage of the growing market for portable and environment-friendly electronics to buoy up sales. They are releasing more power transistors, which are widely adopted in battery-operated devices such as laptops, mobile phones, MP3 and portable media players, and digital cameras. The variant is likewise increasingly utilized in hybrid electric vehicles, solar- and wind-power generation systems, switching power supplies, transformers, chargers and energy-saving lamps. The last is seen as a major growth catalyst, with China accounting for more than 80 percent of worldwide output.

Globally, power transistors make up the majority of the discrete components industry. In 2009, sales from the line represented more than 50 percent of the total. By 2014, the category will account for 58 percent of the $25.1 billion overall revenue for discretes based on IC Insights’ forecast.

Applications of transistors and diodes cover consumer and automotive electronics, computers and peripherals, communication and medical equipment, and electronic instruments and lighting. With increasing demand from these segments, the country’s production is expected to expand by more than 10 percent in the next few years. The local government’s Consumer Electronics Subsidy Program and the construction of 3G networks give an additional boost. In the months ahead, models for automotives, mobile phones, set-top boxes and LCD TVs/monitors are forecast to dominate output.

There are about 200 suppliers in China. Most are located in the Yangtze and Pearl River Delta regions, and the Bohai Bay Rim Economic Region. The key hubs are Jiangsu, Zhejiang and Guangdong provinces, and Tianjin.

Types & mainstream specifications
Materials & components
Hong Kong: Transistor & diode line offers range of types, packages
Taiwan: High-end transistors & diodes emphasized
Product gallery

Types & mainstream specifications

In terms of structure, the discrete semiconductor industry in China is divided into four: diodes, general-purpose and power transistors, and optoelectronic devices. The third makes up half of overall sales.

Diodes: Based on materials, products can be classified into germanium and silicon, with the latter dominating turnout. The last features a higher peak inverse voltage reaching 1kV, wider operating range and lower saturation current. It also has an elevated cutoff voltage of 0.7V. The former has a PIV of 400V maximum, smaller operating range and high saturation current. The cutoff voltage is 0.3V.

By core structure, there are point- and surface-contact, and planar versions. The first is suitable for high-frequency, low-current circuits such as radio detectors. The second is mainly used to transform AC into DC in rectification circuits. The last is commonly employed in switches, and pulse and elevated-frequency circuits.

The other categories depend on target applications. These include detector, rectifier, Zener, isolation and Schottky types. There are also switching, light-emitting and rotating variants.

Transistors: The line may be divided into silicon and germanium kinds, with the former being mainstream. By polarity, products are either NPN or PNP. In terms of usage, there are general-purpose and power transistors, MOSFETs and IGBTs. The first two lead supply in China.

In both categories, TO, SOT, SOD, SOP and SC are the popular packages. In SMD configurations, SOD is mostly used in diodes, while it is SOT for transistors. The last includes SOT-23, SOT-143 and SOT-89. SOD covers SOD-123, SOD-323, SOD-523 and SOD-723.

TO dominates output of leaded models. The selection consists of TO-92, TO-92S, TO-92L, TO-251, TO-252, TO-126 and TO-220. Regardless of type, China makers can develop versions in any package on request.

Like other electronic components, transistors and diodes are mostly based on custom requirements. The majority of manufacturers can provide samples in one week or less. At Yangzhou Yangjie Electronic Technology Co. Ltd, mock-ups in clients’ specifications can be developed in three to five days.

In contrast to foreign counterparts, local enterprises accept low-volume orders. Yangzhou Yangjie, for instance, allows as few as 1,000 units, while Yangzhou Ark permits $100 minimum.

Suppliers offer models from several hundreds to a thousand. Yangzhou Yangjie and Yangzhou Ark specialize in bridge rectifiers and diodes. The first has more than 50 series of such products in over 1,500 specifications. The latter, which also emphasizes transistors and thyristors, has a selection exceeding 2,000 variants.

Materials & components

Wafers and chips are the main components for transistors and diodes. Most makers source these from Japan, the US, South Korea and Taiwan, but an increasing number are turning to the local supply because of improved quality and quantity.

The other inputs are the lead frames, cell-like membranes, plastic, lead and epoxy resins. These are also available from domestic providers.

Although there has not been a significant increase in raw material costs in recent months, overall expenses have climbed due to the rise in labor outlay and the yuan’s appreciation. As a result, prices of transistors and diodes surged by 5 percent in 2010. Companies foresee the trend persisting this year, but adjustments will be limited to 3 percent due to intense competition.

To manage costs more effectively, some manufacturers have stepped into raw material production. Yangzhou Yangjie, for example, set up its own 4in wafer line to control output and product quality better.

General-purpose transistor
The model MMBT3904 small-signal, general-purpose transistor from Sino-Tech has 60V collector-base, 40V collector-emitter and 6V emitter-base voltages.
Hong Kong: Transistor & diode line offers range of types, packages

Transistors from Hong Kong come in different types, including Darlington, power, digital and PNP/NPN small-signal variants, thyristors, regulators and MOSFETs. These are mainly available in TO-92, SOT-23 and SOT-323 packages, and some in TO-220, TO-251, TO-252 and SOT-89.

Versions in DO, LL and LS packages dominate diode output. The other options are DO-213AA, SOD-123, SOD-323 and SOD-523. SOT-523 and SOD-723 series have recently been introduced. Classes include Zener, Schottky barrier, variable-capacitance, switching, trigger and elevated-frequency. There are also transient voltage suppressors, and bridge, fast-recovery and high-efficiency rectifiers.

Each model goes with a data sheet for verifying specifications. High-demand units are kept in stock for rush orders.

There are about 20 suppliers in Hong Kong consisting of manufacturers, EMS providers and sales agents. Some offer related products such as capacitors, RFID chips and LEDs.

United Sources Industrial Enterprises offers thyristors, MOSFETS, general-purpose transistors and diodes. It has 28,000 types of electronic components from more than 20 brands.

Pandex Technology Ltd is an EMS specialist that also supplies a range of transistors, diodes, potentiometers and varistors. Its portfolio includes bipolar versions of the first in TO-126, TO-92, SOT-23, SOT-223 and TO-220 packages, and diode modules in various specifications.

Sino-Tech International (BVI) Ltd’s transistors and diodes are available under its ST brand. The maker is expanding packaging selection and performance characteristics to provide buyers more options.

To keep their clients, many companies continue to adhere to ISO 9001 and 14001, ISO/TS 16949, BSI-OHSAS 18001 and IECQ QC080000 guidelines. They have also set up sales and distribution networks across Asia, North America and Western Europe. Several are aiming for further expansion in the Middle East, South America and Africa. Most products are shipped bearing companies’ own brands.

Makers capitalize on more than 20 years of manufacturing experience and working relationships with technology companies to provide technical advice to customers. They also leverage breakthroughs at local research centers and learning institutions such as the Hong Kong University of Science & Technology.

Schottky diode
Won-Top’s model SK34 Schottky diode features low power loss and high efficiency, and is suitable for telecom equipment and inverters.
Taiwan: High-end transistors & diodes emphasized

Suppliers in Taiwan focus on upscale units to counter foreign domination of the industry and avoid competition with mainland China counterparts. They are releasing more ultrafast, Schottky and transient voltage suppression diodes, thyristors and MOSFETs. Compact, lightweight and affordable designs are likewise in the drawing board.

The mainstream is dominated by SMD versions suitable for automatic equipment. Traditional models adopt manual packaging methods such as axial, TO and bridge.

Accounting for about 10 percent of global shipments of transistors and diodes, makers in the island are improving services to attract more customers and gain a larger market share. Aside from accommodating flexible volume orders and ensuring short lead times, companies allow codesigning arrangements with clients.

They also continue to accept OEM requests, churning out models with lower prices than foreign counterparts and at a faster delivery period.

With these efforts, makers are optimistic of a 5 to 10 percent increase in sales in 1H11. Robust demand from the computer, communication, and consumer and car electronics segments provides an additional boost.

Applications also cover IT, telecom, aerospace, medical, automotive and office automation equipment.

Taiwan has more than 60 manufacturers in the line, with Lite-On, Mospec, Pan Jit International Inc. and Rectron among the major players.

Schottky rectifier diode
Product gallery

Suzhou Wonder Electronic Co. Ltd
(mainland China)

Model: RB721Q-40 Schottky Diode
MOQ: 4,000 units
Description: Schottky rectifier diode; up to 500VAC rated voltage; 3 to 2,500A current; 3-phase filter; one- or two-stage schematic; for telecom, navy and military equipment, inverters, power systems of aircraft or naval vessels

Metal-oxide transistor

United Sources Industrial Enterprises
(Hong Kong)

Model: IRFP15ON
Description: MOSFET N-channel, metal-oxide transistor; 100V drain-to-source voltage; 4V maximum Vgsth at 250µA; 42A continuous drain current at 25 C; 110nC gate charge at 10V; 1,900pF input capacitance at 25V; 160W maximum power

Zener diode

Wuxi Xuyang Electronic Co. Ltd
(mainland China)

Model: 5V1 To 75V
MOQ: 5,000 units
Description: Zener diode; 5.1 to 75V voltage; 2W power; low reverse current; silicon wafer, glass, lead; DO-41 package

Surface-mount general-purpose rectifier

Yangzhou Ark Component Imp. & Exp. Co. Ltd
(mainland China)

Model: S2M
Description: Surface-mount general-purpose rectifier; 1kV peak repetitive reverse voltage; 1.1V forward voltage drop at 2A; 2A maximum average rectified current at 110 C; 60A maximum peak forward surge current; 5µA maximum reverse current at 1kV; glass-passivated chip; UL94V-0-rated plastic material

Bridge rectifier

Yangzhou Yangjie Electronic Technology Co. Ltd
(mainland China)

Model: MB6S
Description: Bridge rectifier; 200V to 1kV maximum reverse, 1V maximum forward voltage; 0.5 or 0.8A maximum average rectified current; 35A peak forward surge current; -55 to 150 C operating temperature

Note:This article was originally published by Global Sources, a leading business-to-business media company and a primary facilitator of trade with China manufacturers and India suppliers, providing essential sourcing information to volume buyers through our e-magazines, trade shows and industry research.

All price quotes in this report are in US dollars unless otherwise specified. FOB prices were provided by the companies interviewed only as reference prices at the time of interview and may have changed.

Disclaimer: All product images are provided by the companies interviewed and are for reference purposes only. Those product images featuring products with trademarks, brand names or logos are not intended for sale. We, our affiliates, and our affiliates' respective directors, officers, employees, representatives, agents or contractors, do not accept and will not have any responsibility or liability for product images (or any part thereof) which infringe on any intellectual property or other rights of a third party.

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