High-thermal conductivity aluminum PCBs prevail

Ceramic substrates are gaining popularity, but cost effectiveness will keep the line of aluminum PCBs the staple in the next few years.

Suppliers of aluminum PCBs in China focus on highlighting the category's high thermal conductivity, and enhanced electrical insulation and mechanical performance in ensuring better power density, reliability and operating life of terminal products. Mainly used in LED lighting, they offer mostly units with 1 to 2W/mK thermal conductivity, with 2 to 3W/mK types under way.

For home appliances, smartphones, solar power systems and automotive applications, makers note rising demand for flexible kinds. Shenzhen CZY Circuits Co. Ltd has introduced such variants for automotive rear lights. The boards, produced in an ISO/TS 16949-compliant facility, have 1W/mK heat conductivity and 2,000kVAC withstand voltage, and meet UL E354470. These adopt an OSP surface finish and are 0.3mm in thickness.

Rival ceramic substrates have been gaining market attention for their greater performance and life span, making them an ideal replacement for aluminum PCBs. Adoption, however, has a higher cost. So, the latter is expected to remain the top choice in the near term.

China makers will continue to expand output to meet the increase in local and global demand. Sunshine Global Circuits Co. Ltd invested $0.25 million in a fully automatic production line, which helped increase its yield by 10 percent in the past year.

The global LED lighting industry's total production volume is expected to rise by up to 7.085 billion units by the end of 2019 and 7.147 billion in 2020 from the 6.879 billion realized in 2018, according to Tencent News. The same upward trend is also projected in China where the total is likely to reach 1.325 billion and 1.426 billion units in 2019 and 2020, respectively.

From this, the local aluminum PCB sector saw a sales growth of 5 to 10 percent in the past two years, a trend expected to continue in the years to come.

There are more than 300 suppliers of aluminum PCBs in China, over two-thirds of which are locally owned and the rest foreign-invested. The majority offers PCBs including rigid, rigid-flex and flexible types, and PCB assemblies. Aluminum PCBs constitute 10 to 30 percent of shipments.

More than half of these companies are spread over the provinces of Guangdong and Fujian. Environmental concerns in the coastal areas have encouraged some suppliers to move inland to Jiangxi, Hunan and Hubei provinces, and Chongqing municipality.

Mainstream selections

Typical aluminum PCBs offered by China makers have thermal conductivity coefficient ranging from 0.5 to 2W/mK. These come in up to two layers and with 8mil minimum line width and spacing. By copper foil thickness, the choices are 18, 35, 70, 105 and 140µm. Board thickness is 0.8, 1.0, 1.2, 1.5, 2.0, 2.5 or 3mm. Surface treatment options include HASL, lead-free HASL, OSP, ENIG, immersion gold and flash gold. Customization is accepted.

Products meet CE, RoHS and UL requirements.

Most companies obtain copper, aluminum and dielectric materials locally, turning to foreign providers only on request. The major sources include Shengyi and ITEQ.

Input costs and prices are expected to stabilize in end-2019 and 2020. Some makers are likely to lower their quotes due to intense competition.

The products in this gallery have been handpicked by our China-based market analyst for representing current trends in aluminum PCBs from China makers.

Aluminum PCB with 3mm board thickness

Model KSL04231 aluminum PCB from Kinglisheng (Shenzhen) Electronics & Technology Co. Ltd has HASL surface finish and 2oz copper. Board thickness is 3mm and diameter 169mm. The unit meets CQC, RoHS and UL requirements.

An order of 1 unit is delivered within 3 days.

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Aluminum PCB has 0.25mm minimum hole size

In single- and dual-layer versions, Shenzhen Topwell Technology Co. Ltd's model Top-18 aluminum PCB can have a lead-free HASL, HASL, immersion gold, flash gold or OSP surface finish. It has 8mil minimum line width and spacing, 0.25mm minimum hole size and 0.05 to 4oz copper. The dielectric is 0.05 to 0.2mm in thickness and the board 0.4 to 4mm. The panel measures 20 to 24in.

A 1-unit order is for delivery within 3 days.

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Aluminum PCB uses 6oz copper

Based on a 1.57mm-thick HT-04503 aluminum board, the model SS1812184 PCB from Sunshine Global Circuits Co. Ltd has 60z finished copper, silver surface finish and green solder mask.

The negotiable order quantity is delivered within 21 days.

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2W/mK single-sided aluminum PCB

From Zitrok Electronics Co. Ltd, this single-sided aluminum PCB, P2516S1A model, has 7.87mil minimum line width and spacing, 1oz copper and 1.6mm board thickness. It has a thermal conductivity of 2W/mK.

A 1-unit order has a delivery lead time of 5 days.

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