The BM54 series from HIROSE Electric Co. Ltd, a global leader in connector technology, is a compact floating board-to-board connector designed to meet demanding automotive specifications while addressing real-world PCB alignment challenges faced by electronic design engineers. By combining a generous floating capability with an ultra-compact form factor, the BM54 series improves mechanical tolerance, design flexibility, and assembly robustness in high-density electronic systems. The connector allows a floating deviation of ±0.4 mm in the XY direction, yet maintains a slim 3.8 mm width, enabling it to absorb board misalignment without consuming valuable PCB area. This floating design helps reduce stress during mating, improves assembly yield, and simplifies integration where tight mechanical tolerances would otherwise be required.
The BM54 series is rated for continuous operation up to 125 °C, a key requirement for in-vehicle electronics, making it well suited not only for automotive applications but also for a wide range of other demanding environments. These include consumer and industrial equipment as well as front, rear, and side camera modules, millimetre wave radar, and LiDAR systems widely used in advanced driver assistance and autonomous platforms. Its wide operating temperature range and robust construction allow engineers to reuse the same connector platform across multiple product families, reducing qualification effort and simplifying design reuse.
Supporting PCB stacking heights from 3.0 mm to 4.5 mm, the BM54 series features a fine 0.4 mm contact pitch combined with a compact 3.8 mm connector width, enabling high contact density while significantly reducing the board space required. Compared with other connectors currently available on the market, the BM54 occupies up to 34% less PCB area, giving designers more freedom to optimise layouts, shrink module size, or add additional functionality without increasing board dimensions.
A key differentiator of the BM54 series is its high-reliability Two-Point contact design, which provides stable electrical performance while resisting the effects of dust and other environmental contaminants. This contact structure is positioned as an industry first for low-profile floating contact board-to-board connectors, delivering enhanced reliability in applications exposed to vibration, thermal cycling, and long service life expectations.
BM54 Series Two-Point Contact Design
The BM54 series is available in 30, 40, and 50 contact configurations, with a 20-contact version under planning, allowing designers to select the most appropriate pin count for their interface requirements. The connector supports high-speed signal transmission, including PCI Express Gen4 at 16 Gbps and MIPI D-PHY version 2.1, making it suitable for modern high-bandwidth data paths found in camera, sensor, and processing modules.
The floating structure on the plug side of the BM54 series allows ±0.4 mm movement in the XY axis, absorbing positional errors that can occur during connector placement, board mating, or final product assembly. This capability significantly improves design flexibility, particularly in systems using multiple board-to-board connections where cumulative tolerances can otherwise lead to assembly difficulty or mechanical stress. Multiple BM54 connectors can be mounted on the same board while maintaining reliable contact, supported by an effective mating length of up to 0.4 mm.
Floating Connector Design
The connectors are rated for currents up to 0.3 A and a maximum voltage of 50 V AC/DC. Housings are manufactured from high-temperature LCP, while the contacts and retention tabs use copper alloy with gold plating over nickel underplating on the contact surfaces to ensure stable electrical performance and long-term durability. With an operating temperature range of −55 °C to +125 °C, the BM54 series is suitable for use in harsh environments where reliability is critical.
Explore the BM54 Series features
The BM54 series offers an exceptional balance of compact size, mechanical compliance, and electrical performance, making it an excellent choice for applications including robotics, autonomous material handling equipment (AGVs), camera systems, LiDAR, radar, automotive electronics, industrial equipment, and advanced consumer products.
Anglia are offering customers FREE samples of the HIROSE BM54 series compact floating board-to-board connectors. To evaluate the benefits in your own design, please fill in the form below to register your interest.
Free samples are subject to availability.
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