Benfield (Trading As Autoroute Circuits) v Life Racing Ltd

A contract for professional design services does not ordinarily contain an implied term that a specified outcome will be achieved unless the desired outcome and the circumstances clearly show that the professional undertook responsibility for achieving it. The conventional obligation is to exercise the ordinary skill and care expected of a professional providing the relevant service.

In PCB design, that obligation includes keeping abreast of current manufacturing capabilities, consulting the intended manufacturer about design rules, and adopting a reasonably simple and manufacturable layout. A designer may be negligent where an inappropriate routing technique is adopted without proper consideration of available alternatives and foreseeable manufacturing risks.

Life Racing Ltd engaged Roger Benfield, trading as Autoroute Circuits, to provide PCB layout and related advisory services for two racing-car engine control units, the F88 v1.0 and v1.1. Life Racing alleged that the layouts caused resistance, impedance and resulting ECU failures, and counterclaimed for losses arising from alleged breaches of contract and duty. Autoroute claimed unpaid fees.

The trial was confined to liability, with causation-related issues concerning loss of turnover, remoteness and scope of duty reserved for a later trial or agreement. The principal issues were the contractual scope of the services, whether the designs were produced with reasonable skill and care, whether the designs caused the failures, and whether the relevant failures were foreseeable.

1. Contractual obligation. The engagement was a contract for professional PCB design and advisory services. The circumstances did not establish an implied term that the PCB would be fit for a stated commercial purpose. The intended outcome had not been sufficiently agreed, and Autoroute had not guaranteed its achievement. The applicable obligation was instead to exercise the ordinary skill and care expected of a PCB layout designer providing professional services (paras [38]-[48]).
2. Scope of the service. The designer’s role was not merely mechanical drafting. It included advising on routing, via selection and the manufacturability and reliability of the layout. The designer had to produce the simplest reasonably practicable layout, consistent with the required components and dimensions, so as to minimise manufacturing imperfections, resistance and impedance (paras [64]-[70]).
3. Breach and causation. Autoroute breached its contractual and professional obligations by failing to keep abreast of current via-manufacturing capabilities, treating blind and buried vias as the only reasonable solution, failing to consider all-through interstitial vias, failing to consult the intended manufacturer’s design rules, and failing to address the crowded BGA connections. These defects caused the heightened resistance and impedance that produced all, or the great majority, of the ECU failures (paras [61]-[78]).
4. Foreseeability. The reduced reliability and increased risk of resistance and impedance arising from complex, crowded layouts and frequent changes of direction were matters of common experience available to a PCB layout designer. The relevant causes of failure were therefore foreseeable (paras [80]-[81]).
5. F88 v1.1. The same defects were carried into the v1.1 redesign. Autoroute was accordingly in breach of contract and duty, and its anticipated repudiatory breach was accepted when the engagement was terminated in March 2004 (paras [82]-[83]).
6. Disposition. Life Racing was entitled to judgment on liability. Questions of causation, remoteness, scope of duty, recoverability and damages were reserved for agreement or a subsequent trial (paras [84]-[85]).