Issue link: https://iconnect007.uberflip.com/i/1515637
24 DESIGN007 MAGAZINE I FEBRUARY 2024 remain on the outer surface of the finished cir- cuit board, the embedded resistors will require a unique reference designator to avoid material procurement errors. For example, a surface- mounted resistor will be defined as "R110" while the embedded "formed" resistor will be designated "ER110" on the schematic diagram and material list to avoid duplication. Regarding tolerance control, the physical stresses experienced during PCB lamination can affect target values. When the specified val- ues of the resistor elements require more pre- cise tolerance, 1% or 2% range for example, or are subject to further adjustment (tweaking), I strongly advise circuit board designers that all high-precision resistors (<5%) be retained as discrete surface mount components for place- ment onto the circuit board's outer surface(s). Note: To prepare for implementing embed- ded resistor technology, the designer and/ or program manager must first seek an expe- rienced supplier company that can furnish practical guidance in selecting a process that will meet both technical and budgetary (cost) goals established for the end product. Many established circuit board fabricators know the materials and processes for embedding resis- tor elements, but not all are prepared to alter procedures established for their more con- ventional multilayer circuit board customer base. For additional guidance in embedding discrete passive and active die elements within the multilayer circuit board, refer to IPC-7092, Design and Assembly Process Implementation for Embedded Components. DESIGN007 Vern Solberg is an independent technical consultant, specializ- ing in SMT and microelectronics design and manufacturing tech- nology. To read past columns, click here. In a pivotal ruling, the U.S. Court of Appeals for the Federal Circuit has decided against Apple in its patent dispute with Masimo, mandating a halt in sales of the Series 9 and Ultra 2 in the US due to their blood oxy- gen features. This decision pushes Apple to poten- tially remove these features via software updates tem- porarily. Despite this setback, TrendForce maintains a positive outlook on bio-sensing tech in the wearables market. Substantial growth is predicted, with the mar- ket value for bio-sensing in smartwatches and smart bands expected to reach US$422 million by 2028, growing a CAGR of 14.7% from 2023. Market leaders in wearable devices, such as Apple, Samsung, and Google Fitbit, are actively advancing the bio-sensing sector. TrendForce's 2024 forecast suggests a focus by Apple and Samsung on improv- ing the precision of bio-sensing features in upcoming smartwatches. They plan to employ photoplethysmo- graph (PPG) technology for enhanced monitoring of heart rate and blood oxygen levels, furthering capa- bilities in personal health management. TrendForce emphasizes two primary strategies among wearable device brands: Expanding bio-sen- sor features and enhancing their accuracy. This dual approach not only differentiates products but also boosts customer engagement and market growth. Bio-sensing, especially when merged with health management, shows promise for integration into medical, insurance, and automotive systems. As a result, securing comprehensive patents for both the software and hardware aspects of bio-sensing technology has become a critical focus for these companies. (Source: TrendForce) Benefited from Enhancing Bio-Sensing Technology, Wearable Device Applications Market to Reach $422M