An overview of the design and development process.
5G radio networks provide increased bandwidth at the expense of reduced range. To compensate for the reduced range and to increase coverage, availability of cost-effective radio units is critical. In collaboration with Intel, Analog Devices, Comcores and Radisys, Whizz Systems has developed a 5G Open Radio Unit (ORU) white box solution to meet this market need. A broader overview of the 5G architecture can be found in Comcores1 and Radisys.2
Here we provide an overview of the design and development process for the various hardware components that make up the 5G ORU white box. Whizz Systems is responsible for the electrical, thermal, mechanical engineering and manufacturing aspects, as well as system validation and bring up of the turnkey white box ORU solution. This includes design of the individual PCBAs and industrial design of the enclosure.
PCB chemical manufacturing processes can violate data independence and normality.
The most critical assumption made concerning statistical process control (SPC) charts is that of data independence from one observation to the next (free from autocorrelation).1,2 The second critical assumption is that the individual observations are approximately normally distributed.1,2 The tabled constants used to calculate the SPC chart limits are constructed under the assumption of independence and normality.
Many printed circuit board chemical manufacturing processes can violate the assumption of data independence. This is because inertial elements drive reduction-oxidation (redox) chemical processes. When the interval between samples becomes small relative to the inertial elements, the sequential observations of the process will be correlated over time.
Statistical process control charts do not work well if the quality attributes charted exhibit even low levels of correlation over time. Correlated data produce too many false alarms – correlated data underestimate the upper and lower control limits.
An overview of the physical and electrical characteristics of rigid and flex laminates.
Electronic devices functioning at high frequencies are currently evolving at a dizzying pace, particularly within the field of wireless communication. When developing new products, therefore, emphasis is placed on utilization of materials suitable for high-frequency work, above 1GHz.
When selecting materials intended for high-frequency printed circuit boards, several characteristics are of importance:
Dielectric constant (Dk) – dielectric coefficient of the resin. This parameter must be low and stable within a wide range of high frequencies. High Dk values may decelerate signal transfer speed.
Dissipation factor (Df) – the parameter responsible for the signal's quality. The Df value should be low. The lower this value, the more stable the signal, and losses will be reduced.
Moisture absorption – another imperative parameter when selecting materials intended for high frequencies. This is important because the Dk of water is Dk;water = 80.4, a value so high, in fact, the absorption of very small amounts of moisture will instigate a significant increase in the overall Dk of the material.
Coefficient of thermal expansion (CTE) – thermal dimensional expansion parameter of the dielectric material. This parameter must be close to the CTE of the conductive metal; in the case of PCBs, it is copper. Working at high frequencies causes increased heating of the PCB and thus if a significant discrepancy exists between the CTE of the dielectric material and the copper, structure delamination may occur during the activation of heating/cooling cycles.
Additional important parameters such as:
The adhesion strength between copper and the dielectric material.
Massive investment suggests the segment could occupy a major portion of the largest fabricators' production.
The heartbreak of the pandemic of 2020-21 is receding, but printed circuit fabricators continued to feel the supply-chain reverberations throughout the past year. The rollercoaster gyrated from a sharp dip to an intense high, with demand for consumer electronics, autos and other electronics resulting in tight inventories and long lead times. Then came the inevitable slowdown. Regionalization, currency swings and price cuts played havoc with manufacturers' order books and financials.
That's the picture drawn by this, the 26th NTI-100 report. As in the past several years, a rough conclusion is "big gets bigger and faster." Due to exchange rates that were favorable to the US dollar in 2022, the author thought there would be changes in the rankings, but they remained approximately the same as in 2021. Japanese fabricators were a surprise. Despite a 20% loss in value against the US dollar, their world ranking remained almost the same as in 2021. Domestic customers wanted to get PCBs from within the country because of supply-chain disruptions in China, resulting in good order intake.
As in the past, the author would like to thank various trade organizations and many firms and friends who provided vital information that enabled the compiling of this report. Any errors in this report are the responsibility of the author.