Technical Library | 2013-04-12 07:31:31.0
As change is inevitable, therefore so is obsolescence. In the electronics sector, stocks of components used in subassemblies will eventually run out, no surprise there! However on many occasions, particularly in the often long product life cycles associated with the traditional UK OEM’s in the industrial, military and medical sectors, to name but three, component supply gets ‘difficult’ long before the customers products themselves reach their ‘end of life’. Component manufacturers work to a commercial agenda; when the popularity of a specific device wanes, or indeed when new features are demanded by the market, they will cease production and redeploy their manufacturing capacity to devices that are being demanded by their high volume customers; the global players.
Technical Library | 2013-04-12 08:20:15.0
There is much to read about the shifting sands of electronics manufacturing, including current moves by OEMs to alter their EMS relationships to better mitigate risk and cost, while EMS companies look for additional ways in which to adjust their business models in an attempt to improve their profitability. Electronics outsourcing over time evolved from a means to buffer manufacturing demand fluctuations into a wide scale shift in capabilities, in part in order to deal with vastly shorter product life cycles. Following the global economic crash of 2000, aka “the internet bubble,” more and more EMS providers responded by transferring their manufacturing to low cost labour regions, and in particular China.
Technical Library | 2020-10-27 02:07:31.0
For companies that choose to take the Pb-free exemption under the European Union's RoHS Directive and continue to manufacture tin-lead (Sn-Pb) electronic products, there is a growing concern about the lack of Sn-Pb ball grid array (BGA) components. Many companies are compelled to use the Pb-free Sn-Ag-Cu (SAC) BGA components in a Sn-Pb process, for which the assembly process and solder joint reliability have not yet been fully characterized. A careful experimental investigation was undertaken to evaluate the reliability of solder joints of SAC BGA components formed using Sn-Pb solder paste. This evaluation specifically looked at the impact of package size, solder ball volume, printed circuit board (PCB) surface finish, time above liquidus and peak temperature on reliability. Four different BGA package sizes (ranging from 8 to 45 mm2) were selected with ball-to-ball pitch size ranging from 0.5mm to 1.27mm. Two different PCB finishes were used: electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) on copper. Four different profiles were developed with the maximum peak temperatures of 210oC and 215oC and time above liquidus ranging from 60 to 120 seconds using Sn-Pb paste. One profile was generated for a lead-free control. A total of 60 boards were assembled. Some of the boards were subjected to an as assembled analysis while others were subjected to an accelerated thermal cycling (ATC) test in the temperature range of -40oC to 125oC for a maximum of 3500 cycles in accordance with IPC 9701A standard. Weibull plots were created and failure analysis performed. Analysis of as-assembled solder joints revealed that for a time above liquidus of 120 seconds and below, the degree of mixing between the BGA SAC ball alloy and the Sn-Pb solder paste was less than 100 percent for packages with a ball pitch of 0.8mm or greater. Depending on package size, the peak reflow temperature was observed to have a significant impact on the solder joint microstructural homogeneity. The influence of reflow process parameters on solder joint reliability was clearly manifested in the Weibull plots. This paper provides a discussion of the impact of various profiles' characteristics on the extent of mixing between SAC and Sn-Pb solder alloys and the associated thermal cyclic fatigue performance.
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