PCB007 Magazine


Issue link: https://iconnect007.uberflip.com/i/1288481

Contents of this Issue


Page 90 of 137

SEPTEMBER 2020 I PCB007 MAGAZINE 91 The driving force for this reaction is + 0.46 v and would proceed spontaneously. Although the reaction is straight forward, the design of the electrolyte for immersion silver is a differ- entiating point from one supplier to the other and may include anti-tarnish components. Immersion tin on copper: E cell = E Sn – E Cu E cell = - 0.14 v – ( + 0.34 v) E cell = - 0.48 v Replacement reaction between Cu and Sn 2 + cannot occur in a standard electrolyte because the EMF voltage is negative (- 0.48 v). The half potential of Cu is + 0.337 v, which is much higher than that of Sn is – 0.136 v. For tin to immerse on copper, the half poten- tial for copper must be reduced below the half potential of tin. The addition of a copper ion complexing agent, such as thiourea, will de- creases the half potential of copper to – 0.620 v. (E 0 for Cu[SC(NH 2 ) 2 ] 4 = – 0.620 v). In the presence of thiourea, the EMF for the immersion reaction is positive and would pro- ceed spontaneously: E cell = E Sn – E Cu[SC(NH 2 ) 2 ] 4 E cell = - 0.14 v – ( -0.62 v) E cell = + 0.48 v A good understanding of the principles of im- mersion plating goes a long way in eliminating costly defects that may occur during fabrica- tion. It is a powerful tool in analyzing failure, as well as the subsequent assignable cause, and recommending corrective action. PCB007 George Milad is the national accounts manager for technology at Uyemura. To read past columns or contact Milad, click here. Cyberattacks have continued to grow in recent years because we never learn how they happen. Many orga- nizations don't know which types of attacks lead to the largest financial losses, nor how to best deploy scarce se- curity resources. A new platform from MIT's Computer Sci- ence and Artificial Intelligence Laboratory (CSAIL) is quan- tifying companies' security risk without requiring them to disclose sensitive. The team received internal data from seven large com- panies that averaged 50,000 employees and annual reve- nues of $24 billion. By securely aggregating incidents that took place at the companies, researchers analyzed which Helping Companies Prioritize Cybersecurity Investments specific steps were not taken. Among other findings, they determined that the three following security vulnerabilities had the largest total losses, each in excess of $1 million. 1. Failures in Preventing Malware Attacks Malware attacks, like the one last month that reported- ly Garmin to pay a $10 million ransom, are still a method. Companies continue to struggle to prevent such attacks, relying on regularly backing up their data and reminding their employees not to click on suspicious emails. 2. Communication Over Unauthorized Ports Every firm in their study said they had implemented the security measure of blocking access to unauthorized ports, yet attacks gaining access to these ports account- ed for a large number of high-cost losses. 3. Failures in Log Management for Security Incidents Every day, companies amass detailed "logs." Compa- nies could be using machine learning and AI more effi- ciently to help understand what's happening, including— crucially—during, or even before, a security attack. (Source: MIT News)

Articles in this issue

Links on this page

Archives of this issue

view archives of PCB007 Magazine - PCB007-Sept2020