Tin Whisker Growth

The National Electronics Manufacturing Initiative s (NEMTs) Tin Whisker Accelerated Test Project Press Release, September 26,2003—NEMI Team Recommends Three Test Conditions for Evaluating Tin Whisker Growth. [Pg.872]

The use of lead in tin plating and solder has been used to inhibit tin whisker growth. Rare reports of tin whiskers have been reported from tin-lead coatings. Whiskers evolve from tin surfaces as a stress-relief mechanism between tin crystals. Most stress in tin deposits arises from the growth of copper-tin intermetallics at the interface with underlying copper. With a much slower rate of nickel-tin intermetallic formation, tin whiskers form at a much lower rate than tin coatings on nickel underplate. [Pg.770]

Prevention of short circuits due to tin whisker growth from pure tin-plated part leads and cases... [Pg.969]

FIGURE 57.11 Tin whisker growth on a tin-plated surface. From Ref. 11. (From IPC-TR-476. Courtesy ofBumdy Corporation.)... [Pg.1330]

The potential compatibility concerns of bismuth (Bi) containing solder alloys and tin-lead component terminations (or tin-lead solder alloys and bismuth containing component terminations), due to the formation of the low melting temperature (98 °C, or 208 °F) Sn-Pb-Bi ternary eutectic phase, have often been discussed in the literature however, the exact concentration of bismuth necessary to cause an actual reliability degradation (based on kinetics considerations) is not yet clear, and component terminations with tin iloys with low bismuth (1-3%) have been used with the tin-lead solder in actual products. As will be discussed later, bismuth is often used as an alloy addition to tin to reduce the risk of tin whisker growth. [Pg.4]

There are several factors which can help mitigate the risk of tin whisker growth (Ref 5, 78-79), especially for copper leadfirames. The mitigation techniques include ... [Pg.12]

Mitigating tin whisker growth on Alloy 42 (Ni-Fe alloy) leadframes have so far proven to be more difficult, due to the CTE mismatch between the leadframe and the plating, which gen-... [Pg.12]

At the present time, tin whisker growth remains an active field for research. Overall, a rational approach should be taken in managing the risk of tin whiskering. Towards this end, predic-... [Pg.12]

N. Vo, I. Boguslavsky, and P. Bush, NEMI Recommends Standard Test Methods to Assess Propensity for Tin Whisker Growth, SMT, Nov 2003, p 36 1... [Pg.26]

Tin Whisker Growth on Lead-Free Solder Finishes... [Pg.147]

Tin whisker growth is a well-known surface relief phenomenon (Ref 1-9). The subject of Sn whisker growth has often been reviewed. One of the latest reviews (Ref 10), covers most of the early work and the proposed mechanisms of Sn whisker growth and will not be repeated here. In this chapter, we limit our review based on our own hndings of spontaneous Sn whisker growth at room temperature on leadframes finished by eutectic Sn-Cu and pure Sn (Ref 11-14). A three-dimensional nonlinear stress analysis on the initiation of Sn whisker has been reported... [Pg.148]

As the mechanism for tin whisker growth becomes clearer, predictive modeling for tin whisker nucleation and growth, which can accurately account for the thermodynamic driving force and the nucleation and growth kinetics, will become a very usefid tool for life prediction and optimization. Accelerated testing methods (with well established acceleration factors) and acceptance criteria for different applications... [Pg.277]

There are several postulated mechanisms for tin whisker growth discussed in detail in Chapter 21, including recrystallization due to strain aging. The main driving force for tin-whisker formation is believed to be stress. The source of the stress can be either internal (i.e., created within the... [Pg.458]

One might conclude that pure tin is the leading high-volume candidate to replace Sn-Pb as a Pb-free component finish as it is abundant, cost-effective, and fairly easy to plate. However, the key concern in utilizing pure Sn as a Pb-free component finish is tin-whisker growth, as mentioned previously. However, there are efforts to mitigate and hopefully eliminate tin-whisker formation. The subject of tin-whiskers is discussed in more detail in Chapter 21. [Pg.462]

Schetty, R. Tin Whisker Growth and the Metallurgical Properties of Electrodeposited Tin, Proceedings from IPC/JEDEC Pb-Free Technical Conference San Jose, CA, May 2002 pp. 137-145. [Pg.463]

TABLE 6 Spontaneous Tin Whisker Growth Rates on Various Substrate Materials... [Pg.884]

A. Conditions of Tin Whisker Growth—Cracked Oxide Theory (COT)... [Pg.896]

B. Compressive Stress as the Driving Force for Tin Whisker Growth... [Pg.896]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...