Electronic soldering

Heterogeneous nucleation is most likely to occur when there is a strong tendency for the crystal to stick to the surface of the catalyst. This sticking tendency can be described by the angle of contact, 6, shown in Fig. 7.3 the smaller 6, the better the adhesion. Anyone who has tried to get electronic solder to stick to a strip of copper will understand this well. If the copper is tarnished the solder will just roll around as a molten blob with 6 = 180°, and will not stick to the surface at all. If the tarnished... 

Arsenic none 0.05 Skin damage circulatory system problems increased risk of cancer ceramics electronics solder Erosion of natural deposits runoff from glass electronics production wastes... 

The classical electronics solder alloy (Sn + 37 wt% Pb) contains the inhalation-toxic element lead and is being replaced in electronics for health reasons. A Pb-free solder is Sn-3.5wt% Ag indium and bismuth alloys are other eutectic-forming alloying additives to Sn. The classical brazing alloy is at the Cu-Ag eutectic (Ag-F 28.1 w% Cu) and is well suited for mechanically strong contacts with Cu and its alloys. 

The Mounting Pin. In this laboratory the best results have been obtained with a specially designed mounting pin, illustrated in Figure 1. The pin is a hollow copper rod with a diameter corresponding to the adaptor hole in the goniometer head (normally 3 mm or 0.125 in). The tip of the pin is tapered down to 0.5 mm. The bore diameter near the tip is -0.5 mm the rest of the bore is 1.5 mm. In preparation for use the fine bore hole is filled with standard electronic solder (by capillary action). A glass fiber of... 

K. Suganuma (2001) Current Opinion in Solid State and Materials Science, vol. 5, p. 55 - Advances in lead-free electronics soldering . 

Chem. Descrip. Low vise, aromatic diacrylate with 770 ppm MEHQ Uses Acrylic for coatings (flooring), electronics (solder masks), and inks (flexo and gravure)... 

Chem. Descrip. Polyester acrylate oligomer Uses Polyester-acrylic for coatings, esp. high temp, coating and electronic solder masks, inks (flexo, gravure, jet, screen)... 

Uses Monomer for adhesives, coatings, electronic solder masks, photopoiymers... 

PLANT, SMELTER, RADIATOR REPAIR SHOP, OR ELECTRONICS/SOLDERING INDUSTRY )... 

Primarily used in electronic soldering applications where low soldering temperatures are required... 

It is beyond the scope of this chapter to provide a detailed explanation of SPC. Rather, there will be a qualitative discussion of process control that addresses those factors affecting circuit board assembly, beginning with defect types in electronic solder joints. Then the discussion will turn to process control as it pertains to the basic assembly steps (e.g., dispensing, pick-and-place, etc.). The various material sets (e.g., circuit board, solder paste, flux, etc.) will be incorporated in the discussion. Also, the use of Pb-free soldering technology will be addressed where applicable. 

J-STD-006, Requirements for Electronic Grade Solder Alloys and Fluxed and Non-Fluxed Solid Solders for Electronic Soldering Applications." This standard prescribes the nomenclature, requirements, and test methods for electronic grade solder alloys for fluxed and non-fluxed bar, ribbon, and powder solders, for electronic soldering applications and for special electronic grade solders. 

J-STD-006 General Requirements and Test Methods for Soft Solder Alloys and Fluxed and Non Fluxed Solid Solders for Electronic Soldering Applications... 

E. P. Wood, K.L. Nimmo, In search of new lead-free electronic solders, J. Electron. Mater. 

D. Shangguan and G. Gao, Lead-Free No-Clean Soldering for Automotive Electronics, Solder. Surf. Mt. Technol, 26 (1997), p 5-8... 

Contamination free environment important for electronics soldering. 

Antimony Increase in blood cholesterol decrease in blood sugar Discharge from petroleum refineries fire retardants ceramics electronics solder 6 20 5.0 n.a. n.a. 

Lead storage batteries represent the major use of lead in the United States, according to data from the U.S. Geological Survey [3] noted in Table 1. The use of lead in electronic solder is only 0.3% of the total lead usage. If one considers consumer electronics, which includes television sets and computers, approximately 90 % of the lead utilized in electronics is contained in cathode ray tubes (CRTs) which are exempt under the ROHS Directive. 

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