Package moisture sensitivity

Performance of the package moisture sensitivity level (MSL) can be impaired by the higher temperature compatibility arising from lead-free requirements. 

Association of Connecting Electronics Industries, IPC-JOStd-006 ICP-J-Std-002, 003 MIL-M-38510 JEDEC J-Std-620A Detailed list of both tin lead and lead-free solders Board and component lead solderability Plating thickness for good component lead solderability Plastic package moisture sensitivity, heat tolerance... 

The acetoxy-based moisture sensitive diacetoxymethylsiloxy-endblocked-PDMS (II) reactive polymer is prepared in situ in the packaging cartridges by mixing silanol-endblocked-PDMS (I) with... 

Situation Two different strengths of plastic foil are in evaluation for the packaging of a moisture-sensitive product. Information concerning the diffusion of water vapor through such foils is only sparsely available for realistic conditions. To remedy this lack of knowledge, samples of the product are sealed into pouches of either foil type and are subjected to the following tests ... 

Badway, S. I. F., Gawronski, A. J., and Alvarez, F. J. (2001), Application of sorption-desorption moisture transfer modeling to the study of chemical stability of a moisture sensitive drug product in different packaging configurations, Int. J. Pharm., 223(1-2), 1-13. 

Allinson JG, Dansereau RJ, Sakr A. The effects of packaging on the stability of a moisture sensitive compound. Int J Pharm 2001 221 49-56. 

Properties Liquid. Mw 190.11, d 0.890, freezing p -17C. Moisture sensitive. Packaged under nitrogen. 

Alkyl and aryl phosphite esters are also effective melt stabilizers. They are often used in combination with hindered phenols to give highly efficient melt stabilizing systems and to reduce discoloration of the polymer because of the oxidation products of the phenols present. Phosphites (particularly those derived from aliphatic alcohols and unhindered phenols) are, however, generally susceptible to hydrolysis. Consequently, moisture-sensitive phosphites affect adversely the handling characteristics (i.e., flow properties) of the additive package and are a source of other problems corrosion of metal surfaces, formation of dark colored spots, and gel formation. In practice, hydrolysis-resistant phosphites based on sterically hindered phenols are used, e.g., AOs 17 and 18, Table 1. 

While PLA was invented about 150 years ago, its moisture sensitivity and relatively high cost meant it did not have any packaging applications. Most uses of PLA were for medical applications where cost is not a harrier, and its biocompatibility is extremely important. When PET degrades, it produces lactic acid, which is also produced naturally in the human body (associated with muscle fatigue, for example). The advantages of something that can be implanted in the human body and then will slowly degrade and disappear over time are obvious. 

To protect a moisture sensitive product you are designing a package that has the following characteristics ... 

Package Size, mm I/Os Substrate Number of Passive Devices Number of Flip-Chip Number of ICs Devices Moisture Sensitivity Level... 

Rigid laminate substrate (with or without soldermask), wire bonds, over-molded Small outline, low profile (1.0 mm), enhanced electrical performance over 2.4 GHz, JEDEC moisture sensitivity level (MSL) 3 Plastic thin fine pitch quad flat no lead package (P-TFQFN), plastic thin shrink small outline no lead package (P-TSSON), and fine-pitch BGA, FBGA (National) Portable applications, flash memory... 

The blocked isocyanate function of aminimides also allows their use as polyurethane adhesives. Thus bis(aminimides) crosslink with polyester or polyether diols to yield a range of elastomers dependent upon the structure of the bis(aminimide) and the co-reactant chosen. For example, bis(aminimides) mixed with polyhydroxyl components can provide stable, single-package prepolymer compositions which yield polyurethanes on heating without the problem of isocyanate moisture sensitivity which can plague polyurethane applications. 

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