English

The dominant trend in packaging DDR DRAM for the future is the face down substrate-on-chip configuration. For this type of package it is critical that the die attach method employed provide precise control of bond line thickness and die tilt, minimal fillet, and prevent contamination of the wire bond pads located on the edge of the center wire bond channel. To date, a film adhesive has been the die attach method of choice because it is well suited to meet those requirements.

MATERIAL SAFETY DATA SHEET 3M™ SP7514, NPE 5 / 226

An adhesive compostion, of the 'instant adhesive' type, comprising:

(a) from 77 to 95% by wight of monomeris 2'-ethoxyethyl 2 cyanoacrylate;

(b) from 3 to 15% by wight of a poly-(C1-5) alkyl acrylate of methacrylate having an average molecular wight within the range from 400,000 to 600,000;

(c) from 2 to 8% by wights of hydrophobic fumed silica; and

(d) from 100 to 1000 ppm by wight of a polymerization stabilizer;

A cyanoacrylate adhesive composition in thixotropic paste form is made by mixing a liquid cyanoacrylate ester with powdered organic fillers selected from (i) polycarbonates, (ii) polyvinylidene fluorides, (iii) polyethylenes, and (iv) acrylic block copolymer resins containing saturated elastomer segments. Concentration of the filler is about 5 to 100 parts by weight. Particle size of the filler is about 2 to 200 microns.

A brief review is given about the development of rubber isostatic pressing (RIP) of powders for magnets and other materials that includes: principles of RIP; RIP apparatuses; recent progress; and advantages of RIP. As the recent progress, a new filling technique, ‘air tapping (AT) and grid separation (GS)’, is presented.

Bubble nucleation in weakly supersaturated solutions of carbon dioxide—such as champagne, sparkling wines and carbonated beers—is well understood. Bubbles grow and detach from nucleation sites: gas pockets trapped within hollow cellulose fibres. This mechanism appears not to be active in stout beers that are supersaturated solutions of nitrogen and carbon dioxide. In their canned forms these beers require additional technology (widgets) to release the bubbles which will form the head of the beer.

Applying RIP (Rubber Isostatic Pressing) to the ferrite sintered magnets, the following have been developed: (1) Ferrite sintered magnets having energy product as high as 5.12 MGOe (2) RIP setup for arc-segment magnets

Abstract BACKGROUND: The powder reaction moulding process uses a reactive monomer as carrier and binder for the moulding of metal or ceramic powders. De-binding is achieved using thermal depolymerisation which is followed by sintering to give the finished component. Binder can be recovered for re-use. RESULTS: Moulding compounds, with various powder volume fractions, have been prepared using stainless steel, silicon nitride and alumina with n-butyl cyanoacrylate as binder, and the stability of the compounds established.

A method of injection moulding or extruding an article is disclosed in which a ceramic and/or metallic powder is dispersed in a carrier to form a flowable composition. The carrier is preferably a monomeric cyanoacrylate which is reversibly polymerisable so as to yield a solid polymer, which in turn is capable of undergoing a thermally activated depolymerisation reaction so as to yield the monomeric species. The composition is injected into a mould or extruded through a die and the carrier polymerised in the mould or die.

New sintered Nd-Fe-B near net-shape magnets with a high remanent polarization of 1.47 T, a coercivity HcJ of 9.6 kA/cm (12 kOe) and a maximum energy density of 420 kJ/m3 (53 MGOe) can be manufactured by rubber isostatic pressing. The optimization of the remanent polarization by an improved alignment process of the powder particles results in a decrease of the coercivity by 0.4 kA/cm per 1 % ∆fφ for alignment coefficients fφ in the range 96 to 98 %. For alignment coefficients between 98 to 99 % the decrease of the coercivity even increases to about –1 kA/cm per % 1 ∆fφ.