Provided herein are sinterable films and pastes as conductive die attach materials having advantageous properties for use in die semiconductor packages. Also provided are formulations useful for the preparation of such films and pastes, as well as methods for making such formulations. In additional aspects of the present invention, there are provided conductive networks prepared from compositions according to the present invention. In certain aspects, the invention relates to articles comprising such sintering films and pastes adhered to a suitable substrate therefor.

The present invention employs a flux which contains rosin, a solvent, a thixotropic agent and an activator. The thixotropic agent contains a polyamide (PA2). The PA2 is a condensation product of an aliphatic carboxylic acid, a hydroxy group-containing aliphatic carboxylic acid and an aliphatic amine having from 3 to 10 carbon atoms; and the aliphatic carboxylic acid includes an aliphatic dicarboxylic acid having from 11 to 20 carbon atoms. With respect to the endothermic amount calculated from the peak area of the differential scanning calorimetry curve of PA2 as obtained by differential scanning calorimetry measurement, the ratio of the endothermic amount within the range of from 50° C. to 190° C. to the total endothermic amount within the range of from 50° C. to 200° C. is 90% or more.

The present invention provides a bottom ohmic silver paste for strontium titanate ring varistor including silver powder, doped SnO.sub.2 micro powder, glass powder, organic solvent and organic binder, and the mass ratio of the silver powder, the doped SnO.sub.2 micro powder, the glass powder, the organic solvent and the organic binder is [65,85]:[0.9,4.3]:[0.5,5]:[10,20]:[10,15]. The present invention also provides a preparation method and use of the bottom ohmic silver paste for strontium titanate ring varistor of the present invention.

Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt % ratio of Sn:Sb of 0.75 to 1.1; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80 wt % of Sn; and a remainder of flux.

A flux paste composition including one or more fluoroaluminate based flux agents, one or more thickening agents, a carrier, a dispersant, a wetting agent, a defoamer, a moderator, and a biocide agent. The flux past composition can be blended with one or more rheological additives selected based upon printing the blended flux composition by a contactless inkjet printing system.

A lead-free, antimony-free tin solder which is reliable at high temperatures and comprises from 3.5 to 4.5 wt.% of silver, 2.5 to 4 wt.% of bismuth, 0.3 to 0.8 wt.% of copper, 0.03 to 1 wt.% nickel, 0.005 to 1 wt.% germanium, and a balance of tin, together with any unavoidable impurities.

There is provided a bonding paste capable of forming a uniform bonding layer by reducing occurrence of voids at edges even when a bonding area is large, and bonding method using the paste, and provides a metal paste for bonding containing at least metal nanoparticles (A) having a number average primary particle size of 10 to 100 nm, wherein a cumulative weight loss value (L.sub.100) when a temperature is raised from 40° C. to 100° C. is 75 or less, and a cumulative weight loss value (L.sub.150) when a temperature is raised from 40° C. to 150° C. is 90 or more, and a cumulative weight loss value (L.sub.200) when a temperature is raised from 40° C. to 200° C. is 98 or more, based on 100 cumulative weight loss value (L.sub.700) when the paste is heated from 40° C. to 700° C. at a heating rate of 3° C./min in a nitrogen atmosphere.

Provided herein are sinterable films and pastes as conductive die attach materials having advantageous properties for use in die semiconductor packages. Also provided are formulations useful for the preparation of such films and pastes, as well as methods for making such formulations. In additional aspects of the present invention, there are provided conductive networks prepared from compositions according to the present invention. In certain aspects, the invention relates to articles comprising such sintering films and pastes adhered to a suitable substrate therefor.

A metal composition that includes a first metal; and a second metal containing a first transition metal element added to a first alloy having a melting point higher than a melting point of the first metal, and the second metal is an alloy capable of producing an intermetallic compound with the first metal.

High reliability leadfree solder alloys for harsh service conditions are disclosed. In some embodiments, a solder alloy comprises 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a component comprising: a main ceramic body, and a side surface having disposed thereon an electrode and a thermal pad; a copper substrate; and a solder alloy electrically coupling the component and the copper substrate, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a light-emitting diode (LED) component; a Metal Core Printed Circuit Board (MCPCB); and a solder alloy electrically coupling the LED component and the MCPCB, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn.