Conductive composition

Abstract

The purpose of the present invention is to provide a means which exhibits excellent heat resistance and mounting reliability when a semiconductor power element is bonded to a metal lead frame, and which is free from lead, thereby placing little burden on the environment. Namely, a conductive composition that contains, as essential components, at least a sulfide compound represented by R-S-R' (wherein R is an organic group containing at least carbon; R' is an organic group that is the same as or different from the R moiety; and the R and R' moieties may combine with each other to form a so-called cyclic sulfide) and metal particles containing at least Cu, Sn or Ni. A conductive paste and a conductive bonding film, each of which is produced using this conductive composition; and a dicing diebonding film which is obtained by bonding the conductive bonding film and an adhesive tape.

Description

technical field [0001] The present invention relates to a conductive composition. Specifically, it relates to a conductive paste, a conductive adhesive composition, a conductive adhesive film made of the same, and a dicing die-bonding film bonded to an adhesive tape. Background technique [0002] Lead-free solders have been widely used in the past to join semiconductor power devices such as IGBTs (Insulated Gate Bipolar Transistors) and MOS-FETs (Field Effect Transistors) to metal lead frames. However, the harmfulness of lead has recently become a problem. In addition, in recent years, in the context of seeking higher density energy control, research on power elements using wide bandgap semiconductors such as SiC and GaN that can withstand junction temperatures of 200°C or higher is underway. The crystal melting point is low, and the insufficient heat resistance of the joint part becomes a bottleneck. [0003] Based on the above background, various types of lead-free solde...

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Problems solved by technology

However, even diffusion sintering type solder has slightly poorer wettability than lead solder, so bonding 5mm 2 For the above large-area components, there is still the risk of solder leakage, and the sintered body is hard and brittle, and the stress relaxation is low. Therefore, it has the disadvantages of low thermal fatigue resistance and short component life.

[0005] In addition to the above-mentioned lead-free solder, Ag paste and the like are also used, but the material cost becomes very high, and contamination due to the migration of Ag ions becomes a problem

[0006] In addition, in many lead solders and lead-free solders, fluxes composed of carboxylic acids and alcohols are usually added for the purpose of removing metal oxide films. Both the oozing of flux and the oozing part of the flux have a negative impact on the reflow resistance reliability (MSL) after moisture absorption in the hermetic package of the semiconductor device. In the past, it was necessary to clean the flux after soldering, and the handling and cleaning waste liquid treatment was as a problem

However, in order to reduce moisture absorption and bleeding, if carboxylic acid and alcohol are not added, the ability to remove the oxide film is insufficient, and it is difficult to express conductivity and other properties

[0007] Moreover, in Patent Document 4, it is described that mercaptans and thioethers are used as fluxes in an adhesive composition using silver as an inorganic filler for semiconductor devices, but silver is expensive and ion migration is likely to occur. , there is a greater risk of an undesired short circuit between the electrodes

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