Advanced Materials Technologies Pte, Ltd.

Kay-Leong Lim

Lye-King Tan

Eng-Seng Tan

Robin Baumgartner

This invention describes a novel production method of manufacturing metal/ceramic articles with complex internal undercut features using powder injection molding processes The shape of the undercut/hollow feature is initially molded using a disposable material such as a degradable polymer. The PIM feedstock is then molded onto this to form the required shape geometry, in effect encapsulating the polymeric feature in the PIM feedstock. The resulting two-material part is then sent for processing which removes the polymer through solvent or thermal process. After the polymer and the binder have been removed, the part now comprises a powder skeleton that contains the internal undercut feature within itself. After sintering the result is a metal/ceramic part having an internal undercut feature. The technical advantage of the present invention is that it does not require complex toolings or costly secondary operations while retaining the flexibility to design any internal undercut features of complex geometry. An additional embodiment of the invention is also disclosed in which a solid structure is encapsulated inside a hollow shell said structure being free to move around inside the shell.

Net shaped articles having complex internal undercut features

A method to form a combined enclosure and heat sink structure for a semiconductor device is achieved. A first feedstock comprising a first mixture of powdered metal materials, lubricants, and binders is prepared. A second feedstock comprising a second mixture of powdered metal materials, lubricants, and binders is prepared such that the difference between the sintering shrinkage of each of the first and second feedstocks is less than 1%. The first and second feedstocks are pressed to form a first green part having an enclosure shape and a second green part having a heat sink shape. The lubricants and the binders from said first and second green parts are removed to form a first powdered skeleton and a second powdered skeleton. The first and second powdered skeletons are sintered to complete the combined enclosure and heat sink structure. The first and second powdered skeletons are in intimate contact during the sintering. Optionally, at least one hollow cooling channel is formed in the combine structure by burning away a fugitive plastic structure during the sintering process.

Enclosure for a semiconductor device

The invention shows how powder injection molding may be used to form a continuous body having multiple parts, each of which has different physical properties such as magnetic characteristics or hardness. This is accomplished through careful control of the relative shrinkage rates of these various parts. Additionally, care is taken to ensure that only certain selected physical properties are allowed to differ between the parts while others may be altered through relatively small changes in the composition of the feedstocks used. An additional application of the present invention is a process for forming, in a single integrated operation, an object that is contained within an enclosure while not being attached to said enclosure. This is accomplished by causing the shrinkage rate of the object to be substantially greater than that of the enclosure. As a result, after sintering, the object is found to have detached itself from the enclosure and is free to move around therein. Several examples of structures formed using these processes are presented.

Growing community of inventors

Singapore, Singapore

Kay-Leong Lim