“Rey Resin Dispense Pattern” A Solution to Package Voids Defect on Thinner Package Thickness in Compression Mold

This paper will discuss how package voids Mold defect was addressed on thinner Compression mold packages like BGA (Ball Grid Array) and Sensor Devices. Significant action was the application of “Rey Resin Dispense” pattern in compression mold granule compound dispensing was a key action in reducing package voids defect. Using a DMAIC methodology (Define, Measure, Analyze, Improve and Control), a powerful analytical tool that serves as a guide towards the success of eliminating package voids defect. Using this methodology, all Key Process Input Variables (KPIVs) of compression mold and its molding compound material were identified as X’s or potential causes and test its significance to affect Y-response which is the package voids. Funneling of X’s further trimmed to the most possible contributor to package voids. The remaining possible contributor X’s undergo statistical validation which point to granule compound resin dispensing as the main contributor to induce package voids defect. Several actions were tried but failed to zero-out the defect. With the help of brainstorming and imaginative ideas and data gathered on how to improve granule resin dispense of compression mold positive outcome was realized. From the concept of light ray, to naming it as “Rey Resin Dispense” significantly reduce package voids defect in all thin BGA and Sensor devices. This learning was then applied to all existing thin packages and to new packages in compression molding process.

Enabling Artificial Intelligence as Input Variable Control to Prevent Package Thickness Related Defect in Compression Molding

This paper aims to identify the causes of package thickness related defects in compression mold process. Related defects include wrong package thickness, exposed wire and/or die and mold bleed out. There are three scenarios why package thickness problem is encountered in compression molding. These include wrong mold recipe selected against the actual lot, wrong lot loaded against the current recipe loaded and product input to mold having irregularities such as presence of stray die or damage on strip side rails and end rails. Applying artificial intelligence (AI) the mold machine to detect all abnormalities identified at input and prevent it from proceeding to molding. Applying AI was able to eliminate occurrence of all package thickness related defects and machine related downtimes.

Improvement of Surface Quality of Casting Produced by Casting under Pressure

The article considers the surface roughness of compression molds castings received by casting under pressure depending on the condition of the form-building surface. The technological process of casting under pressure is presented for the "Strike plate" product, concrete technological parameters values are specified. The pilot studies of the roughness of the castings throughout the entire period of operation of a compression mold are conducted. Based on the received values the recommendations about improvement of quality of a surface of castings by drawing sheetings are submitted by phisical vapour deposition method.

Foamed lignin–silicone bio-composites by extrusion and then compression molding

Lignin-reinforced foams are efficiently prepared in a compression mold.

Compression Molding for Thin PoP Top Packages

The package on package (PoP) has become the preferred method for vertical stacking of logic processors and memory in mobile applications. The industry is constantly working toward reducing the total stack height, and current road maps point toward a total stack Z-height of 1mm. One approach to reduce the package height is to reduce the mold cap thickness as well as reduce the mold cap clearance (the distance between the top silicon die to the mold top). In this study, we used the compression molding for manufacturing top PoP packages with 200μm, 250μm, 300μm, and 350μm mold cap and with sub-100μm mold cap clearance. As part of the mold material selection, two different form factors, granular and powder form, of the mold compound were used for the compression mold process. The key objective for this study is to investigate compression mold process and to study its effect on the package integrity. The major challenge for PoP stack up is the package warpage at reflow temperatures. All the PoP packages must meet certain critical warpage criterion to meet board mount yield requirements. Warpage of the packages was measured by the shadow moiré method, and the warpage results for the packages molded by the transfer mold were compared against that of the compression molded packages. Results indicate that there is considerable difference in warpage behavior betwee n the pellet and powder form of the same mold compound. However, the granular form of the same mold compound resulted in similar warpage behavior of the pellet form mold compound. Further analysis was done to compare the filler distribution in the mold for transfer versus the compression mold process. Results indicate much uniform filler distribution in compression mold furthering evidence that the warpage for the unit level package will be uniform across the strip. Warpage results were analyzed using finite element methods, and the results are extrapolated to different package XY dimensions. The data obtained from these experiments show that the compression mold method can be potentially implemented for thin PoP top packages in the future.

Compression Molding of Polyethylene Foams under a Temperature Gradient: Morphology and Flexural Modulus

For any type of polymer foam, it is well known that careful control of the processing temperature has an important effect on final morphology. In this work, density graded polyethylene foams were produced by imposing a temperature gradient while foaming the sample. This was done by controlling independently the top and bottom plates of a compression mold at different temperatures. By doing so, different density profiles across the part's thickness are produced. In this work, the resulting morphologies are presented with their respective flexural moduli.