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

2015 ◽  
Vol 17 (9) ◽  
pp. 4647-4656 ◽  
Author(s):  
Jianfeng Zhang ◽  
Etienne Fleury ◽  
Michael A. Brook
Keyword(s):  
Compression Molding ◽  
Compression Mold

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

Compression Molding for Thin PoP Top Packages

2010 ◽  
Vol 2010 (1) ◽  
pp. 000554-000558
Author(s):  
Ravikumar Adimula ◽  
Jason Brand ◽  
Myung Jin Yim ◽  
James Zhang ◽  
Richard Strode ◽  
...  
Keyword(s):  
Material Selection ◽  
Form Factors ◽  
Compression Molding ◽  
Mold Material ◽  
Powder Form ◽  
Road Maps ◽  
Moire Method ◽  
Pellet Form ◽  
Filler Distribution ◽  
Compression Mold

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.

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

2020 ◽  
pp. 9-21
Author(s):  
Ernani D. Padilla ◽  
Emmanuel P. Birog
Keyword(s):  
Artificial Intelligence ◽  
Compression Molding ◽  
Variable Control ◽  
Related Defect ◽  
Die And Mold ◽  
Compression Mold

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.

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

2009 ◽  
Vol 28 (4) ◽  
pp. 237-248 ◽  
Author(s):  
Mohamad Reza Barzegari ◽  
Jiaolian Yao ◽  
Denis Rodrigue
Keyword(s):  
Temperature Gradient ◽  
Flexural Modulus ◽  
Compression Molding ◽  
Processing Temperature ◽  
Polymer Foam ◽  
Density Profiles ◽  
Careful Control ◽  
Different Temperatures ◽  
Compression Mold

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.

PRESSURDIE-3

Alloy Digest ◽  
1954 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Compression Strength ◽  
Heat Treating ◽  
Compression Molding ◽  
Type Alloy ◽  
High Compression ◽  
Steel Industries ◽  
Class Iv

Abstract PRESSURDIE-3, developed particularly for injection and compression molding, has high compression strength, wear resistance, and corrosion resistance. It is a ASM Class IV-B type alloy. This datasheet provides information on composition and hardness. It also includes information on forming, heat treating, and machining. Filing Code: TS-19. Producer or source: Continental Copper & Steel Industries Inc..

scholarly journals Dynamic Crosslinking: An Efficient Approach to Fabricate Epoxy Vitrimer

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 919
Author(s):  
Yin Ran ◽  
Ling-Ji Zheng ◽  
Jian-Bing Zeng
Keyword(s):  
Stress Relaxation ◽  
Production Efficiency ◽  
Specific Property ◽  
Sebacic Acid ◽  
Compression Molding ◽  
Diglycidyl Ether ◽  
Self Healing ◽  
Gel Fraction ◽  
A New Technique ◽  
Transesterification Catalyst

Epoxy vitrimers with reprocessability, recyclability, and a self-healing performance have attracted increasingly attention, but are usually fabricated through static curing procedures with a low production efficiency. Herein, we report a new approach to fabricate an epoxy vitrimer by dynamic crosslinking in a torque rheometer, using diglycidyl ether of bisphenol A and sebacic acid as the epoxy resin and curing agent, respectively, in the presence of zinc acetylacetonate as the transesterification catalyst. The optimal condition for fabricating the epoxy vitrimer (EVD) was dynamic crosslinking at 180 °C for ~11 min. A control epoxy vitrimer (EVS) was prepared by static curing at 180 °C for ~11 min. The structure, properties, and stress relaxation of the EVD and EVS were comparatively investigated in detail. The EVS did not cure completely during static curing, as evidenced by the continuously increasing gel fraction when subjected to compression molding. The gel fraction of the EVD did not change with compression molding at the same condition. The physical, mechanical, and stress relaxation properties of the EVD prepared by dynamic crosslinking were comparable to those of the EVS fabricated by static curing, despite small differences in the specific property parameters. This study demonstrated that dynamic crosslinking provides a new technique to efficiently fabricate an epoxy vitrimer.

Decreasing the cycle time for in‐mold coating (IMC) of sheet molding compound (SMC) compression molding

2019 ◽  
Vol 59 (6) ◽  
pp. 1158-1166 ◽  
Author(s):  
Mohammad S.K. Bhuyan ◽  
Seunghyun Ko ◽  
Maria G. Villarreal ◽  
Elliott J. Straus ◽  
Lee James ◽  
...  
Keyword(s):  
Cycle Time ◽  
Compression Molding ◽  
Molding Compound ◽  
Sheet Molding Compound
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