Managing Epoxy Tailing in Die Attach thru Design of Experiment

Die attach epoxy dispensing is an automated factory environment that creates some special challenges. A robust production process begins with an understanding of the adhesives in their fluid state and which important parameters must be controlled. One of the most common problems encountered with adhesives in Die attach process is epoxy tailing. Tailing in this sense means the peak of the dispensed material falls away from the center of the dot when the nozzle finishes dispensing. Dispensing requirements, techniques, and equipment resulting from this experience are discussed. Guidelines for optimizing quality is given. In this research, epoxy-associated defects are eliminated by optimizing the Break tail parameter using the Design of Experiment (DOE) methodology. The DOE prediction profile result shows that the tailing parameters recommended is Broken tail delay: 200 ms and Break tail offset is 350 counts. This study is applicable for silver filled conductive adhesive epoxy with greater than 9K Viscosity and greater than 4 Thixotropic Index.

Multivariate Curve Resolution–Alternating Least Squares (MCR-ALS) with Raman Imaging Applied to Lunar Meteorites

Lunar meteorites provide a more random sampling of the surface of the Moon than do the returned lunar samples, and they provide valuable information to help estimate the chemical composition of the lunar crust, the lunar mantle, and the bulk Moon. As of July 2014, ∼96 lunar meteorites had been documented and ten of these are unbrecciated mare basalts. Using Raman imaging with multivariate curve resolution–alternating least squares (MCR-ALS), we investigated portions of polished thin sections of paired, unbrecciated, mare-basalt lunar meteorites that had been collected from the LaPaz Icefield (LAP) of Antarctica—LAP 02205 and LAP 04841. Polarized light microscopy displays that both meteorites are heterogeneous and consist of polydispersed sized and shaped particles of varying chemical composition. For two distinct probed areas within each meteorite, the individual chemical species and associated chemical maps were elucidated using MCR-ALS applied to Raman hyperspectral images. For LAP 02205, spatially and spectrally resolved clinopyroxene, ilmenite, substrate-adhesive epoxy, and diamond polish were observed within the probed areas. Similarly, for LAP 04841, spatially resolved chemical images with corresponding resolved Raman spectra of clinopyroxene, troilite, a high-temperature polymorph of anorthite, substrate-adhesive epoxy, and diamond polish were generated. In both LAP 02205 and LAP 04841, substrate-adhesive epoxy and diamond polish were more readily observed within fractures/veinlet features. Spectrally diverse clinopyroxenes were resolved in LAP 04841. Factors that allow these resolved clinopyroxenes to be differentiated include crystal orientation, spatially distinct chemical zoning of pyroxene crystals, and/or chemical and molecular composition. The minerals identified using this analytical methodology—clinopyroxene, anorthite, ilmenite, and troilite—are consistent with the results of previous studies of the two meteorites using electron microprobe analysis. To our knowledge, this is the first report of MCR-ALS with Raman imaging used for the investigation of both lunar and other types of meteorites. We have demonstrated the use of multivariate analysis methods, namely MCR-ALS, with Raman imaging to investigate heterogeneous lunar meteorites. Our analytical methodology can be used to elucidate the chemical, molecular, and structural characteristics of phases in a host of complex, heterogeneous geological, geochemical, and extraterrestrial materials.

ANALISIS PENGUJIAN STRUKTUR BALOK LAMINASI KAYU SENGON DAN KAYU KELAPA

Wood Sengon (Sengon) is a type of timber that can quickly grow, accessible but its use as a construction material has not been optimized. The technology used to support the wood as a construction material is a laminate. Engineering experiments was done by making laminated beams of wood Sengon and wood coconut. The purpose of this study is to determine how much the increase in flexural strength for laminated wood Sengon beams and wood Coconut beams as a replacement of structural beam with a variety of adhesive and timber placement. The method used is an experimental method for flexural strength testing of laminated beams. The results showed an average flexural strength of the maximum obtained in laminated beams with variations EP-S (adhesive epoxy glue and placement position in the wood Sengon) amounted to 679 350 kg / cm2. An increase in the strength of 254 025 kg / cm2 (59.72%) are from wood Sengon bending strength 425 325 kg / cm2 (probe grade IV) to 679 350 kg / cm2 (strong class III). The use of technology should pay attention to the position of the bearing laminated wood. Wood with strong higher class should be put on the outside position to provide reinforcement for the wood with a powerful low grade placed in the position.Kayu Sengon (Sengon) termasuk dalam jenis kayu yang dapat dengan cepat tumbuh, mudah di dapat tetapi penggunaannya sebagai bahan konstruksi belum optimal. Teknologi yang digunakan guna mendukung kayu sebagai bahan konstruksi adalah dengan laminasi. Rekayasa eksperimen dilakukan dengan membuat balok laminasi dari kayu Sengon dan kayu Kelapa. Tujuan penelitian ini adalah untuk mengetahui seberapa besar peningkatan kuat lentur balok kayu dengan laminasi Sengon dan Kelapa sebagai pengganti balok struktur dengan variasi bahan perekat dan perletakan kayu. Metode penelitian yang digunakan adalah metode eksperimen untuk pengujian kuat lentur balok laminasi. Hasil penelitian menunjukkan kuat lentur rata-rata maksimum diperoleh pada balok laminasi dengan variasi EP-S (perekat lem epoksi dan perletakan posisi kayu Sengon didalam) sebesar 679.350 kg/cm2. Terjadi peningkatan kekuatan sebesar 254.025 kg/cm2 (59.72%) yaitu dari kuat lentur kayu Sengon 425.325 kg/cm2 (kelas kuar IV) menjadi 679.350 kg/cm2(kelas kuat III). Penggunaan teknologi laminasi hendaknya memperhatikan posisi perletakan kayu. Kayu dengan klas kuat lebih tinggi diletakkan pada posisi luar untuk memberikan perkuatan pada kayu dengan kelas kuat rendah yang terletak pada posisi dalam.