Thermal Conductivity Measurement Method for the Thin Epoxy Adhesive Joint Layer

Epoxy adhesives, particularly for non-conductive pastes, are used in 3D chip-stack flip-chip packages to reinforce the mechanical strength of joints. Although the thickness of the adhesive layer is relatively small, its thermal conductivity is known to have a major effect on the heat dissipation behavior of chipstack packages. Because conventional thermal conductivity measurement methods such as the laser flash method are based on the bulk specimens having thicknesses greater than several mm, they are limited in their ability to measure the thermal conductivity of thin adhesive layers between silicon dies. In this study, a modified guarded hot-plate method is proposed using standard joint layer samples of known thermal conductivity, and the measurement results are compared with those of the laser flash method. Results showed that, based on a constant heat flux from heat source to heat sink, the temperature difference at both sides of the joint layers was proportional to the thermal resistivity of the joint layer materials. The thermal conductivity of the under-test joint layer could therefore be determined from the thermal conductivity spectrum of the known samples using a graphical method. Although the measured values by the modified guarded hot-plate method were slightly higher than those derived from the laser flash method due to the thickness effect, it was concluded that the modified guarded hot-plate method could be a practical method in measuring the thermal conductivity of thin adhesive joint layers.

Guarded hot plate apparatus design and construction for thermal conductivity measurements

A Guarded Hot Plate (GHP) appartus was designed and built for high temperatue applications, consistent with or better than the established standards. This apparatus consists of a hot and a cold plate, attached to a frame, which allows the plates to be tilted from horizontal to vertical and configured for heating from the top to the bottom. The plates are independently heated by passing heat transfer fluid through a flow distribution system consisting of manifolds and internal flow passages, machined in each plate. Attached to the hot plate are an electrically heated heater plate and a heat flux meter, configured consistent with the hybrid method for measuring heat flux. This apparatus is designed to measure thermal conductivity of soils at different moisture contents and for temperatures ranging from -20⁰C to 200⁰C. An error analysis for the thermal conductivity measurement shows a conservative estimate of the bias error to be around [plus or minus] 2%.

Guarded hot plate apparatus design and construction for thermal conductivity measurements

A Guarded Hot Plate (GHP) appartus was designed and built for high temperatue applications, consistent with or better than the established standards. This apparatus consists of a hot and a cold plate, attached to a frame, which allows the plates to be tilted from horizontal to vertical and configured for heating from the top to the bottom. The plates are independently heated by passing heat transfer fluid through a flow distribution system consisting of manifolds and internal flow passages, machined in each plate. Attached to the hot plate are an electrically heated heater plate and a heat flux meter, configured consistent with the hybrid method for measuring heat flux. This apparatus is designed to measure thermal conductivity of soils at different moisture contents and for temperatures ranging from -20⁰C to 200⁰C. An error analysis for the thermal conductivity measurement shows a conservative estimate of the bias error to be around [plus or minus] 2%.

An experimental study of soil thermal conductivity using a guarded hot plate apparatus

A guarded hot plate apparatus was used to generate comprehensive sets of thermal conductivity for two types of soils, namely Ottawa sand and Richmon Hill clay-loam, for temperature variation from 2 to 92°C and moisture content variation from complete dryness to full saturation with measurement errors of less than 3%. Numerical simulation of heat transfer within the apparatus with sample inside was performed to validate the experimental design and setup. To prepare the samples, a consistent specimen preparation technique was developed for the cases of dry, barely-to-moderately moist, and highly-to-fully saturated moist soils. On the basis of gathered datasets, empirical correlations for soil thermal conductivity were developed as a function of both temperature and moisture content. The proposed correlations produced excellent fit to majority of the experimental data, and could be easily integrated into numerical analysis of underground heat transfer. As an application example, one of the correlations was employed to evaluate soil thermal conductivity in a numerical study of underground heat loss from a basement wall and floor, in order to illustrate the importance of considering the dependence of soil thermal conductivity on soil texture, temperature and degree of saturation.

An experimental study of soil thermal conductivity using a guarded hot plate apparatus

A guarded hot plate apparatus was used to generate comprehensive sets of thermal conductivity for two types of soils, namely Ottawa sand and Richmon Hill clay-loam, for temperature variation from 2 to 92°C and moisture content variation from complete dryness to full saturation with measurement errors of less than 3%. Numerical simulation of heat transfer within the apparatus with sample inside was performed to validate the experimental design and setup. To prepare the samples, a consistent specimen preparation technique was developed for the cases of dry, barely-to-moderately moist, and highly-to-fully saturated moist soils. On the basis of gathered datasets, empirical correlations for soil thermal conductivity were developed as a function of both temperature and moisture content. The proposed correlations produced excellent fit to majority of the experimental data, and could be easily integrated into numerical analysis of underground heat transfer. As an application example, one of the correlations was employed to evaluate soil thermal conductivity in a numerical study of underground heat loss from a basement wall and floor, in order to illustrate the importance of considering the dependence of soil thermal conductivity on soil texture, temperature and degree of saturation.

KOMPOSIT SANDWICH HYBRID KOMBINASI SERAT TANDAN KOSONG KELAPA SAWIT DAN SERAT KACA DENGAN MATRIX POLYURETHANE

<p>Komposit Sandwich Hybrid kombinasi antara serat tandan kosong kelapa sawit dan serat kaca dengan matrix polyurethane adalah sebuah trobosan baru sebagai bahan pengganti yang mampu menyerap suara dan penyerap panas dengan ramah lingkungan. Kemampuan penyerapan suara dan penyerapan panas sangat di perhitungkan. Pada penelitian ini memiliki tujuan untuk mendapatkan hasil dari pengaruh penambahan fraksi serat pada penyerapan suara dan penyerapan panas. Metode pegujian mengacu pada standar ASTM C177-13. Pengujian ini bertujuan untuk mengetahui nila koefisien perpindahan panas secata konduksi, dengan cara mengetahui seberapa besar konduktivitas thermal dari suatu material. ASTM C 177-13 merupakan metode yang pengujiannya menetapkan syarat desain yang diperlukan dalam membuat dan mengoperasikan guarded hot-plate Pada penyerapan panas penambahan fraksi membuat menurunnya nilai Konduktifitas thermal karena bertambah padatnya strukur pada inti atau core yang diisi dengan serat tandan kosong kelapa sawit. Nilai Konduktifitas yang baik terdapat pada fraksi 20% dikarenakan jumlah serat yang sedikit maka mampu terjadinya perpindahan panas. Perbandingan dari penelitian yang sudah pernah dilakukan menghasilkan nilai koefisien konduktifitas termal pada penelitian ini lebih besar dikarenakan bertambahnya nilai fraksi yang digunakan atau semakin banyak serat yang digunakan semakin rapat dan mempersulit penyebaran suhu. Dari penelitian ini dapat disimpulkan bahwa pada komposit sandwich hybrid serat tandan kosong kelapa sawit dan serat kaca dengan matrix polyurethane ini akan semakin menurun konduktivitasnya jika penambahan serat tandan kosong kelapa sawit.</p>