For an antenna-like-element model appearing in a configuration of printed circuit boards consisting of a driver and a receiver boards separated by spacers on the chassis of which signal is connected each other through a semi-rigid cable, an equivalent circuit model is proposed and then the relation between input impedance and radiated emission characteristics is studied. By making a measurement of the radiated emission from the assembly and comparing the measured and the computed results of the input impedance of the concerned signal-ground containing the metal spacers, it is shown that the resonance frequencies in the input impedance characteristics and the peak frequencies in the radiated emission are in a good agreement. This means that the signal-ground system having the metal spacers results in a serious role of antenna. The equivalent circuit model proposed here is effective to estimate the peak frequencies in the radiated emission in addition to the evaluation of the input impedance characteristics.

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In this paper, prediction methods of solder joint shape, such as solder joint height and contact angle, for BGA package, which is effective on high density packaging, are studied. Various calculation methods to predict the solder joint shape are studied, and results of the calculation are compared to experimental results to confirm the validity of each calculation methods. Approximate polynomial of solder joint shape, such as solder joint height and contact angle are induced by combining numerical differential method and response surface method using orthogonal table. Next, FEM calculation of board warpage are analyzed to evaluate residual stress in solder solidification process.

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The examination of the STO (SrTiO₃) film capacitor process technology, which should be applicable to a resin-molded high frequency MCM, and the evaluation of high frequency characteristic of the capacitor fabricated using this technology have been carried out. The following results were obtained : (1) By the resin hardening treatment in vacuum and the coating a 200-nm-thick Pd or Al film on the Cu substrate, adhesion force between Cu substrate and the molded-resin became as about six times as that without coating on the Cu substrate, leading to the prevention of resin peeling from the Cu substrate. (2) 200-nm-thick STO film capacitors were formed on a resin multiple-layer film and showed the flat frequency performance up to 3GHz, the relative dielectric constant of 35 and the capacitor density of 1400 pF/mm². (3) It was clarified that the improvement of the STO film and the decrease of parasitic inductance are indispensable to the characteristic improvement of the STO film capacitor. The characteristic of the STO film should be going to be improved in terms of the MCM total process.

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The purpose of this paper is to investigate the effect of inside laminates on residual stress generated in multi-plied copper clad laminates during molding process, which is used widely for printed wiring board. First, a viscoelastic model including not only thermal shrinkage but also plastic deformation is proposed. The generation mechanism of residual stress introduced in the multi-plied copper clad laminates during molding process is qualitatively explained by using this viscoelastic model. Second, the fundamental equations are derived for the residual stress in the multi-plied copper clad laminates considering visco-elastic-plastic deformation. With the fundamental equations, the residual stresses in the multi-plied copper clad laminates with various inside laminates are calculated using each material characteristic. Finally, the residual stresses in the multi-plied copper clad laminates are measured carefully using the layer removal method. Comparing the theoretical and experimental results, the effect of inside laminates on residual stress generated in multi-plied copper clad laminates is discussed.

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A novel method is presented for the direct metallization of copper on a semi-cured polyimide resin substrates by the process of carboxylation of the resin surface, adsorption and reduction of copper ( II ) ions followed by thermocompression bonding. The potassium hydroxide treatment on polyimide resin lead to cleavage of imide ring to form the carboxyl group onto the resin surface, being responsible for the adsorption of copper ( II ) ions. The conductivity of the copper thin film formed by the reduction process was over 1.6×10^-2S/_??_ which was suitable for subsequent copper electroplating. The peel strength between polyimide film and copper film was reached to be 1.l0kN/m by thermocompression at 300°C under a pressure of 24.5MPa.

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The underfill process was examined to encapsulate the gaps less than 10μm in thickness between the 10-mm-square silicon chips and the interposer connected with 12μm bumps in 20μm pitch. The analysis by the finite element method (FEM) found that the filler particles in epoxy resin were necessary for the relaxation of the thermal stress on the top surface of the 50-μm-thickness thin silicon chip at the decrease of temperature, because the fillers could reduce the thermal stress contraction of the underfill resin. Then, the diameter of the filler particles incorporated in epoxy resin at 50% in weight was optimized as the 0.3pm in average and 0.35μm in maximum for the 3μm gap in thickness. As the results of the experiment on the encapsulation, it was confirmed that the optimum filler-dispersion could realize the underfill encapsulation for 20-μm-pitch flip-chip interconnections leading to the die-stacked 3D LSI.

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This paper reports on impedance analyses of power distribution planes for a BGA (Ball Grid Array) . The impedance characteristics were analyzed by using simple lumped constant circuits for the power distribution plane with various power supply paths, decoupling capacitors and layer thickness between ground plane and it. The analyzed characteristics were compared with the impedance characteristics obtained from the measurement of S₁₁. As a result, the analyzed characteristics agreed well with the measured characteristics. It is concluded that the impedance analyses using simple lumped constant circuits are effective for the estimation of impedance characteristics of power distribution planes for a BGA.

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Semiconductor optical device packages require precise positioning of submicron meter order and long term stability. When adhesive resin made of organic material is used to fix optical parts, one important concern is that it may reduce the stability of the packages. To clarify the moisture attack in adhesive resin, the material properties of the widely-used adhesive epoxy resin for optical parts fabrication have been investigated here by exposing it to high temperature and humidity. Length, weight, transition temperature and thermal expansion were measured in reliable test conditions of semiconductor packages. It is shown that severe degradation is caused when humidity is combined with conditions of high temperature. The decrement of transition temperature was expressed by a logarithmic equation in the range of 1000 hours. It was revealed that the degradation of epoxy resin was closely connected with the semiconductor laser package's power life.

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The dry film solder resist, named CFP1122, has been developed for tape CSP. This material mainly consists of thermosetting resin and photosensitive resin. This film can be easily laminated on uneven copper circuits without bubble by using the vacuum laminator. Though this resin is able to dissolve into the TMAH (tetramethyl- ammonium hydroxide) aqueous solution, this material can be developed without the infection of ionizable impurities with this resin. Also, the cured film has good properties as solder resist.

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We investigated the influence of organic nitrogen compounds (leveler) as additive for acid copper plating for via-filling. By applying of Cyclic Voltammetric Stripping (CVS), we confirmed the effect of leveler to copper electrodeposition. The leveler which is effective to via-filling inhibits electrodeposition with an increase in rotation speed of rotating disk electrode, and the effect to suppress electrodeposition is controlled by thickness of diffusion layer. Therefore, the electrodeposition at via outside having thin diffusion layer is suppressed and preferentially fill the via bottom. However, many levelers influence to film properties. Cationic dye decreases elongation and thiourea derivative increases internal stress. By selecting proper levelers (polyamine derivative), we could gain the additive having excellent via-filling effect and film properties.

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