Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Transfer moulding evaluation

EVALUATION OF EPOXIDE-BASED TRANSFER MOULDING COMPOUNDS... [Pg.166]

The TMS rheometer has been used to study mould release in rubbers. It contains a biconical rotor (representing the mould surface). The polymer is placed in the transfer chamber, injected around the rotor and cures in situ. Fig. 1. The shear stress required to free the rotor is taken as the mould-sticking index . The rheometer has the advantage that small experimental mixes of rubber can be evaluated. Further, the rotors are easily changed, so as to evaluate changes in mould surface, and the parted surfaces are amenable to examination by XPS and other methods of surface analysis. The obvious disadvantage is that access to special equipment (the TMS rheometer) is required. The same basic concept could be adapted for the study of mould adhesion of non-elastomeric polymers. [Pg.288]

Figure 44 Package constructions used to evaluate the thermal transfer properties of the die attachment materials and substrates. TO-3 steel package is composed of steel case la, OFHC copper 2a, nickel film 3, soft solder 4a, and integrated circuit 5. TO-3 aluminium package is formed of aluminium header lb plated with nickel 3 on the top of which a silver-filled epoxy adhesive 4b is employed to bond the semiconductor device 5. The 24-lead CERDIP package is based on nickel-plated alumina substrate Ic with soft solder bonded silicon chips. In 40-lead plastic package, integrated circuits 5 are bonded to leadframes 2b by using silver-filled epoxy adhesive 4b and then encapsulated in moulding... Figure 44 Package constructions used to evaluate the thermal transfer properties of the die attachment materials and substrates. TO-3 steel package is composed of steel case la, OFHC copper 2a, nickel film 3, soft solder 4a, and integrated circuit 5. TO-3 aluminium package is formed of aluminium header lb plated with nickel 3 on the top of which a silver-filled epoxy adhesive 4b is employed to bond the semiconductor device 5. The 24-lead CERDIP package is based on nickel-plated alumina substrate Ic with soft solder bonded silicon chips. In 40-lead plastic package, integrated circuits 5 are bonded to leadframes 2b by using silver-filled epoxy adhesive 4b and then encapsulated in moulding...
The characteristics of fluid flow and related mass transfer phenomena in the web forming systems have been simulated and compared, with the emphasis on the imiform distribution of fibers in the duct and mould chamber. The model was evaluated by comparing the actual fabric aerial density distributions of the three-dimensional nonwoven products. It was foimd that the vertically oriented web forming system significantly improved the imiformity of air velocities and fiber concentration around the moulds compared to the horizontal system. Also the experimental results for the aerial density distributions of the nonwoven products followed similar airflow pattern and fiber distribution obtained by the CFD model simulation. [Pg.278]


See other pages where Transfer moulding evaluation is mentioned: [Pg.403]    [Pg.5]    [Pg.122]   


SEARCH



Transfer moulding

© 2024 chempedia.info