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- LOCTITE ABLESTIK QMI3555R
LOCTITE ABLESTIK QMI3555R
- Wide processing window
- Low temperature profile
- Low stress on die
Product Description
LOCTITE ABLESTIK QMI 3555R is a low temperature processing, no dry, silver glass die attach adhesive for the attachment of integrated circuits in both solder seal and glass seal hermetic packages. It is designed for fast firing large die or small dies on either gold plated or bare ceramic substrates. The paste fires into a film that provides high thermal and electrical conductivity as well as excellent initial adhesion. It is extremely resistant to degradation during temperature cycling from -65°C to +150°C.
LOCTITE ABLESTIK QMI 3555R incorporates a patented silver/vanadium glass. Sub-350°C firing enhances the reliability of devices fabricated with sub-micron design rules. Also, in cofired package applications, nickel diffusion through gold plated seal rings and leadfinger pads are minimized at lower temperatures. QMI3555R low stress allows for a thin bondline, offering improved thermal performance for high power devices.
QMI 3555R can be fired at temperatures between 300°C and 450°C on bare ceramic. On gold plated parts, the minimum peak should be 325°C. The minimum dwell time should be at least 14 minutes above 300°C when the peak is <325°C. Higher peak temperatures require less dwell time. There should not be any rapid spikes in the ramp that would volatilize the solvents and create voids.
Technical Specifications
| General Properties | |||||||||
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| Physical Properties | |||||||||
| Thixotropic index Thixotropic index Thixotropic Index is a ratio of a material s viscosity at two different speeds in Ambient temperature, generally different by a factor of ten. A thixotropic material s viscosity will decrease as agitation or pressure is increased. It indicates the capability of a material to hold its shape. Mayonnaise is a great example of this. It holds its shape very well, but when a shear stress is applied, the material easily spreads. It helps in choosing a material in accordance to the application, dispense method and viscosity of a material. | 10 | ||||||||
| Viscosity Viscosity Viscosity is a measurement of a fluid’s resistance to flow. Viscosity is commonly measured in centiPoise (cP). One cP is defined as the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP. A product like honey would have a much higher viscosity -around 10,000 cPs- compared to water. As a result, honey would flow much slower out of a tipped glass than water would. The viscosity of a material can be decreased with an increase in temperature in order to better suit an application | 35,000 mPa.s | ||||||||
| Chemical Properties | |||||||||
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| Thermal Properties | |||||||||
| Thermal Conductivity Thermal Conductivity Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance. Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system. | 80 W/m.K | ||||||||
Additional Information
QMI 3555R can be fired at temperatures between 300°C and 450°C on bare ceramic. On gold plated parts, the minimum peak should be 325°C. The minimum dwell time should be at least 14 minutes above 300°C when the peak is <325°C. Higher peak temperatures require less dwell time. There should not be any rapid spikes in the ramp that would volatilize the solvents and create voids.
See the Technical Data Sheet for Firing profiles.