KONISHI FB500HB Electronic Adhesive for Flame-Retardant PCB Component Fixing

KONISHI FB500HB Electronic Adhesive Performance

FB500HB is the black version of the FB500H grade. It is supplied as a ready-to-use paste and cures through moisture in the surrounding air, eliminating resin-and-hardener weighing, mixing, and ratio-control errors. The material remains highly viscous after dispensing, helping it retain bead height and shape on vertical, curved, overhead, and irregular electronic components.

Current Konishi technical information lists a viscosity of approximately 130 to 280 Pa·s at 23°C and a skin-forming time of approximately 5 to 15 minutes at 23°C and 50% relative humidity. These characteristics provide a practical application window for component placement while reducing uncontrolled flow into connectors, switches, contacts, test points, and other areas that must remain free from adhesive.

After curing, the elastic polymer helps distribute stress between materials with different coefficients of thermal expansion. This is useful when bonding plastic components to metals or when securing components that experience vibration and repeated heating and cooling. Unlike a rigid adhesive, the flexible bond line can absorb movement and reduce concentrated stress around sensitive components and soldered areas.

KONISHI FB500HB Electronic Adhesive Applications

KONISHI FB500HB Electronic Adhesive is designed primarily for electrical and electronic component assembly. Typical applications include fixing capacitors, coils, relays, connectors, resistors, transformers, heat sinks, integrated circuits, lead wires, and other components to printed circuit boards or equipment housings. It may also be used for localized sealing, reinforcement, vibration damping, and gap-filling applications after process qualification.

The adhesive is suitable for bonding many compatible rigid materials, including polycarbonate, ABS, selected engineering plastics, aluminum, stainless steel, and other metals. It is especially useful for joining dissimilar materials where vibration or thermal cycling could cause a rigid adhesive to crack or transfer excessive stress to the component.

Konishi also identifies FB500H for evaluated heat-dissipation bonding between electronic components and aluminum housings. The product should not automatically be treated as a substitute for a dedicated high-performance thermal interface material, however. Designers should confirm thermal conductivity, bond-line thickness, operating temperature, heat flow, electrical requirements, and long-term reliability using current batch documentation and representative production assemblies.

7 Benefits of KONISHI FB500HB Electronic Adhesive

• UL 94 V-0 flame-retardant performance: Supports electronic assemblies with controlled flammability requirements.
• High-viscosity consistency: Retains bead shape and reduces sagging on vertical or irregular components.
• One-component processing: Requires no weighing, mixing, or separate curing agent.
• Flexible cured bond: Helps absorb vibration, impact, thermal expansion, and repeated temperature changes.
• Electronic insulation: Provides a high-resistivity elastic layer for properly designed electrical assemblies.
• Broad substrate adhesion: Bonds compatible polycarbonate, ABS, rigid plastics, metals, and electronic components.
• Environmental formulation: The product family is designed without tin compounds and low-molecular cyclic siloxanes.

KONISHI FB500HB Electronic Adhesive Technical Properties

Konishi’s current reference data lists maximum tensile stress of approximately 4.3 N/mm², elongation at break of about 38%, and cured durometer hardness near 88 Shore A. These properties create a comparatively firm elastic material that can retain components while still offering more movement accommodation than a rigid epoxy adhesive.

The published values are representative laboratory results and should not be treated as guaranteed finished-assembly specifications. Actual performance depends on the substrate grade, surface condition, adhesive thickness, ambient humidity, curing temperature, component geometry, operating load, chemicals, and environmental exposure.

Applying KONISHI FB500HB Electronic Adhesive

Ensure all surfaces are clean, dry, and free from oil, grease, dust, moisture, flux residue, release agents, oxidation, and loose contamination. Adhesion to smooth metal or plastic surfaces may benefit from controlled abrasion or an approved surface-treatment process, followed by complete removal of residue.

Cut the cartridge nozzle to the required opening and dispense a controlled bead around or beneath the component. Position the part before a surface skin forms and use clips, fixtures, or temporary support when necessary. Avoid applying excessive pressure that could squeeze all adhesive from the joint or push material into electrical contacts and ventilation areas.

Moisture-curing materials cure from the exposed surface inward. Thin beads with good atmospheric exposure cure faster than deep, enclosed, or completely sealed sections. Filling applications can therefore require additional curing time. Do not package, energize, thermally load, or expose the assembly to demanding service until sufficient cure has been confirmed.

Quality Control, Packaging, and Availability

Production qualification should evaluate dispensing consistency, bead dimensions, skin time, adhesion, component retention, electrical insulation, flammability requirements, vibration, humidity, thermal cycling, and long-term aging. The UL 94 V-0 classification applies to the manufacturer’s tested material and conditions; it does not automatically certify the complete electronic assembly.

The FB500HB commercial item is commonly identified as a black 333 ml cartridge with Konishi item number 05436. Japanese distributor records currently identify this exact item as discontinued, although Konishi continues to reference the FB500H product family in its electronic-material information. Customers should confirm genuine stock, manufacturing date, current technical documents, or the recommended successor before ordering.

Review the official Konishi electrical and electronic adhesive guide and the official Konishi electronic materials brochure for current properties, applications, regulatory information, and technical support.

Explore our flame-retardant electronic adhesives for additional PCB and component-fixing materials. Browse our flexible electronic adhesives for vibration resistance, sealing, insulation, reinforcement, and dissimilar-material bonding.