CHO-BOND adhesives are electrically conductive epoxy and silicone resins. Curing mechanisms are either room temperature, elevated temperature or moisture. Both single and two-component systems are available, depending on the resin system selected.
Rigid Epoxy Adhesives
CHO-BOND epoxies are two-part, silver-filled or silver-plated-copper-filled adhesives which cure at room or elevated temperatures into rigid structural bonds. They’re used for bonding EMI vents, windows, ormesh gaskets, to shield permanent seams and for filling cracks and gaps.
CHO-BOND 360 compounds have large (>50 micron), silver-plated-copper particles, and are designed to bond poorly toleranced surfaces. The gritty filler bites through thin non-conductive surfaces such as oxide layers and MIL-C-5541 Class 3 irridite. Because its filler is a blend of pure silver and silver-plated-copper particles, CHO-BOND 360-208 adhesive offers superior shielding performance without requiring contact pressure, making this material an ideal fillet seal. Applications include bonding and shielding of cast aluminum housings, conduit bulkhead pass-throughs, filters, and fabricated metal cabinets.
CHO-BOND 500 series compounds are pure silver-filled materials used where tight tolerances require thin bond lines. Various cure cycles are available, and the materials are formulated for easy application by caulking gun, spatula, needle-spotting, or silkscreening. Their use for mesh gasket bonding, PC board repair, chip bonding, rear window defogger repair and as low-temperature-activated flexible solders demonstrates their versatility.
|Specifications and Product Characteristics (Contact Chomerics for complete specifications and test procedures)|
|Binder||epoxy||epoxy||epoxy||epoxy||epoxy||silicone||silicone||silicone||primer for 1029||primer for 1030|
|Mix Ratio (by wgt.)||1:1||100:33||100:6.3||1:1||100:50||1.0:2.5||1-part||1-part||1-part||1-part|
|Consistency||Medium paste||thick paste||thin paste||medium paste||nearly liquid||thick paste||gritty paste||medium paste||thin fluid||thin fluid|
|Specific Gravity||5.0± 0.30||4.0± 0.40||2.5± 0.20||2.7± 0.20||2.6 ±0.25||3.0 ±0.35||3.75 ±0.25||2.0± 0.25||0.87± 0.15||0.78± 0.10|
|Minimum Lap Shear Strength, psi (MPa)||1600 (11.04)||1400 (9.66)||1200 (8.28)||700 (4.83)||1500 (10.35)||450 (3.11)||200 (1.38)||100 (0.69)||N/A||N/A|
|Maximum DC Volume Resistivity, ohm-cm||0.005||0.01||0.002||0.005||0.05||0.06*||0.05||0.001||N/A||N/A|
|Use Temperature||-80 to 212°F(-62 to 100° C)||-80 to 212°F(-62 to 100° C)||-67 to 257°F(-55 to 125° C)||-80 to 210°F(-62 to 99° C)||-80 to 210°F(-62 to 99° C)||-67 to 257°F(-55 to 125° C)||-67 to 392°F(-55 to 200° C)||-67 to 392°F(-55 to 200° C)||-112 to 392°F(-80 to 200° C)||-112 to 392°F(-80 to 200° C)|
|Elevated Temperature Cure Cycle||2.0 hrs. @ 150°F (66°C)||0.75 hrs. @ 212°F (100°C)||0.25 hrs. @ 235°F (113°C)||0.75 hrs. @ 212°F (100°C)||0.5 hrs. @ 212°F (100°C)||0.5 hrs. @ 250°F (121°C)||N/A||N/A||N/A||N/A|
|Room Temperature Cure Time||24 hrs.||24 hrs.||24 hrs.||24 hrs.||1 wk.||1 wk.**||1 wk.**||1 wk.**||0.5 hr.||0.5 hr.|
|Working Life||1.0 hr.||1.0 hr.||0.5 hr.||1.0 hr.||4.0 hr.||2.0 hr.||0.5 hr.||0.25 hr.||N/A||N/A|
|Shelf Life, mos.||9||9||9||9||9||6||6||6||6||6|
|Coverage, in2/lb. (cm2/g)||500(7.1)||700 (9.9)||11,000 (156.1)||10,000 (141.9)||12,000 (170.3)||1,800 (25.5)||1,300 (18.5)||1,200 (170)||N/A||N/A|
|Recommended Thickness, in. (cm)||0.010 min. (0.03)||0.010 min. (0.03)||0.001 min. (0.003)||0.001 min. (0.003)||0.001 min. (0.003)||.008 max. (0.020)||0.010max. (0.03)||0.010 min (0.03)||.0002 max (0.001)||.0002 max (0.001)|
* Value represents DC resistance in ohms through a 0.4 in2by 0.008 in. (2.58 cm2 by 0.02 cm) thick sample.
** Cure is sufficient for handling in 24 hours. Full specification properties are developed after 1 week (168 hours.)
*** Values shown for 1075 reflect typical properties.
|360-20||Large particle size allows for thick bond-lines and oxide layer bite-thru.||1029||Two-component compound used with primer. Bond line <8 mils. (Conductivity decreases sharply>20 mils.) Long pot life. Cured under pressure (6 psi/0.04 MPa). For quick bonding of conductive elastomers.|
|360-208||Same as 360-20; no contact pressure required.||1030||One-component. Cures at room temperature and moderate humidity. Highly conductive. No corrosive curing agents. 30-minute set. Bond line must be<10 mils. High peel strength.|
|584-29||Excellent conductivity, easy application. Best general-purpose system. Available in pre-measured, ready-to-mix CHO-PAKs.||1075||For bonding Ag/Al conductive elastomers.|
|584-208||Ease of application for circuit board repair.||1085||Wipe on surface and let air dry 30-60 min.|
|592||Bonds dissimilar materials.||1086||Wipe on surface and let air dry 15-30 min.|