SH 0408
                                                                            (Epoxy Encapsulant)
PRODUCT DESCRIPTION
SH0408 is a two component, unfilled, rigid potting epoxy resin for encapsulation of mainly LED SMD
devices. SH0408 has a special stress relieving mechanism that will allow superior reliability
performance. Special UV retardant is added to enhance the UV resistant properties. When casted, it
provides excellent clarity, thermal shock resistant and excellent environmental protection.
Key advantages of SH0408:
                     a) Achieve full cure in less than 6 hours
                     b) High purity material to ensure good consistency
                     c) Low mixed viscosity to allow easy casting
                    d) Stress relieving mechanism to offer superior reliability performance
TYPICAL PROPERTIES
Uncured:
Property                                                         04 (Part A)                       08 (Part B)                      Test Method
Color                                                                 Blue                                   Clear                          Visual

Viscosity @ 25°C, cP                                        2200±500                           95±55                        ASTM2393
Shelf life @ 30°C (from date of
manufacturing), month                                          12                                      12                           Use test
Property Specification Test Method                                      Color Water clear                             Visual
Mix Viscosity @ 25°C, cP                                                         500 ± 200                                      ASTM2393
Glass transition temperature (midpoint), °C                              160 ± 5                                        ASTM D3418
Coefficient of thermal expansion (a1),ppm                                < 75                                            ASTM D 696
Hardness @ 25°C,                                                                     Shore D 80-90                              ASTM D2240
Moisture absorption @ 100°C/24hrs, %                                           < 2                                        ASTM D570
HANDLING & MIXING
             Pre-Heating Part A (before mixing) = 70°C/ 1hour
              Mix Ratio (R: H) = 100 : 100

              Recommended weighing tolerance = ± 0.1g
              Pot Life (upon mixing Part A&B) = 4 hours
Caution!
Visually inspect containers of the resin before use. The Part B may crystallize upon storage due tohigh purity of the material. Do not use the material directly if crystal or sedimentation is visible.The Part B can be heated up to 60oC for 1 to 3 hours until material is totally liquid. Allow the PartB to cool down naturally to about 35oC before use. The anhydride system in Part B is moisturesensitive. Always reseal the opened container immediately after use. It is a good practice to purgewith nitrogen before resealing. Shake the bottle right before use and make sure that all ingredientsinside are properly mixed after storage. Preheat Part A to 70°C for an hour to reduce the viscosityand allow ease of flow. No reaction will take place. Pour the required quantity of Part B into thecontainer first. This is important as Part A has high viscosity and will adhere very well to the sidewall of the container making it difficult to mix homogeneously. Then stir gently manually to havepartial mix. Then use automated (preferably vacuum mixer) mixer to mix the Part A and Part B.Proceed to degassing if necessary. The degassing process can be facilitated with slight heating upto 35oC. Application of pressure should be around –30in Hg. Due to low molecular weight of Part
B, continuous bubbling may occur. Do not over degas the Part A and B mixture as continuousevaporation of Part B may offset the optimum mix ratio (10 to 20 minutes should be sufficient).

Initial cure Tg                              120°C/1hr
Subsequently cure Tg                150°C/3hrs
Oven ramp up from                     60 to 80 deg °C
Important!
SH0408 was found to be superior when cured using a step cure profile (continuous). We wouldsuggest the curing Tg at 1st Curing @ 120 -125 deg C, 2nd curing @ 135 -145 deg C.We are glad to suggest the initial curing profile for your kindly reference.1st Cure: 120 deg C @ 1 hour - Demold at 60 to 80 deg C , follow by 2nd Cure: 140 deg
C @ 2 – 3 hours. Temperature ramp up/start from 60 to 70 deg C. This is to avoid thestart temperature will ramp above 140 deg C if we start from 130 /135 deg C.As the oven setting temperature and the actual temperature may varied, the actual cureprofile may be varied, please refer to the Tg as a better reference.After cured the epoxy will have good adhesion with the lead frame and mold cupinterface. It is critical that customer apply mold release to the mold cup prior to castingthis material. If not increased demolding stress will compromise the packageperformance. It is recommended to apply the mold release before casting to reduce thedemolding force after cured.For demolding, it is recommended that the demolding temperature is ~40°C below Tg toavoid undesirable crazing or micro-crack (i.e. If product initial cure yields Tg of 100°C,the max recommended demolding temperature is at 60 to 80 °C
SAFETY AND FIRST AID
Prevent prolonged or frequent skin contact. Wear protective gears when mixing. Avoidinhalation of vapor. Mix in a well ventilated area. If contact occurs, was with soap and water. Please refer to MSDS for more information.
PACKAGING & STORAGE
SH0408 is available in 20kg per box (small packaging in 5kg for each Part A and Part B).It should be stored in a dry place, preferably in the sealed original container.
                                                                                                                                         Last update on 25 Mar 2011