www.bergquistcompany.comAll statements, technical information and recommendations herein are based on tests we believe to be reliable, andTHE FOLLOWING IS MADE IN LIEU OF ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING THE IMPLIEDWARRANTIES OF MARKETABILITY AND FITNESS FOR PURPOSE. Sellers’ and manufacturers’ only obligation shall be toreplace such quantity of the product proved to be defective. Before using, user shall determine the suitability of the productfor its intended use, and the user assumes all risks and liability whatsoever in connection therewith. NEITHER SELLER NORMANUFACTURER SHALL BE LIABLE EITHER IN TORT OR IN CONTRACT FOR ANY LOSS OR DAMAGE, DIRECT,INCIDENTAL, OR CONSEQUENTIAL, INCLUDING LOSS OF PROFITS OR REVENUE ARISING OUT OF THE USE ORTHE INABILITY TO USE A PRODUCT. No statement, purchase order or recommendations by seller or purchaser notcontained herein shall have any force or effect unless in an agreement signed by the officers of the seller and manufacturer.

APN_Liquid TIMs_0115

Automated Dispensing of Liquid Thermal Interface Materials

Liquid Dispensed Materials Application Note

IntroductionThe automated dispensing of liquid Thermal InterfaceMaterials (TIMs) can lead to significant material cost and laborsavings in many applications. This application note describesconsiderations and recommendations when evaluating automated liquid dispensing.In order to optimize material usage, minimize cycle times and reduce total TIM cost, many customers are evaluating automated liquid dispensing. Bergquist offers one and two-component Thermal Interface Materials (TIMs) packagedin container kits compatible with this type of automated dispensing equipment. Typical container sizes for one-component materials are 600cc cartridge, 1-gallon & 5-gallonpails. For two-component materials, typical kit sizes are 400cc(200cc each of part A & B), 1200cc (two 600cc containers,one each of part A & B) and 10-gallon (two 5-gallon pails, one of each part A & B).Bergquist has aligned with specialized automated dispenseequipment manufacturers to further assist our customers increating an optimized dispensing process. For informationregarding dispense equipment manufacturers, please contactyour local Bergquist representative.

Dispense Equipment ConsiderationsBergquist recommends customers work closely with the selected dispense equipment manufacturer to conduct dispensing trials during the process design phase to confirmcompatibility of equipment with the selected TIM. This will helpensure the equipment is capable of handling expected TAKTtime, dispense rate, pattern design, placement precision, andvolume accuracy.Preventative Maintenance (PM) of equipment dispensing highlyfilled TIMs must be considered. The TIM filler particles are abrasive and can wear the moving parts and seals of a dispensing system. To ensure a high reliability dispensing system,the components in contact with the TIM must be designed forabrasion resistance. Adherence to the PM schedule will result inimproved accuracy and reduced down time.

Dispense Volume ControlThermal Interface Materials have inherent lot-to-lot variationin viscosity, therefore constant pressure or time-based dis-pensing will not provide consistent dispense volume accuracy,resulting in TIM waste and higher costs. The dispense equipment must accommodate this normal viscosity variationto achieve precise control. As standard practice, Bergquist recommends multiple product lots be considered in yourequipment qualifications.

To ensure consistent dispensed volume accuracy, Constant Volume Displacement Metering (CVDM) is highly recommended. This type of metering system dispenses a controlled volume of material regardless of the material viscosity.

Static Mixing Nozzles for Two-Component MaterialsDisposable plastic static mixing nozzles are used tothoroughly mix parts A andB together. They are reliable,accurate (+/- .5%) and inexpensive to use. Bergquistrecommends using mixingnozzles with a minimum of

21 mixing elements to ensure optimum mixing. Material should not sit idle in the mixing nozzle longer thanthe stated pot life of the material, as it will begin to thickenand eventually cure in the mixing nozzle. If this occurs, themixing nozzle must be replaced. In general, as temperatureincreases, pot life decreases. Therefore, if the ambient temperature at the point of dispensing is greater than 25°C,there may be a need to change out the mixing nozzle morefrequently than the typical pot life as published would indicate.The actual frequency of replacement should be determined bythe customer, based on their specific plant operating conditions and expectations.

The Bergquist Company - Asian HeadquartersHong KongPh: 852-2690-9296Fax: 852-2690-3408

The Bergquist Company - European HeadquartersNetherlandsPhone: 31-35-5380684Fax: 31-35-5380295

The Bergquist Company -North American Headquarters18930 West 78th StreetChanhassen, MN 55317Phone: 800-347-4572Fax: 952-835-4156

Filler Separation

Under normal storage conditions there will be minimal inherent separation of highly filled materials in the suppliedpackaging during the shelf life (up to 5% by weight possible).However, separation is normal and precautions should beimplemented when dispensing from a new cartridge or pail. Itis recommended to purge sufficient material until a uniformconsistency is achieved, prior to dispensing on product.Highly filled materials are pressure sensitive and can separateunder long term exposure to high pressures. The low molecular weight silicone portion of the material is verymobile and can migrate to low pressure areas. The remainingmaterial will have a slightly higher concentration of filler particles and may restrict the lines. Therefore it is important todispense the material with the lowest possible pressure.Placement of the CVDM pumping equipment as close to thedispensing head as possible to minimize the length of tubingrequired, and maximizing the diameter of the tubing, has beenshown to significantly reduce the overall pressure needed todispense the material.Avoiding sharp turns and elbows in the dispense lines will minimize pressure drops and prevent stagnant flow areas thatcan lead to filler build-up. Details of the tubing configurationand layout should be determined by working closely with theBergquist Field Applications Engineer and selected dispenseequipment vendor. Another likely cause for material separation is leaving pressure on the material during extendedinactivity. Since filled materials are not designed to withstandstatic pressure over long periods of time, Bergquist recommends removing all pressure from the dispensing system when not actively dispensing for periods extendingbeyond 30 minutes.

Air Entrainment

Care should be taken to avoid introducing air into the materialduring dispensing. The most common cause of air introductionis during cartridge or pail changeover. When changing to anew container, follow the dispense equipment manufacturer’sinstructions for purging any air from the system. Other causesof air introduction include air bypass around seals when usingpneumatic systems.

Material Bypass

Due to the high filler content of liquid TIMs and the specificdesign of each automated dispensing system, some materialbypass around the cartridge end caps or at the interface

between the pail follower plate may be noticed during dispensing. Bergquist products are packaged in cartridges andpails designed to minimize this phenomenon. Shipping packaging has been optimized to orient the cartridge tipdownward. It is recommended to store and dispense in thistip-down orientation, however, Bergquist cannot guaranteezero bypass during dispensing/application.

Material Compatability for Two-Component Silicone Materials

The following is a list of general categories of compounds thatmay inhibit or impact the rate of cure or poison the curingcatalyst in silicone based Thermal Interface Materials. It isimportant to understand the chemicals used in your processing and to avoid the use of these compounds forcleaning or priming of parts that will be in contact with silicone based TIM products.Compounds Containing Unsaturated Bonds• Alkenes and Olefins• Alkynes• AcrylatesCompounds Containing Nitrogen• Amines• Amides• Nitriles• Cyanates• Oximo, Nitroso, Hydrazo, and Azo compounds• Chelates– EDTA– NTA

Compounds Containing Sulfur• Sulfides• Thio compoundsCompounds Containing Phosphorous• Phosphines• PhosphitesOrganotin Compounds• Tin alkoxides• Tin carboxylatesIf there are potential compatibility concerns, please contactyour Bergquist representative.

www.bergquistcompany.comAll statements, technical information and recommendations herein are based on tests we believe to be reliable, andTHE FOLLOWING IS MADE IN LIEU OF ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING THE IMPLIEDWARRANTIES OF MARKETABILITY AND FITNESS FOR PURPOSE. Sellers’ and manufacturers’ only obligation shall be toreplace such quantity of the product proved to be defective. Before using, user shall determine the suitability of the productfor its intended use, and the user assumes all risks and liability whatsoever in connection therewith. NEITHER SELLER NORMANUFACTURER SHALL BE LIABLE EITHER IN TORT OR IN CONTRACT FOR ANY LOSS OR DAMAGE, DIRECT,INCIDENTAL, OR CONSEQUENTIAL, INCLUDING LOSS OF PROFITS OR REVENUE ARISING OUT OF THE USE ORTHE INABILITY TO USE A PRODUCT. No statement, purchase order or recommendations by seller or purchaser notcontained herein shall have any force or effect unless in an agreement signed by the officers of the seller and manufacturer.

APN_Liquid TIMs_0115

Automated Dispensing of Liquid Thermal Interface Materials

Liquid Dispensed Materials Application Note

IntroductionThe automated dispensing of liquid Thermal InterfaceMaterials (TIMs) can lead to significant material cost and laborsavings in many applications. This application note describesconsiderations and recommendations when evaluating automated liquid dispensing.In order to optimize material usage, minimize cycle times and reduce total TIM cost, many customers are evaluating automated liquid dispensing. Bergquist offers one and two-component Thermal Interface Materials (TIMs) packagedin container kits compatible with this type of automated dispensing equipment. Typical container sizes for one-component materials are 600cc cartridge, 1-gallon & 5-gallonpails. For two-component materials, typical kit sizes are 400cc(200cc each of part A & B), 1200cc (two 600cc containers,one each of part A & B) and 10-gallon (two 5-gallon pails, one of each part A & B).Bergquist has aligned with specialized automated dispenseequipment manufacturers to further assist our customers increating an optimized dispensing process. For informationregarding dispense equipment manufacturers, please contactyour local Bergquist representative.

Dispense Equipment ConsiderationsBergquist recommends customers work closely with the selected dispense equipment manufacturer to conduct dispensing trials during the process design phase to confirmcompatibility of equipment with the selected TIM. This will helpensure the equipment is capable of handling expected TAKTtime, dispense rate, pattern design, placement precision, andvolume accuracy.Preventative Maintenance (PM) of equipment dispensing highlyfilled TIMs must be considered. The TIM filler particles are abrasive and can wear the moving parts and seals of a dispensing system. To ensure a high reliability dispensing system,the components in contact with the TIM must be designed forabrasion resistance. Adherence to the PM schedule will result inimproved accuracy and reduced down time.

Dispense Volume ControlThermal Interface Materials have inherent lot-to-lot variationin viscosity, therefore constant pressure or time-based dis-pensing will not provide consistent dispense volume accuracy,resulting in TIM waste and higher costs. The dispense equipment must accommodate this normal viscosity variationto achieve precise control. As standard practice, Bergquist recommends multiple product lots be considered in yourequipment qualifications.

To ensure consistent dispensed volume accuracy, Constant Volume Displacement Metering (CVDM) is highly recommended. This type of metering system dispenses a controlled volume of material regardless of the material viscosity.

Static Mixing Nozzles for Two-Component MaterialsDisposable plastic static mixing nozzles are used tothoroughly mix parts A andB together. They are reliable,accurate (+/- .5%) and inexpensive to use. Bergquistrecommends using mixingnozzles with a minimum of

21 mixing elements to ensure optimum mixing. Material should not sit idle in the mixing nozzle longer thanthe stated pot life of the material, as it will begin to thickenand eventually cure in the mixing nozzle. If this occurs, themixing nozzle must be replaced. In general, as temperatureincreases, pot life decreases. Therefore, if the ambient temperature at the point of dispensing is greater than 25°C,there may be a need to change out the mixing nozzle morefrequently than the typical pot life as published would indicate.The actual frequency of replacement should be determined bythe customer, based on their specific plant operating conditions and expectations.

The Bergquist Company - Asian HeadquartersHong KongPh: 852-2690-9296Fax: 852-2690-3408

The Bergquist Company - European HeadquartersNetherlandsPhone: 31-35-5380684Fax: 31-35-5380295

The Bergquist Company -North American Headquarters18930 West 78th StreetChanhassen, MN 55317Phone: 800-347-4572Fax: 952-835-4156

Filler Separation

Under normal storage conditions there will be minimal inherent separation of highly filled materials in the suppliedpackaging during the shelf life (up to 5% by weight possible).However, separation is normal and precautions should beimplemented when dispensing from a new cartridge or pail. Itis recommended to purge sufficient material until a uniformconsistency is achieved, prior to dispensing on product.Highly filled materials are pressure sensitive and can separateunder long term exposure to high pressures. The low molecular weight silicone portion of the material is verymobile and can migrate to low pressure areas. The remainingmaterial will have a slightly higher concentration of filler particles and may restrict the lines. Therefore it is important todispense the material with the lowest possible pressure.Placement of the CVDM pumping equipment as close to thedispensing head as possible to minimize the length of tubingrequired, and maximizing the diameter of the tubing, has beenshown to significantly reduce the overall pressure needed todispense the material.Avoiding sharp turns and elbows in the dispense lines will minimize pressure drops and prevent stagnant flow areas thatcan lead to filler build-up. Details of the tubing configurationand layout should be determined by working closely with theBergquist Field Applications Engineer and selected dispenseequipment vendor. Another likely cause for material separation is leaving pressure on the material during extendedinactivity. Since filled materials are not designed to withstandstatic pressure over long periods of time, Bergquist recommends removing all pressure from the dispensing system when not actively dispensing for periods extendingbeyond 30 minutes.

Air Entrainment

Care should be taken to avoid introducing air into the materialduring dispensing. The most common cause of air introductionis during cartridge or pail changeover. When changing to anew container, follow the dispense equipment manufacturer’sinstructions for purging any air from the system. Other causesof air introduction include air bypass around seals when usingpneumatic systems.

Material Bypass

Due to the high filler content of liquid TIMs and the specificdesign of each automated dispensing system, some materialbypass around the cartridge end caps or at the interface

between the pail follower plate may be noticed during dispensing. Bergquist products are packaged in cartridges andpails designed to minimize this phenomenon. Shipping packaging has been optimized to orient the cartridge tipdownward. It is recommended to store and dispense in thistip-down orientation, however, Bergquist cannot guaranteezero bypass during dispensing/application.

Material Compatability for Two-Component Silicone Materials

The following is a list of general categories of compounds thatmay inhibit or impact the rate of cure or poison the curingcatalyst in silicone based Thermal Interface Materials. It isimportant to understand the chemicals used in your processing and to avoid the use of these compounds forcleaning or priming of parts that will be in contact with silicone based TIM products.Compounds Containing Unsaturated Bonds• Alkenes and Olefins• Alkynes• AcrylatesCompounds Containing Nitrogen• Amines• Amides• Nitriles• Cyanates• Oximo, Nitroso, Hydrazo, and Azo compounds• Chelates– EDTA– NTA

Compounds Containing Sulfur• Sulfides• Thio compoundsCompounds Containing Phosphorous• Phosphines• PhosphitesOrganotin Compounds• Tin alkoxides• Tin carboxylatesIf there are potential compatibility concerns, please contactyour Bergquist representative.