1- What is 2- How does it work? 3- How do we make it? 4- Applications 5- Processing?
WHAT IS?
Thick aluminium based substrate, cladded in ED copper foil. Designed for an effective thermal dissipation and high electrical insulation. Our proprietary formulated polymer-ceramic, ensures high thermal conductivity, dielectric strength, and thermal endurance. Insulated Metal Substrate allows: *Processing by standard PCBs procedures. *Integrating heat dissipation with no need for extra components *SMD assembly process
HOW DO AND OTHER IMS WORK?
Heat Generating Component q in T 1 (1) Cu (2) Dielectric layer (3) Al T 2 T 3 k A =thermal conductivity of Cu (W/mᵒC) k B =thermal conductivity of dielectric (W/mᵒC) k C =thermal conductivity of Al (W/mᵒC) x A = Cu thickness (m) x B = Dielectric thickness (m) x C = Al thickness (m) q out (conduction to dissipator) T 4 T environment q in /A=q out /A=-k A (T 2 -T 1 )/ x A =-k B (T 3 -T 2 )/ x B =-k C (T 4 -T 3 )/ x C q/a=(t 1 -T 4 )/( X A /k A + X B /k B + X C /k C ) *steady state conditions
q, A, fixed by design. Ideally: T 1 T 4 (environment) So: Small X, Large k desired Limitations for X: Limitations for k: dielectric properties, conductivity, mechanical constraints, production limitations, etc. dielectric properties, material choice limitations.
External radiators are usually added to the system to enhance heat dissipation q in T 1 Cobritherm Thermal interface material. Radiator/Dissipator q out T 6 =T environment (natural or forced convection to environment)
H E A T D I S S I P A T I O N PCB Laminates (Copper clad materials FR-4) Composite IMS (COBRITHERM ) Ceramic Substrates (DCB), Alumina or Aluminium Nitride and Copper COST
ADVANTAGES OF IMS Perfect for cooling surface mount components Insulating layer: The key element of IMS, allows high electrical isolation and good thermal dissipation Thermal Conductivity in the range of 0,6 to 3 W/mK Low cost Greater robustness Good workability Possibility of bigger dimensions than DCBs
CERAMIC SUBSTRATES(DCB), ALUMINA OR ALUMINIUM NITRIDE AND COPPER Advantages The most effective in thermal dissipation. Thermal Conductivity of typical alumina DCB:20 W/mºK Ideal for operating at high temperatures Elevated price Disadvantages Fragility Limited size of the substrates Low workability
PCB LAMINATES (COPPER CLAD MATERIALS FR-4) *Thermal Conductivity: Max. 0,3 W/mK. *Thermal performance: Far below IMS and DCB *Not recommended for components with high thermal operation.
HOW DO WE MAKE?
ALUMINIUM uses aluminium type 5052 or 6061, the most suitable for large series and mechanical processes Standard Thicknesses: 1-1,5-2 - 3 mm. Chemical composition AlMg2.5 Thermal conductivity, w/mºk 170 Brinell Hardness (HB) 70 Melting range ºC 605-650 Tensile strength, N/mm2 340 0.2% proof strength, N/mm2 310 Modulus of elasticity, Gpa 69 METAL Thermal Cond W/mºK CTE ppm/ºc Density gr/cc Aluminium 170 25 2.7 Copper 400 17 8.9
DIELECTRIC LAYER THE MOST IMPORTANT ELEMENTS OF IMS Organic resin, with ceramic filler to increase thermal conductivity Filler type, size, shape, etc., determines IMS performances (% Filler-Polymer) Usual ceramic fillers: Al2O3, AlN, BN,
COPPER Type of copper: Electrodeposited Copper (ED Copper) with special dendritic growth finishing Standard Thicknesses: 35µ, 70µ, 105µ Other thicknesses available upon request. Peel Strength: 70 mic 1.8N/mm (typical values 2.8N/mm)
Thermal Impedance (Th. Resistivity) DIELECTRIC LAYER KEY POINTS Thermal Conductivity Peeling Strength (Adherence to metal substrates) Breakdown voltage (Dielectric strength) Proof Voltage Test
is the only worldwide IMS supplier that proof-tests 100% of its production. ELECTRICAL PROOF TEST Production electric control test, performed in 100% of the Cobritherm sheets: Exposes sheets to a DC (1000, 2000, 3000 V) electric field, raising it at 500 V/min. and holds voltage test for five seconds. DIELECTRIC BREAKDOWN Performed according IPC-TM-650, part 2.5.6.2. Increases AC voltage until dielectric layer fails by electric short. Test is made on relatively small surface area on the dielectric part using metal electrodes. Values obtained should be treated statistically, and are only a dielectric performance reference, not guaranteed values. Volts 3500 3000 2500 2000 1500 1000 500 0 Proof Test 3000V 2000V 1000V HTC AlCuP AlCuPG 0 5 10 15 20 t (sec) Proof Test from 1000 V DC to 3000 V DC: guarantee for the dielectric request.
Temperature Gradient (ºC) Thermal dissipation Properties of vs FR-4 110 100 90 80 70 60 50 40 30 20 10 0 Self-heating of the active device PCB FR4 Cobritherm AlCuPG Cobritherm AlCuP Cobritherm HTC 0 5 10 15 20 25 30 35 40 Applied power (W) Study performed by the CNM (National Microelectronic Center) in collaboration with the R+D department of AISMALIBAR
Tg: Glass transition: Is the reversible transition in amorphous materials from a hard and relatively brittle state into a molten or rubber-like state. MOT: An operating temperature is the temperature at which the PCB operates. The PCB will operate effectively within a specified temperature range, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature). Outside of this range, the PCB the life time is dramatically reduced or may fail.
TESTING ENDURANCE TEST
PRODUCT RANGE Cu 35µm, 70µm, 105µm Thermally conductive dielectric layer from 80µm to 150µm Al/Cu 0,5 to 3 mm TYPES HTC 2W ALCUP ALCUP-G Thickness Al µm (optional Cu RA) Thickness Cu µm 1000-1500- 2000-3000 1000-1500- 2000-3000 1000-1500 35-70 -105 35-70 -105 35-70
PRODUCT RANGE UL approved File: QMTS2 E47820 improved 2011 DIELECTRIC PROPERTIES HTC-2W AlCuP AlCuP-G Dielectric µ (+ - 0,015) 130 120 125 TC: W / m ºK (Dielectric) 2,2 1.80 1,30 T Impedance: ºK * m2 / W 0.000059 0.000067 0.000096 Proof test: Volts (DC) 3000 2000 1000 Dielectric breakdown: kv (AC) 8 7 6 Time to blister at 288ºC, floating in solder >120" >120 >120 Peel Strength, after 20 /288ºC: N/mm 2,8 2,8 2,3 Comparative tracking Index CTI: V 600 600 600 Max Operating Voltage MOV: (V AC) 450 450 400 Max Operating Temperature MOT: (ºC) 150 150 130 Aluminium 5052/6061 5052/6061 5052/6061 Tg ºC 90-100 90-100 90-100 The laminate is supplied with a polyetilene ( PE) protective film on the aluminium side to protect it against wet (developing & etching) PCB processes.
Other Product Range Alternatives THIN LAM BOND SHEET* Al-P (UNCLADDED) TYPES THIN LAM BOND SHEET Al-P UNCLADDED Dielectric µ 300 74 120 Thickness Al µm (optional Cu RA) 0,15mm 0,22mm 0,3mm - 1,62 ± 0,01 mm Thickness Bond Sheet µm 50-70 µm 0,08mm 0,120mm Other thicknesses available upon request Bond sheet: Ceramic resin prepreg, thickness 50-70µm
THIN LAM HTC-2W PP HTC2W Al-P Uncladded Thickness 0,15mm 0,22mm 0,3mm 0,08mm 1,62 ± 0,01 mm Copper 18µ, 35µ, 70µ, 105µ - - Dielectric (+ - 0,015) microns 300 74 120 Thermal Conductivity: W / m ºK (Dielectric) 1,3 2.2 2.2 T Impedance: ºK * m2/ W 0.00022 0.000059 0.000059 Dielectric breakdown: kv (AC) >10-8 Time to blister at 288ºC, floating in solder >120" - - Peel Strength, after 20 /288ºC: N/mm >1,6 - - Comparative tracking Index CTI: V 600 600 600 Max Operating Voltage MOV: (V AC) 450 - - Max Operating Temperature MOT: (ºC) 150 150 150 Tg ºC 90-100 90-100 90-100
Available Sizes (Cut to size upon request: tolerance ±0,3mm) SHEET SIZE 1220 x 930 PP 1220 (roll) PP 980 (roll) 1170 X 1060 1210 x 1000
PRODUCTION CAPACITY 100. 000 m 2 of Bonding Sheet per year 500.000 m 2 of per year
APPLICATIONS
APPLICATIONS - LIGHTING INDUSTRY LEDS - SOLDERING INDUSTRY - AUTOMOTIVE INDUSTRY: REGULATORS, IGNITERS, LIGHTS. - BATTERY CHARGES - POWER BOARDS: INVERTERS AC DC CONVERTERS, THYRISTORS (COMPUTERS, HIFI...) - MOTOR DRIVES - POWER SOURCES - PHOTOVOLTAIC ENERGY
The Agbar Tower, landmark of the Barcelona skyline and worldwide reference in modern architecture, iluminates by night using ims
CUSTOMER PRODUCT APPLICATION ORIENTATIVES Type Standard Construction (Al/INS/Cu µ) Thermal impedance (ºK. m 2 /W) Proof Test (V) Orientative Applications HTC-2W 1500/130/70 0,000059 3000 High Power applications, AC- DC Power converters, Motor drivers, Inverters, High Power Leds > 2W AlCu-P 1500/120/70 0,000067 2000 High and Medium Power applications, 1W 2W Max. cost-effectiveness AlCu-P G 1500/100/70 0,000067 1000 Medium and Low Power applications, <1W
PROCESSING & DESIGNING WITH
PROCESS ADVANTAGES - Avoids additional heat sinks when mounting - Prevents irregularity and overcoating with thermal conductivity dielectric - Impedes possible air gaps. - Reduces handling costs - Adequate for constructions and suitable for Multilayer - Solder Flow up to 300ºC (HTR), thermal endurance cycles between - 40ºC and +150ºC
PROCESS RECOMMENDATIONS Wet Process Laminate is ALWAYS supplied (except upon request) with a polyetilene ( PE) protective film on the aluminium side to guard it against wet (Etching and developing) PCB processes. Properties of Protective Film Adhesive Acrylic Thickness 50 microns Fusion temperature 180 ºC Max Operating Temperature 90 ºC Surface Finishing is suitable for typical surface finishing like Tin Wave, HAL, OSP and immersion tin or silver Ni-Au finishes: Not recommended due to possible contamination is suitable for sawing, drilling, routing with special tools for alumnium Scoring (v-cut with diamond tools) and punching. Strongly recommended for cost saving
MULTILAYER PROCESS RECOMMENDATIONS PRESS CYCLE Prepreg (Bond Sheet) parameters have been adjusted for low flow performance. Bond Sheet is suitable for heating rates around 4ºC to 7ºC/min. (20 bar through cycle). Vacuum applied during the press cycle is mandatory to avoid air gaps. Using synthetic thermal resistant press pads is the best choice. Curing temperature cycles 1 hour of material temperature 190ºC. METAL (Aluminium conditioning) The Aluminium is supplied with a mechanical treatment and special primer in order to guarantee the correct adherence in the ML process. B U I L D U p ML ML ML ML
DESIGN RECOMMENDATIONS [1/2] Large copper pads are prefered as they are in the beginning of the chain. Thick underside aluminium improves heat sink effect, when aluminium is direct to air. When aluminium underside is in contact with another dissipator, less thickness of Al on the back side will improve the speed heat of transmition. Maximum solder mask coverage of bare dielectric, close to Cu tracks and pads, is recommended. It reduces risks of dilectric damages by creepage discharges or external agents. Component package Component heat sink (Cu) Solder (reflow) Heat source Circuit pattern (Cu) Thermal conductive dielectric Aluminium backside sheet
DESIGN RECOMMENDATIONS [2/2] Security distance OK Cu Dielectric NOT OK For relatively nominal high voltages, a free pattern frame around the board edges should be designed, to avoid risk of electrical discharges Air Al Electrical component Cu Dielectric Al Use correct assembling procedures, to minimize risks in heat conduction failures ( interfacial air gaps) Suitable for hal, silver, immersion tin, osp. Assembling process (peak thermal 300ºc) Warpage in Cobritherm applications is influenced by a thick metal base that ensures mechanical stability CTE mismatch between Copper and Aluminium Cu 16 ppm s Al 25 ppm s Standard Cobritherm constructions are more stable than FR4 ones. CTE mismatch has influence when copper layer is more than 1/10of the metal base.