Efficient cooling. With Plansee heat spreaders.
Greater power densities in ever smaller electronic components represent a major challenge for thermal management of high power electronics. Inadequate cooling impacts on the reliability and service life of semiconductor components. Electronic components often fail because of damage resulting from excessive operating temperatures or other thermal factors such as mechanical stresses due to temperature differences.
Electronic components are attached to substrates and base plates that are able to dissipate the heat generated. There are only a few materials that possess the necessary thermal conductivity and appropriate thermal expansion properties to dissipate heat reliably in electronic components. The diagram shows the generic structure of a hermetically sealed electronic package.
We have the ideal material.
Our MoCu and WCu composites and Mo/Cu laminates reliably dissipate heat in electronic components and provide cooling of components such as high-power transistors, for instance IGBT modules or RF amplifiers, as well as LED chips. Our materials combine the low thermal expansion of molybdenum and tungsten with the excellent thermal conductivity of copper. We have optimally adjusted the composition of these engineered composite materials to meet the requirements of silicon, GaAs and GaN-based semiconductor materials. Failures resulting from overheating or mechanical damage induced by thermal stress can thus be avoided using our materials.
MoCu composites
The MoCu composites consist of ultra-pure molybdenum with 30 % of OF copper by weight. The composition provides in higher thermal conductivity and lower density compared with pure molybdenum. Our MoCu composites are particularly suitable for applications requiring high power densities but where low weight is of the essence. For example in the aviation and automotive industries.
PMC®(Cu-MoCu-Cu) composites
When excellent heat spreading needs to be combined with low thermal expansion, we recommend our PMC® laminates. PMC® is a 3-layer composite with a MoCu core plated with pure OF copper. This laminate is usually structured with a thickness ratio between layers of 1:4:1. As a result, we can guarantee excellent heat distribution and dissipation in LDMOS transistors and other applications with particularly high power densities.
CMC (Cu-Mo-Cu) and SCMC (Cu-Mo-Cu-…-Cu) laminates
Our laminates (CMC and SCMC) are ideally placed to meet the thermal requirements in the field of high-frequency electronics. The structure and thickness of the copper and molybdenum layers can be varied, allowing the coefficient of thermal expansion to be perfectly matched to common semiconductor materials and achieving high levels of thermal conductivity. We offer 3-layer laminates with uniform layer thicknesses, such as our CMC 111, and 5-layer laminates with different thicknesses of copper and molybdenum, such as our SCMC 313-5 off-the-shelf. If you require a different layer structure, our materials experts will be happy to help.
Finished parts matched to your application.
We supply our materials in the form of sheets, pre-cut components and plates or as finished heat spreaders, base plates and submounts. Coatings protect the materials against corrosion and form the basis for a perfect connection between the chip and the base plate.
Our metal compounds.
Thermal conductivity and coefficient of thermal expansion for different materials compared and contrasted:
| Material (Product name) | Composition [wt%] | Density at 20°C [g/cm3] | Coefficient of thermal expansion at 20-150°C[10-6/K] | Thermal conductivity at 20 °C [W/(m·K)] |
|---|---|---|---|---|
| Molybdenum | Mo 99.97% | 10.2 | 22°C5.5/20-800°C5.7 | xyz142 |
| Tungsten | W 99.95% | 19.3 | 22°C4.5/20-800°C4.8 | xyz165 |
| MoCu | Mo-30% Cu | 9.7 | 22°C7.1/20-800°C7.8 | xyz205 |
| WCu | W-10% Cu | 17.1 | 22°C6.4 | xyz195 |
| WCu | W-15% Cu | 16.4 | 22°C7.3 | xyz215 |
| WCu | W-20% Cu | 15.5 | 22°C8.3 | xyz235 |
| Cu/Mo-30Cu/Cu(PMC®) | 1:4:1 /Mo-52%Cu | 9.4-9.6 | 20-150°C7-8/20-800°C6.5-8.5 | xy280/z170 |
| Cu/Mo/Cu (CMC) | 1:1:1 /Mo-66%Cu | 9.3 | 20-150°C6.5/20-800°C6.6 | xy305/z>220 |
| Cu/Mo/Cu/.../Cu(S-CMC) | 3:1:3:1:3 /Mo-80%Cu | 9.2 | 20-150°C8.1/20-800°C7.5 | xy350/z>250 |
Do you have a specific requirement? Talk to us. We will deliver your customized material.
Material properties in detail.
Selecting materials with suitable physical properties is the key to reliability and a long service life for electronic packages. In this context, the coefficient of thermal expansion is of special significance when selecting the material for the base plate. With our materials the thermal properties can be tailored to the requirements of the semiconductor and the package.
Typical values; GaN monocrystal provided by the Institue of High Pressure Physics - Unipress.
CTE = Coefficient of thermal expansion
Alongside thermal expansion of the material, thermal conductivity also plays a crucial role. The use of Mo/Cu composites significantly increases thermal conductivity compared with pure molybdenum.
The table below lists typical values for yield strength (Rp0.2) and tensile strength (Rm). The exact properties depend on the extent to which the material has been treated.
| Material | Rp0.2[MPa] | Rm[MPa] |
|---|---|---|
| MoCu30 | > 650 | < 750 |
| PMC® 141 | > 600 | < 700 |
| CMC 111 | > 400 | < 410 |
| SCMC 612-5 | > 380 | < 400 |
Simulation of the heat flow.
The following simulations show the importance of selecting the right material. The heat source was assumed to be a GaN chip (output power 240 W, pulsed operation) soldered to the heat sink using AuSn20 solder.
See where else our materials are used.
You will find our base plates and heat spreaders in components in the fields of opto-electronics, high-frequency applications, power electronics and micro-electronics. The most important applications for our materials include:
- Si LDMOS transistors (LDMOS = laterally diffused metal oxide semiconductor)
- GaN/GaAs HEMT transistors
- Microwave packages for HPA (High Power Amplifiers) and MMIC (monolithic microwave integrated circuits) in radar applications
- Radio base stations in telecommunications
- Laser diodes, Crystal carriers for solid state lasers
- High-power LEDs, single-emitter LEDs, multi-emitter LEDs
- IGBT modules for electric vehicle motors (EV/HEV) and stationary transformers
Let us know your application. Whether Cu/Mo/Cu (CMC), Cu/MoCu/Cu (PMC®), MoCu, WCu or pure moly - our thermal management team we will find the perfect material for you.
