Adequately treated surface is needed for heatspreaders to bond semiconductor elements and package members. Also a good surface condition is necessary to provide highly reliable members that will not rust or corrode under severe environmental conditions. We have a wide variety of surface treatment facilities. And as part of the integrated manufacturing process including processing raw materials, we conduct such surface treatment operations as plating and metalizing.
Heatspreaders need to quickly release the heat generated by semiconductor operation to the radiator plate, etc. To join them are various methods such as Ag brazing, Pb-free solder, Au solder, Ag nano-paste, etc. For this purpose, we can conduct Ni electro-plating, Ni-P electro-less plating, electric Au plating, etc. We also conduct plating with good adhesion to W and Mo, which have poor plating properties, ensuring good heat radiation.
We have preliminary solder* products that simplify the production process of bonding the power modular semiconductor and heatspreader, improve bonding reliability, increase yield, and simplify managing the purchase of parts.
(*heatspreader with solder)
We form a solder film of Au/Sn eutectic alloy suitable for bonding of semiconductor elements using our film forming technology. We can adjust the composition ratio of Au and Sn at request. By forming a film on the sub-mount, workability and yield improvement during the semiconductor elements bonding process can be expected.
Heatspreaders used for optical communication are required to have high form accuracy in the order of micron. Submounts for high-power laser need to have sharp edges. A.L.M.T. owns many machine tools including machining centers and electric discharge machines to do highly precise machining internally.
Our advanced machinery and experts who know every detail of properties of materials work together to offer complex shapes realized by highly precise machining accuracy in the order of micron.
We have a wide variety of machines and equipment to meet customer requirements for the production of a small quantity to a large quantity in a short delivery time.
We can offer sharp edges for Cu-W, Cu-Diamond, CVD diamond and Sumicrystal.
The standard edge R is 30 μm or less, but we can offer 20 μm or less according to product specifications.
In Hybrid Electric Vehicles, the inverter system converts direct current stored in the batteries into alternating current to run the motor and assist driving. Conversely, when the vehicle decelerates, the inverter system converts alternating current generated by the motor into direct current and charges the batteries.Electric Vehicles have a similar inverter system, just without power generation by the engine. The inverter generally uses a semiconductor device called the Insulated Gate Bipolar Transistor (IGBT).For the inverter system to operate stably in harsh environments such as in the engine bay, heat dissipation and thermal stress reduction are important, and therefore heatspreaders are used for that purpose. For large-type heatspreaders, Cu-Mo (PCM35 and CPC232) is widely used.The ductility of Cu-Mo allows for rolling and press-forming in low cost. Also, it makes warping in advance possible, which can control the final warpage.The amount of Mo to be used can also be reduced. To further improve heat dissipation, a system has been developed that directly attaches pins to the heat dissipation plate at the bottom and incorporates them into the water-cooled radiator. This system uses large Cu-Mo heatspreader with pins.
IGBT device and then the insulating substrate and large Cu-Mo heatspreader are joined from the top down, and underneath a water-cooled radiator is installed.By greasing and screwing the large heatspreader, it comes in tightly contact with the radiator and dissipates heat efficiently. The major advantage of this system is its ease of assembly and replacement.
To further improve heat dissipation, a system has been developed that directly attaches pins to the heat dissipation plate at the bottom and incorporates them into the water-cooled radiator. This system uses large Cu-Mo heatspreader with pins.
Instead of a large Cu-Mo heatspreader, this system is putting a Cu-Mo heatspreader only directly under the chips to ensure heat dissipation and thermal stress reduction.
A high performance heatspreader is indispensable to achieve the design performance of the semiconductors being developed day by day. We are working to develop new heatspreaders day and night by taking each customer's request individually.
Mg-SiC, manufactured from Mg ingot and SiC powder using our own powder filling and infiltration technologies, is suitable for the mass production of large products.
We can change the composition ratio of Mg and SiC for the Mg-SiC material having thermal expansion of 7.0 ppm and thermal conductivity of 230 W/mK to customize the thermal expansion.
Ag, having a higher thermal conductivity than Cu, is the material with the highest thermal conductivity among metals. This Ag and diamond powder are mixed and sintered by our own technology to successfully produce a new material with thermal conductivity of 600 W or more. This new material, allowing us to manufacture materials larger than the conventional diamond materials, is the diamond heat radiation material to be used for various applications including the PKG base plates for large output and the heat dissipation substrate for large-size devices.
CPC is a composite material with a laminated structure with Cu layers above and below the Cu-Mo composite material. Thermal conductivity and linear expansion coefficient can be changed by combining the composition of the core material Cu-Mo and the lamination ratio. In addition, because both surfaces are Cu, the initial heat radiation effect is excellent.
* SEI Technical Review is a technical journal that describes the technical content of the Sumitomo Electric Group.