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About the difference between HMC1118 chip storage and channel temperature

I used a 150°C heat gun to heat up the HMC1118 chip for a minute recently and quickly found that nearly half of the IC was blown, which showed a significant drop in insertion loss performance and return loss performance. Should I heat up the chip at a temperature lower than the channel temperature or the memory temperature? If the storage temperature indicates the temperature at which the IC can be stored for a long time, is 135 the maximum operating temperature of the IC?

  • Hi Cheersion,

    Both the max reflow temperature and the storage temperature is defined when the part is unbiased, and not operating. The differentiating factor between these two is the length of exposure. The part can be exposed to the max reflow temperature only for a short while - the duration of the reflow. 
    We typically do not recommend to use heat guns for rework. We have found that they tend to be wildly inaccurate in their heating.
    It is possible that the part was exposed to temperatures much higher than the max reflow temperatures specified by applying heat directly to the part using a heat gun. 

    The max channel temperature (or junction temperature) is when the part is biased, and operational. This is the highest temperature the channel (or junction) of the transistors internal to the die is allowed to get to. Using the thermal resistance values and thermal equations, you can ensure the channel temperature does not exceed +135C.

    The max operating temperature is defined in the 'Recommended Operating Conditions' in the 'Electrical Specifications' table on Page 3 of the datasheet. The recommended operating temperature for this part is -40C to +85C.