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About temperature sensitive component

FengAng

#30685

About temperature sensitive component | 24 September, 2004

So many people have concerns on the MSD(moisture sensitive device), but I want to know if anybody can SHARE me some information about the TSD(temperature sensitive device). And I think there are also a lot of knowledges need us to learn. In my opinion, attention is more concentrated on the materials of TSD.

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#30691

About temperature sensitive component | 24 September, 2004

We're not sure what you mean by temperature sensitive components. From an assembly process stand-point, every component we use is temperature sensitive to one level or another.

More specifically, some of our products use polyphenylene sulfide (PPS) capacitors, and we see delamination after going through water wash. There are many layers of the plastic film to protect the dielectric layers underneath. We had similar concerns about the delam so we have run 2000 temperature cycles, from -54*C to +125*C on 200 of various package sizes of these parts with 50% of the rated voltage applied, postcoated and unpostcoated, without any failures or increase in leakage current. We have since allowed for delamination of these parts in our component specification. These are great capacitors electrically, that can have higher capacitance values without the leakage issues of ceramic caps.

Polyester, the workhorse of the film capacitor industry, cannot withstand the high temperatures of IR reflow and some forms of wave soldering, which makes it unreliable in a film chip design (when wave soldering is hot and fast, film chips melt during the process). ["Extruded and Metallized Films for the Global Capacitor Industry" PASSIVE COMPONENT INDUSTRY MAY/JUNE 2000, p25]

Electrolytic capacitors can only tolerate a maximum temperature of 110�C - far below reflow temperature.

We have found thermal shock cracks that cause a leakage problem in ceramic chip capacitors.

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