Evaluation of Magnetic and Thermal Semiconductor Energy Modules


Over the previous few years, semiconductor know-how has come a great distance, particularly within the fields of energy electronics with purposes in analysis and heavy trade purposes. Insulated-gate bipolar transistor (IGBT) modules play an important position as they’re applied in purposes with excessive working temperatures, quick switching speeds, increased reliability, and many others. In such conditions, getting exact outcomes is of utmost significance as there could also be a number of harmful outcomes to the circuits and even the customers working the circuits if not calculated accurately.

To allow simulation in a multi-dimensional state of affairs, starting from nanoseconds to seconds, and enhance circuit efficiency, quite a lot of methods for integrating EM domains to investigate electro-thermal interplay have been examined. Analysis on the electro-thermal properties of the IGBT chip has been extensively carried out for a 3-D packaging construction in such chips.

Ⅰ.  Magnetic and Thermal evaluation of Energy Modules

The experiment carried out presents a simulation whereby, {the electrical}, thermal and magnetic traits of the IGBT are examined throughout the circuit operations.

Fig 1 Schematics of the proposed EM-electro-thermal analysis method..png
Fig 1: Schematics of the proposed EM-electro-thermal evaluation technique.

The parasitic properties between the chip surfaces (collectors, emitters, and gates) and the module exterior terminals are represented by this electromagnetic community. The electro-thermal IGBT chip mannequin is constructed within the circuit representing the working level circumstances dependency utilizing curve-fitting and weighted interpolation of experimental check outcomes or information sheets. This electro-thermal mannequin acts as an essential hyperlink between the thermal and EM networks, having to just accept Tj s info from every chip and returning energy loss values to the previous, and accepting present info and restoring chip on-state voltage drop (Vce(on)) values to the latter.

Fig 2.png
Fig 2: 1700V/450A half-bridge IGBT energy module format.

The information on the frequency-dependant resistance and inductance values between exterior terminals and chip surfaces, akin to from the module’s DC+ energy terminal to the collector surfaces of the high-side change IGBT chips is included as proven in Fig 2.

Ⅱ.  Extraction of the Proposed Mannequin

Till latest occasions, analysis on the self-consistent interplay between {the electrical} and thermal traits of energy modules has been an thrilling matter because it contains applied sciences that can be utilized in overcoming a number of obstacles utilizing the ROM technique.Whereas conducting the assessments, all thermal traits have been thought of together with an assumption of an intact cooling boundary on the backside for additional simplification and effectivity. Furthermore, a baseplate temperature of 90 was set throughout the simulation of the underside course of.

Fig 3 Temperature distribution when power loss is applied only to U5.png

Fig 3-1 Temperature distribution when power loss is applied only to U5.png
Fig 3: Temperature distribution when energy loss is utilized solely to U5

As proven above, Fig 3 depicts the thermal conduct of all the packaging construction which was recorded to review correct electro-thermal coupling.

Fig 4 Comparing results of Icepack SVM, Simplorer thermal network and experimentation test.png
Fig 4: Evaluating outcomes of Icepack SVM, Simplorer thermal community and experimentation check

Fig 4 exhibits the effectiveness of the extraction course of to display its comparability with completely different outcomes. For example, the comparability was completed amongst Icepak FVM simulation, Simplorer thermal community simulation and experimental check outcomes to examine the thermal resistance of the low-side change. The graph with thermal community topologies exhibits equivalent simulation outcomes to that of the usual FVM simulation. The present sharing properties of the IGBT rely on the frequency of the parasitic elements of the module packaging which additionally contains the resistance and inductance of the conduction paths. Throughout its software, every conduction path from the exterior bus bar terminals to the chip surfaces within the IGBT module software might affect how present is unfold among the many chips and the way every chip switches by itself.  This makes it essential for the modules to characterize the parasitic values from all exterior terminals to the surfaces of every chip.

Ⅲ.  Simulations and Outcomes

As soon as the extraction means of the IGBT chip mannequin is full, simulations for the thermal and EM networks and their analytical representations are considered for the examine of their module efficiency in chopper circuits. In such chopper circuits, whereas IGBT modules are working at excessive frequencies, a 900V DC energy provide is ready with a load related in parallel to the excessive aspect change for 3 IGBT switches and three FRD chips

Analytical Resolution: In a chopper circuit, it is vitally essential to take into consideration the present sharing and temperature dependency of the ability losses because of which the loss could be considered in an analytic answer.

𝑃𝑠𝑤,𝐼𝐺𝐵𝑇 = (𝐸𝑜𝑛 + 𝐸𝑜𝑓𝑓) ⋅ 𝑓𝑠w

From the above equation, 𝐸𝑜𝑛 and 𝐸𝑜𝑓𝑓 is the activate and switch off of the IGBT chip at a set 90℃ and 𝑓𝑠w is the switching frequency.

Electro-Thermal Simulation: As proven within the beneath determine, an addition of a thermal community above {the electrical} simulation was utilized in getting the simulated output. The temperature-sensitive electrical properties of the chips, such because the loss vitality and Vce(on) values, could be dynamically up to date by linking the thermal pins of the electro-thermal chip mannequin to the thermal community. This allows the ability losses calculated from the circuit simulation to be provided into the thermal community.

Fig 5 Electro thermal simulation topology.png
Fig 5: Electrothermal simulation topology


EM-Electro-Thermal Simulation

As seen above, the thermal and EM networks which present the completely different imbalances in impedance and parasitic elements ought to at all times be reviewed for easy operations. Networks with zero-dimensional setups have been additionally utilized within the EM-electro-thermal evaluation.

Fig 6 EM-electro-thermal simulation topology..png
Fig 6:  EM-electro-thermal simulation topology.

In Fig 6, the EM and thermal networks are built-in collectively within the simulation circuit. Utilizing EM networks, the IGBT chip electro-thermal fashions are embedded into the applying circuit throughout the working.

Fig 7 Simulation results (a) Gate driver voltage and Vge of chips (b) IGBT chip current values (c) IGBT chip averaged total power losses (d) IGBT chip Tj variation..png
Fig 7: Simulation outcomes (a) Gate driver voltage and Vge of chips (b) IGBT chip present values (c) IGBT chip averaged complete energy losses (d) IGBT chip Tj variation.

In determine 7, the simulated outputs in several circumstances and temperatures are proven for additional understanding of the IGBT and its efficiency. The IGBT chip U6 in Fig. 11 (a) has the best Vge worth because of its proximity to the module packaging’s gate management terminals, Determine 7 (b) shows the present distribution among the many three paralleling chips. As per Fig. 11, Chip U6 describes the best averaged complete energy loss (c) and In Fig. 7, the Tj variation over time is depicted (d). If there are temperature instabilities within the IGBT, there are numerous prospects for long-term points which can improve energy loss and thermal stress.

Ⅳ.  Conclusion

The conduct of IGBT semiconductor energy modules with the EM-Electro-Thermal coupling, together with present sharing properties and thermal traits was studied. The simulation outcomes carried out have been achieved completely as per the prediction making it additional scalable in varied bodily and digital domains. With the outcomes obtained, it may be stated that there are increased probabilities to disclose the consequences of IGBT energy module packaging on the electro-thermal conduct of the chips. With extra in depth analysis on this matter, such techniques may even be deployed in complicated units and have enhanced reliability.

Authored Article by: Saumitra Jagdale, Utmel Electronics


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