Thermal Calculators

Benefits of Using Thermal Calculators

GSA is pleased to have coordinated with Amkor Technology, a longtime member of GSA, to provide access to Thermal Calculators for GSA members. Thermal Calculators can be very useful “what-if” analysis tools when trying to select a package type and configuration to meet general thermal performance requirements for technical project managers and designers. Moreover, they quickly provide information to help balance thermal performance with cost and size in the beginning stages of a design. Amkor has calculators available for wirebond CSP, PBGA, QFN, QFP and TSSOP SuperBGA package types.

How does the Thermal Calculator Work?

As shown in the example of the PBGA Thermal Calculator, a minimal amount of information is needed to quickly calculate θja, θjb, θjc, Ψjt and Ψjb under a standard set of air velocities:

• Choose a package type.
• Choose a ball pitch which filters the list of available standard body sizes.
• After choosing a body size, the thermal ball list will populate with available options. The number of thermal balls and signal balls can be adjusted to produce a valid combination of balls for the chosen body size. In addition, thermal vias can be added to improve thermal performance.
• Results for numerous combinations can be saved and evaluated in order to select the optimal configuration.

Several thermal calculators are available to address your needs:

• The PGBA Thermal Calculator predicts the thermal performance of BGA packages with laminates of varying copper content. The substrate options range from 2 layer to 4 layer with 36µm and 72µm copper planes for improved heat transfer to the perimeter balls. In addition, the TEPBGA-2 option can be used to see the affect of using a heatspreader on a BGA package.
   
• The wirebond CSP Thermal Calculator will quickly calculate θja, θjb, θjc, Ψjt and Ψjb for standard, thin and very thin CSP packages as well as Stacked die configurations. It also has the flexibility to change the die attach and mold compound materials to analyze the effects of the different thermal conductivities associated with standard, lead free and thermally enhanced materials. Furthermore, the film material and thickness can be specified for Stacked die configurations.
   
• The QFN Thermal Calculator will calculate θja, θjb, θjc, Ψjt and  Ψjb for custom die sizes using standard body sizes, lead-counts and die pad sizes. Additionally, there is an option to have the exposed pad soldered to the application board.
   
• The TSSOP Thermal Calculator is useful for predicting the thermal performance of MSOP type packages ranging from 8 to 80 leadcounts.
   
• The QFP Thermal Calculator can be used to estimate thermal performance for various body thicknesses as well as embedded heatsink and exposed heatslug versions.
   
• The SuperBGA Thermal Calculator is available for evaluating the thermal performance of devices that require high-power BGA packages.

General Assumptions and Guidelines

Thermal Calculators cannot predict the actual performance of a package in a specific environment. In addition, the calculators were developed using the properties of Amkor’s standard material sets. Common design rules were also imposed to specify laminate thickness and routing rules as well as leadframe design, so the thermal performance of a custom package may differ from calculator values depending on chosen material set and design rules. Therefore, the calculators should be used as a general guideline for selecting a package to meet thermal performance specifications.   

The calculator results were obtained using Finite Element Analysis (FEA) to predict thermal parameters for many package and flow conditions. Then, the FEA simulated results were curve fit to a simple algebraic equation. The accuracy of the calculators was validated by comparing calculated values to test data.  The disagreement between the calculated theta ja and test report data is less than 15% in most cases.

Request a Thermal Calculator Account

To gain access to Amkor’s Thermal Calculators, please click on the link below. You will be asked to fill out an information request form that will be sent to a representative at Amkor Technology. Upon receipt, an Amkor representative will contact you to discuss your needs. This normally occurs within one week. Shortly after, an Amkor representative will create a password protected account and send instructions explaining how to access the Thermal Calculators. Please note, Amkor Technology reserves the right to deny access. In general, access is reserved for customers engaged with Amkor.

To request additional information and access to Amkor’s thermal calculators, please visit http://www.amkor.com/contact/request/request.cfm?company=FSA