How to import large pin count devices to Allegro X APD?

Allegro X Advacned Package Designer offers an extremely rich environment for supporting and manipulating data from text files, GDSII, some 3rd part EDA vendors and Microsoft Excel spreadsheets in xml format.

Today’s digital design complexity continues to escalate in terms of size, high-speed interfaces, technology pitch, constraints, routing, and bump and ball pin counts.

It is quite common, particularly in the GPU, FPGA, and desktop/server processor market, to see dies with 15k or more bumps. Also, a new trend that is growing quite quickly is both 3D and 2.5D interposers, which can easily grow to 50K bumps or even more, depending on the ASIC, memory, and other glue logic required to make it a system.

These large numbers of pins put pressure on CPU cost, memory, and the layout tool when reading the data and concurrently running the DRC engine.

Importing Device Pins

You can use BGA Text-In, Die Text-In, DIE format, DEF, and GDSII to import pin data. However, the most common format has been the use of Die/BGA Text-In.

Using the spreadsheet import format, you have a new and more efficient process with an overall performance improvement for loading large pin-count device data.

The following Die/Interposer parameters provide processing time metrics for both Die Text-In and Spreadsheet Import for the following design;

The Die/Interposer example above has over 44000 pins and signals.  For this application note, we will use the Die/Interposer based XML spreadsheet option vs. the typical Die Text-In process.

A small section of this large Die is shown below that depicts partial die spreadsheet XML information from the excel spreadsheet below (too large to display the entire view since there are 44000 plus cells!.

Additionally, will also include additional settings on how to process BGA/package carrier data using a slightly different option than that of the Die/Interposer method. 

The steps below can be used as the generic process for importing large pin count devices via Excel spreadsheet information into Allegro X APD. These will apply to DIE, Interposer and BGA/package carriers.

1. Set Allegro X APD Layout to Symbol Editor Application mode and go to Setup > Application > Symbol Edit…

2. In Canvas, RMB > Add Component. For your Die/Interposer xml data, define the information on the Options form for your type of component to be created and all the related information.

3. Enter all associated parameters for your Die/Interposer

4. Alternatively, for your BGA/package carrier xml data, define the information on the Options form for your type of component to be created and all the related information.

Select Create Component at the bottom of the Options form

6. Set Find Filter to Symbols.

7. Select Edit > Properties

8. Select your Symbol

9. In Edit Property Form, Select   NODRC_SYM_SAME_PIN

Note; The NODRC_SYM_SAME_PIN property needs to be set to command the online DRC engine not to check same pins defined within the symbol instance.  Imagine the DRC engine doing a spacing check on 44,000 or more pins and variable pitches!

There is no other way to add the NODRC_SYM_SAME_PIN property before a symbol is created and thus controlling the import processing performance of these large pin count devices.

10. Select Apply then OK

Note: This CANNOT be done using the die or BGA text in editor or any other import data option in SiP Layout.

11. Set Find filter to Comps or Symbols, right-click, and then choose Add pin.

12. Set Find filter to Comps or Symbols, right-click, and then choose Pin pitch settings.

13. Optionally, Set Find filter to Comps or Symbols, right-click, and choose Pin numbering settings

14. In the Option pane, set parameters for Pin configuration. Ensure you either select the correct pad stack or create a new one as required.

15. Select Pattern definition and select Spreadsheet from the Pattern style list.

16. In File name, specify the XML file and configure the rest of the fields.Spreadsheet bump/ball array is attached to the cursor.

17. Place ball/bump array within boundary of component definition