In an IC package design, it is common for the designer to customize the BGA component, or even the die components (if they are still subject to changes by the IC owner) in order to optimize the package substrate for cost and efficiency. In order to do this, changes to the components and physical symbols representing them in the substrate layout are often necessary. Since the 14.2 release, Cadence IC Packaging physical layout tools like APD and Cadence SiP Layout have provided context-based editing commands for making changes to the BGA and die symbols directly within the package substrate design (instead of modifying the library symbols via the symbol (.dra) editor, as would be done for a PCB design).
With the release of 16.5 Allegro Package Designer, these aging BGA and die editor commands are being phased out and replaced with the Symbol Editor application mode. As a package designer, this new application mode environment gives you all the same power of those old commands – and more! – in an intuitive environment specifically geared towards productive editing of your components.
Want to know more details? Read on!
It might be best to watch a video of this feature (available on Cadence Online Support – COS) before reading the exhaustive information below.
IC package designers normally consider the package BGA component as a part of the package design and therefore changeable. In addition, the IC design team may be developing one or more of the dies within the package or SiP concurrently with the package, and thus the package designer may be able to suggest die changes. This means that the package designer may need to be able to add, remove, rename, or move pins and even change the body size of die and BGA components during package layout. As system designs become even more complex and dense, customers are becoming increasingly dependent on system-level floor planning, partitioning and concurrent design. As a result, PCB/Package co-design is developing as a vital requirement for systems customers.
Gone are the large forms that hide areas of your canvas window, the frequent cursor movements between the canvas and the forms themselves, the lack of show element support while editing a symbol, and the inability to run other features and make efficient design trade-offs. Replacing this is a context-sensitive environment where you can move naturally between modifying pins to updating escape routing and bond finger placement; an application mode that reacts to what you are working on, and works to make your life easier. It stays out of the way until it is needed, and fades into the background once you are done with it.
This change may seem like a dramatic design flow impact, but it is really not. The user will still be performing the same edits that they do today, but the manner in which they do them will be much faster and more intuitive. It will also better align with the current use model of the rest of the tool.
The following are some key features of the new 16.5 APD and SiP capabilities.
• You can move seamlessly between editing the symbol and the package substrate. You can move a pin to eliminate a wire-wire DRC at the die side, then move immediately into updating the wire bond pattern to compensate. Or, you could be changing a BGA ball padstack to get more routes through a channel, then go and change the via structure that connects to the ball and update the pin escape.
Here is an example of how a pin was deleted in 16.3:
Here is a screenshot of deleting a pin in 16.5 (using the PCB Editor):
Here is a screenshot of deleting a pin in 16.5 (using the Symbol App mode):
• Full-context editing: You can see the current routing, all the other components in the substrate, etc. all while making edits to the components as necessary. No need to look at separate windows, get in/out of a different command environment, etc. Use show element, highlighting, net coloring, data tips, etc. to get the info you need to make the most intelligent design decisions quickly and efficiently.
Here is an example of a pin being added to the BGA ball pattern in 16.3:
Here is an example of how this is done in 16.5:
• Multi-instance editing. Because the app mode modifies the symbol/component definitions, if you have 4 instances of a die in your design, as an example, adding a pin on one instance through the app mode instantly updates all three other instances with those same changes. The “stretch etch” settings are applied across all instances, as well. So, if each instance of the die had a slightly different fanout pattern, that is compensated for as a pin is moved, deleted, swapped, etc. at each instance level.
• Editing of additional component types. Previously, you could only edit dies and BGAs. Now, if your design flow permits, you can edit any component type by this method -- Modify your plating bar, make changes to that discrete, etc. all from the comfort of that one environment::
• No big, bulky forms taking up screen real estate. The BGA and Die editors had a massive form that you had to use to control everything. Now, all the things you can do in the app mode have been simplified to the point where their settings fit in the options tab of the main window, leaving the full canvas available and visible at all times.
• “Instant on” editing. With the older editors, you had to start the command, pick the component to edit, enter the command, make changes, and then get back out. Depending on the complexity of the component and the level of completeness of the substrate routing, this could take quite some time just to get in/out. Now, there is none of that.
• Context-sensitive RMB menus. This is like all other app modes. There’s no switching between different states or tabs of forms or anything like that. RMB on a pin or set of pins and pick move. The pins show up on your cursor and you can move them around. You can even customize what operations are performed when you do a double-click or a click-and-drag of an object. So, you don’t have to do anything to move a pin beyond dragging it to where you want it to go
I look forward to your feedback on this new 16.5 capability!
Jerry "GenPart" Grzenia