IC Packaging and SiP Blogs

Are you like me? Do you forget things and have a running to-do list for your designs? Would you like to leave instructions and comments for your colleagues to remind them of actions needing doing?

There are many places to record this type of information in an Allegro^® Package Designer layout design. Some work better than others, and only some are useful for bi-directional information sharing with the front-end schematic engineer. We’ll go through some of the most common here. My hope is that you’ll use one of these to speed up your design (or just make it less likely you forget something!).

Properties, Properties, Everywhere Properties! 

Properties are one of the most natural ways to record data in the database. They can be added to almost any object (save for individual segments of a cline/line), even the database itself. AND, they are unique in that they are the only direct mechanism for sending data between the backend design and front-end schematic. Any properties set to flow between the two tools will move, though remember that these are, largely, limited to the logical elements of the design – nets, components, and pins – so you won’t be able to record properties on a shape, routing structure, or mechanical symbol.  

Since you can define your own custom properties in terms of both value AND name, one strategy I’ve found handy in the past is to create a property definition – able to go on any object in the database – targeted at myself.

Not only does a “TYLER_TODO” property with a string type let me record tasks and reminders, but I can also use the find by query tool to rapidly locate and even prioritize my assignments. When I come back in the morning after a long day, these little sticky notes give me a jump on diving back in right where I left off. Of course, if you’re working as part of a team, having one of these for every member of the team is a great way to communicate assignments, status updates, even suggestions.

Depending on what objects you add these properties on, if you don’t want to use find by query, another convenient way to tag your open tasks is to assign the nets you’re working on a specific color. Then, adjust your datatips configuration to show your to-do information when you hover over. Instant reminders!

Dear Diary… 

… today I routed 109 of my differential pairs. Tomorrow, I must complete the remaining 47. Yes, the database diary (available from the Tools menu) is a wonderful place not just to record key events like the last ECO done on the die, but also events, reminders, and upcoming requirements.

The diary automatically tags your user ID and the time you recorded the note, so you get the newest to the oldest history of recording. I mention this as a useful listing area because you can quickly and easily remove diary entries whenever you have finished the action.

Be aware that if you’re sharing this design with a third-party contractor, you may need to remove the diary if you don’t want them accessing your notes. The export button allows you to save out a copy of the diary so it isn’t lost.

Keeping it Basic 

The simplest method for recording notes is, of course, the Add - Text command. Pick a layer that is otherwise not in use and add your text notes here. There are some disadvantages to this simple mechanism, though.

• Each line of text is its own object, which can make moving or manipulating them, more difficult.

• Some characters (like the exclamation mark) are not legal for use in database text objects. You might have to use alternative characters.

• If you place the text where the object is, it can interfere with selection, while if you place it off to the side, seeing it is more difficult.

The last bullet can be worked around, mostly, with the split view canvas. This lets you have one panel focused on your to-do list while the other is pointing at the design elements like in the screenshot below:

If you have a large screen display, dedicating a portion to displaying your action items is probably not a big impact. But, should you be working on a laptop or other small screen, the split view might take away too much screen real estate you need for design tasks.

What’s Your Strategy? 

How do you keep track of things in your designs? Do you use one of these methods or one of your own? Is there something that Cadence can add to the tool which will make you more productive? If so, you know where to reach us!