Counting once, counting twice...

Panel single scLet's say you have two options: First, you could send in your PC boards for assembly as individuals. Second, you could send them in a panel. That's all fine and dandy. For a few, send individuals. For a bunch, panels might make more sense. But, when you do go to quote and order, how do you count the parts?

Let's take this example. As a single, this board has 32 line items on it's bill of materials. That's 32 unique parts. Counting all of the individual part placements, there are 56 total parts: 42 smt and 14 thru-hole. So, naturally, if you quoted the assembly of 20 of this board at Screaming Circuits, you would enter your desired board quantity as 20, Panel 4-up sc32 total unique parts, 42 smt and 14 thru-hole.

But what do you do if you send it in panel form? How do you count? It's actually not as difficult as it seems. In this example, it's in a panel of four. There are still only 32 BOM line items, but there are four times as many placements. That means that if you quoted this, as a panel, you would enter 32 total unique parts, 168 smt and 56 thru-hole parts. If you still need 20 of the final boards assembled, you would enter 5 as your desired board quantity.

In the end, you will have 20 assembled boards. In case you are wondering about the cost, there won't be a difference. As long as the final number of boards (after the panel is broken apart) are the same, your cost will be exactly the same for panel vs. one up. You don't save any money by sending in singles. However, if your board is panelized and all of your parts on on reels, full or partial, you can save money by ordering Short-Run production.

Duane Benson
50 Years ago today
Robert Rushworth flew the X-15 to Mach 5.03 at 100,400 feet altitude

Fiddling with Fiducials again

I recently posted a note about fiducials but I didn't have any images. Here's a couple of examples:

IPC acceptable fiducialsThis first example shows what IPC would like to see. If this is an individual board, this would be it. If it were part of a panel, you would follow the same pattern on the panel rails and also put it on each individual board in the panel.

As I wrote in the earlier post, we don't require these, but it's always a good idea. You'll need them once you go into volume manufacturing anyway.

The next example won't make IPC happy, but it will make Screaming Circuits happy:

Also acceptable fiducialsIt only uses two fiducial dots, but it isn't reversible. Reversibility is okay for jackets, but not for circuit boards. Since one of the dots is offset, it can't be placed on the machine and recognized as correct in any way except in the proper orientation.

The important aspect of both of these examples is that they remove ambiguity. There can't be any uncertainty, which is good because uncertainty is your enemy. It's a subtle enemy. It might not bother you 99.9 times out of a hundred, but then, when you're not looking, it can strike. So, give a hoot and stomp out ambiguity.

Duane Benson
False data can act only as a distraction. Therefore, I shall refuse to perceive.

Ode to Competition

Thanks to Theodore Roosevelt, we almost all have competition of some sort or another. I'm not a big fan of the statement made so often: "We welcome the competition, It validates the market." or similar such sentiments. You usually hear that from a spokesperson when a new competitor enters the market. My guess is that most people who say that are probably thinking to themselves: "Yeah. In a pig's eye" while stating it.

Theodore RoseveltI'm also not a big fan of the phrase so often heard in start-up companies: "We don't have any competition." To me, that's a warning sign. You might not have much competition, but you always have some. At minimum, other companies (maybe even with non-competing products) are competing for the same dollars. If someone thinks they don't have competition, I would suggest they look a little closer at what their customers need and are doing.

The number three statement that I'm not a big fan of: "Imitation is the fondest form of flattery." I do understand it. If someone is copying you, that must mean that you're doing something right (the possibility of the blind leading the blind not withstanding). In a business context I do believe that all three of those statements are a form of saving face. You can't stop competition from showing up, but you can pretend to be noble and welcome it. It's not always possible to stop people from copying you, but you can pretend it's a complement.

Here's what I think about competition: It's my job to give you better value than our competition. Plain and simple. If you come to me for business and I give you better value: What you want, when you want it at a fair price, then I have earned your business. If a competitor gives you better value, it means that I'm not doing my job right. We are all in this to make money, but we're in this to make money in such a way that we are the best value for you. Not the lowest price, but when you add up our reliability, quality and technical capabilities, doing business with us should save you time, aggravation and money.

So why the maefesto? It annoys me when competitors place comments on our blog linking to their website. Especially when they don't identify themselves. Yes, it means that they believe that we are doing things right. Yes, it means they think we have enough customers that it's worth trying to lure some away from us. So, in a sense, it is validation that they think we're doing a good job. I don't really see that form of "validation" as being worth much though. What I really care about is that the people who give us money think we're doing a good job and that they get their money's worth.

Duane Benson
We are with you, sire! For Sparta, for freedom, to the... to the... Um...
to the sucess of your project!

Is it your fiduciary duty to use fiducials?

We don't require fiducials here. It's not mandatory. That's because we live in a prototype world and in that world, theory doesn't always match up with reality. That being said, there are things we can do and things we would prefer to do. Personally, I would prefer to get some ice cream, but my belt suggests otherwise.

So we do like fudicials, which begs the question: "how do we like them?" Well, the objective of a fiducial is to make machine registration of your PCB easy. That means the pattern should not be reversible. It should only have one correct orientation. Use three of them separated as far apart from each other on the board as you can. But don't put them any closer than 4.75mm from the edge. Ideally, it would be a 1mm copper area centered in a 3mm circle with no solder mask. Oh, and all of the fiducials on the board should look the same and be the same size.

Duane Benson
Over easy, yolk not broken.

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