Why do prototype PCB makers charge extra for panelized boards and sub-PCBs?

[splin]

I don't suppose they all do, but at least some of the cheap Chinese manufactures do. Eg. for 5cmx5cm 2-layer board, Elecrow want an extra $8 for 2 to 5 copies and $12 for each different sub-PCB. Since their prices are based on area why does it make a difference?

Shouldn't panelized boards be cheaper as the alternative is that you would be ordering more smaller non-panelized boards and thus get a better price for larger quantities? (Ok. some of pricing seems a bit erratic - some seem to charge more than double for 20 boards than for 10 for some reason).

How could they even tell your layout has more than one design if you have some dummy tracks interconnecting them (so long as it isn't obvious from the silk screen).

[zapta]

I don't suppose they all do, but at least some of the cheap Chinese manufactures do. Eg. for 5cmx5cm 2-layer board, Elecrow want an extra $8 for 2 to 5 copies and $12 for each different sub-PCB. Since their prices are based on area why does it make a difference?

Shouldn't panelized boards be cheaper as the alternative is that you would be ordering more smaller non-panelized boards and thus get a better price for larger quantities? (Ok. some of pricing seems a bit erratic - some seem to charge more than double for 20 boards than for 10 for some reason).

How could they even tell your layout has more than one design if you have some dummy tracks interconnecting them (so long as it isn't obvious from the silk screen).

The cost is based on the average area and they want to keep it as small as possible so they make it difficult for you to optimize it. Imagine if all 5x5 max boards will really be 5x5.

[free_electron]

they pinch pennies in drill strokes , milling strokes.
so : no sub panels. that makes their routing easy

[hagster]

They run multiproject panels. If the number of boards you want are all on one panel, that means they only get to use the masks once. What they want is to use the masks as many times as possible. Hence by pooling other people's boards onto the same panel they can use the masks many times. Obviously some end up being overproduced. This is why some companies have standard order multiples.

[Ice-Tea]

Not 100% sure I understand your question (seems like it's more than one actually) but the reason you're paying extra for a panelised PCB is because probably because they "pool" all PCBs together (from all customers) and do it so that from their "mother" panels little to nothing is lost. So, if you order 5 little PCBSs they can fill in the "gaps" more efficiently. If you order a large slab (ie 5 little ones in a panel) they will have less jigsaw options

[Richard Crowley]

I think many people here are missing the point of the question.  The issue is that some vendors will penalize you if they see that you have "pre-panelized" multiple copies of something into your arbitrary-size rectangle. 

If you send in a board that is 50 square cm, everything is fine.  But if you send in that same 50 square cm that consists of two 25 square cm boards, they charge you double for the same board area and number of holes, vias, etc.  Even if you don't ask for extra routing to separate the boards.  I can't even make a board that will be cut to form a right-angle part without it being considered 2 different "boards".  Those are the companies that are controlled by bean-counters.  As with anything else, shop wisely and leave the bean-counting to your accountant.

[splin]

I think many people here are missing the point of the question.  The issue is that some vendors will penalize you if they see that you have "pre-panelized" multiple copies of something into your arbitrary-size rectangle. 

If you send in a board that is 50 square cm, everything is fine.  But if you send in that same 50 square cm that consists of two 25 square cm boards, they charge you double for the same board area and number of holes, vias, etc.  Even if you don't ask for extra routing to separate the boards.  I can't even make a board that will be cut to form a right-angle part without it being considered 2 different "boards".  Those are the companies that are controlled by bean-counters.  As with anything else, shop wisely and leave the bean-counting to your accountant.

Yes exactly. However, having taken a closer look at Elecrow, smart-prototyping and www.shenzhen2u.com I realise I was mistaken - they don't charge extra for multiple or panelized designs if they are separated only by silk screen. The extra charges apply if the sub-PCBs or panels are separated by V-grooves.

But that raises the question as to why that is so expensive - Elecrow want $9.9 for 10 5x5cm boards but an extra $12 for one v-groove across the board if the design has 2 different 2.5cmx5cm sub-PCBs! I can understand them disallowing the use of lines of close holes for separation purposes due to the drilling costs, but they allow milled slots for free 'providing they aren't used to separate sub-PCBs'.

Why? And why do they charge $12 for each sub-PCB but only $8 for up to 8 copies (I assume they mean panels) - why the distinction?

Unless these offers are loss leaders for some reason, these charges seem to be way out of line with their actual costs. I doubt a 5cm groove /slot is going to cost more than a few cents at most - especially given that the boards are milled around the edges anyway. You would expect competition to lead to someone to offer to allow milled/grooved sub-PCBs for free or minimal cost - there must be plenty of demand for it. Cutting PCBs at home isn't especially easy unless you have a guillotine or don't mind the dust and mess from power tools.

Has anyone designed layouts with sub-PCBs, mostly separated by a milled slot to make separation easy, but included some dummy tracks between sub-PCBs to get round these restrictions?

[ve7xen]

Many of them allow it, so just use a vendor that does. I know iTeadStudio explicitly allows it and does free v-scoring (they have instructions on how to order it properly), and DirtyPCBs allows it on 2-layer boards. But only panelizing the same design.

I'm not sure if any will allow multiple designs within your $area purchase. They're selling flat rate within a specific area, not flat rate for a certain area. This seems fair to me, since it generally costs more to order from places that bill by area, though I'm not quite sure of the economics behind that. I assume it's just averaging, and their choice of whether to allow multiple designs / panels or not will affect the average price.

[splin]

Many of them allow it, so just use a vendor that does. I know iTeadStudio explicitly allows it and does free v-scoring (they have instructions on how to order it properly), and DirtyPCBs allows it on 2-layer boards. But only panelizing the same design.

They only do free v-scoring for 50+ boards, as do others. But for their 10 PCB  prototype service their charges are even more ridiculous than most. Their panelization/sub-PCB rules are clearly described here:

http://support.iteadstudio.com/support/solutions/articles/1000160585-pcb-panelization-rules

Like the other suppliers they also allow multiple designs on one board, but you can't use slots or holes as separaters and you can't have a slot longer than 2/3 of the panel length/width. Fair enough. But make that slot slightly more than 2/3 or you want one v-groove your 10 5x5cm boards at $9.9 will cost an additional $20!! (Actually for panelized boards they require them to be > 8x8cm so you'd have to buy >= 10x10cm boards at $19.9+)

Now look at 2 (a) & (b) in that link. If you have 5 panels of 4 or 5 different sub-PCBs you incur an extra charge of $80 for the 3 v-grooves in that example!!! So $19.9 for 10 10x10cm boards + $80 = $99.9. But if each of your sub-PCBS were less than 5x5cm, you could get them as separate PCBs for half the price at 5 x $9.9 = $49.5!

As I understand it, they don't differentiate between panels or sub-PCBs so if you wanted them panelized into 5 identical panels they would still cost $99.9. But since you are now ordering 50 panels in total, the alternative would be to buy 50 5x5cm boards at less than a third of the cost for $30.65! Of course you'd lose the advantages of panelization with this option.

As the number of panels/sub-PCBs increase the disparity gets even more extreme; a surcharge of $140 for 8 panels?!!!

Many seem to have similar pricing/policies so I must be missing something significant, but this pricing seems bizarre.

I'm not sure if any will allow multiple designs within your $area purchase. They're selling flat rate within a specific area, not flat rate for a certain area. This seems fair to me, since it generally costs more to order from places that bill by area, though I'm not quite sure of the economics behind that. I assume it's just averaging, and their choice of whether to allow multiple designs / panels or not will affect the average price.

They do allow multiple designs for free so its nothing to do with averaging - its just that you get hit with excessive charges for v-grooves or slots > 2/3 width or length.

I see that dirtypcbs allow 2-layer panelized boards but don't do v-grooving - so not even an extra cost option.

[zapta]

Why? And why do they charge $12 for each sub-PCB but only $8 for up to 8 copies (I assume they mean panels) - why the distinction?

Because they want you to pay for another set of 10 up to 5x5cm pieces.

Oshpark doesn't have this problem, you charge for the rectangular area you use.