If I order top side only assembly from jlc will they send bottom side components

[Ram80]

So first time ordering a PCB and I'm ordering from jlcpcb. I didn't realize the cost difference between single sided PCB assembly and double sided(my design has components on both sides).

So I thought I'd choose top side assembly only, on the back side I have header pins and a battery holder, will they just send these parts separately with the assembled PCB if I choose top side only assembly?

[Pilatus]

JLCPCB will only deliver to you components that they have placed on the pcb. If they cannot place them, they will not deliver them to you, even if you pre-ordered the components.

For components, you need to order from their sister company LCSC. These get shipped to you directly. Those component orders cannot be "added" to your JLCPCB order as a combined ship to save money.

Their game, their rules.

[wraper]

Those component orders cannot be "added" to your JLCPCB order as a combined ship to save money.

You get $15 shipping discount at LCSC if you make PCB order at JLCPCB (before it's dispatched), therefore you should always order PCB first. Not sure about PCBA order but could be the same. If I need parts from LCSC but don't have PCB to order, I just order some random PCB from JLCPCB for $3.5 delivered and then order parts with free or heavily discounted shipping depending on weight.

[brucehoult]

The cost to JLC of stopping the production line and hand-picking the components you don't want assembled would be a lot higher than just allowing the production line to assemble them.

Back in the dark days of the 1960s and 1970s and early 1980s the New Zealand government (wrongly) wanted to improve the economy by employing people to assemble TVs and cars here. The Japanese manufacturers had to get someone to run around and pick one component from each bin and put them in a bag. They charged us more for the kitset than they would for a fully-assembled TV or car, because it cost them more to do.

And then we had to pay people to (inefficiently) assemble them, people buying TVs and cars had to pay a higher price than they otherwise would, and as a result had less money to spend on other things that might have gainfully employed the people who were working in those factories. In fact we would have been better off to import assembled products and pay those workers full salary to sit at home and do nothing -- and better off still if they found some other work (as they would, in time).

This was studied by Alan Gibbs, maybe as part of his M.A., Economics, or perhaps later when he was already working at one of those import substitution businesses.

Sidetracked, sorry ...