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Bobb Fwed
12-29-2009, 02:06 AM
I have never done this before, and I am looking for some help. I need to keep the assembly in the United States (for certain reasons I'd rather not need to explain).

The board will have about 60 SMT components, there will be places for through-hole parts, but I can do those by hand if there is some way to get surface mounted [only] cheaper/easier (pick and place stuff?).

I am getting the PCB made by ExpressPCB, and I will get the gerber file from them once I order my boards. Are there are any changes or precautions I need to make to the PCB for assembly?

How does part ordering work? Do I supply all components to assembler? Do they need to come in some specific form (tape and reel or whatnot), I don't know if the QFP Prop comes in such a form; I am confused as to how these components get machine placed when they aren't in a machine-friendly package.

Does anyone on the forum do this type of stuff (that way I might get a little more personal assistance through this new step)? Or are there any places that people use in the states that may be able to do this assembly for me (and maybe help a little through the process as well).

Any help would be greatly appreciated.

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Some of my objects:
MCP3X0X ADC Driver (http://obex.parallax.com/objects/488/) - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database (http://obex.parallax.com/objects/493/) - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library (http://obex.parallax.com/objects/543/) - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm (http://obex.parallax.com/objects/546/) - Fast communication between two propellers (1.37MB/s @100MHz)!

Leon
12-29-2009, 02:50 AM
Try Screaming Circuits.

Most PCB assembly companies supply the more common parts, they can get them much cheaper than you can.

Leon

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Amateur radio callsign: G1HSM

Post Edited (Leon) : 12/28/2009 6:56:16 PM GMT

James Long
12-29-2009, 02:56 AM
Bobb Fwed said...
I have never done this before, and I am looking for some help. I need to keep the assembly in the United States (for certain reasons I'd rather not need to explain).

The board will have about 60 SMT components, there will be places for through-hole parts, but I can do those by hand if there is some way to get surface mounted [only] cheaper/easier (pick and place stuff?).

I am getting the PCB made by ExpressPCB, and I will get the gerber file from them once I order my boards. Are there are any changes or precautions I need to make to the PCB for assembly?

How does part ordering work? Do I supply all components to assembler? Do they need to come in some specific form (tape and reel or whatnot), I don't know if the QFP Prop comes in such a form; I am confused as to how these components get machine placed when they aren't in a machine-friendly package.

Does anyone on the forum do this type of stuff (that way I might get a little more personal assistance through this new step)? Or are there any places that people use in the states that may be able to do this assembly for me (and maybe help a little through the process as well).

Any help would be greatly appreciated.


Bobb,

I will try to answer your questions in order.

You say you will have 60 components. Is that 60 total components or 60 different components. Many assemblers will want to know.

You are having ExpressPCB do the boards, which is a good first run. You should try and put fiducials on the boards somewhere for visual machine recognition. Fiducials are circles which are bare copper, with no silkscreen or soldermask for a certain distance. Fiducials are really a minimum for automated assembly. We use fiducials, but each assembler has a minimum size. You would need to ask what the assembler recommends (can be a problem if you do not have one).

Part ordering is somewhat dependent of the assembler. We require the customer to supply the parts. Others will supply the parts, and you may get a better deal on the parts. But you may be restrained to the parts they use (can't choose a certain capacitor manufacturer.....not necessarily a good thing).

Parts must be in a usable form. Some assemblers can handle loose parts with vibratory bowl feeders, but most of those will want a very large assembly run (in the thousands of boards). We do have a number of matrix trays we can put parts in, but do prefer you purchase them in tape/reel form. Be careful ordering in trays. Mouser list parts in trays, but they are not matrix trays. They provide more of a box which the parts in sandwiched between foam (these are not matrix trays).

We provide assembly, and really started because of Parallax. Parallax got us hooked on making gadgets, and we went on to design boards, only to find out assembly is very expensive. We are cheaper than most (in the USA anyway), but there are some things we do not provide like the larger assemblers. We help first time customers through the gambit of hurdles which are not known. There is a lot of information which is not readily available, and that is our job.

What is great about our service, we will teach the customer what is needed. The customer can use this with us or any other assembly service.

If you would like to converse more about the steps, you can email me from this forum (use the email button on the upper left of this post).

James L

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James L
Partner/Designer
Lil Brother SMT Assembly Services (http://www.lil-brother.com)

Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits (http://www.savagecircuits.com). Learn to build your own Gizmos!

Post Edited (James Long) : 12/28/2009 7:06:37 PM GMT

James Long
12-29-2009, 03:01 AM
Leon said...
Try Screaming Circuits.

Most PCB assembly companies supply the more common parts, they can get them much cheaper than you can.

Leon


Leon,

I do agree that you may get parts cheaper with a large assembler which provides parts, but you may be restricted to the brand they use. If I were restricted to Kemet capacitors I would have to pass. I won't use them on something I'm going to throw away.

I rather spec out the parts I want to use (including brand), and assemble it.

Just my opinion........

James L

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James L
Partner/Designer
Lil Brother SMT Assembly Services (http://www.lil-brother.com)

Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits (http://www.savagecircuits.com). Learn to build your own Gizmos!

Cluso99
12-29-2009, 03:05 AM
Bob, you seem to be requiring info for professional assembly.

I had a financial interest and management role in a pcb assembler in Australia nearly 10 years ago. Here are some things that were done here that would apply equally to the USA.

PCB Design...

PCB Design. You need to consult with the pcb assembler as they will have certain requirements such as Layout Fiducials Size and space for carrying the pcb thru the factory Depending on size, panelisation Minimum space between components (for the robot to place parts) Pad size and paste size for various components Manufacture They will have specific requirements and some suppliers may not meet these Components. You need to consult with the assembler What components you supply and what they supply They will most likely want to supply the common parts such as resistors and capacitors This is because they will likely have them already setup for the robots It is cheaper for them to supply due to setup and traceability They like to supply other parts because They buy cheaper than you and they will make money on it They have the infrastructure to handle this The propeller chip (smt) must be supplied in trays or tape or tube(QFN)·from Parallax (don't think they have tape, trays are 160? for QFP) A recent purchase I made direct from Parallax would have been unsuitable for robot assembly because the·ICs were in a small antistatic box/foam and the pins were distorted by this method Parts should preferably be on tape, otherwise in tubes or trays for the robots For tape, you require blank leadins and trailers, so you cannot just buy cut tape Any parts for machine or hand soldering ? Setup costs. These may not be individually quoted, but they exist internally anyway Setup costs for the first job Setup costs for each job Minimum runs Testing How are they going to test In circuit testing? Functional testing? Visual inspection? Packing How are they going to pack and ship to you?
For small volumes, a smaller assembler may be able to do hand placement of the smt·parts and reflow them for you.

I hope this helps.

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade (http://forums.parallax.com/showthread.php?p=786418),·RamBlade (http://forums.parallax.com/showthread.php?p=849265),·SixBlade (http://forums.parallax.com/showthread.php?p=780033), website (http://bluemagic.biz/cluso.htm)
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator) (http://forums.parallax.com/showthread.php?p=790917)
· Prop Tools under Development or Completed (Index) (http://forums.parallax.com/showthread.php?p=753439)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) (http://forums.parallax.com/showthread.php?p=778427) ZiCog (Z80) (http://forums.parallax.com/showthread.php?p=788511) , MoCog (6809) (http://forums.parallax.com/showthread.php?p=811043)
· Search the Propeller forums (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)

James Long
12-29-2009, 03:10 AM
Cluso99 said...
Bob, you seem to be requiring info for professional assembly.

I had a financial interest and management role in a pcb assembler in Australia nearly 10 years ago. Here are some things that were done here that would apply equally to the USA.

PCB Design...




Cluso,

Good post....you cover most of the items, but there is one that doesn't apply to our company:

"Cut tape"

We will use cut tape of any item that is not a passive (resistor, capacitor, etc).

We do a lot of IC cut tape assembly. This keeps the customer from having to buy a 2000 part reel, where each part costs $7.00.

James L

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James L
Partner/Designer
Lil Brother SMT Assembly Services (http://www.lil-brother.com)

Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits (http://www.savagecircuits.com). Learn to build your own Gizmos!

TonyWaite
12-29-2009, 03:42 AM
Bobb,

Just my advice: I would talk first to your chosen assembler _before_ ordering the PCB's.

They may be picky about the finish most appropriate to their process, which may impact on pricing and more importantly yield.

As an example, I now specify gold finish on all boards with fine-pitch parts; then the assemblers can place every part efficiently.

And if they supply the boards as well, then the responsibility for the job is all theirs.

It's taken me about ten different designs over the last year to learn this lesson ...

Regards,

T o n y

James Long
12-29-2009, 04:15 AM
TonyWaite said...
Bobb,

Just my advice: I would talk first to your chosen assembler _before_ ordering the PCB's.

They may be picky about the finish most appropriate to their process, which may impact on pricing and more importantly yield.

As an example, I now specify gold finish on all boards with fine-pitch parts; then the assemblers can place every part efficiently.

And if they supply the boards as well, then the responsibility for the job is all theirs.

It's taken me about ten different designs over the last year to learn this lesson ...

Regards,

T o n y


It is true that the finish on the boards is important. We ask the customer what the finish is, and adjust the stencil apertures to accomplish the correct amount of solder put on the boards.

A gold finish (or bare copper pads) is one which requires the least amount of work. HSL requires the most aperture adjustment.

It should be noted that gold, and silver will grow "whiskers" over time.

The plating on the boards is very important to the assembler. If the stencil is not right......they will have a huge amount of rework (solder bridging).

James L

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James L
Partner/Designer
Lil Brother SMT Assembly Services (http://www.lil-brother.com)

Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits (http://www.savagecircuits.com). Learn to build your own Gizmos!

Bobb Fwed
12-29-2009, 06:01 AM
Thank you for all of the information! I will post again if I need additional help. I will talk to an assembler to continue the process.

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Some of my objects:
MCP3X0X ADC Driver (http://obex.parallax.com/objects/488/) - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database (http://obex.parallax.com/objects/493/) - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library (http://obex.parallax.com/objects/543/) - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm (http://obex.parallax.com/objects/546/) - Fast communication between two propellers (1.37MB/s @100MHz)!

James Long
12-29-2009, 06:19 AM
Bobb Fwed said...
Thank you for all of the information! I will post again if I need additional help. I will talk to an assembler to continue the process.


Bob,

There is one more thing that should be considered. A small assembler like ourself are usually not the fastest at getting jobs out. Your time requirements should be considered when choosing an assembler.

If you need it fast, places like Screaming Circuits will get them out pretty quick, but be prepared for the bill. It can be hefty. Even our quotes are not small for hobbyist.

James L

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James L
Partner/Designer
Lil Brother SMT Assembly Services (http://www.lil-brother.com)

Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits (http://www.savagecircuits.com). Learn to build your own Gizmos!

Bobb Fwed
02-25-2010, 02:24 AM
I have been trying to get a hold of James Long. Any one know if something happened to him? Or some way I can contact him other then the listed email (here in the forums) or PM?

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Some of my objects:
MCP3X0X ADC Driver (http://obex.parallax.com/objects/488/) - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database (http://obex.parallax.com/objects/493/) - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library (http://obex.parallax.com/objects/543/) - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm (http://obex.parallax.com/objects/546/) - Fast communication between two propellers (1.37MB/s @100MHz)!

Leon
02-25-2010, 05:41 AM
His last post was 1/30/2010.

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Leon Heller
Amateur radio callsign: G1HSM

Bobb Fwed
02-25-2010, 05:51 AM
Thanks. Just after I posted, I received an email from him. He has been having medical problems and consequently lowered his priorities on responding to emails and the like; which is very understandable.

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Some of my objects:
MCP3X0X ADC Driver (http://obex.parallax.com/objects/488/) - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database (http://obex.parallax.com/objects/493/) - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library (http://obex.parallax.com/objects/543/) - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm (http://obex.parallax.com/objects/546/) - Fast communication between two propellers (1.37MB/s @100MHz)!