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SMT electronics assembly manufacturing forum.


John Martell

#11169

pitch | 4 June, 1999

We are changing from through-hole to SMT, wondering what pitch requirements would an 8 pin SOAC require for pick and place? We think that this would be our finest pitch part.

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#11170

Re: pitch | 5 June, 1999

| We are changing from through-hole to SMT, wondering what pitch requirements would an 8 pin SOAC require for pick and place? We think that this would be our finest pitch part. |

John: Never heard of an "SOAC." SO packages are 50 ptch (50 mil, 1.27 mm).

I think you should anticipate that your pitch requirement will become more stringent as you become more involved in SMT and your requirements change.

Plus, with good 50 mil pad design, reasonable solder paste deposits, and an OK reflow oven; you don't need to be concerned about placement accuracy. Getting a 50 pitch component somewhat on the pad is all you need to do. The capiplulsive force of the solder will snap that puppy in position, like blam!!!

I think you should be asking yourself "what kind of production mix will we be assembling 2-3 years down the road?"

We'll help

Good luck

Dave F

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John Martell

#11171

Re: pitch | 7 June, 1999

Thanks a lot,, so assuming we are using standard parts, with nothing out of the ordinary we could safely assume that a machine capable of 20 mil would be more than able to meet our needs down the road. | We are changing from through-hole to SMT, wondering what pitch requirements would an 8 pin SOAC require for pick and place? We think that this would be our finest pitch part. | | | | John: Never heard of an "SOAC." SO packages are 50 ptch (50 mil, 1.27 mm). | | I think you should anticipate that your pitch requirement will become more stringent as you become more involved in SMT and your requirements change. | | Plus, with good 50 mil pad design, reasonable solder paste deposits, and an OK reflow oven; you don't need to be concerned about placement accuracy. Getting a 50 pitch component somewhat on the pad is all you need to do. The capiplulsive force of the solder will snap that puppy in position, like blam!!! | | I think you should be asking yourself "what kind of production mix will we be assembling 2-3 years down the road?" | | We'll help | | Good luck | | Dave F |

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#11172

Re: pitch | 7 June, 1999

| | We are changing from through-hole to SMT, wondering what pitch requirements would an 8 pin SOAC require for pick and place? We think that this would be our finest pitch part. | | | | | | | John: Never heard of an "SOAC." SO packages are 50 ptch (50 mil, 1.27 mm). | | | | I think you should anticipate that your pitch requirement will become more stringent as you become more involved in SMT and your requirements change. | | | | Plus, with good 50 mil pad design, reasonable solder paste deposits, and an OK reflow oven; you don't need to be concerned about placement accuracy. Getting a 50 pitch component somewhat on the pad is all you need to do. The capiplulsive force of the solder will snap that puppy in position, like blam!!! | | | | I think you should be asking yourself "what kind of production mix will we be assembling 2-3 years down the road?" | | | | We'll help | | | | Good luck | | | | Dave F | | | | Thanks a lot,, so assuming we are using standard parts, with nothing out of the ordinary we could safely assume that a machine capable of 20 mil would be more than able to meet our needs down the road. | Yes, but also think about:

OTHER MACHINE CAPABILITY REQUIREMENTS: BGA inspection and placement, board size, CAD download, product change-over time, and peculiarities of your (assumed to be) wacky operation. PRODUCT MIX: I mentioned that didn�t I? SUPPLIER: Ability meet your short and long term support requirements. PREVIOUS CUSTOMER SATISFACTION: Does what the cheerleaders say mean more to you than what the whiners say? VALUE COMPARED TO SIMILAR MACHINES: Placement rate is a small piece of this equation.

Each January "Circuits Assembly" publishes a flawed, but useful comparison of placement machine suppliers� machines. It also is at their site. Look at "SMT" magazine�s "10 Steps" at their site.

Push on

Dave F

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John Martell

#11173

Re: pitch | 7 June, 1999

Thanks for the advice, I'll check out that site.

| | | We are changing from through-hole to SMT, wondering what pitch requirements would an 8 pin SOAC require for pick and place? We think that this would be our finest pitch part. | | | | | | | | | | John: Never heard of an "SOAC." SO packages are 50 ptch (50 mil, 1.27 mm). | | | | | | I think you should anticipate that your pitch requirement will become more stringent as you become more involved in SMT and your requirements change. | | | | | | Plus, with good 50 mil pad design, reasonable solder paste deposits, and an OK reflow oven; you don't need to be concerned about placement accuracy. Getting a 50 pitch component somewhat on the pad is all you need to do. The capiplulsive force of the solder will snap that puppy in position, like blam!!! | | | | | | I think you should be asking yourself "what kind of production mix will we be assembling 2-3 years down the road?" | | | | | | We'll help | | | | | | Good luck | | | | | | Dave F | | | | | | | Thanks a lot,, so assuming we are using standard parts, with nothing out of the ordinary we could safely assume that a machine capable of 20 mil would be more than able to meet our needs down the road. | | | Yes, but also think about: | | OTHER MACHINE CAPABILITY REQUIREMENTS: BGA inspection and placement, board size, CAD download, product change-over time, and peculiarities of your (assumed to be) wacky operation. | PRODUCT MIX: I mentioned that didn�t I? | SUPPLIER: Ability meet your short and long term support requirements. | PREVIOUS CUSTOMER SATISFACTION: Does what the cheerleaders say mean more to you than what the whiners say? | VALUE COMPARED TO SIMILAR MACHINES: Placement rate is a small piece of this equation. | | Each January "Circuits Assembly" publishes a flawed, but useful comparison of placement machine suppliers� machines. It also is at their site. Look at "SMT" magazine�s "10 Steps" at their site. | | Push on | | Dave F | |

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