STM32F407VGT6 Molding mark or pin 1?

[Andrei Chichak]

Posted on July 15, 2017 at 00:48

Our tech managed to mount a '407 180 degrees out. We figured out that it was because there is a molding mark 180 degrees from the pin 1 mark and they really aren't that different.

Why not use the pin 1 mark as the injection port? That way you can even save a feature on the mold.

Just a thought.

Andrei from The Great White North.

[Tesla DeLorean]

Posted on July 15, 2017 at 02:57

I think the pin one dimple and it's counterpoint are ejector points, so I doubt there's a savings to be made, but the clarity on pin one could certainly be improved. Not sure that's best done with the laser, or a different type of mark.

[STOne-32]

Posted on July 16, 2017 at 16:42

Dears,

The optional marking / ejector holes depends on our supply chain operations  that may change as described below for LQFP144.  as a general recommendation for LQFP packages : Pin 1 is on bottom left corner when you read the Product identification : STM32Fxxx.

Cheers,

STOne-32.

[Tesla DeLorean]

Posted on July 16, 2017 at 17:05

While the text is certainly a big cue, you definitely have parts where the pin 1 is less than crystal clear

Note also the round, some what indistinct round laser mark next to the ST Logo, these aren't helpful to the casual inspection

[John F.]

Posted on July 17, 2017 at 11:44

Andrei,

On the current STM32F407 Data Sheet    DocID022152 Rev 8       09-Sep-2016   it says above that diagram, 'The following figure gives an example of topside marking and pin 1 position identifier location. Other optional marking or inset/upset marks, which depend on supply chain operations, are not indicated below.'

On this maybe, give them a break?

[Tesla DeLorean]

Posted on July 17, 2017 at 17:52

I don't think any of this is meant with meanness or anger, it's just frustrating. The manual really should have a comprehensive set of examples covering the assorted supply chain and encapsulation variations, it can be a separate document for all I care. I can provide my people on the line and in the lab with an array of photos to help identify pin one, but there's no guarantee its current or has 100% coverage. I've got other 407 from China here also, and don't think I've got pictures of all the other variants to hand.

My frustration would be the counter-pointed ones, where the ejector mark is opposite and of similar depth, radius and profile, and result in 180 placement. The manual picture with two ejection points counter to each other and not opposite pin 1 perhaps less so.

[Tesla DeLorean]

Posted on July 17, 2017 at 18:05

Addendum : Having a disclaimer that basically translates to 'parts might not look like this at all' seriously devalues the document and it's fitness for purpose.

[STOne-32]

Posted on July 18, 2017 at 00:09

Dear  all,

As said earlier , we provide only examples of packages in our product datasheets, However  we are following standard of industry,  Our MCUs in LQFP packages are shipped and supplied in tape and reel media  compliant with

 with EIA 481 and IEC 60286-3 standard specifications.

You can refer to this Technical Note 

http://www.st.com/content/ccc/resource/technical/document/technical_note/f0/34/45/53/15/72/4e/2e/DM00156963.pdf/files/DM00156963.pdf/jcr:content/translations/en.DM00156963.pdf

applicable to all STM8/STM32 Products, then Section 4 - Device Orientation.

Cheers,

STOne-32. 

For @ Andrei : I missed yesterday New GOT Season 7,  It was at 3:00 Central Europe Time  ;)

[Andrei Chichak]

Posted on July 18, 2017 at 07:51

I'm just passing along the information. Apparently mitigating a hazard through labeling was not enough to prevent our tech from mounting the part backward.

Recently I even published an article on identifying pin 1. One of the things I pointed out was the need to refer to the documentation because of the variations in implementation.

for

benahmed.mohamed

‌, I had to google GOT. I was watching the British Grand Prix.

Andrei