PLCC footprints

[ouabache]

I am going to start working on a generate script for PLCC packages unless someone else is already working on one.

Do we have a wish list of items that we need someone to create?

[dbrgn]

Hm, maybe that could be integrated into the QFP generator? https://github.com/LibrePCB/librepcb-parts-generator/blob/master/generate_qfp.py

From Wikipedia:

A package related to QFP is PLCC which is similar but has pins with larger pitch, 1.27 mm (or 1/20 inch), curved up underneath a thicker body to simplify socketing (soldering is also possible).

Is there a document (e.g. from JEDEC) that standardizes PLCC footprints?

[ouabache]

That was my approach was to take that script and modify it to produce the plcc packages. The main thing is getting the IPC names right. We may also need another pkgcat for plcc's Right now I am fighting with jedec to try and get the right docs

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On Sat, Jan 25, 2020 at 11:57 AM Danilo Bargen ***@***.***> wrote: Hm, maybe that could be integrated into the QFP generator? https://github.com/LibrePCB/librepcb-parts-generator/blob/master/generate_qfp.py From Wikipedia: A package related to QFP is PLCC which is similar but has pins with larger pitch, 1.27 mm (or 1/20 inch), curved up underneath a thicker body to simplify socketing (soldering is also possible). — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#74?email_source=notifications&email_token=AAKX3XGULY44C4VANOYGOVLQ7SKTBA5CNFSM4KLSNDV2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJ5EG2Q#issuecomment-578437994>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKX3XHMF5PULYRJ4GLW3STQ7SKTBANCNFSM4KLSNDVQ> .

[dbrgn]

IPC name is as follows:

PLCC + Pin Qty. + P Pitch _ Lead Span L1 X Lead Span L2 Nominal X Height + L Lead Width

[dbrgn]

Oh, what might make this a bit more difficult: PLCC packages have different pin numbering scheme. Pin 1 is at the middle of a side, not at a corner.

[dbrgn]

I think after about 15 minutes of searching I found the relevant standard: MO-047: https://www.jedec.org/system/files/docs/Mo-047b.pdf (free registration required).

Topline PLCC packages may also be helpful: https://www.topline.tv/PLCC.html

[ouabache]

This seems to work: for p in range(1, config.lead_count + 1): group_size = config.lead_count // 4 mid = (group_size + 1) // 2 x = (p + mid ) if x > config.lead_count : x = x - config.lead_count pad_uuid = uuid_pads[x - 1]

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On Sat, Jan 25, 2020 at 1:34 PM Danilo Bargen ***@***.***> wrote: Oh, what might make this a bit more difficult: PLCC packages have different pin numbering scheme. Pin 1 is at the middle of a side, not at a corner. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#74?email_source=notifications&email_token=AAKX3XGW7B7WWUDZ76PROHDQ7SV6PA5CNFSM4KLSNDV2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJ5F5TA#issuecomment-578445004>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKX3XEF6HBFNWUNM2ZBM73Q7SV6PANCNFSM4KLSNDVQ> .

[ouabache]

I found another ipc-7351B that calls out Plastic Leaded Chip Carriers .................................................. PLCC + Pitch P + Lead Span L1 X Lead Span L2 Nominal X Height - Pin Qty

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On Sat, Jan 25, 2020 at 1:32 PM Danilo Bargen ***@***.***> wrote: IPC name is as follows: PLCC + Pin Qty. + P Pitch _ Lead Span L1 X Lead Span L2 Nominal X Height + L Lead Width — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#74?email_source=notifications&email_token=AAKX3XHVYIIQQAETSNFXPLLQ7SVYFA5CNFSM4KLSNDV2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJ5F4TI#issuecomment-578444877>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKX3XHRNG44FF4BSEPGYOLQ7SVYFANCNFSM4KLSNDVQ> .

[dbrgn]

I found another ipc-7351B that calls out

Use IPC7351-C, not -B: https://www.pcblibraries.com/downloads/Guidelines!Library-Expert-Land-Pattern-Naming-Convention.asp

[ouabache]

Changes made. Pull request is in

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On Sun, Jan 26, 2020 at 3:48 AM Danilo Bargen ***@***.***> wrote: I found another ipc-7351B that calls out Use IPC7351-C, not -B: https://www.pcblibraries.com/downloads/Guidelines!Library-Expert-Land-Pattern-Naming-Convention.asp — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#74?email_source=notifications&email_token=AAKX3XFFGGVPCMQ36TATLDLQ7VZ7BA5CNFSM4KLSNDV2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJ5R53Y#issuecomment-578494191>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKX3XCGLY575FPPP46ONF3Q7VZ7BANCNFSM4KLSNDVQ> .