STM32WL SoC Package Selection: QFN-48 vs. BGA-73

[azerimaker]

ST is now offering in two different package types for the STM23WL SoC. Part numbers: BGA-73: STM32WL55JCU6 QFN-48: STM32WLxx_QFN48

Why do we need decide? This will be a deciding factor affecting the final PCB cost.

BGA-73 Pros:

• Offers 43 IO pins
• Smaller package (5mm x 5mm)

Cons:

• Cost of PCB fabrication goes high (see the comparison quotes below)
• Hard to visually inspect and do quality check

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QFN-48 Pros:

• Cheaper PCB cost
• Easier to do a visual inspection
• Easier to adopt reference design by a larger amount of systems integrators

Cons:

• Slightly bigger package (6.8mm x 6.8mm)

• Offers less IO pins (25)

  Test quote from the PCBWay.com

• Quantity: 100x
• Layers: 4
• Track/via hole size:
• For BGA: 4mil/0.15mm (required for BGA)
• For QFN: 6mil/0.30mm (enough for QFN)

Results Test quote for the BGA-73: 400$ Test quote for the QFN-48: 144$

[wienke]

My additional pro for QFN-48 would be:

• Easier to adopt reference design by a larger amount of systems integrators

[azerimaker]

@wienke good point. adding now.

[elsalahy]

We used a QFN-48 package in the prototypes and we plan to use it for the final design, Closing issue, as there are no further updates on the subject.

[azerimaker]

There's some news from the Seeed's STM32WL modules:

• They're currently going through the FCC ,CE ,TELEC certifications
• Planned launch date of the module is end of August, latest early September
• No price info is available ATM
• Seeed's LoRa-E5 module datasheet (draft)

[azerimaker]

Yesterday in our call with Movesolutions from Italy, they mentioned that they have also developed an STM32WL based module (128KB Flash version) and their pricing is 8.5 Euros for 5K . It's on the final stage of certification and will be available for sale next month. Datasheet attached: Movesolutions MAMWLExx Module Datasheet

[elsalahy]

We went with the QFN package for the V0.2 iteration.