Recently WorkingBear got complaint from R&D and ask increase the solder paste volume on the MLCC (Multi-Layer Ceramic Capacitor) component pads to improve the capacitor broken issue. R&D said he had verified that the capacitor’s footprint in the board design is correct and followed manufacturer’s design guidelines. However, looks like there is not enough solder paste to form proper heel fillet on the terminal of capacitor. This insufficient solder paste volume make the solder cracking?
Recently one of my top manager ask to mount the shielding-can or call shielding-cover directly on the Printed Circuit Board to instead of mount the shielding-clip or call shielding-frame on the board first then cover the shieling-can. He said this “new process” is more cheap and can reach better RF (Radiation Frequency) performance. Also most of current popular cell phone board apply this solution.
Well, I must say yes. Directly mount the shielding-can on the board is cheaper and save labor hours as compare it with mount one component (frame or clip) on the board first then install another component (can or cover) to cover it. But this new requirement also got lots of negative feedback from SMT factory and repair center. Because of directly mount shielding-can on board means that repair guy must de-solder the shielding can first before repair the component under the shielding can. It make the repair job more difficult and may give more trouble and damage the board during repair.
Related article: The benefit to use shielding clips to instead of shielding frame
| Trouble | Suggested Remedies (Solutions) |
| DIMENSIONAL PROBLEMS | |
| Shot-to-shot dimensional variations |
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| Warping 彎曲變形 |
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Due to the rapid growth of mobile phone technology, the Electronic Manufacturing Service (EMS) in mainland China sometimes faces serious labor shortages. Additionally, Industry 4.0 promotes the need for factory automation in EMS. As a result, certain parts that cannot undergo SMT reflow process must fulfill the Paste-In-Hole (PIH) process, including type-A USB connectors, Ethernet connectors, power supply sockets, transformers, and others. Previously, most of these devices were touch-up soldered after SMT processing.
One day, my manager asked me a question: “Will changing the components from SMDs (Surface Mount Devices) to THDs (Through Hole Devices) and using the PIH (Paste-In-Hole) process affect the process and design?”
I later realized that the question aimed to prevent damage to connector components due to customers using excessive force.
Sometimes, Paste-In-Hole (PIH) is also referred to as Pin-In-Paste (PIP).
First, when considering traditional components inserted using the PIH process, there are several design considerations:
