{
  "id": 14245823,
  "title": "Via-in-Pad: The Space Saver That Quietly Drains Your Solder Joints",
  "url": "https://urgent.news/2026/10/13/via-in-pad-the-space-saver-that-quietly-drains-your-solder-joints",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-13T16:53:58.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/dibyaprakash_pradhan/via-in-pad-the-space-saver-that-quietly-drains-your-solder-joints-1eg3"
  },
  "original_language": "en",
  "account": "Vias placed directly on SMD pads are a design choice that can lead to weaker solder joints. The issue lies in the behavior of the hole after plating; during the reflow process, solder flows into the via and runs down its barrel, resulting in a joint that has less solder than originally intended. On larger pads, this creates a weaker connection, while on smaller components or fine-pitch leads, the joint may be entirely absent, leading to intermittent connections that are difficult to detect. This phenomenon can cause dog-bone fan-out structures, via-in-pad configurations, and QFN thermal vias to become problematic. In some cases, it can also lead to a specific failure known as tombstoning, where small parts stand upright on pads containing a single via, while those without a via lie flat. The decision to use via-in-pad depends on several factors, including the availability of space for a via alongside the pad on a short trace, the presence of thermal pads under QFN or power packages, and the need for fine-pitch BGAs. However, small passive components or ordinary fine-pitch leads do not require an open via. The impact of via-in-pad extends to manufacturing processes, as filled and capped vias, often referred to as VIPPO (Via-in-Pad Plated Over), must be specified to the fab to ensure proper joint formation. While via-in-pad isn't a layout trick, it is a manufacturing decision that requires careful consideration and communication with the fabrication partner.",
  "summary": "\"Vias directly on SMD pads?\" is one of the most-viewed PCB questions on Electrical Engineering Stack Exchange, and the answers there all say some version of \"it depends\". It does, but on one thing only: what happens to the hole. The problem with an open hole A plated hole is a capillary. During reflow, molten solder on the pad flows into the via and runs down the barrel. The joint above is left…",
  "key_points": [
    "Vias on SMD pads can weaken solder joints due to solder flow during reflow.",
    "Dog-bone fan-out structures and tombstoning can result from via-in-pad configurations.",
    "Via-in-pad is a manufacturing decision requiring communication with fabrication partner."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}