FPC / PCB 工程計算機

Coverlay 開窗計算器

依 pad 尺寸、對位公差與溢膠預留估算 coverlay 開窗與橋寬。

Coverlay 開窗計算器怎麼用

Coverlay 開窗會影響 pad 露出、對位容差、溢膠風險與焊接可靠度。這個工具用 pad 尺寸、對位公差、基本 clearance 與 adhesive overflow allowance 估算建議開窗。

Coverlay opening design affects pad exposure, registration tolerance, adhesive overflow and soldering reliability. This calculator estimates opening size and bridge width from practical process allowances.

Coverlay opening allowance

公式: Opening size = pad size + 2 x (clearance + registration + adhesive allowance)

Pad size: copper pad width or height.
Clearance: desired exposed margin around the pad.
Registration: coverlay-to-copper alignment tolerance.
Adhesive allowance: allowance for adhesive squeeze-out or flow.

公式依據

Formula basis: practical DFM allowance stack using pad size, clearance, registration tolerance and adhesive flow allowance.
Engineering note: final coverlay opening and bridge rules should come from manufacturer capability and lamination trials.

範例

A 0.6 x 1.2 mm pad with 0.2 mm total allowance per side gives a 1.0 x 1.6 mm coverlay opening.

輸入欄位

Pad width
Pad height
Pad pitch
Base clearance
Registration tolerance
Adhesive allowance
Minimum bridge

結果輸出

Recommended opening width
Recommended opening height
Allowance per side
Bridge width estimate

工程注意事項

Small coverlay bridges can tear, shift or create adhesive squeeze-out problems.
Connector pads and fine pitch pads often need factory-specific coverlay rules.
For production release, verify pad exposure after lamination and coverlay registration.

驗證檢查

Pad exposure
Coverlay bridge width
Adhesive overflow
Alignment tolerance

FAQ

Why add adhesive allowance?

Coverlay adhesive can flow during lamination. Leaving allowance reduces the risk of adhesive covering solderable pad area.

Is the bridge width final DFM?

No. It is a quick estimate. Minimum coverlay bridge depends on material, thickness, tooling and factory capability.

Coverlay 開窗計算器