HDI PCB Assembly with Fine-Pitch BGA, μBGA and CSP
INDIC provides HDI PCB assembly for engineering teams building dense, miniaturised vision, RF, edge and sensing devices. INDIC assembles fine-pitch BGA, μBGA and CSP packages on HDI boards, verifies hidden joints with Nikon X-ray, and already ships 8-layer HDI sensing boards, HDI camera modules and RF IoT modules at close to 60,000 units a month.
- HDI with blind, buried and micro-vias
- μBGA, CSP and 0.35 mm BGA
- 01005 passives
- Koh Young 3D SPI
- Nikon X-ray
| ~60K | HDI units built every month across three production programs |
|---|---|
| 97.78% | Flying-probe test coverage on a smart-lighting module with no test specs (case study) |
| 0.35 mm | Finest BGA pitch, with 01005 passives |
| 3 stages | Of inspection: Koh Young 3D SPI, Mirtec 3D AOI and Nikon X-ray |
HDI PCB Assembly Builds Already in Production
INDIC manufactures these HDI designs for real devices today, at close to 60,000 units a month across the three programs.
| Build | Board and packages | Application |
|---|---|---|
| 8-layer HDI motion-sensing boards | 8-layer HDI | Motion and sensing devices |
| HDI camera modules | High-layer HDI with μBGA | Vision devices |
| Fine-pitch BGA RF IoT modules | BGA-dense, RF-shielded layouts | Connected and RF devices |
Process Controls for HDI PCB Assembly and Fine-Pitch BGA
On dense boards, most defects start with paste volume, panel warpage or a small placement shift. INDIC controls each one before reflow.
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Stencil and paste engineering
INDIC tunes stencil apertures per design, chooses paste type and rheology for tight apertures and shield step-ups, and verifies every print with Koh Young 3D SPI. See stencil services.
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Placement stability
INDIC tunes pick-and-place programs package by package and uses dedicated nozzles, support bars and tight jig tolerances to prevent micro-shifts.
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Controlled reflow profiles
INDIC profiles nitrogen reflow on Heller and ERSA Hotflow ovens for μBGA, CSP and shielded packages, so joints form fully under components that can't be seen.
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Damage-free depaneling
INDIC matches router bits, jigs and fixture support to each module revision to prevent burrs, cuts and shield scratches.
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Test coverage with limited access
INDIC combines flying probe testing, boundary-scan JTAG, ICT and FCT when HDI layouts leave little room for test points. On a smart-lighting module with no test specs, flying probe testing reached 97.78% coverage. See testing and quality.
Three-Stage Inspection for HDI PCB Assembly
INDIC verifies every hidden joint on an HDI board with three inspection stages.
| Stage | Equipment | What it checks |
|---|---|---|
| 1. After paste print | Koh Young 3D SPI | Paste volume, height and offset on every pad |
| 2. After reflow | Mirtec 3D AOI; Magic Ray VS300 double-sided AOI | Component presence, polarity, offset, bent or missing pins and visible solder joints, top and bottom, with results streamed into WATS analytics |
| 3. Hidden joints | Nikon X-ray | Voids, bridging and head-in-pillow defects under BGA, μBGA and CSP packages |
Standard BGA work is covered on the BGA assembly page. Every INDIC service is listed under PCB assembly services.
INDIC scaled a fine-pitch RF IoT module for a fast-growing IoT company
A fast-growing IoT company backed by a leading silicon provider moved its RF modules to INDIC after its previous supplier struggled with precision and scale. The build used 0.3 mm pitch parts, 01005 passives and five or more BGAs per board. Read the full RF IoT module case study.
| Problem | INDIC solution |
|---|---|
| Solder paste printing | Type 5 paste, redesigned stencils and a dedicated print support block removed insufficient solder and solder balls around the shields |
| Placement stability | Package-level pick-and-place tuning, dedicated nozzles and support bars eliminated component shift and frame distortion |
| Depaneling | Matching router bits and redesigned cushioning fixtures removed burrs, deep cuts and shield scratches |
INDIC HDI and BGA capability specifications
Items marked 'as a capability' are qualified processes INDIC sets up for a specific program after an engineering review; everything else runs in production today. The full equipment list is on the PCB assembly services page.
| Parameter | Capability |
|---|---|
| Layer count | Up to 12 layers in production; more than 21 layers as a capability |
| Board types | HDI, rigid and flex |
| Via structures | Through-hole, blind, buried and micro-vias |
| Smallest passives | 01005 |
| BGA pitch | 0.35 mm, 1 mm and 1.27 mm |
| Leaded fine pitch (QFP, TSOP) | Down to 16 mils (about 0.4 mm); 12 mils (0.3 mm) as a capability |
| Package types | BGA, fine-pitch BGA, μBGA, CSP; package-on-package as a capability |
| BGA I/O count | 10 to 676 and above |
| BGA package size | 1.9 × 2.4 mm up to 32 × 32 mm and larger |
| Inspection | Koh Young 3D SPI, Mirtec 3D AOI, Magic Ray VS300 double-sided AOI, Nikon X-ray |
HDI PCB assembly questions
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What is HDI PCB assembly?
HDI PCB assembly is the placement of components on high-density interconnect boards that use micro-vias, blind and buried vias and fine line widths. It is typical of camera modules, RF modules and sensing devices. It needs tighter paste, placement and inspection control than standard PCB assembly.
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Can INDIC assemble μBGA and CSP packages?
Yes. INDIC assembles μBGA, CSP and fine-pitch BGA packages. These packages are already in production in INDIC-built HDI camera modules and RF IoT modules.
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How does INDIC inspect BGA solder joints that can't be seen?
INDIC uses Nikon X-ray inspection to check the joints under BGA, μBGA and CSP packages for voids, bridging and incomplete joints. Koh Young 3D solder paste inspection before placement and Mirtec 3D AOI after reflow cover the earlier stages.
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What HDI boards has INDIC built?
INDIC's production builds include 8-layer HDI motion-sensing boards, high-layer HDI camera modules with μBGA, and fine-pitch BGA RF IoT modules with RF shielding. Each of these is manufactured for real devices, not as a capability demonstration, at close to 60,000 units a month in total.
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What is the finest pitch and smallest component INDIC can assemble on HDI boards?
INDIC places passives down to 01005 and BGAs down to 0.35 mm pitch. Leaded packages such as QFPs run down to 16 mil (about 0.4 mm) pitch in production, with 12 mil (0.3 mm) pitch available as a capability, the class of 0.3 mm pitch parts used on INDIC's RF IoT module.
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How many PCB layers can INDIC assemble?
INDIC assembles boards of up to 12 layers as standard, with capability for 21+ layers. It handles through-hole, blind, buried and micro-via structures on HDI, rigid and flex boards.
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How does INDIC test dense boards with few test points?
INDIC combines flying probe testing, boundary-scan JTAG, ICT and functional testing to close coverage gaps. On a smart-city lighting module with no test specs, flying probe testing reached 97.78% coverage, up from about 50% under the previous outsourced approach.
Have a dense design that other suppliers won't quote?
Send INDIC your Gerbers, stack-up and BOM, and its engineers will review paste, placement and inspection risks and explain how they would build it.
