📘 Pick and Place – Component Mounting Process: Overview

The Pick and Place process, also known as Component Mounting, is a central operation in Surface Mount Technology (SMT) assembly. After solder paste is printed and inspected, this step involves accurately placing surface-mount components (SMDs) onto the PCB pads using high-speed robotic machines.

This process requires:

• Precision alignment

• Correct feeder setup

• Optimal vacuum handling

• Component type recognition

Proper execution ensures high throughput and defect-free mounting for reliable downstream soldering.

🛠️ 10 Detailed Steps in the Pick and Place Process

1. PCB Loading into Pick and Place Machine

Description:
The PCB is conveyed or manually loaded into the machine. The transport system aligns the board to the machine’s work area.

2. Fiducial Mark Detection and Board Alignment

Description:
Vision systems detect fiducial marks on the PCB to calibrate X-Y positioning. This compensates for minor board placement shifts and ensures exact component placement.

3. Program and Job File Selection

Description:
The correct job program (based on the BOM and CAD data) is loaded. It includes:

• Component reference locations

• Feeder slots

• Nozzle types

• Placement sequence

4. Feeder and Component Setup

Description:
Component reels, trays, or tubes are loaded into feeder slots. Each feeder is assigned a part number and position in the software. Components must be oriented correctly for accurate picking.

5. Nozzle Selection and Tool Calibration

Description:
The machine selects the appropriate nozzle for each component type. Nozzles are calibrated for height, vacuum pressure, and drop point accuracy. Some machines auto-change nozzles mid-process.

6. Component Pickup with Vacuum Tool

Description:
The placement head moves to the feeder, picks the component using a vacuum nozzle, and checks pickup success via vision or vacuum feedback.

7. Vision Inspection and Centering

Description:
Before placement, the component is passed over a vision camera to:

• Detect rotation/orientation

• Adjust center alignment

• Verify size and shape

High-precision components (e.g., BGAs) often use bottom vision systems.

8. Component Placement on PCB Pads

Description:
The robot head moves to the target position and places the component on the solder paste pads with calibrated force to prevent damage or shift.

9. Vacuum Release and Confirmation

Description:
The vacuum is released, and sensors confirm the component is successfully placed. Some systems use force sensors or image verification for high-accuracy placement.

10. PCB Unloading or Transfer to Reflow Oven

Description:
After mounting, the PCB is moved to the next stage—reflow soldering. It may go through a buffer, visual inspection station, or directly into the oven conveyor.

❓ 10 “How To” Questions for the Pick and Place Process – Detailed Answers

1. How to Select the Right Pick and Place Machine for Production Needs?

Detailed Description:
Consider:

• Placement speed (CPH – Components Per Hour)

• Feeder capacity

• Component size range (e.g., 01005 to connectors)

• Vision and alignment capability

• Integration with SPI/AOI systems
  High-mix production needs flexibility; high-volume lines need speed.

2. How to Create and Optimize a Pick and Place Program?

Detailed Description:
Start with:

• Importing CAD/BOM data

• Mapping feeder slots

• Assigning nozzles to part types

• Setting placement order for speed

• Validating XY positions and rotation angles
  Use offline software to reduce machine downtime.

3. How to Calibrate Nozzles and Placement Tools?

Detailed Description:
Calibrate:

• Pickup height and placement height

• Vacuum strength for different components

• Nozzle change alignment

• Placement force
  Incorrect calibration can cause dropped parts or PCB damage.

4. How to Load and Validate Component Feeders?

Detailed Description:
Steps:

• Match part number with reel label

• Install feeder in assigned slot

• Set tape indexing (pitch, width)

• Run test picks
  Use barcode systems for traceability and error reduction.

5. How to Handle and Place Fine-Pitch and BGA Components?

Detailed Description:
Use:

• High-resolution bottom vision cameras

• Controlled placement force

• Slower speed for delicate parts

• Nozzles with anti-static and soft tips
  For BGAs, pre-placement inspection ensures balls are aligned properly.

6. How to Deal with Pickup Failures and Dropped Components?

Detailed Description:
If pickup fails:

• Retry from feeder

• Use spare nozzle

• Alert operator if repeated
  Dropped parts go to reject bins. Frequent failures indicate vacuum issues, nozzle wear, or feeder misfeeds.

7. How to Reduce Placement Misalignment and Rotation Errors?

Detailed Description:
Solutions include:

• Vision system tuning

• Fiducial calibration

• Correct polarity marking detection

• Ensuring component packaging accuracy
  Rotational errors are common with passive components and ICs.

8. How to Optimize Pick and Place Speed Without Losing Accuracy?

Detailed Description:
Tactics:

• Group similar components for batch pickup

• Use multi-nozzle heads effectively

• Shorten head travel distance

• Enable simultaneous vision inspection
  Balance speed with quality by monitoring CPH vs defect rates.

9. How to Perform Routine Maintenance on Pick and Place Equipment?

Detailed Description:
Daily/weekly checks include:

• Nozzle cleaning and replacement

• Feeder indexing wheel inspection

• Vacuum system leak checks

• Rail and conveyor lubrication

• Camera lens cleaning

Scheduled maintenance avoids unplanned downtime.

10. How to Train Operators and Technicians for Pick and Place Operation?

Detailed Description:
Training should cover:

• Machine startup and shut down

• Feeder loading and part verification

• Job file loading and validation

• Basic troubleshooting (pickup errors, head jams)

• Safety precautions

Hands-on practice and certification improve efficiency and reduce errors.