What Is a DIP Production Line? A Complete Guide

How SMT and DIP Lines Work Together

For mixed-technology PCBAs, SMT is usually completed first.

A typical complete process is:

PCB Loader → Solder Paste Printer → SPI → SMT Placement → Reflow → AOI → THT Insertion → Wave/Selective Soldering → Inspection → Testing

This allows high-density surface-mount components and large through-hole components to be assembled on the same PCB.

Why Is THT Still Used If SMT Is More Automated?

SMT dominates modern electronics manufacturing, but THT remains useful for certain component and product requirements.

Through-hole mounting may be selected for:

• Large connectors
• Terminal blocks
• Transformers
• Relays
• Large capacitors
• Electromechanical components
• Selected power components

It may also provide additional mechanical support in applications where the component or connection is mechanically loaded.

However, THT should not be considered universally stronger or more reliable than SMT.

The correct mounting method depends on component, PCB, mechanical, electrical, and production requirements.

How to Calculate DIP Production Line Capacity

A common mistake is to calculate capacity from the wave soldering machine alone.

Actual line output is determined by the bottleneck.

For example:

Although wave soldering can process 70 boards per hour, the complete line may only deliver around 25 finished boards per hour if testing remains the bottleneck.

Therefore, manufacturers should evaluate the whole process.

Why THT Insertion Is Often a Bottleneck

THT insertion may require significant manual work because many components are:

• Large
• Heavy
• Irregular
• Differently packaged
• Difficult to automate

Factories can improve insertion efficiency through:

• Component kitting
• Better workstation layout
• Parallel operators
• Automatic component preparation
• Semi-automatic insertion
• Automatic insertion for suitable components
• Standardized work instructions

The goal is not necessarily to automate every component.

The goal is to balance the complete production line.

How Many Operators Does a DIP Line Need?

There is no fixed number.

Operator requirements depend on:

• Number of THT components per PCB
• Manual insertion time
• Target cycle time
• Product mix
• Component preparation
• Inspection
• Testing
• Automation level

For manual insertion, line balancing can be performed by measuring operator cycle time.

For example, if one PCB requires 120 seconds of total manual insertion and the target takt time is 30 seconds, multiple balanced workstations may be required.

DIP Production Line Layout

Factory layout affects productivity.

A good layout should support:

• Logical material flow
• Minimal PCB handling
• Short operator movement
• Component replenishment
• Maintenance access
• Exhaust routing
• Inspection
• Testing
• Rework

A simple linear layout can be:

Loading → Preparation → Insertion → Soldering → Inspection → Testing → Unloading

A U-shaped layout may be useful where floor space is limited or operators need to support multiple processes.

Factory Utilities Required for a DIP Line

Depending on equipment configuration, utilities can include:

• Electrical power
• Compressed air
• Exhaust
• Ventilation
• Nitrogen where required
• ESD grounding

Wave and selective soldering equipment may have specific exhaust and electrical requirements.

These should be reviewed before machine installation.

ESD Control in DIP Assembly

THT assembly still involves electronic components that may be sensitive to electrostatic discharge.

An ESD-controlled production area may include:

• ESD workbenches
• Grounding systems
• ESD flooring or mats
• Wrist straps
• ESD-safe storage
• Suitable material handling

The exact ESD program depends on factory and product requirements.

Fume Extraction for Soldering Equipment

Wave and selective soldering may generate process fumes.

Factories should plan appropriate:

• Exhaust connections
• Ventilation
• Fume extraction
• Maintenance access

Requirements depend on equipment design, flux chemistry, factory environment, and local regulations.

Material Management in a DIP Production Line

Unlike SMT reels, THT components may arrive in many packaging formats.

Examples include:

• Tubes
• Trays
• Bags
• Taped radial components
• Taped axial components
• Bulk packaging

Good material preparation and kitting can reduce operator searching and insertion errors.

Workstations should clearly separate:

• Component part numbers
• Polarity
• Position
• Quantity

How to Improve DIP Production Line Efficiency

Manufacturers can improve efficiency by focusing on:

• Bottleneck analysis
• Component preparation
• Operator balancing
• Material kitting
• Conveyor flow
• Changeover reduction
• Wave soldering stability
• Defect reduction
• Testing capacity
• Preventive maintenance

Improving only one machine may not improve finished output.

For example, increasing wave soldering capacity provides little benefit if manual insertion remains the limiting process.

Common DIP Production Line Problems

Factories may experience:

Slow Manual Insertion

Possible improvements include:

• Better workstations
• Component kitting
• Parallel operators
• Automated preparation
• Partial insertion automation

Frequent Soldering Defects

Common defects can include:

• Solder bridges
• Poor wetting
• Incomplete hole fill
• Insufficient solder

Review:

• Flux
• Preheat
• Solder temperature
• Conveyor speed
• PCB design
• Component solderability
• Equipment maintenance
• Excessive WIP

High WIP usually indicates poor process balance.

Compare cycle times across:

• Insertion
• Soldering
• Inspection
• Testing

Long Changeover Time

Changeover can be improved through:

• Standardized work
• Material preparation
• Recipe management
• Adjustable conveyors
• Organized tooling

High Rework

High rework reduces effective capacity.

Track defects by:

• Component
• Station
• Operator
• PCB model
• Soldering process

Then address root causes rather than only increasing inspection.

Wave Soldering Machine Selection

When choosing a wave soldering machine, consider:

• PCB dimensions
• Conveyor width
• Fluxing system
• Preheat capacity
• Solder pot
• Wave configuration
• Conveyor speed
• Cooling
• Control system
• Maintenance access

For high-thermal-mass products, preheat and thermal capacity deserve particular attention.

Selective Soldering Machine Selection

For selective soldering, evaluate:

• THT joint locations
• Bottom-side clearance
• Nozzle access
• Nozzle sizes
• Fluxing accuracy
• Preheat
• Soldering path
• Cycle time
• Product changeover
• Conveyor compatibility

A representative PCB should be reviewed before machine selection.

Should You Automate the DIP Line?

Automation can improve:

• Material flow
• Repeatability
• Labor efficiency
• Capacity
• Traceability

But automation should be applied selectively.

Do not assume every THT process should be automated.

Automation makes the most sense when:

• Tasks are repetitive
• Product design is stable
• Component packaging is suitable
• Production volume justifies investment
• Labor or capacity is a real bottleneck

High-mix production may benefit more from semi-automation than from a fully automated line.

New vs Pre-Owned DIP Production Line Equipment

Manufacturers can use:

• New equipment
• Pre-owned equipment
• A combination of both

Pre-owned equipment can be useful when manufacturers want to:

• Reduce initial investment
• Expand capacity
• Use established equipment platforms

However, equipment should be evaluated for:

• Mechanical condition
• Control system
• Maintenance history
• Spare parts availability
• Technical support
• Compatibility with current products

Total cost of ownership should be considered rather than machine price alone.

How Much Does a DIP Production Line Cost?

There is no universal fixed cost.

Investment depends on:

• Automation level
• Number of insertion stations
• Automatic insertion equipment
• Wave vs selective soldering
• PCB handling
• Inspection
• Testing
• Exhaust
• Tooling
• Installation
• Training
• Spare parts

A basic manual line requires significantly less investment than a highly automated THT line.

For this reason, suppliers should first understand the product and production target before preparing a quotation.