SMT vs DIP vs Mixed Technology PCB Assembly: Which Process Should Buyers Choose?

For most modern electronics, SMT is the primary PCB assembly process, but it is not automatically suitable for every component or product. Buyers should choose SMT, DIP, or mixed-technology assembly according to component package, mechanical stress, current requirements, board design, production volume, and testing requirements. For boards containing both dense surface-mount ICs and large through-hole connectors, relays, or power components, mixed SMT+DIP assembly is often the more practical manufacturing route.

Which PCB assembly process should buyers choose?

The three common assembly approaches are:

• SMT: Surface Mount Technology for components mounted directly onto PCB pads.

• DIP/THT: Through-hole components inserted through PCB holes and soldered.

• Mixed technology: SMT and through-hole assembly combined on the same PCB.

The choice affects not only assembly cost but also PCB design, stencil requirements, soldering sequence, inspection, component sourcing, and final testing.

For procurement teams, the correct question is not “Which assembly method is cheaper?” but rather:

Which process can manufacture this specific PCB repeatedly while meeting mechanical, electrical, thermal, and quality requirements?

Benewave supports both SMT and DIP assembly and handles mixed-technology boards, including BGA and QFN packages as well as through-hole components. Its current manufacturing capability includes 6 SMT lines, 3 DIP lines, and dedicated functional-testing lines.

What is the difference between SMT and DIP assembly?

The table should be treated as a selection framework rather than a universal ranking.

A compact consumer device may be almost entirely SMT, while an industrial controller can require through-hole connectors, relays, terminal blocks, and heat-generating components.

When is SMT assembly the right choice?

SMT is generally appropriate when the PCB uses a high density of surface-mount components and requires automated placement.

Modern electronic products often contain small passive components, fine-pitch ICs, BGAs, QFNs, and other packages that are designed for SMT.

SMT can also make sense when:

• PCB space is limited.

• Component density is high.

• Production volume justifies automated placement.

• Components are available in standard SMT packages.

• Double-sided assembly is required.

• The design needs compact packaging.

However, the board must be designed for manufacturing.

A footprint that is electrically correct may still create problems with solder-paste printing, component placement, reflow, inspection, or rework. Benewave's SMT process uses automated equipment and inline AOI/SPI, while its engineering workflow supports DFM review before production.

What SMT problems should buyers watch for?

Typical risks include:

• Incorrect footprints

• Poor solder-paste aperture design

• Component placement limitations

• Tombstoning of small passive components

• Bridging on fine-pitch devices

• Insufficient solder on thermal pads

• Hidden BGA/QFN solder defects

• PCB warpage during assembly

These risks are influenced by the PCB design, component package, stencil, solder paste, reflow profile, and production equipment.

Therefore, purchasing teams should ask the supplier to review the manufacturing data before releasing a large order.

When should buyers choose DIP or through-hole assembly?

Through-hole assembly remains relevant when components need strong mechanical attachment or are not practical in SMT packages.

Typical examples include:

• Large connectors

• Terminal blocks

• Power components

• Mechanical switches

• Relays

• Large transformers

• Components subject to repeated insertion or mechanical stress

For example, a connector that users repeatedly plug and unplug may experience mechanical forces that influence the preferred mounting method.

Through-hole technology allows component leads to pass through the PCB and provides mechanical anchoring in addition to soldered electrical connections.

The limitation is that through-hole components generally consume more PCB area and may require additional drilling and soldering operations.

Benewave's DIP capability includes semi-automated insertion and manual soldering for complex through-hole assemblies, and its service information states that DIP assemblies undergo inspection and electrical testing according to project requirements.

When is mixed SMT and DIP assembly better?

Mixed technology is particularly relevant when a PCB contains both:

• High-density SMT components

• Large through-hole connectors

• Relays

• Terminal blocks

• Power components

• Mechanically stressed components

In this situation, forcing every component into SMT can require redesigning components or compromising mechanical requirements. Converting everything to DIP can create an unnecessarily large PCB and increase assembly complexity.

A mixed process allows each component to use the mounting technology appropriate to its package and function.

What does a mixed SMT+DIP process involve?

A typical manufacturing sequence may include:

1. Solder-paste printing

2. SMT component placement

3. Reflow soldering

4. AOI/SPI inspection

5. Through-hole component insertion

6. Wave, selective, or manual soldering as applicable

7. Visual inspection

8. ICT or functional testing

9. Programming

10. Final inspection

The exact sequence depends on the board design and soldering process.

How should buyers compare SMT-only and mixed assembly costs?

Unit price alone can be misleading.

Mixed assembly can have a higher process cost per board, but that does not automatically make it more expensive at the product level.

If using SMT-only requires changing the connector, PCB, enclosure, or component architecture, the additional engineering cost may outweigh assembly savings.

How does component package affect the assembly decision?

Component package is one of the first technical parameters buyers should review.

For example:

These are typical tendencies rather than fixed rules.

The component manufacturer's recommended mounting method and the actual product design should always take precedence.

What should buyers ask a PCBA supplier before choosing the process?

A useful supplier discussion should include:

Component capability

Ask whether the supplier can handle the actual package types, dimensions, pitch, and component height.

PCB capability

Confirm layer count, board thickness, copper weight, surface finish, and maximum board dimensions.

Benewave's current PCB fabrication information lists boards from 1 to 50 layers, rigid thickness from 0.2 mm to 7 mm, copper thickness from 0.5 oz to 4 oz, and maximum board size of 500 × 500 mm. These are published capability figures and should still be confirmed against the specific project.

Soldering process

Ask whether the project requires reflow, wave soldering, selective soldering, or manual soldering.

Inspection

Confirm AOI, X-ray, ICT, and FCT requirements according to the board's failure modes.

Programming and testing

If the PCB contains firmware, MCU, communication interfaces, or sensors, determine how programming and functional verification will be performed.

What are the biggest failure risks when selecting the wrong process?

The consequences can appear at different stages.

Design stage: The PCB footprint or component choice may not support the selected assembly method.

Production stage: Soldering defects, insufficient mechanical strength, or inefficient manual operations may appear.

Testing stage: Poorly assembled connectors or solder joints may cause intermittent failures.

Field stage: Components exposed to mechanical or thermal stress may fail earlier than expected.

This is why assembly technology should be reviewed during DFM rather than after the PCB has already entered production.

Should buyers choose one assembly process for every product?

No. Different products and even different PCB revisions may require different assembly strategies.

A low-density industrial controller may contain more through-hole components, while a compact IoT gateway may be dominated by fine-pitch SMT.

For OEM buyers, the useful procurement strategy is to give the supplier the complete Gerber, BOM, assembly drawing, component specifications, and testing requirements and request a process review before final quotation.

Frequently Asked Questions

Is SMT always cheaper than DIP assembly?

Not necessarily. SMT can be highly efficient for dense boards and automated production, but the overall cost depends on component type, PCB design, volume, setup, inspection, and rework. A mixed board may cost more to assemble but avoid expensive component or mechanical redesign.

Can a PCB contain both SMT and DIP components?

Yes. Mixed SMT and through-hole assembly is common when a board combines compact ICs with connectors, relays, terminal blocks, or mechanically stressed components. The production sequence should be determined during the manufacturing review.

Does BGA assembly require a different manufacturing process?

BGA is assembled using SMT, but its hidden solder joints require appropriate inspection and process control. X-ray inspection is commonly used to examine joints that cannot be visually inspected from the PCB surface.

What files should I send for an SMT or DIP assembly quotation?

A typical quotation package should include Gerber or ODB++ files, BOM, pick-and-place/centroid data where applicable, assembly drawings, PCB specifications, and testing requirements. Providing complete revision-controlled data reduces quotation and engineering clarification time.

Can Benewave handle both SMT and DIP assembly?

Yes. Benewave currently lists 6 SMT lines and 3 DIP lines and supports mixed SMT/DIP assembly for OEM projects. Its manufacturing service also covers PCB fabrication, component sourcing, programming, functional testing, and box build integration.

What should buyers do before placing the production order?

The most practical approach is to make the assembly process a documented part of the RFQ, rather than allowing the supplier to determine it only from the BOM.

Provide the PCB files, BOM, component package information, expected volume, mechanical requirements, and testing requirements. Then compare suppliers on their ability to manufacture the complete board—not simply on SMT placement price.

For complex products, mixed technology may provide the necessary balance between compact PCB design and mechanical robustness. For highly integrated boards, SMT may be the natural manufacturing route. The correct decision should come from the actual component and product requirements.