Temperature Forcing System vs. Direct Thermal Head for IC Testing

Start with the package and fixture

A thermal stream needs a usable airflow path. Socket walls, tall components and cable bundles can affect how conditioned air reaches the target. A shroud or compact enclosure helps define the exposure area, but it must also fit around the populated board.

A direct thermal head needs a suitable contact surface and support arrangement. Package geometry, contact-piece fit and allowable load matter together; clearance above the chip is only one part of that assessment.

Consider an IC measured with a probe approaching from above. A contact head may occupy that approach path, while an air-stream head or shroud may obstruct it too. Place the thermal interface and the required probe positions on the same layout drawing.

Assess each arrangement in its test position. Space that appears available with the head parked may disappear once the interface is installed

Match SANWOOD's airflow and control options to the DUT

SANWOOD's Temperature Forcing System provides an air-temperature range of −80°C to +225°C, adjustable outlet airflow of 4–18 scfm, and Air and DUT control modes.

In DUT mode, a sensor attached to the device supplies temperature feedback, and the controller adjusts the air output in response. The sensor location and attachment therefore become part of the setup. That reading represents the sensing point; it does not by itself establish junction temperature.

SANWOOD offers shrouds, insulation accessories and local temperature-control enclosures for different DUT dimensions, fixtures and exposure areas. Accessory selection should account for operating dissipation and the connections that must remain accessible. Identify the selected accessories in the quotation.

Low-temperature installation planning also needs to cover the clean, dry compressed-air supply and the drying and condensation-control arrangements.

Compare time to a usable measurement

SANWOOD specifies reference air-temperature transitions of approximately 10 seconds from −55°C to +125°C, and approximately 10 seconds from +125°C to −55°C. These are air-temperature conversion figures under reference conditions, not guaranteed DUT stabilization times.

For an electrical test, the relevant interval ends when the required temperature condition is established at the agreed measurement point. Device mass, power dissipation, fixture, airflow path, enclosure sealing and sensor placement can all affect that interval. A direct-contact head requires the same distinction: its temperature change does not establish an identical change at the IC.

Compare both proposals using the same DUT, operating state, temperature reference, permitted variation and stabilization criterion. If power changes during the measurement sequence, include those changes in the evaluation.

Make the choice around the existing test setup

An air-stream arrangement is a candidate when the local enclosure and airflow path fit the board while preserving the required measurement access. A contact arrangement is a candidate when the mating surface, support and allowable load can be accommodated.

When both are feasible, use temperature records under the intended load and a review of loading, probing and device replacement to decide. Record any fixture or routing changes needed for each option.

If the procedure requires exposure of the complete board or assembly, begin with that requirement. SANWOOD's semiconductor test chamber selection guide discusses when an environmental test chamber or a localized system is appropriate.

Frequently asked questions

Will a thermal stream leave neighboring components at room temperature?

Not necessarily. Air can reach nearby components, and heat can travel through the PCB and fixture. Define which surrounding areas may change temperature and which must remain within specified limits. Where that distinction affects the electrical result, include nearby measurement points in the setup evaluation.

Can one fixture serve several IC packages?

Possibly, but a shared footprint does not establish compatibility. Package height, socket arrangement and connector positions can change the fit. For airflow testing, review the enclosure opening and sealing surfaces; for contact testing, review the mating piece and load path. Identify which parts remain common and which require a changeover.

What should be confirmed before adding the system to an automated test sequence?

SANWOOD's Temperature Forcing System supports LAN and CAN communication interfaces for host-based remote monitoring and control. Confirm the available commands, temperature-ready criteria, fault handling and data exchange against the intended test sequence. Communication capability alone does not establish a complete ATE integration or include DUT power, stimulus and electrical measurement instruments.

Discuss the thermal arrangement with SANWOOD

Send SANWOOD the DUT package details, PCB or socket layout, temperature profile, operating heat load and required probe or connector positions. These inputs help us evaluate a Temperature Forcing System configuration, including the airflow arrangement, local enclosure and accessories, around your laboratory’s existing electrical test setup.