QX2 Rework System

Staying ahead of developments in SMT

Metcal changed rework with the introduction of SmartHeat^® Technology which minimizes process variability and sets new standards for ergonomic design and ease-of-use. For years, Metcal users have been realizing significant increases in throughput, process control and scrap rates.

QX2 Convection Rework System

With today's large, high pin-count, fine-pitch components and multilayer boards, convection systems have become increasingly necessary. Convection systems heat all leads simultaneously, ensuring even reflow. Gentle temperature rise rates protect boards and components. There is no direct mechanical contact on the leads, so the risk of pad damage is minimal and components can be easily salvaged for reuse. Because a wide variety of components can be accomodated by a simple nozzle change, convection systems are potentially very flexible.

A new approach to convection

From the moment you take it out of the box, you know the QX2 is like no other convection system. Set-up is fast and easy, requiring no special tools, fixturing, or testing.

Unlike conventional convection systems, the Metcal QX2 provides simplified controls and automation, reducing operator training requirements. The system controller is moveable to suit your preferences and simplifies operation with its push-button configuration.

The need for shielding is minimized through the use of focused convection nozzles, which direct heat exactly where it is needed. Nozzles can be changed in seconds with a simple quick-release system. An easy-to-use underboard preheater is available to evenly heat boards and prevent warping during the rework of large components and multilayered boards.

To maintain greater process control, the heater exhaust temperature is held constant. The temperature setpoint is low to minimize thermal stress. Should it be necessary to change the setpoint to accomodate process changes, such as new soldering alloys, the QX2 incorporates a lockout code allowing authorized personnel to reprogram it.

To vary heating all that is required is that the airflow level be adjusted. This makes optimizing heat delivery very simple.

During the removal cycle, the vacuum pick-up automatically lifts the component from the board when the solder reflows, and then shuts off the heat. The time used in the removal cycle is stored and displayed as a guide for establishing the minimum time to reattach a similar component.

Never before has convection rework been so safe, fast, and easy.

QX2 System Elements and Functions

Power Supply

The power supply unit provides airflow, vacuum, and heat, and forms the main base unit of the system.

Heater head assembly

Integrated with the frame, the heater head assembly allows controlled vertical movement, and includes the heater and the vacuum pickup.

Z-axis knob

The Z-axis knob provides fine vertical adjustment of the heater head over the PCB.

Theta rotation and nozzle release lever

The theta rotation and nozzle release lever allows you to adjust the angle of the nozzle around the Z-axis, to enable the nozzle to be exactly aligned with the component and leads. Pushing the lever past its stop actuates the nozzle release mechanism, allowing nozzles to be changed easily.

Nozzles

A selection of nozzles is available for the QX2 that permit a large range of components to be reworked. Focused convection nozzles, rather than box nozzles, direct hot air only at the leads, where it is required.

Remote controller

The controller provides the main interface between you and the QX2. It can be moved to suit your needs.

Airflow selector

The airflow selector determines the rate at which thermal energy is transferred to the component.

Temperature display

Displays the temperature of the heater exhaust or the temperature measured by an auxiliary thermocouple in either °C or °F. The heater exhaust temperature is preset at 350°C and may be reset by the process engineer to anywhere between 250°C and 450°C by entering an unlock code.

Mode selector

By turning the mode selector ring, the user selects attach mode or remove mode.

Remove mode

This mode activates the vacuum pickup, which applies about 3 oz. of upward force to the component. When component liftoff is sensed, the heater is automatically turned off.

Attach mode

This mode reflows a new component to the PCB. By adjusting the time stored in Remove mode with the ± Keys, you can ensure an appropriate reflow time, which may be adjusted on the fly if desired.

Timer

By counting up during removal and down during attachment, the timer removes a source of subjective guesswork from the rework process.

Start/Stop button

Pressing the Start/Stop button initiates or ends the remove or attach cycle. In remove mode, stopping the cycle also shuts off the vacuum, to release components after liftoff.

Work tray

This unit provides a working surface of the correct height for the PCB when the optional board holder is not in use. The underboard preheater cannot be used with the worktray. The worktray can also be used to store nozzles.

Board holder

The board holder can accomodate PCBs in a size range from 2" x 2" to 14" x 18". It is self-centering, and the spring clips can be moved along their rails to hold the board securely, with minimal force. It also allows use of the preheater.

Preheater

This forced convection heater has a 6" x 6" heating surface, providing a 2°C/cm temperature gradient. The temperature is preset at 180°C, and is not adjustable, to protect the board and components from possible overheating.

Airflow control

This controls the amount of power applied to the work. Four settings give a range from 150-950W, to yield a board temperature range of 90-120°C.

Start/Stop button

The preheater connects to the QX2 via a control cable to enable automatic operation during removal and reattachment. For use without the QX2, or if underboard heating is not needed, the manual Start/Stop button can switch the preheater on or off.

Removal tool

The removal tool has a spring clip which assists in safe removal of hot nozzles. The other side is a tray for catching hot components after removal.

QX2 Features
Vacuum	Self Contained
Operator Control Interface	Movable controller with: Start/Stop button Airflow control Time control LCD display Remove/Attach control
Component Removal	Automatic lift off and heater shutoff
Component Attachment	Manual, Timer controlled
Nozzle Attachment/Removal	Push on, quick release
Other	Auxiliary thermocouple port for component/board temperature monitoring

System Packages

QX2 Nozzles

Metcal has a comprehensive range of nozzles for use with the QX2. For non-standard components, we offer a custom nozzle program. Please contact your Metcal Representative for more information about custom nozzles.

Standard Nozzle Range

Box Reflow Nozzles

In addittion to our standar nozzles, we offer a range of "box reflow nozzles" designed for removal shielding cans, connectors and BGA components.

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QX2 Accessories

The following accessories are available for use with the QX2 Convection Rework System: