CORFIN AUTOMATION

The LRT-2000 is a fully programmable 5 axis robotic lead finish system. This system is designed to solder coat the leads on a large variety of electronic components, with specific emphasis on fine pitch devices. It provides a defect-free, cost-effective process for solder coating QFPs, SOICs, PGAs, PLCCs, ceramic LCCs as well as TAB devices, conformal coated parts and multi-chip modules.
The ability to accept a wide variety of robot tooling and the ease of programming makes the system adaptable to a wide range of different processes and products, for example handling wafers, fusible links and connectors. Minimal transition time is required when changing from one component to another. With the appropriate tooling option, the LRT-2000 can process multiple components at a time, to meet higher throughput requirements. Even fine pitch devices can be accurately processed up to twelve components at a time with consistency and reliability.
The LRT-2000 is typically configured with the load/unload function at one end, allowing the system to be operated by a single technician. Placing this system in-line requires only a programming change to load at the left end and unload at the right end, or vice versa. 

The LTR-2000 system may be specified to run lead-free alloys with little or no equipment modification. To convert existing machines to lead-free requires only a change in solder module to avoid contamination.

The central processing module is totally enclosed, with sliding tempered glass panels at the front and rear of the system, enabling easy access and allowing for the process to be viewed and monitored. The process chamber is ventilated via exhaust stacks located at top of the enclosure; one or two stacks can be used, depending on the process requirements. The standard system footprint is 84" long by 34" wide by 74" high (2134mm x 864mm x 1880mm), excluding the exhaust stacks. The standard system incorporates:        

DOOR AND WINDOW INTERLOCKS

Window interlocks are installed on all sliding windows covering the main processing module to prevent operators from accessing the interior of the system during processing. Interlocks also protect the doors on electrical power enclosures. Should a door or window be opened, the system will immediately stop.

FOUR AXIS ROBOTIC HEAD

The four axis robotic head is operated by a stepper motor drive system that permits accurate location of the head. The head can be programmed for movement in the X-axis, Y-axis, tilt, and rotate modes, either independently or simultaneously. The X-axis can move at traverse speeds up to 10 inches (250 mm) per second; the Y-axis up to 1 inches (25 mm) per second maximum. If selected, the optional carrier indexing table operates as the fifth robot axis.

SINGLE ROTATING VACUUM GRIPPER

A single vacuum gripper is supplied which is suitable for holding one device. The spindle can be rotated through 360 degrees for processing multi-sided components. The single gripper can be easily removed and interchanged with other optional or custom tools.

WAVE FLUXING MODULE

The fluxing module is constructed of PVC. The height of the flux wave is controlled by a variable speed DC motor driven pump. Fine adjustment of the wave is made at the module location using a thumbwheel potentiometer. Two air knives are used to remove excess flux. A drain is provided for quick clean-up at the end of the work schedule, or for rapid changeover if more than one type of flux is being used. This module can accommodate all standard flux types.

HOT AIR PREHEATING MODULE

The preheating module is constructed of stainless steel and uses compressed air passing through in-line heaters as the heating medium. The module has a digital temperature controller with a thermocouple located in the hot air stream at the nozzle. The controller has high / low alarm band. Use of the preheating module allows for evaporation of excess flux and volatiles, activation of the flux, and warming of the package body to eliminate thermal shock during the soldering process.

SOLDER MODULES

The soldering module consists of a stainless steel solder pot with 250 lbs (114 kg) capacity. Corfin's dual chamber pot is designed to draw solder from the base of the pot, minimizing the possibility of recirculating dross through the wave. The pot has a thermally protected D.C. motor driven pump, which provides precise wave height control; fine adjustment of the wave is made using a thumbwheel potentiometer. The standard nozzle is 4" x 8" (102 x 203mm), enlarged to provide a greater solder surface when processing multiple devices.
A digital temperature controller with high and low temperature alarms (audible and visual) is provided. A low solder level alarm is also provided as standard. Two plate heaters mount directly against the walls of the solder pot, providing for excellent heat transfer. Because the heaters are in contact covering the full height of the solder, there is no danger of an eruption during the warm-up phase. The solder module is mounted on a lead screw, which allows it to be moved back to facilitate draining the solder and servicing the solder module.

INERTING SYSTEM

The solder pot is equipped with an inert gas enclosure around the solder wave, with stainless steel gas diffusers that provide a non-turbulent protective gas cover over the wave.  The controlled atmosphere reduces dross formation on the solder wave, promotes wetting and ensures uniform solder coverage of the component leads. The process of solder coating component leads is greatly enhanced by the inerting process, with the virtual elimination of icicles and flags.  A stainless steel shroud that covers the rear of the solder pot, including the pump area, is injected with inert gas to reduce the formation of dross and black powder from the pump shaft. Consumption of solder and maintenance times are greatly reduced by the inerting system.

POST-CLEAN RINSE/DRY MODULE

The post-cleaning module is constructed of PVC. It has an aqueous whirlpool for cleaning the components designed for minimal use of tap or DI water. A specially designed air dryer is located above the cleaner that uses quiet compressed air nozzles to remove all traces of moisture before the components are returned to their original pick-up position.

CONTROL SYSTEM

The system uses a personal computer as its controller. The software is menu-driven and user friendly. Programs for different part types can be generated very easily and stored in memory. The following parameters are programmable: (a) conveyor speed, (b) dwell times for fluxing, preheating and solder immersion, (c) solder temperature, (d) immersion depths, (e) immersion and withdrawal angles, (f) speed of immersion and withdrawal.
A printer is recommended (customer supplied) if hard copy print-outs are desired. The printer must utilize the parallel printer port.
In addition to the computer controlled functions, there is a control console mounted above the operating chamber with on/off switches, temperature controllers, pump speed controls and warning lights. This console can be protected by the optional upper panel covers and locks.

JOYSTICK & SOFTWARE

The joystick can be used instead of the computer keyboard to program mechanical movements of the robot. It allows the engineer greater mobility and the opportunity to walk the length of the system to facilitate setting the process parameters.

CARRIER INDEXING TABLE

An indexing table that moves in the depth of the system is available for the load/unload area. This table can be used when processing parts that are presented in matrix trays or multi-device carriers, and performs as a 5^th axis for the robot head.

90° INDEXING ADAPTOR

A 90° indexing adapter for the robot head permits the tilt direction to be re-oriented. This allows front to rear tilting, which is required in some applications for multi-component pick up.

PRECLEANING MODULE

A precleaning module is available for the removal of severe oxidation from the component leads. This module is constructed of CPVC with a capacity of 3.8 gallons (14.6 litres). A variable speed DC motor pump controls the height of the wave; fine adjustment of the wave is made using a thumbwheel potentiometer. The module is fitted with quick drain and overflow protection. The precleaning bath has it's own lip vent connecting to the main exhaust duct. If required, the precleaning operation can be followed by a rinse/dry step, using the post-clean rinse/dry module.

HEATER FOR PRECLEANING MODULE

A Teflon coated immersion heater heats the precleaning liquid to a preset temperature. The unit is equipped with a digital temperature controller with high/low limit alarms. A level sensor prevents the heater from switching on if the liquid level is too low. To protect the heater from corrosion due to condensation, the Teflon jacket is continuously purged with compressed air.

AUTO LIQUID FEEDER WITH LEVEL DETECTOR FOR PRECLEAN 

This provides a separate pump to automatically feed preclean solution from a container housed in the base of the machine, in order to maintain the correct liquid level in the tank. This auto liquid feeder provides level control with a high and low limit. 

AUTO FLUX FEED / LEVEL CONTROL 

A flux reservoir bottle is housed in the base of the machine, with a pump that feeds the fresh flux to the main fluxer tank. A level sensor in the tank provides the signal to the pump, ensuring that the flux is maintained at the correct operating level. The bottle is easily accessed through the doors in the base for quick and clean changeover.

FLUX DENSITY CONTROL 

The flux density control system automatically adds the necessary amount of flux or thinner to maintain the specific gravity setpoint, as well as the correct liquid level in the flux tank. The fresh flux and thinner containers are housed in the base of the machine, with pumps that feed flux or thinner to the main fluxer tank, as directed by the flux density controller. The FDC unit also has a built-in temperature sensor, with a compensation feature to ensure correct density at different operating temperatures.
The flux density controller incorporates the features of the Auto Flux Feed / Level Control option.             

AUTOMATIC SOLDER WIRE FEEDER

This unit holds a 44 lb (20 kg) spool of solder which is released upon a signal received from a fixed level probe at the surface of the solder pot. The unit is self contained, driven by its DC motor sending solder wire through a flexible Teflon tube into the solder pot. The probe is positioned to maintain a constant preset solder level. The function is fully automatic.

SOLDER EXHAUST MODULE

The supplementary solder exhaust module is located directly at the solder wave area and extracts fumes as soon as components touch the solder. This minimizes the spread of fumes through the interior of the machine and is recommended when solder coating large surface areas, which may generate excessive flux fumes.

ROTATING VACUUM GRIPPERS

These grippers are available with from one to six rotating spindles, so that a number of multi-sided devices can be processed at the same time. The pitch of the spindles can be specified to suit the specific device. A single device spindle is included as standard with the machine.

VACUUM GRIPPER - MULTIPLE CUP

Multiple Cup Vacuum Grippers are available for customer specific applications for processing multiple parts. Gripper may be ordered with up to 12 cups (or more on special request), with cup spacing configured to suit the specific application. The devices cannot be individually rotated, but the entire gripper head rotates through 360 degrees.

MECHANICAL GRIPPER

Mechanical grippers are available to handle from one to a multiple of 5 devices. The device is held mechanically in titanium fingers, custom-designed for the component. The devices cannot be individually rotated, but the entire gripper head rotates through 360 degrees. Higher device count may be feasible, depending on part size and configuration. Quotations will be supplied on request.

TUBE TO TUBE LOAD / UNLOAD (OPTION) 

For components which are handled in tubes, an automatic feeder using linear vibratory means is available for input and output. Single lane or multiple lanes are available.

MATRIX TRAY LOCATOR (OPTION)  

A machined interface plate for mounting on the indexing table to accept Jedec or other standard tray configurations, locate precisely and lock in position.

AUTOMATIC LOAD/UNLOAD (OPTION)

For the many package, tube, tray, etc., styles produced, Corfin offers a large variety of  tooling and handling options developed to meet your requirements. The system can be configured to handle special requirements in a fully automatic mode. Quotations will be supplied on request.

UPPER PANEL COVERS AND LOCKS

Transparent acrylic panels can be installed with locks to restrict access to any of the process controls on the overhead panels.  Strategic cut-outs in the panel can permit operator access to customer specified controls.

ADDITIONAL SET OF INSTRUCTION MANUALS

The hard-copy operating manual for the system is normally supplied in two 3-ring binders; one with the operating and maintenance instructions; one with a full set of bills, assembly drawings, and electrical schematics. This option provides a full duplicate set of binders. 

SPARE PARTS KIT

The spares kit is recommended to ensure that first line spare parts are available at customer location. The 5% of system cost guideline is normally sufficient to ensure a comprehensive range of essential spares. 

Safety features are built into the LRT-2000 and are clearly outlined in the system operating manual.
Audible and visual alarms are standard on the system to monitor the levels and temperature in each module and report any faulty conditions. The operator may stop the audible alarm using the computer keyboard, but the visual alarm will continue until the faulty condition is corrected.
An exhaust system with interlock ensures that all process fumes are evacuated from the machine. Local venting at the process modules supplements the overall evacuation of the process chamber.
Door and window interlocks protect the operator from electrical hazards and from moving parts in the process chamber.