The LRT-3000 Robotic Lead Finish System is designed as an extremely flexible, yet precise, tool for the solder coating of leads on a large variety of electronic components. 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.

The LRT-3000 specializes in processing fine pitch devices, and is capable of solder coating 4 mil TAB components, without bridging or icicling the leads. Material handling and tooling systems are available to handle these fine pitch devices through the trim, form and solder coating processes, then return them to matrix trays, while maintaining co-planarity.

With the appropriate tooling option, the LRT-3000 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 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.

CENTRAL PROCESSING MODULE

Standard Features:

Main Frame / Enclosure:   The central processing module has a total footprint of 122 inches in length, 34 inches width and 70.5 inches height, excluding exhaust stacks and light tower (3098 x 864 x 1790 mm). It incorporates a four axis robotic processing head, a wave fluxing module, hot air preheat module, wave solder module with inert gas, rinse and dry postclean module, an indexing table for input/output, interface for customer specified trim and form press. This module is enclosed with sliding tempered glass panels for the front and rear of the system enabling easy access and allowing for the process to be viewed and monitored. Access to the interior of the system and electrical enclosures is protected by window and door interlocks.

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 all 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 closed loop servo-driven system that permits accurate location of the head up to plus or minus one thousandth of an inch. The head can be programmed for movement in the X-axis, Y-axis, tilt, and rotate modes, either independently or simultaneously. The Y-axis movement mechanism has been completely re-designed to improve accuracy and allow greater clearance above the process modules. The X-axis can move at a speed of travel of up to 84 inches (2130 mm) per second; the Y-axis up to 22 inches (560 mm) per second maximum.

Tilt Shuttle Shift Axis:   The tilt shuttle provides an additional Z-Axis (front to back) movement to the robotic head, allowing the gripper assembly to be re-aligned with the center of the process nozzles when in the tilt position.

90° Indexing Head:   A quick-change 90° indexing of the robot head permits the tilt direction to be re-oriented without the need to remove the tool. This allows front to rear tilting, which is required in some applications for multi-component pick up.

Carrier Indexing Table (5th axis):   An indexing table that moves in the depth of the system is used for the load/unload area. This table can be used when processing parts that are presented in matrix trays or multi-device carriers.

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 gripper is mounted to the robotic head via quick disconnect to allow for quick change to other tools.

Quick Tool Change:   End effectors are mounted to the robotic head by a quick release mechanism. This allows for changeover in a matter of seconds, without the need for any hand tools.

PROCESS MODULES

Standard Equipment:

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.

Flux Density Controller:   The flux density controller is designed to control the specific gravity of the flux. Once the operator has set the recommended specific gravity, the controller will automatically add the necessary amount of flux or thinner to maintain the setting and the proper level in the module. The FDC unit has a built-in temperature compensation feature. Reservoirs for fresh flux and thinner are housed on a stainless steel slid-out tray in the base of the machine, with level sensors to warn of low liquid level.

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 and low alarm band. The preheating module evaporates excess flux and volatiles, activates the flux, and warms the package body to eliminate thermal shock during the soldering process.

Solder Module:   The soldering module consists of a stainless steel solder pot. The machine may be fitted with a 9" or 12" wide pot, depending on the application (see Process Module Options). The pot has its own thermally protected D.C. motor driven pump which provides for precise wave height control; fine adjustment of the wave is made at the module location using a thumbwheel potentiometer. The standard nozzle is 4 x 8 inches (102 x 203 mm). Custom designed wave nozzles are available. 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.

A digital temperature controller with high and low temperature alarms (audible and visual) is provided. A low solder level alarm is also provided as a standard. The system uses two non-contact heaters, which uniformly heat the walls of the pot, thereby minimizing the danger of a solder eruption during the warm-up phase. The solder module is mounted on a leadscrew, 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.

COMPUTER CONTROLS / SOFTWARE

Standard Features:

On Board Computer:   PC based computer control provides flexibility to develop and store the operating programs on hard disk. The on-board computer works in conjunction with a programmable logic controller (PLC) to provide a stable and robust operating system.

Windows Software:   Windows based software provides easy to use, intuitive user interface.

Joystick Programming:   The joystick can be used instead of the computer keyboard to program mechanical movements of the main robotic arm and the transfer arm. It allows the engineer greater mobility and the opportunity to walk the length of the system to facilitate setting the process parameters.

On-Screen Manuals & Troubleshooting Guide:   In addition to standard hard copy documentation, the operating and maintenance manuals are available on the system computer, as well as a diagnostic troubleshooting guide. All bills of material, assembly drawings, electrical diagrams, etc are also available on-screen, with links set up to facilitate navigation. The CD-ROM format allows the manual, bills and drawings to be loaded on any PC, giving access to engineering and maintenance personnel. Updates and revisions can be easily loaded using CD-ROM.

SYSTEM OPTIONS

Transfer Arm Robot (Option):   The four-axis transfer arm robot allows for motion in the X, Y and Z axes, as well as THETA rotation. The motion functions are stepper driven. The transfer arm is equipped with a custom vacuum cup tool, used to pick up components from the load area (usually a matrix tray located on the indexing table). The transfer arm robot is used to perform functions on the component prior to transfer to the main tinning robot. This may involve vision alignment, trim and form operations, or special nesting arrangement for multi-part transfer, depending on how the machine is configured.

Trim and Form Press (Option):   This consists of an integrated one ton electronically controlled pneumatic press, with floating anvil feature for automatic stand-off adjustment. The machine must be equipped with the transfer arm robot if the press is installed. The transfer arm robot picks up the component from a matrix tray on the indexing table. Component alignment can be adjusted at the optional Vision System (see below), before travelling to the press for trim and form operations. The transfer arm automatically retrieves the device from the press and brings it to the transfer area. The press may be equipped with interchangeable die sets, depending on the components to be processed (die sets not included).

Vision Alignment System (Option):   The vision system uses a medium resolution camera to capture a 2-D image of the device. The image is analyzed to determine the offset of the centre of the part from its ideal location and the transfer arm mechanism makes the necessary adjustment to the component position, before transporting to the next operation. This is normally a requirement for precise alignment in the trim and form press, but may also be used to locate the device prior to transfer to the main tinning robot, if component orientation is critical.

SRS Slug Removal System (Option):   This unit consists of an adjustable array of air nozzles and a collector. After each stroke of the trim and form press, the SRS is activated to remove any lead trimmings from the upper and lower portion of the die set.

PROCESS MODULE OPTIONS

Precleaning Module (Option):   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 (Option):   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 (Option):   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.

High Temperature Solder Module:   For certain alloys and processes, higher than normal operating temperatures are required. A specially treated stainless steel solder pot, pump and nozzle assembly are available for operating temperatures in excess of 650^oF (343^oC). This option is also required if lead-free alloys are used in the process.

Automatic Solder WireFeeder:   This unit draws solder wire from a 44 lb (20 kg) spool.  When a signal is received from a fixed probe at the surface of the solder, the DC motor/wire feeder drives the required quantity of solder wire through a guide tube into the solder pot. The probe is positioned to maintain a constant pre-set solder level. The unit is self contained and functions automatically.

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.

12" Process Modules:   The standard process modules are 9". For some applications, e.g. where running multiple parts in multiple rows is required, it may be necessary to use the larger 12" version of the modules. Corfin will make the appropriate recommendation, based on the application.

ROBOT TOOLING OPTIONS

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 gripper is supplied as standard with the machine.

Offset Rotating Vacuum Gripper:   The offset gripper handles one device with full 360 degree spindle rotation. The offset allows the device to be process at a full 90 degree angle to the solder wave.

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 Grippers:   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; on request.

HANDLING OPTIONS

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

Machined Component Nest:   The component nest may be required for accurate multiple part location prior to pick-up by the robotic arm end effector. The nest may be positioned on the interface plate mentioned above, or located adjacent the indexing table. Different nests for other components can be interchanged onto the same interface plate.

Automatic Load / Unload:   For the many package, tube, tray, etc., styles produced, we offer 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 supplied on request.

MISCELLANEOUS OPTIONS

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-3000 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.

Canada:
Corfin Automation
2001 Rue Patrick-Farrar
Chambly, QC J3L 4W8
Canada
Phone: 450-658-9900  
Fax: 450-658-6800  
E-mail: support@corfinautomation.com