The MPP1 unit is a manual pick & place system for the surface mount of electronic components. It is packed with convenient features to maximize prototyping and small run throughput, while minimizing operator strain and the occurrence of defects.
The system requires a solder bumped board (solder paste to have been applied to the PCB prior to SMT component placement). Customarily, the paste is stencil printed; dispensed solder bumps is also an option, though very tedious and often impractical. Once components have been placed, the PCB assembly requires ‘reflow’ in an appropriate oven to complete the fabrication cycle. Stencil printing hardware, or, a reflow oven is not supplied with the basic system. T
This unit can accommodate PCB panels of up to 320 x 180 mm (~ 12″ x 7”).
The machine frame is constructed of anodized aluminum extrusions. Composite panels with carbon fibers embedded in conductive ESD resin, produce safe platforms for the electronics environment.
All molded plastic components in critical ESD paths are produced from a blend of compounds and fillers which offer high stiffness, while producing 105 – 1010 Ω/sq. of surface resistivity for proper electrostatic discharge. Long glass fibers are embedded to achieve stiffness while an IDP resin (Inherently Dissipative Polymer) renders the blend conductive.
Various other components are fabricated from metal alloys. However, the SMD components will never find a direct, metallic path to ground, hence, eliminating the chance of ultra-fast electrostatic discharge which can damage the components.
Planar manipulation for the pick & place system is achieved through a 2-axis, gantry linear motion system. The ways are custom designed, utilizing 12 ball bearings per axis. Standard, recirculating ball, linear bearing systems inherently produce random hesitation when transitioning from rest to motion. This hesitation is detrimental for manual manipulation of axes, while attempting to produce very finite movements (as is necessary for placement of fine pitch SMT components). Motorized systems are not sensitive to this phenomenon since servo controls can easily overcome this behavior. Ball bearings virtually eliminate this problem through their inherent design with integrated ball retainers.
Hardened and chrome plated shafting facilitates long life and rust protection. The shafts do not require lubrication and should be kept clean and particle-free for smooth operation.
Link chain cable tracks have been custom developed to smoothly and safely guide the cables and pneumatic lines. The track links are also produced from conductive polymers, grounded at the end, to eliminate exposure to electrostatic charge which may build up in cable insulation and soft silicone hoses.
Cable failure in flexing motion presents a tough challenge in moving apparatus with electrical wiring. The power cable is custom developed with molded ends, ferrite bead for noise reduction, and utilization of a continuous flex, flat cable for power management. Additionally, four redundant current paths for each power line further increases system reliability. The cable life is estimated at over 10 million flex cycles! A standard USB cable is deemed to fail after only a few thousand flexes of equal radius.
The main platform is constructed of a thin, top layer of ESD compliant composite, laminated over a thicker, galvanized steel panel. Magnetic PCB locators can be arranged around the PCB, in virtually any shape, to securely affix the PCB for assembly. No screws or clamps are utilized for convenient and quick PCB setup. The PCB locator components are all ESD compliant, including the elastomeric pads, conducting any accumulated charge onto the platform.
Pick & Place:
Vacuum is used for component pick & place. An integrated vacuum pump is utilized. The pump is housed in an acoustically isolated enclosure and mounted via elastomeric suspension components to minimize audible noise and vibration. Pump operation is very quiet! The pump can be turned off during setup periods and inactivity.
The spindle provides for vertical and rotary motions. The spindle accepts a pick stylus of choice (various styli are provided for different component sizes). The spindle utilizes a pneumatic suspension, providing for a light and constant pneumatic spring force, and, producing a compact package by eliminating the need for a large stroke mechanical spring. The spindle pneumatic lines are ergonomically managed through the cable track, without dangling attachments to the spindle.
Once a component has been placed, the vacuum release button is depressed to release the component. Smaller components tend to eliminate the need for a button release as the surface tension of the solder paste overcomes the vacuum force.
An articulated arm support mechanism with multiple rotary joints provides comfort and stability during operation. The links are quite rigid to support the weight of a human arm; all joints boast double ball bearings for smooth and rigid manipulation. A slight friction/damping in each primary joint is integrated to stabilize fine motions and render better placement results. A very compliant and cushioned rest pad is molded from ESD elastomer and supported by ESD foam, eliminating the need for an ESD wristband which can be quite inconvenient. The articulated linkage internally conducts the human body electrical charges into the ground. This linkage follows the arm through all ranges of motion necessary to operate the SMT Caddy. The ground path is automatically produced via the ground line in the power cable, for all standards with 3-prong power receptacles.
SMT Caddy is quite small and lightweight; as such, a counterweight has been incorporated opposite side of the armrest to balance and stabilize the platform under the weight of the human arm. The armrest and counterweight may swap sides for left-handed or right-handed operation.
MMP1 is equipped with a digital microscope, utilizing a 5 MP color camera, directly interfaced to the Raspberry Pi. Our microscope produces virtually no latency on live video, with 30 frames per second refresh rate for no detectable flicker.
A custom application provides for microscope controls as well as other functions. The microscope window can be zoomed and panned to desired magnification and location on the screen with any of the the standard, supplied lenses. Three lenses are included in the basic system for a range of optical magnifications, beyond the digital zoom function of the microscope. Additional lenses are available for other magnification ranges, for special applications. Lenses are quickly interchanged, via a magnetic lens mount with the focusing range staying with the lens for preset focus convenience. The soft-zoom feature allows for an additional 3x zoom, beyond the basic optical magnification.
A miniature, electronically dimmable LED lighting system is integrated for component and workspace illumination.
The microscope serves as the centerpiece for SMT Caddy, providing proper imaging for management of very fine-pitch, as well as larger components. Components smaller than 0402(inch) (down to 1005!) will require special styli (available from our web store) with a micro, spring-loaded vacuum tip, as the dictated stylus tip length must be rather short for rigidity and practicality.
The microscope also serves for inspection of the bumped PCB prior to assembly, post placement or soldering inspection, and any other tasks benefiting from a color, digital microscope on a movable gantry.
The MPP1 is equipped with a solid state, diode laser pointer. The laser pointer can be adjusted and aimed to illuminate the target landing position of the component on the stylus with a tiny red dot! Considering the two-dimensional nature of video microscopes, the laser dot aids with depth perception in the image view, so that the XY guidance can be tuned into position prior to final component descent. Of course, fine positioning is performed with the aid of the digital microscope.
The Mpp1 is powered by a Raspberry Pi™ (model 3) computer module. Raspberry Pi-3 is a complete computer system with a quad-core ARM Cortex-based processor, running at 1.2 GHz, with 1.0 GB of RAM, built-in LCD driver, HDMI connector for external monitor, µSD card for storage (up to 32 GB), multiple USB ports, LAN port, and built-in wireless network and Bluetooth adapters.
A high speed (80x), 16 GB µSD card is installed, preloaded with the operating system, supporting libraries, Mpp1 application and documentation, reserving ample space for future software upgrades, additions and features.
Raspbian, an open source Linux based environment has been installed as the Mpp1 operating system.
A 7” multi-touch LCD screen is utilized for displaying the graphics. The screen is directly interfaced to Mpp1 LCD & Touch Driver, leaving the HDMI port available for a larger external monitor, if desired. The 7” LCD monitor resolution is 800×480, producing better than 130 DPI for very fine graphics. If an external monitor is opted, a Standard 1080P unit is recommended. Video will be streamed at 30 frames per second on a 1080P monitor. In either configuration, the end-result is live video, with virtually undetectable latency or flicker!
Future software versions will be always free and upgrades are performed over the internet.
SMT Caddy is primarily suited for taped and reeled components. Infrequent and odd-shaped components are managed through manual presentation on the provided small tray. Taped (cut tape for small quantities and reeled for larger volumes) are by far the most common supply method for electronic components.
SMT Caddy provides two feeder banks, each capable of accepting up to 10 individual and modular feeders if configured for 8mm width tape. Wider feeder configurations reduce the number of maximum, concurrent feeders. A 4mm feeder bank pitch allows for dense population of feeder modules in the bank, independent of the feeder width configuration.
Each feeder module is supplied as a kit, with the necessary components to configure the feeder in 8, 12, or 16 mm wide tape formats. The rails, take-up spool, and supply reel widths can be configured in any of the three tape widths. No tools are necessary to reconfigure the feeders. A feeder can be set up with new tape within about a minute.
These subminiature feeders are motorized and manually activated. Depressing the button on the feeder (via the pick stylus) advances the tape forward and automatically peels the protective cover tape. The cover tape is spooled on a small bobbin. The component tape is advanced through spooling the cover tape.
A feeder module is simply plugged into any location in the bank, automatically making electrical contacts for the motor.
Generally, paper tapes are not to be spooled (customarily used for passive components). Paper tapes are quite rigid and do not spool well on small reels. A cut section of tape (virtually, any length of interest) is loaded into the feeder.
Plastic tapes are much more flexible and can be spooled onto the provided reels (100mm OD, 40mm ID). The reel is loaded over an idler hub with a light, built-in friction mechanism to avoid unwanted tape unspooling through flex memory of the tape material.
Feeder changeover and setup can be performed in about a minute.
The system boots into the native Raspbian operating system. Launch of the SMT Caddy application manages all required functions to operate SMT Caddy without need for further knowledge or familiarity with Raspberry Pi, Raspbian, or Linux.
Further functionality of the Raspberry Pi may be explored by the more experienced users, beyond the functions of the SMT Caddy. There are various websites and extensive documentation available on the net about the details of the Raspbian, Linux based operating system and its features, as well as the inherent capabilities of the Raspberry Pi.
It is highly recommended to establish a wireless connection to the net, via any available local wireless hub, to take full advantage of system features, access to the net, automatic software upgrades, etc.
Beyond the inherent functionality of the SMT Caddy through the touch display, it is convenient to set up a Bluetooth or wireless keyboard and mouse to conveniently navigate and control the extended functionality of the Raspberry Pi. A simple net search will reveal numerous resources and options. Alternatively, one can always use a wired, USB keyboard or mouse, though not necessary for basic operation of SMT Caddy.
The main power button facilitates for system reboot.
Execution of the SMT Caddy application presents the dedicated App’s wallpaper:
The Documentation Icon launches a PDF viewer, displaying the support documentation, help items, etc. Other PDF documents may be viewed and edited via the standard viewer.
The microscope icon casts the live video onto the screen. The default zoom level at boot is set to 1x. This is the default mode for the assembly process. Double tapping anywhere on the screen exits the view mode and returns to the main application background.
The settings icon invokes the learning mode for the microscope zoom/pan settings. The image can be sized for a digital zoom of up to 3x further magnification (2-finger mode). Once the desired magnification level has been decided, the image may be panned to the desired location with respect to the stylus tip. As above, double-tapping will return to the application background, having memorized the preferred zoom/pan settings.
The Browser icon launches an internet browser, given an internet connection has been established through the built-in wireless network or a direct LAN cable.
The exit icon terminates the SMT Caddy application and returns the system to the boot screen. SMT Caddy or any other installed applications may be run again at any time.