Case Studies - Fixture Design

For any project requiring mechanical design, mechanism design, fixture design, tool design, or chuck design, Concurrent Design provides complete mechanical engineering design services, from concept, analysis, and machine design / tool design to documentation and complete fabrication and testing.

  1. Overhead Lifting Fixture for Heavy, Critical Loads
  2. 3-Axis Assembly Fixture for Complex Multi-Sided Workpiece
  3. Routing Fixture for Plastics Processing
  4. Dual Axis Linear / Rotary Universal Positioning Fixture
  5. Installation Fixture for Assembly of Complex Workpiece
  6. Process Fixture for Semiconductor Wafer
  7. Alignment Fixture for Multi-Axis Positioning of Adjacent Equipment
  8. Vacuum Attachment Fixture for Part Alignment During Assembly
  9. Wiring Harness Assembly Fixture
  10. Assembly Fixture for Workpiece Alignment
  11. Vibration Isolation Fixture for Solar Panels on Rail Cars
  12. Vibration Isolation Fixture for Bar-Code Scanner
  13. Micro-Positioning Fixture for Polishing Process
  14. Destructive Testing Fixture for Cyclic Life Testing
  15. Shipping Fixture for Capital Equipment
  16. Six Degree of Freedom (6-DOF) Fixture for Airfoil Machining

Case Study - Overhead Lifting Fixture for Heavy, Critical Loads

The client, nLine Corp., was developing semiconductor equipment for wafer inspection. The wafer stage was a Newport product with granite base and air bearing axes. It weighed ~½ ton. The overhead lifting fixture was a custom mechanical design to lift the stage from the shipping crate and deliver it to the custom-designed machine base. An overhead crane would provide the lift. The overhead lifting tool would require a custom mechanical design to address the physical constraints surrounding the stage / machine base interface. As with any overhead lifting fixture designed by Concurrent Design, the unit was engineered, designed, built and tested under appropriate loads prior to implementation. This lifting fixture was engineered to satisfy >5X safety factor, tested at >3X safety factor and implemented to lift a rated load of 1000 pounds. Additionally, alignment tools were developed to be used in conjunction with the lifting tool. These alignment tools served to very accurately align the wafer stage to the machine base.

Fixture Design
Tool design of overhead lift fixture provides dual-axis adjustment for load balancing of unknown center of gravity.

Fixture Design
Safety engineering testing of overhead lift fixture under safety factor load prior to implementation.

Fixture Design
Implementation of overhead lifting fixture - placing Newport air bearing stage onto custom machine base. Additional alignment tools provided final alignment.


Case Study - 3-Axis Assembly Fixture for Complex Multi-Sided Workpiece

The client, Applied Materials, is a manufacturer of semiconductor process equipment. Some equipment, including deposition process chambers, is complex and sophisticated, with many parts assembled on four sides and the bottom of the chamber. Some of these elements are relatively fragile compared to the large, heavy process chamber. The challenge was to design and build a multi-axis assembly tool that would allow the assembly technician to address the work-piece from any angle, orientation or elevation. The tool design provides for such volume production features as quick part alignment and attachment, easy no-load reorientation to any attitude, and OSHA safe ergonomic part access and assembly.

Fixture Design
Mechanical design of multi-axis assembly fixture allows for quick and easy addressing of work piece from any attitude or ergonomic elevation.

Fixture Design
Three-axis assembly tool provides non-marring interfaces to the work piece and features that lock the tool in any position during assembly.


Case Study - Routing Fixture for Plastics Processing

The client, Siemens, is a manufacturer of commercial products. Within the numerous manufacturing processes associated with traffic-light products, there is a machining requirement. The plastic hood of the traffic light is molded in plastic. Piece parts must be machined, using a manual router, to create the final curved shape of the product. The custom tool design of the routing fixture holds the work piece while the operator traces the contours with the manual router. Special attention is given to clearance of part features and part location for repeatability.

Fixture Design
Mechanical design of manufacturing routing fixture assembly allows for quick location of work piece and securing during routing process.

Fixture Design
Routing fixture secures raw work piece (seen at left) during machining operation to yield finished machined part (right).


Case Study - Dual Axis Linear / Rotary Universal Positioning Fixture

This simple, mechanical positioning fixture is designed for use in a test engineering department. Various products (device under test – DUT or unit under test – UUT) will be addressed by the test equipment. Because of continuous minor variability in the physical dimensions of the DUT's, this fixture mechanism allows for rigid positioning through two quickly adjustable axes - axial and rotary. The platen allows for the mounting of the DUT.

Fixture Design
Simple two axis (linear and rotary) positioning fixture allows secure positioning of widely varied workpiece.

 

Case Study - Installation Fixture for Assembly of Complex Workpiece

The client, Applied Materials, is a manufacturer of semiconductor process equipment. Some equipment, including deposition process chambers, are very sophisticated and complex. A central element in the process chamber is the electro-static chuck assembly. This chuck assembly is large, heavy, and unwieldy, with a large diameter head, lengthy rotary shaft, and umbilical harness for utilities. The manual assembly of the electro-static chuck into the process chamber requires many hands in a tight space. This assembly / installation fixture allows one technician to assemble the workpiece in a safe and controlled manner. The fixture is attached at the top plane of the chamber. The chuck assembly is cradled in the fixture tooling and secured safely. This removes the weight of the workpiece from the technician. The linear axis of the fixture allows the technician to slowly and carefully feed the complex harnessing through the chamber and secure the mounting flange with no physical strain.

Fixture Design
Tool design of installation fixture securely relates the two assemblies to be integrated and allows for ergonomic single technician installation of a heavy and complex workpiece.

 

Case Study - Process Fixture for Semiconductor Wafers

The client, Teravicta Technologies, is engaged in the design, manufacture, and distribution of micro-electromechanical-systems (MEMS) switches. They maintain laboratory-scale research and development, as well as pilot-scale production equipment. This custom designed, semiconductor wafer process fixture is built to support these activities.

Fixture Design
Semiconductor wafer process fixture secures wafer accurately during process operation.

 

Case Study - Alignment Fixture for Multi-Axis Positioning of Adjacent Equipment

The client, Jenoptik Infab, is a developer of person guided vehicles (PGV’s). These vehicles (hand carts – as shown elsewhere in this website) are to be located accurately, relative to the “load port” of semiconductor process tools. This location must be held through repeated engagements of the PGV to the load port. This multi-axis alignment fixture is designed to accurately position a load port to a docking flange (profile shown in Figure 2), such that upon removal of the fixture and associated tooling, the PGV may be successfully located to the load port. This is accomplished as the approaching PGV engages the docking flange which then provides default orientation to the load port. This technique and all related hardware as developed and built by Concurrent Design is now the semiconductor industry standard. Reference: Semiconductor Equipment and Materials International (SEMI) standard. SEMI E83 SPECIFICATION FOR PGV MECHANICAL DOCKING FLANGE.

Fixture Design
Custom designed multi-axis alignment tool with tooling plate to accurately locate the docking flange of a load port to a PGV.

Fixture Design
End view of docking flange (SEMI E83 Specification for PGV Mechanical Docking Flange)


Case Study - Vacuum Attachment Fixture for Part Alignment During Assembly

The client, Applied Materials, is a manufacturer of semiconductor process equipment. During assembly of large equipment, certain parts being assembled must be located accurately, relative to each other and to the current assembly. This vacuum attachment assembly fixture registers to the frame of the tool and provides for accurate locational placement of new components. For environmental health and safety (EHS) considerations, the tool is designed to absorb the load of the workpiece such that the technician avoids strain and may work safely during installation of these parts. The assembly fixture is shown being load tested here.

Fixture Design
Assembly fixture with vacuum attachment and locating features to support workpiece during installation.

 

Case Study - Wiring Harness Assembly Fixture

The client, Emcore, is in the photovoltaics manufacturing business. This wiring harness assembly fixture is custom-designed to facilitate the wiring of 14 separate components into one serial electrical harness assembly. The components are photovoltaic (solar cell) subassemblies complete with photovoltaic, optical and wiring interconnect elements on a common mounting plate. Each subassembly is placed in an opening, allowing the safe protection of the optics. The mounting plate is secured with a clamp to prevent movement. The serial wiring is completed between sub-assemblies, thus creating the fully integrated harness. With the fully secured wiring harness assembly complete, the fixture is delivered to the product for final assembly integration.

Fixture Design
Custom assembly fixture for the manufacture / assembly of wire harness.

Fixture Design
Assembly fixture provides for proper locating of 14 workpieces to facilitate the uniform assembly of wire harness.

Fixture Design
The opto-electro-mechanical photovoltaic subassemblies are fixtured to set locations as the wiring of the entire “string” is completed.


Case Study - Assembly Fixture for Workpiece Alignment

The client, Emcore, is in the photovoltaics manufacturing business. One area of application is terrestrial high concentration photovoltaics (HCPV). This assembly fixture is custom designed to facilitate the assembly of two halves of a modular unit. The first workpiece is placed into the fixture and then high strength adhesive bonding tape is applied to the joint surfaces. The second workpiece is located on pins and slipped into position accurately onto the first and secured with the bonding tape.

Fixture Design
Simple assembly and alignment fixture provides locating pins to provide proper registration of two parts relative to each other.

Fixture Design
Manufacturing assembly fixture provides easy access flat surfaces for rolling out high strength adhesive bonding tape.


Case Study - Vibration Isolation Fixture for Solar Panels on Rail Cars

The client, Georgetown Rail, is a manufacturer of railroad equipment. There is a need for electrical power to be available to the railcars while in remote locations and while moving. Solar energy is an attractive choice. The original solar module (panel) installations, however, failed very quickly due to heavy shock and vibration loads from normal railcar usage. Concurrent Design instrumented a representative railcar and collected these transient and steady state dynamic vibration measurements. Using these dynamic signatures, Concurrent Design designed the shock and vibration isolation fixture to safely isolate the crystalline silicon solar module from the damaging inputs. The fixture design was proven in the lab by installing the assembly on a shaker table and applying the dynamic shock and vibration signatures, with additional safety margin. Custom fixturing was designed to mount the assembly to both the railcar and the test equipment.

Fixture Design
Common railroad shock and vibration loads were causing premature failures to the mobile power source (solar modules).

Fixture Design
Custom shock and vibration isolation fixture designed to address specific dynamic signatures and isolate the solar module.

Fixture Design
Laboratory testing of the shock and vibration isolation fixture on the shaker table.


Case Study - Vibration Isolation Fixture for Bar-Code Scanner

The client, Dell, uses high speed conveyors to move product through its factory. Bar code scanning of all product is required during transport. There are many levels of conveyors and these are not all securely attached to structural ground. As a result, there is the potential for vibration to set up, which can overwhelm the results of the bar code scanners. Concurrent Design developed a custom vibration isolation fixture to mount the bar code scanner. This successful fixture design became a standard for bar code scanner mounting when vibration was a challenge.

Fixture Design
Vibration isolation fixture for bar code scanner mounting

Fixture Design
Vibration isolation fixture provides for multiple degrees of freedom in mounting for the bar code scanner as well as variation in the isolator selection.


Case Study - Micro-positioning Fixture for Polishing Process

The client required laboratory scale tools for research and development of a new process. The fixture was to allow very fine control for polishing of the work piece. A piezo-electric stage was used to provide micro-scale tip-tilt control for the polishing fixture. Once positioned, the workpiece must be clamped at the proper attitude and final inspection prior to polishing assures proper positioning of the workpiece.

Fixture Design
Piezo electric stage used to provide micro-scale tip-tilt control of the workpiece when presented to a polishing process.

Fixture Design
With the integrated piezo-electric stage tip-tilt adjustment completed, clamping fixturing is engaged to secure the workpiece. Microscopic inspection assures final position for polishing.


Case Study - Destructive Testing Fixture for Cyclic Life Testing

The client is a manufacturer of consumer products which require a minimal life expectancy. Simple and inexpensive tooling was needed to test the product and assure this life expectancy through a range of motions. The tooling / fixturing provides for the cold work hardening of the base metals leading to failure. This destructive test fixture was developed to cycle the product through these various ranges of motion while the pneumatic control system counts the cycles until failure.

Fixture Design
CAD design of destructive test fixture for life testing of consumer product.

Fixture Design
Test sample installed in destructive test fixturing. Fixturing is driven by pneumatic system.

Fixture Design
Sample is cycled through a bending deflection until cold work failure occurs. The pneumatic system provides the cycle count.
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Case Study - Shipping Fixture for Capital Equipment

Shipping fixtures are very common in the transport of expensive capital equipment. These examples are comprised of a welded frame with features to secure and protect sensitive equipment during transport. Castors allow easy movement while extension feet provide a stable base when needed.

Fixture Design
Shipping fixture comprised of welded frame with removable sidewall to allow easier handling of the capital equipment.

Fixture Design
Locking / swivel castors allow easy movement of the equipment through the facility during delivery. Extension feet provide a stable base for the shipping frame as the equipment is secured or removed.


Case Study - Six Degree of Freedom (6-DOF) Fixture for Airfoil Machining

This sophisticated fixturing is designed to allow precise control over the positioning of a jet engine turbine blade during 5-axis CNC machining. All six degree of freedom must be addressed. The fixture is based upon a 3-2-1 architecture, with three points of contact to initiate the positioning, then two points, and finally one point to fully (and repeatably) establish the location of the workpiece in 3-dimensional space. Lastly, pneumatic cylinders are moved into position to secure the workpiece during machining. This machining operation is the high tolerance machining of the outboard mounting features.

Fixture Design
Six degrees-of-freedom fixture begins with the placement of the work piece on three datum targets. Two adjustable edge guides and one edge stop complete the 6-DOF architecture.

Fixture Design
With all six degrees of freedom addressed and the workpiece located accurately, air cylinders are moved into position.

Fixture Design
With the air cylinders engaged, the workpiece is secured in 3D space in a known location. The machining fixture is located accurately in a 5 axis CNC mill to complete the machining process.