Final Design

Our Final Designs for the Universal Force Measurement Fixture and the Mock DUT Fixture are analyzed in this page.

Universal Force Measurement Fixture

Our final design for the primary objective of this project is an adapter that connects to the SLK Head of Cohu's Eclipse XT Machine. The adapter comes in three different sizes to accommodate for the universality of the head modules. The final designs for the 3 different adapter configurations are as shown:

(Figure 1) The above figure displays our three different variations of the universal force measurement fixture. On the left is the adapter for a x16 SLK Head, on the middle is for the x2 SLK Head, and on the right is for the x1 SLK Head. Overall, these adapters include alignment holes, to align our adapters to the SLK Heads, as well as Captive Screw Holes to connect our adapters to their respective SLK Heads. The three different adapters will experience different loading conditions; therefore, the size and the amount of material in each adapter is varied.

These adapters would be installed onto their respective SLK Heads via the use of 4 Captive Screws. The adapter includes an S-Beam Load Cell to convert the force applied into an electrical signal. This electrical signal, then is sent to a handheld display, which will convert the signal from the load cell into an accurate force reading. The S-Beam Load Cell that was chosen by the team is the LFS 210 500 by Cooper Instruments & Systems. Furthermore, our handheld display choice of Mark-10 M3i also comes from the same company due to its compatibility with the load cell. We decided to choose this company for our force sensor and display due to their reliable relationship with Cohu on previous projects.

(a) (b) (c)

(Figure 2) Our purchased components for the adapter designs are shown above. Our S-Beam Load Cell Force Sensor Choice is displayed in (a) which is the LFS 210 500. (b) shows our choice for the digital handheld force display. The overall plug and test technology and compatibility from the load cell to the display is shown in (c). The reason for this particular display was to cater to the ease of use for the customers that would use our product.

Once the adapter is locked in place, the SLK head can then move down using the input pressure, which pushes down our adapter and the attached S-Beam Load cell onto a Base Plate. This base plate would be a flat and even surface for the load cell in our adapter to push against in order for an accurate and precise force reading. The base plate would be attached to the bottom of Cohu's Eclipse XT Machine.

(Figure 3) The image of our base plate design is shown above. This plate would connect to the bottom of Cohu's Eclipse XT Handler, and acts as an even surface for our adapter to push against. This plate is built to withstand the loading conditions exposed from the SLK Heads to minute deformation, such that the force reading given is accurate to +/- 1lb.

Mock DUT Fixture

The final design for our secondary objective is a modular Mock DUT that would connect to various insulating adapters that are designed to fit with the different SLK Head sizes. This design consists of several key individual components that come together to form a Mock DUT Fixture that emits heat to the SLK Head. The initial component of this design is the Mock DUT, which is made of a Copper body, and includes a Cartridge Heater, a RTD, as well as a Thermostatic Switch.

(Figure 4) The exploded view of our Mock DUT with all its components are shown in this image. The idea behind this structure for this Mock DUT is based on it being modular for different adapter variations. The same Mock DUT that would be used for a x1 SLK Head could be used for a x16 SLK Head by only interchanging the adapter.

(Figure 5) A rotating view of the Mock DUT with all the components in place can be seen above. This piece of the final design is interchangeable with the adapters build for different SLK Head sizes.

The three fixed adapters like the ones for the Force Measurement Fixture, are used for the x1, x2, and the x16 SLK Heads. However, the material of these adapters, unlike the ones for the Force Measurement Fixture, are made from an insulating plastic called Ultem, formally known as Polyetherimide. The reason for this design choice is primarily to prevent any heat from going into the SLK Head.

Figure(6) From left to right, the x1, x2, and x16 SLK head adapters, respectively. The modular design of the mock DUT allows for fast and easy installation into an adapter.

The Mock DUT Fixture utilizes captive screws and locating features on the top surface for quick and easy attachment to the SLK head.

Figure(7) From left to right, the Mock DUT Fixture securely affixed the x1, x2, and x16 SLK head, respectively.

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