Insights

Are you ready for parallelism test?

2021-06-20  |  7 min read 

It is just in our nature to push boundaries. When things are good, we want better. When thing gets better, we want it to be the best. Afterall, that’s what keeps technology alive and feeds innovations. In my earlier posts, I discussed about parallelism test. Now let’s talk about the test systems that allow you do perform parallel test operations.

In early 2018, Keysight launched the FlexiCore Parallel In-Circuit Test (ICT) test system, which supports up to four independent cores of the i1000 test engine. Five years later, parallel test now takes on a whole new meaning with the launch of i7090 Massively Parallel ICT test system that offers up to a total of 20 parallel cores.

Is it time to upgrade the production line with the i7090, or should you stay with the FlexiCore?

i7090 and FlexiCore FlashStation

There are many differences between the i7090 and the FlexiCore FlashStation, ranging from their outlook, system structure, use model, features, to test capabilities. Therefore, I’m going discuss a few major ones in this post and leave the rest for future posts. If it triggers any questions, don’t hesitate to contact me.

For a start, let’s talk about the mechanical differences between the systems.

Table1 - Mechanical comparison between FlexiCore FlashStation and i7090

The major difference between these two systems is their size. In particular, the width of the system. The i7090 width is only 600 mm, which give you the narrow floor space that you need when configuring a production line. The narrower the systems, the shorter the line and more floor space savings. The narrow width results in mechanisms packed much closer to each other inside the system, leaving limited space for fixture troubleshooting as compared to the FlexiCore, where it is much more spacious.

Lifter stations before and after i7090 to handler bypass boards

The next notable difference is that the i7090 offers a bypass conveyor option which is not available in the FlexiCore. The bypass conveyor of the i7090 is at a fixed height above the moving press plate. It does not move up and down with the press operation. Therefore, to utilize the bypass conveyor, the upstream and downstream conveyor system will need to have a lifter station included to lift the incoming board up to height of the bypass conveyor before transferring it into the i7090. Similarly, on the downstream side, the conveyor system will need to have the same lifter station to receive the board from the i7090 and then set it back down to the normal conveyor to continue to the next station.

Conveyor operations are also different. There are no obstructions to the test points placed close to the board edge on the FlexiCore. This is because its conveyors open outwards when it lowers the board onto the test fixture. The i7090 conveyor does not open outwards and test points placement will need to stay clear from the board edge clearance. 

The narrow width of the i7090 limits the length of board to a maximum of 460 mm for a single panel operation or 206 mm for dual-panel operation. However, the increased depth of the system allows the conveyor to support wider board of up to 460 mm. Supporting larger conveyor width means that the main press will need to be able to handle greater imbalanced counter force from the test fixture while it is engaging the DUT downwards.

Unbalanced press force due to board placement

Conveyor rails transport the boards into the test system. The fixed conveyor rail at the front of the system is the reference for all board placements on test fixtures. This creates an imbalanced counter force to the main press cylinder when it is trying to engage the DUT onto the test fixture.

Having an imbalanced press force stresses the main press cylinder and the guide rods that ensure coplanarity of the press plate movement. To prevent that from happening, the i7090 uses a twin cylinder press system which places one cylinder on the front and another at the back of the system. Controlling both cylinders using a single valve ensures the synchronization of their movements.

The compact design of the i7090 limits the accessibility for maintenance work. With the system in a production line and machines occupying both sides of the system, it is impossible to gain access to the center part of the system in the test engine area. So, the idea of a detachable test engine solves the problem.

With a detachable test engine, maintenance is much easier and accessible. Technically, it is even possible to swap out a defective test engine and replace it with a working one. In a nutshell, the i7090 is mechanically very compact whereas the FlexiCore allows more space in the system for easier maintenance access.

i7090 detachable test engine design allows easier access for maintenance

That’s all for now. See you in the next post.

Stay tuned and stay healthy!

Ping me up with your questions or comments ! 

kwan-wee_lee@keysight.com