My company Asymtek has a WIN3 program, that allows us to work with the customer and many adhesive suppliers, to provide a win situation for all three parties. unfortunately I cannot recommend any one adhesive or company. However there are many fine companies out there that supply adhesives.

I think what you should do is write a list of requirements. You have given us a couple adhesive that can withstand solder temperatures and easy to remove, not easy tasks. You may also have other requirements like solvent resistance and shock / vibration testing criteria.

When you have your list I would then go shopping. Beware of companies that say try my materials, they want you to do the testing. Look for companies that can show you the test results you are looking for. No one company is going to have everything you need, but the good ones do a lot of testing.

However because they will have done some of the work for you. Expect to pay more for their services because they are more than just an adhesive manufacture.

NF-260 is a reworkable no-flow underfill which could do the job.

See Indium Corporations rework video.

A no-flow underfill is an epoxy & flux combined:

• Products that require underfill are typically reflow soldered and then underfilled
• A no-flow underfill combines these 2 steps into 1 step with both reflow & underfilling happening in 1 step

In this application, NF260 can be used as the reworkable epoxy/adhesive and soldering can also be done simultaneously.

There are a number of adhesives that can be used to provide support to the sensor. You want to make sure they are compatible with the electronics, in other words, a material that won't outgass or leech corrosive products.

In most cases an epoxy system would be ideal - providing good adhesion and good chemical resistance. There are systems available that cure during the SMT reflow process, therefore you could save a step by curing the same time as reflow. There are some other systems that are quick cure thermal, or even UV - depending on your process needs.

If you want reworkability, that narrows down the available materials. It depends on how you describe "reworkable" some of the epoxies may work, it just depends how much effort you are willing to use to remove the adhesive.

There are some silicone materials (RTV or room temperature curing) or UV cure materials that may work in the application. Once again be careful to choose a material that is compatible with electronics.