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Low-temp curing resin Material Development Department of Company C, an electronic materials manufacturer

Resin supports low-temp electronic component processing

Curable resin that combines low-temperature hardening and storage stability!

Electronics
Dispersion / Aggregation Durability/stability Curing/crosslinking

Company C develops, manufactures, and sells a wide range of materials for electrical and electronic components. With the increasing performance of electronic devices and advances in communication technology, there is a growing demand for mass production and low cost of devices and components that transmit information. Mr. U and his team from the development department received a request from a client electronic component manufacturer to develop a resist resin that would allow the use of low-cost film substrates as electronic circuit board materials, with an eye toward mass production and cost reduction.

* This is a hypothetical example posted as a reference for those with similar challenges

Challenges

The curing process must be cooled to match the heat resistance of low-cost film substrates...

Mr. U recalls a recent exchange he had with a client: The client is considering using low-cost polyester (PET) or polycarbonate (PC) for the film used in the circuit boards of electronic components that they are aiming to mass-produce, but while these materials are low-cost and easy to process, they have a problem with their low heat resistance.

"After forming the circuit pattern on the film substrate, our client performs a post-cure process to improve chemical resistance and mechanical strength. However, with conventional resists, the post-cure temperature is higher than the heat resistance of films such as PET, so there was concern that this could cause problems such as deterioration of the film substrate." (Mr. U)

Additionally, there are plans to increase the line speed during curing in preparation for mass production, so reducing the post-cure temperature was also a necessary development requirement.

In order to develop a resist that would match the low-temperature curing process, Mr. U and his team decided to search for a base curable resin.

We immediately explained this concept to a resin manufacturer we have a relationship with, ordered various resist resins, and began prototyping and evaluating them. However, under the process conditions we used, the heat curing did not progress sufficiently during the post-cure process, making it difficult to ensure solvent resistance.

Therefore, we considered lowering the curing temperature by adding a curing agent or curing accelerator, but this shortened the pot life and confirmed a tendency for the viscosity to increase during storage, leaving us with concerns about storage stability.

Considering the mass production schedules of electronic component manufacturers, there was not much time left until the development deadline, and Mr. U and his team felt anxious, thinking, "If things continue like this, we won't be able to meet the delivery date."

Key Challenges

  • As component manufacturers began mass-producing electronic circuit boards, they began using low-cost films such as PET film, and there were concerns that the film had poor heat resistance.

  • In a low-temperature curing process where the post-cure temperature was lowered, conventional resist resins did not cure sufficiently, causing problems such as in solvent resistance.

  • We tried to lower the curing temperature by adding a hardener or curing accelerator, but this resulted in problems with the storage stability of the resist.

Solutions

Solution Summary

  • ACRYCURE™ low-temperature curing type has low-temperature thermal crosslinking groups and alkali-soluble groups, and thermal crosslinking progresses even at curing temperatures below 100°C.

  • ACRYCURE™ low-temperature curing type is a one-pack formulation with excellent storage stability.

  • The resin was able to complete curing even at a curing temperature of around 90°C, making it well suited to low-temperature curing processes.

A ray of hope is shining with ACRYCURE™ low-temperature curing type. Efforts toward low-temperature curing processes for electronic components are accelerating!

To overcome this situation, Mr. U and his team decided to split up and search for a resin that could lower the post-cure temperature. One of the team members reported to Mr. U that at an exhibition he attended, Nippon Shokubai, a company with a reputation for its resist resins, had introduced a low-temperature curing resin and had requested that he send them the technical information.

After looking at the technical documents that were sent and the videos posted on the website, Mr. U and his team felt that this was a promising product, so they contacted the sales representative to request a meeting to hear more about it.

We met with Nippon Shokubai and were introduced to a low-temperature curing product they had developed. This resin has low-temperature thermal crosslinking groups and alkali-soluble groups, and thermal crosslinking proceeds even at curing temperatures below 100°C, making it a perfect match for the low-temperature curing process we were considering.

In addition, after receiving data showing that the product can be used as a one-component liquid and that there is little increase in viscosity under specified storage conditions, Mr. U and his team immediately obtained samples to begin prototyping and evaluation.

In the study using samples, it was confirmed that the resin hardened completely even at a hardening temperature of about 90°C, and that the physical properties of the hardened coating were also good. I reported the results to my superiors and decided to propose it as a resist to component manufacturers.
　
The product has been well received by component manufacturers, and expectations are high for mass production as productivity can be expected to improve by lowering the temperature of the curing process and increasing the line speed during curing.

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