Ishii: When the decision was made to develop a new DC/DC converter to grow our automotive products business, as a member of the Design Department I looked into the specifications on the basis of a market survey. The decision was made to develop a cost-competitive product for the purpose of business growth, and from the perspective of production capacity on production sites, to launch it using labor-saving automated lines.
We initially looked into building the line in consultation with external businesses, but given the large scale of investment that would be needed, we ended up speaking to the Production Machine Technology Department that designs and develops production facilities in the Electronic Device Division Group.

Yamazaki: The project got underway from the start of 2021 with us working together with the Car Electronics Division Group. I’ve thus far been responsible for things like the design of production facilities for the power semiconductors that are developed in the Electronic Device Division Group, so this was my first experience of being involved in the construction of a production line for a car electronics product. There are more processes than there are for semiconductors and the scale of the production line is on a different level. In this project, I was involved from before the completion of product design, and starting to look into the production facilities while the specifications had still not been firmed up was something that I had no real track record of. I was quite puzzled at first.

Ishii: The construction of an automated production line takes time, so we took the investigation into production facilities forward in parallel with the product design work. I had very little experience of investigating facility design while the design of a product still had not been finalized, and so I wondered what kind of information I should provide to Koji and the other members of the facilities investigation team and at what time so that they might be able to take their investigations forward. It was a matter of feeling things out at first, but the fact that the environment was one that enabled you to quickly have a meeting if you noticed anything was very helpful.

Yamazaki: In almost all cases, an investigation into production facilities for semiconductors starts when product design is complete. While it is easy to proceed with work at this stage because everything has been put into drawings, specification changes to fit with requests from the facilities side are difficult, and as a result, in some cases it takes a toll on the facilities side. With the TW115, the product design still wasn’t firmed up, but based on information from Car Electronics about which stage things had progressed to and which parts had been firmed up, we were able to take the design of the facilities forward. Even when components that we hadn’t initially expected were added, the fact that we had left some leeway in the design based on the information we’d received in advance bore fruit, and we were able to alter our trajectory with no major modifications.
Thanks to the fact that we were able to start our investigation before the specifications were finalized, we didn’t have to force specifications onto facilities and we were also able to discuss specification changes to fit the automatic machinery.

Ishii: When we were checking the laser welding process that had been newly introduced, we found that the laser went in a direction that we had never thought it would, and this resulted in a part that must not be irradiated being struck by the laser. This was already at the stage where we were manufacturing samples before the start of mass production, so it would be a significant inconvenience for the customer if we had to rethink the specifications. The facilities were already complete but this was not something that could be resolved by the design side alone, and so, clutching at straws, I ended up contacting Koji to work out what measures to take.

Yamazaki: The facilities side was just performing the final checks for setup on the production site, but when Yasuhiro contacted me I immediately started working on measures. Fortunately we still had time to modify the facilities, but we were aware that we simply had to resolve this issue with the teamwork we had built up to that point.

Ishii: COVID-19 was happening at the same time and we almost gave up during development, but thanks to the support we got from the Electronic Device Division Group among other things, we were able to see it through to the end. The knowledge we gained in this development has been shared as guidelines within the Car Electronics Division Group, and we have ensured that it is available for use in the development of products to be manufactured on a labor-saving production line going forward.

Yamazaki: As soon as the line for TW115 production got underway, we immediately started receiving ideas for improvement from those on the site. We are now working to incorporate each idea one by one. There have already been moves towards the development of a new model, and the Design Department and Production Engineering Department have already discussed things together on the production site. They have compiled the resulting opinions in order to prevent trouble in areas where it might occur and take forward development with an awareness of simplicity and stable quality in manufacturing.