Please note that JavaScript and style sheet are used in this website,
Due to unadaptability of the style sheet with the browser used in your computer, pages may not look as original.
Even in such a case, however, the contents can be used safely.
Volume 21 (June 18, 2004)
The challengers who developed the PDP Driver IC (1/2)
Part 2: The early morning meetings begin once again.
As progress was being made toward the realization of Tape Carrier Package (TCP), additional difficulties awaited the team-it was then that the early morning meetings were reinstated
In the case of a TCP mounted with a high-voltage SOI chip, there were problems in which electrical changes in the SOI support substrate affected the special characteristics of the IC, including changes in breakdown voltage. It was proposed that fixing the SOI support substrate potential to the ground from the chip's surface could act as a countermeasure to stabilize the SOI breakdown voltage characteristics.
Having received a great deal of attention for having excellent characteristics such as thin and lightweight large-size displays and the ability to realize high definition, the PDP market is witnessing rapid growth. The market is currently growing at an annual rate of 70%, and is expected to pass the three-million level in domestic sales in 2005. Behind the scenes of the rapid diffusion of PDPs in the marketplace is the story of the struggles faced by the engineers who supported the development of PDP technology.
It was the end of the year 2000. At the time, the Tape Carrier Package (TCP) (Figure 1) was required for the realization of further size and cost reductions and to replace the four-chip Chip-On-Film (COF) module mass produced as a PDP driver IC. Satoshi Gotou, who was involved in the development of TCP process technology, carried out investigation after investigation in his efforts to commercialize a TCP with two chips built in that would meet the demands of the market. However, there was obviously no reason to create a trial production line for a two-chip prototype that was not even ready for the market yet. Then Gotou came up with an idea-he could use the LCD driver IC production line, for which TCP had already been achieved, to test the TCP prototype of the PDP driver IC. There and then he made up his mind to take on the challenge of finding a way to create a two-chip TCP prototype. After many trials and tribulations, he was able to confirm that there were no problems in reliability with the production line. At this point in time, however, not even Gotou could have predicted the problems awaiting the development team as they moved forward toward the realization of TCP.
The customers who had actually called for the development of TCP began to strongly doubt its reliability. Some began to ask, "Are you sure there won't be any problem with reliability if you use TCP for high-voltage PDP drivers just as if you were using it for a low-voltage LCD driver?" Despite the confidence of the project team in the reliability of TCP, their customers were skeptical. The project team would need to pull together to prove their assertions. To find a way to convince their customers of the reliability of TCP, the early morning meetings that had been discontinued were reinstated and continued on for quite some time.
2001: The year of the birth of TCP
On December 27, with the end of the year fast approaching, customers were invited to attend a meeting to address their numerous doubts as well as to find ways to meet their various demands. It turned out to be a rather somber event that lasted several hours. It was only natural for these customers to be cautious since this project was the first attempt in the world to mass produce TCP exclusively for PDP and it would be necessary to solve a number of difficult issues, including the realization of large-scale cost reduction and provision of proof of reliability. In the end, very little headway was made at the meeting, and the problems were not solved until after the start of the new year.
To provide fine-tuned responses and prepare for emergency situations, the project members created a 24-hour mobile phone hotline for their customers at the beginning of 2001 that was aimed at providing complete support. Moreover, in an effort to persuade their customers, the team prepared numerous samples and a large amount of data related to Tape Automated Bonding (TAB) connection technology, including an electrode simultaneous connection made using a tin/gold eutectic alloy. As a result, they were finally successful in finding a basis for confirming TCP reliability and gaining the understanding of their customers. Thus, once they had won the trust of their customers regarding the technology, the product was finally ready for mass production. Later on, the project team received a letter of thanks from one of their customers for the support they had provided, and the thank-you letter currently adorns the division's conference room. Takahashi comments, "I was very pleased and honored to receive the thank-you letter. When our customers told us, 'This product has really improved,' we felt as if all of our hard work had paid off and were filled with joy." It can be said that 2001 was the year of the birth of TCP.
The third series of early morning meetings culminating with the press release issued for the 192-output PDP data driver IC.
It was now 2002. The PDP driver IC for which TCP had been successfully realized was making steady increases in terms of shipments. The development team, which had achieved success in the market, decided to go with the flow and aim toward the creation of a one-chip product (Figure 2). However, all of the team members had their hands full with their own issues. Even still, no move was made to increase the number of members on the team. Even Akira Fujiwara found that providing guidance for his subordinates took up much of his time, and he was therefore unable to devote his undivided attention to chip development. To lift his own spirits, however, he offered to work on the design. Just as expected, the days of hard work continued. Yet no compromises whatsoever were made with regard to the specifications. On the contrary, he focused his efforts on making it an even more advanced technology by working to further strengthen its efficiency through the incorporation of functions such as dual/single conversion for the clock and over-temperature detection. During this time, the third series of early morning meetings aimed at the realization of a multi-output one-chip product started. These meetings were much more positive than those held before them, which had been filled with pessimism. This was because the meetings were now focused on the improvement of a product that had already been completed. Fujiwara had rarely even participated in the trouble-filled first and second series of early morning meetings, but he did have opportunities to hear about them and fully understood the struggles his senior colleagues had faced. In effect, he had grown alongside the team members who were burdened with the task of next-generation development. Early morning meetings, prototypes, modifications, more early morning meetings . . . While receiving cooperation from his senior colleagues, Fujiwara immersed himself in the design day and night. The sample proceeded smoothly through initial-stage evaluations and reliability evaluations, and then at long last, a press release was issued for the 192-output product. For development to proceed this smoothly was certainly a rarity. Fujiwara, however, would later on fully realize that in actuality it wasn't all that simple.
209KB)