IPS Alpha 2 Goes Ink-jet…Really?
May 12th, 2008by Charles Annis, Vice President, Manufacturing Research
On April 28 the Japanese press reported that Dai Nippon Printing (DNP) will spend ¥30-40 billion (around $300-$400 million depending on the volatile exchange rate) to build a Gen 8 color filter fab for IPS Alpha’s planned line in Himeji, Japan. In General, Japanese news organizations such as Nikkei are much more conservative about running controversial stories than newspapers in other Asian countries. I am not sure if this qualifies as controversial, but I was surprised to read this, a story that we have been following closely in our TFT LCD Quarterly Supply/Demand and Capital Spending and Quarterly Color Filter Reports. After reading the article, I checked the Japanese websites of both DNP and IPS Alpha to try to confirm the story, but there was, and still is, no announcement by either company.
DNP building a by-plant ink-jet color fab for IPS Alpha Himeji Gen 8 certainly is one of the scenarios we have been forecasting. The others are Toppan Printing building a by-plant photolithography based color filter line, DNP using photolithography rather than ink-jet or both DNP and Toppan building by-plant fabs to each supply half of IPS Alpha’s needs; like they are doing for Sharp Gen 10 in Sakai. We have heard from equipment and materials suppliers that they are in discussions with both printing companies to support all of these scenarios, but as far as we have heard, no final decision has been reached.
If the April 28 news story is accurate or not, or what supply scenario will eventually play out, is of less interest than the fundamental question it raises, one we come back to over and over again: Is ink-jet RGB color filter printing ready for mass production, and if not, when?
DNP is significantly further along in ink-jet color filter printing than any other manufacturer. It is now mass producing ink-jet CF on multiple Gen 6 and Gen 8 lines, both in Kameyama and Kurosaki, Japan. DNP is building a Gen 10 color filter line for Sharp that reportedly will use ink-jet. Furthermore, DNP has a very strong relationship with Hitachi and IPS Alpha. Currently DNP supplies 100% of IPS Alpha’s Gen 6 color filters.
However, we believe that all of the current Gen 6 color filter supply is lithography based. Rumors are that DNP has been trying for a long time to get IPS Alpha to qualify its ink-jet based CF, but to date they have not passed the test. Also, IPS Alpha has suggested that it will make 32” and other relatively small TV panels on its Gen 8 line. Ink-jet is challenged to accurately print within the comparatively small pixel area of 32” high definition panels. In addition, we recently have heard that leading Japanese panel makers continue to push black matrix design widths, from around 20 µm down to 9 µm. The purpose of this is to increase aperture ratio and brightness in order to reduce the number of backlight CCFLs or optical films; in turn reducing the cost of the backlight unit. Some ink-jet experts have suggested that such thin black matrix lines will be further complicate ink-jet printing, as ink will be more likely to spill over into the next pixel and cause a color mixing defect. Since backlights are the most expensive component in LCD modules, the narrower black matrix margins and brightness gains it enables could potentially reduce costs more than the benefits of ink-jet RGB printing. Even Sharp, who uses a significant number of DNP ink-jet color filters in its TV products, still plans to procure lithography based color filter at Gen 10 to hedge risks. And Toppan continues to push the limits of manufacturing productivity of lithography based CF manufacturing, keeping its color filters highly competitive.
In sum, we do not know at this time how accurate the news story is. If true, and if IPS Alpha does indeed become the first TFT LCD fab to rely solely on ink-jet color filters, we would be encouraged that ink-jet is well on its way to becoming a mature manufacturing technology. However, we still think quality and cost issues remain for ink-jet, and that both are moving targets. In any case, IPS Alpha’s Gen 8 Himeji factory color filter procurement plans will likely be confirmed in the relatively near future. When that happens, it will help clear up some of the questions on of the status of RGB ink-jet color filter technology.
