Roll-to-roll atomic layer deposition process for flexible electronics applications

Atomic Layer Deposition (ALD) is the technology of choice where very thin and highquality films are required. Its advantage is its ability to deposit dense and pinhole-free coatings in a controllable manner. It has already shown promising results in a range of applications, e.g. diffusion barrier coatings for OLED displays, surface passivation layers for solar panels. Spatial Atomic Layer Deposition (SALD) is a concept that allows a dramatic increase in ALD throughput. During the SALD process, the substrate moves between spatially separated zones filled with the respective precursor gases and reagents in such a manner that the exposure sequence replicates the conventional ALD cycle. The present work describes the development of a high-throughput ALD process. Preliminary process studies were made using an SALD reactor designed especially for this purpose. The basic properties of the ALD process were demonstrated using the wellstudied Al2O3 trimethyl aluminium (TMA)+H2O process. It was shown that the SALD reactor is able to deposit uniform films in true ALD mode. The ALD nature of the process was proven by demonstrating self-limiting behaviour and linear film growth. The process behaviour and properties of synthesized films were in good agreement with previous ALD studies. Issues related to anomalous deposition at low temperatures were addressed as well. The quality of the coatings was demonstrated by applying 20 nm of the Al2O3 on to polymer substrate and measuring its moisture barrier properties. The results of tests confirmed the superior properties of the coatings and their suitability for flexible electronics encapsulation. Successful results led to the development of a pilot scale roll-to-roll coating system. It was demonstrated that the system is able to deposit superior quality films with a water transmission rate of 5x10-6 g/m2day at a web speed of 0.25 m/min. That is equivalent to a production rate of 180 m2/day and can be potentially increased by using wider webs. State-of-art film quality, high production rates and repeatable results make SALD the technology of choice for manufacturing ultra-high barrier coatings for flexible electronics.

Elementtikoon vaikutus väsymismenetelmien tarkkuuteen

Kandidaatintyössä tutkittiin kolmen hitsatun palstalevyliitoksen väsymiskestävyyttä äärellisten elementtien menetelmällä. Tutkimuksen pääpaino oli 2D-mallin antamien tulosten suppenevuudessa kolmella eri elementtikoolla ja kolmessa eri mittasuhdetapauksessa. Tutkimustuloksissa havaittiin noin 5 % muutos harvimman ja tiheimmän elementtiverkon tulosten välillä. Tutkimuksessa havaittiin myös että muutos harvimman ja tiheimmän elementtiverkon tuloksissa pieneni hiukan mitä suurempia kappaleet ja niiden hitsausliitokset olivat.

Inclusion or Exclusion? Trade union strategies and Labor migration

Inclusion or Exclusion? Trade Union Strategies and Labor Migration This research identified and analyzed immigration-related strategies of the Finnish Construction Trade Union (FCTU) and the Service Union United (SUU); e.g. how the unions react to labor immigration, whether unions seek to include migrants in the unions, and what is migrants’ position in the unions. The two unions were chosen as the focus of the research because the workforce in the sectors they represent is migrant-dense. The study also analyzed the experiences that migrants who work in these sectors have with trade unions. The Estonian labor market situation –including the role of Estonian trade unions– was also examined as it has a considerable impact on the operating environment of the FCTU. The results of the study indicate that immigration is a contradictory issue for both unions. On the one hand, they strive to include migrants as trade union members and to defend migrants’ labor rights. On the other hand, they, together with their umbrella organization the Central Organisation of Finnish Trade Unions (SAK), seek to prevent labor immigration from outside the EU and EEA countries. They actively defend current labor immigration restrictions by drawing atten- tion to high unemployment figures and to the breaches of working conditions migrants encounter. In contrast, the employer organizations promote a more liberal state policy on labor immigration because they see it as a boost for business. Both the unions and the employer organizations ground their arguments on national interest. However, the position of the trade union movement is not uniform: unions belonging to the Confederation of Unions for Professionals and Managerial Staff in Finland (Akava) embrace more liberal labor immigration stances than the SAK. A key trade union strategy is to try to guarantee that migrants’ working condi- tions do not differ from those of the natives. The FCTU and the SUU inform migrants about Finnish collective agreements and trade union membership in the most common migrant languages. This is important for the unions because it is not in their interest that migrants’ working conditions are undercut. The interviewed migrants said that natives had more negotiating power with employers, which is often negatively portrayed in migrants’ working conditions. Migrants perceive that trade unions have an important role in protecting their working conditions. However, they stressed that migrants’ knowledge of unions is often very limited. The number of migrants in both two unions studied here is increasing. Espe- cially in the SUU, a considerable proportion of the new members are migrants. The FCTU is in a more challenging situation than the SUU because migrant construc- tion workers often work only for short periods in Finland and are consequently not interested in becoming union members. The unions’ strategies partly differ: the FCTU was the first Finnish trade union to establish a trade union branch/lo- cal for migrant members. The goal is to facilitate migrants’ inclusion in the union and to highlight the specific problems they face. The SUU, for its part, insists that such a special strategy would exclude migrants within the union organization. Despite the unions’ strategies, migrants are still underrepresented as union members and officials, which some of the interviewed migrants saw as a problem. Immigrants’ perception of trade unions was pragmatic: they had joined unions when membership yielded concrete benefits. In spite of the unions’ strategies, migrants –and temporary migrants– encoun- ter specific problems in terms of working conditions. Both unions demand more state intervention to protect migrants’ labor rights because overseeing working conditions consumes union resources. However, without the unions’ intervention, these problems would be more common than is currently the case. For instance, some of the interviewed migrants had received trade union assistance in claim- ing unpaid wages. The study demonstrated with the help of building on Walter Korpi’s power resources theory, that immigration is a power resource issue for the unions: suc- cessful immigration-related strategies strengthen unions –and vice versa. The research also showed how the unions’ operating environments constrain and enable their immigration-related strategies. This study has illuminated a previously ignored dimension: the immigrant- inclusive strategies of the Finnish trade unions. The research material consists of 78 qualitative interviews, observation in trade union events, and trade unions’ and employer organizations’ public state- ments.