Kesätyöntekijän mietteitä

Kesätyöntekijän mietteitä

Nyt kun arki on lomien jälkeen koittanut ja ulkona on syytä kiskoa aamuisin lapaset käteensä, on hyvä aika palata kesäisiin tunnelmiin kesätyöntekijämme Anniinan kirjoittaman blogin muodossa. Tältä näyttivät työtehtävät Trelicillä 18-vuotiaan lukiolaisen silmin!

”Terveiset Trelicin kesätyöntekijältä!

Tosiaan olen Anniina. Olen lukio-opiskelija ja tänä kesänä myös Trelicin kesätyöntekijä. Tätä Blogia kirjoittaessani on kuukauden mittaisen työjaksoni viimeinen, tosin vajaa, viikko. Työjakson aikana olen ehtinyt tehdä paljon erilaisia mielenkiintoisia asioita ja päässyt kokeilemaan jopa etänä työskentelyä kahden päivän ajan.

Pelkistyksessä käytettävien kuparikuponkien valmistelua (taiteilija: Roosa, TET-harjoittelu 2020).

Kun otin kesätyön vastaan, en oikeastaan tarkalleen tiennyt mitä kaikkea tulisin tulevan kuukauden aikana tekemään. Näin työjakson loppupuolella vastaus on: Paljon erilaisia asioita. Loppujen lopuksi kuukausi on aika pitkä aika johon mahtuu paljon uuden opettelua ja rutiinihommia. Päällimmäisenä työtehtävistäni mieleen nousee pelkistys. Ymmärrykseni mukaan pelkistyminen on kemiallinen reaktio, joka laboratoriossa toteutetaan tyylikkäällä ja erittäin monimutkaisen näköisellä laitteistolla. Todellisuudessa pelkistyksessä tehtäviäni olivat näytteen valmistelu, typpipullon avaaminen ja napin painaminen.

Pelkistyksen lisäksi minulla on ollut muitakin mielenkiintoisia ja vähemmän mielenkiintoisia työtehtäviä. Esimerkiksi näytteiden valu epoksilla oli kivaa siihen asti kunnes näytteet piti niiden päällä pomppimalla irroittaa astioista. Henkilökohtaisesti pidin myös näytteiden hiomisesta, joka kuluneen kuukauden aikana on ehtinyt tulla erityisen tutuksi. Tietenkin olen tehnyt paljon myös sellaisia pakollisia asioita, joihin vakituisilla työntekijöillä ei vain ole ollut aikaa kuten kaappien järjestely ja niiden sisältöjen läpikäynti ja yleinen siivoaminen. Nämäkään tehtävät eivät ole olleet varsinaisesti epämieluisia, koska tiedän, että jonkun ne on kuitenkin tehtävä.

Ilmeisesti rento ilmapiiri on aika yleistä teknisellä alalla ja Trelicissä se ainakin toteutui. Sillä vaikka olenkin täysin kokematon työntekijä, sain tehdä paljon myös yksin, ilman, että joku oli koko ajan vahtimassa. Myöskään avun pyytämisessä ei ollut suurta kynnystä ja joku vakituinen työntekijä oli aina tarvittaessa paikalla.

Yleisesti ajatellen työjakson loppuminen ei mitenkään valtavasti sureta, mutta Trelic oli hyvä paikka olla ensimmäistä kertaa pidempi pätkä töissä kerralla. Oli kivaa, että töitä oli keksitty riittävästi, koska välillä kuulee tarinoita kesätöistä, joissa kesätyöntekijät vain istuvat tekemättä mitään. Eikä minua varsinaisesti olisi harmittanut jatkaa vielä töitä, mutta on hyvä, että saan vähän lomailtua ennen kuin syksyllä taas jatkan koulua. Toivotan siis itselleni ja jokaiselle lukijalle hyvää kesää ja lämpimiä lomapäiviä.”

Polymers- general properties

Polymers- general properties

Material selection plays a crucial role in product development. Lately we have shared infographics about metals and ceramics. This week we deal with polymers. Polymers are often used to replace other materials for cost and weight saving purposes. They are very versatile materials, but we are also quite often working with polymers because they cause lots of reliability issues.

Metals – general properties

Metals – general properties

Material selection plays a crucial role in product development. Materials have huge effect in reliability of the product, but they also determine things like cost and weight. Additionally, certain functionalities such as electrical conductivity can only be achieved with certain material groups.

Materials are often divided into a few main categories according to their properties which include metals, ceramics, polymers and composites. Everyone somehow involved with R&D should know the basic properties of material groups, and therefore we decided to make a few simple infographics about them. Here is the first one about metals.

Comparison between mixed flowing gas and flowers of sulphur corrosion testing

Comparison between mixed flowing gas and flowers of sulphur corrosion testing

Corrosion is a major cause for failures in electronics and its importance is increasing. Therefore, corrosion testing is also getting more and more attention these days. Choosing the most suitable test method is, however, complicated because corrosion processes are very complex and difficult to replicate. Additionally, the knowledge how to link corrosive environment to testing environment with similar corrosion effect is not yet available. This is a major topic we, at Trelic, are currently solving.

Various corrosion test methods are available. In the last weeks we have been extensively working with mixed flowing gas (MFG) and flowers of Sulphur (FoS) tests. In all of our corrosion tests, corrosion has been monitored with corrosion coupons for which gravimetric analysis as well as coulometric reduction have been performed. Additionally, a wide range of different test structures has been tested.

Our CEO, Laura was recently presenting some of the results in Celcorr 2021 seminar. She was especially talking about MFG and FoS tests. The image below is a link to the slides!

Slides available also here.

Which factors affect the reliability of a product?

Which factors affect the reliability of a product?

Several factors affect the reliability of a product or the reasons for its failures searched. In this post we go through some of these factors.

1. Poor design

Sometimes the cause for failure may be due to poor design. The error may have occurred for example due to too small margins of safety or due to too optimistic design. Such mistakes may occur if the use environments and requirements are not adequately known. Too little knowledge of materials and components used or pressure to cut down the costs may also lead to selection of improper materials/components for the needed use conditions or use life. Sometimes reliability considerations are not properly analysed in design, and they are found only in later stages of production or in use.

Chosen plastic material has not withstood the heat caused by internal heating of the cable.

2. Manufacturing defects and mistakes

For complex products manufacturing may require lots of different steps and processes. These can significantly stress the products and some failures may be caused already during manufacturing of the product. For example, processing may cause internal stresses or thermal damage to the product, which results in a failure immediately or later in the hands of customer. Human errors may also happen in the manufacturing line, especially, if the process control is poor, which may cause poor reliability to the product.

One typical cause of failure is the change of some material/components used in the product. This can happen for example when material is no longer available or somewhere in the supply chain it is changed to a cheaper one. On paper the materials may look the same but in real life the new one may have much poorer properties than were originally designed for the product. For example, plastics with same name may have very different properties.

3. Quality problems

Sometimes certain batches of products have large number of failures even though most of the products manufactured are functioning fine. This may be due to a quality problem. Quality problems may be caused due to manufacturing errors, but also due to differences between supply batches. For example, the properties of materials may vary markedly, and this may cause problems for some batches. Therefore, properties of materials should be occasionally measured for quality control.

In addition to materials, quality problems also apply to components. Quality of components may be poor for certain batch or for certain supplier. Components may also be fake. In this case the insides of a component are not what they should be, and the manufacturer is different from the one stated in the papers.

4. Environmental conditions

The environment in which the product is used or stored has naturally a considerable effect on the reliability. For example, high temperature, temperature changes, high humidity or corrosive environments tend to cause failures. These are important factors to consider, when reliability testing method is chosen or when reason for failure is investigated. When environmental factors are considered, often use conditions are thought. However, the determination of use conditions can be tricky especially, if the product is used internationally and can see any conditions from tropical heat and humidity to cold seashore or highly polluted big cities.

It is important to notice that the use environment is not the only environment which should be considered. Products are also exposed to environments which are present during their transportation and storage. This might mean hot temperatures due to being stuck in a shipping container in direct sunlight, resulting in much higher thermal exposure that was designed for the use environment. Or in the worst case the products are stored outside in rain and polluted areas for prolonged time while waiting for installation.

Improper storage of packages in winter conditions.

5. Overstress

Overstress often causes rapid and surprising failures. In overstress a critical limit of material, structure or component is exceeded which leads to failure. Overstress can be any kind of stress, such as too high temperature, too quick temperature change, too humid or dry environment, exposure to chemicals which can break for example polymer chains in plastics, exposure to highly corrosive environments etc.

Overstress may occur in manufacturing if for example chosen processing temperature exceed the thermal limits of some material present in the product. Another cause for overstress is misuse. The product may be stored in wrong conditions or the customer may be handling the product incorrectly, for example using it in conditions exceeding the specifications of the product.

6. Wear

Wear means that a failure occurs because products, their materials, and components age and therefore lose their original properties. All products wear in time. The process is slow, and therefore failures due to wear develop slowly over time.  Wear causes lots of different failure mechanisms depending on the materials, structures, and conditions. For example, solder joints tend to crack due to fatigue or plastic casings become fragile and crack due to prolonged exposure to increased temperatures or UV. When a failure due to wear occurs in the end of useful lifetime of a product, it is not reliability issue but a part of the normal lifecycle of a product.

Corrosion is one the most common reason for failures and poor reliability.