Study and analysis of temperature effect on in-mold labeled RFID tags
Jahra, Nisatuz (2021)
Jahra, Nisatuz
2021
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2021-12-09
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202112089030
https://urn.fi/URN:NBN:fi:tuni-202112089030
Tiivistelmä
Radio frequency identification (RFID) technology is the most effective automated object identification solution in today’s product markets. Among the enormous applications of RFID technology, In-mold labeled (IML) RFID tags are becoming very popular as it provides identification to the tags from the initial stage of production. In the manufacturing process of IML RFID tags, high temperature melted plastic is injected into a mold where the RFID tag is placed beforehand. After injection, the plastic gets cold within a few seconds, and the product comes out with RFID tags in the shape of the mold. Due to this large temperature variation, the RFID tags get bumps or wrinkles. As a result of the uneven outlook, the customers reject these RFID tags, which is not cost-effective in production.
This study first attempts to find the root causes with the simulation and experiments to solve this problem. One possible reason for the wrinkled RFID tag can be uneven heat distribution on the antenna conductor. To verify this hypothesis, there are several steps have been taken including, (i) simulation of antennas, (ii) different mesh to decrease the conductor of the antenna without affecting its performance, (iii) prototyped antennas are tested with IML. The second potential cause of this problem is the inconsistency of the material properties (e.g., how a material behaves under high-temperature variation) of the multi-layer structure of the antenna. To verify the second hypothesis, different materials are used as antenna elements and substrates to overcome the wrinkling problem. The finalized antenna versions are sent to Tampere University’s polymer laboratory to produce IML samples to analyze the solution.
As a result of this thesis, it is demonstrated that changing the antenna design has no influence on the temperature distribution of the IML process. Wrinkles emerge whether conductive materials are present or not. The key to resolving the wrinkling problem is to use the proper material type. Although the design adjustment has no influence on the wrinkling process, it becomes an environmentally friendly antenna with less conductive inks and a cost-effective solution.
This study first attempts to find the root causes with the simulation and experiments to solve this problem. One possible reason for the wrinkled RFID tag can be uneven heat distribution on the antenna conductor. To verify this hypothesis, there are several steps have been taken including, (i) simulation of antennas, (ii) different mesh to decrease the conductor of the antenna without affecting its performance, (iii) prototyped antennas are tested with IML. The second potential cause of this problem is the inconsistency of the material properties (e.g., how a material behaves under high-temperature variation) of the multi-layer structure of the antenna. To verify the second hypothesis, different materials are used as antenna elements and substrates to overcome the wrinkling problem. The finalized antenna versions are sent to Tampere University’s polymer laboratory to produce IML samples to analyze the solution.
As a result of this thesis, it is demonstrated that changing the antenna design has no influence on the temperature distribution of the IML process. Wrinkles emerge whether conductive materials are present or not. The key to resolving the wrinkling problem is to use the proper material type. Although the design adjustment has no influence on the wrinkling process, it becomes an environmentally friendly antenna with less conductive inks and a cost-effective solution.