Sharif, Mohamad Fikri Mohd (2018) A Study On Thermoforming Process Of Stretchable Circuit And Its Performance In Manufacturing Of Automotive Lighting. Masters thesis, Universiti Sains Malaysia.
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Abstract
Litar tercetak telah berkembang bermula daripada papan litar tercetak ke litar fleksibel dan peranti acuan sambung (MID). Evolusi litar jenis-jenis ini adalah disebabkan oleh batasan dan permintaan yang tinggi terhadap reka bentuk litar kompleks bagi memenuhi kehendak pelanggan. Walau bagaimanapun, proses pembuatan MID memerlukan proses yang kompleks kerana melibatkan peralatan yang maju seperti mesin laser untuk menghasilkan litar tercetak di atas bahagian 3-D. Dalam kajian ini, proses pembuatan alternatif diperkenalkan untuk membina litar-litar berfungsi menggunakan dakwat boleh diregang yang dicetak pada substrat 2-D dan kemudian dijelmakan kepada bentuk 3-D melalui proses termopembentukan. Satu produk lampu bahagian belakang kereta kebangsaan dipilih sebagai produk rujukan. Acuan untuk proses pembentukan termo dibuat berdasarkan kaedah kejuruteraan terbalik yang mana dimensi bahagian lampu diukur menggunakan mesin pengukur koordinat (MPK) dan kemudian dipindahkan ke dalam lukisan 3-D menggunakan perisian Solidworks. Lukisan itu dibaca oleh mesin kawalan berangka berkomputer (KBC) melalui kod yang dihasilkan oleh pembuatan berbantu komputer (PBK) untuk menghasilkan acuan. Dakwat pada mulanya dicetak pada substrak termoplastik yang rata menggunakan teknik percetakan skrin. Dakwat tercetak dirawat di bawah 120oC selama 30 minit di dalam ketuhar untuk membentuk litar berkonduktif tinggi. Litar dengan substrat telah dijelmakan kepada bentuk 3-D melalui proses pembentukan termo mengikut bentuk acuan yang direka serupa dengan reka bentuk lampu automotif sedia ada. Kemudian, diod pemancar cahaya (LED) dipasang pada litar dengan mendispenskan perekat konduktif pada sambungan LED dan dirawat sekali lagi pada 120oC selama 10 minit untuk membentuk ikatan yang kuat pada sambungan LED. Prestasi mekanikal dan elektrik lampu automotif reka bentuk baru dicirikan dan dibandingkan dengan reka bentuk sedia ada menggunakan peralatan seperti meter pelbagai, probe empat titik, spektrometer, mikroskop elekron pengimbas (MEP) dan mesin ujian universal. Walaupun litar reka bentuk baru telah meregang dan berubah bentuk yang membawa kepada pertambahan rintangan litar, prestasi elektriknya menunjukkan hasil yang menjanjikan. Tidak terdapat perbezaan yang ketara antara reka bentuk baru dan reka bentuk sedia ada lampu automotif dari segi penggunaan kuasa oleh sistem dan fluks bercahaya LED. Proses pembuatan litar bercetak yang baru ini menawarkan kaedah alternatif masa depan dalam pembuatan produk lampu automotif. _______________________________________________________________________________________________________ Printed circuits have been developed started from printed circuit board to flexible circuit and moulded interconnect devices (MID). The evolution of these kinds of circuit is due to limitation and highly demand of complex circuit design to fulfil the requirements of customers. However, manufacturing process of MID requires complex process since it involves advance equipment such as laser machine to produce printed circuit on 3-D part. In this research, an alternative manufacturing process was introduced to construct functional circuits using stretchable ink printed onto 2-D substrate and then transformed into 3-D shape by thermoforming process. A rear lighting product of national car was chosen as a reference product. Mould for the thermoforming process was fabricated based on reversed engineering technique where the lighting part dimensions were measured using coordinate measuring machine (CMM) and then transferred into 3-D drawing using Solidworks. The drawing was read computer numerical control (CNC) machine through coding generated by computer aided manufacturing (CAM) to manufacture the mould. The ink was initially printed on a flat thermoplastic substrate using screen printing technique. The printed ink was cured under 120oC for 30 minutes in an oven to form a highly conductive circuit. The circuit with the substrate were transformed into 3-D shape through thermoforming process according to the shape of mould which was designed similar to the existing design of automotive lighting. Light emitting diode (LEDs) were then assembled on the circuit by dispensing conductive adhesive at the LEDs joints and cured again in the oven at 120oC for 10 minutes to form strong bonding at the joints. Mechanical and electrical performances of the new design of automotive lighting were characterised and compared with the existing design using equipment such as multimeter, four point probes, spectrometer, scanning electron microscopy (SEM) and universal testing machine. Even the circuit of the new design had stretched and deformed that led to increase in circuit resistance, its electrical performance shows promising results. There was no significant difference between new design and existing design of automotive lightings in terms of power consumption by the system and luminous flux of LEDs. This new manufacturing process of printed circuit offers a future alternative method in manufacturing the automotive lighting product.
| Item Type: | Thesis (Masters) |
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| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=4689 |
| Subjects: | T Technology T Technology > TJ Mechanical engineering and machinery > TJ210.2-211.47 Mechanical devices and figures. Automata. Ingenious mechanisms. Robots (General) |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Kimia (School of Chemical Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 12 Jun 2019 09:18 |
| Last Modified: | 12 Jun 2019 09:18 |
| URI: | http://eprints.usm.my/id/eprint/44571 |
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