Application of laser processing technology in tablo sikwi fleksib

Segondè dansite tablo sikwi fleksib se yon pati nan tablo a sikwi antye fleksib, ki se jeneralman defini kòm liy lan espas mwens pase 200 μ M oswa mikwo atravè mwens pase 250 μ M tablo sikwi fleksib. Segondè dansite tablo sikwi fleksib gen yon pakèt aplikasyon pou, tankou telekominikasyon, òdinatè, sikwi entegre ak ekipman medikal. Vize nan pwopriyete yo espesyal nan materyèl tablo sikwi fleksib, papye sa a entwodui kèk pwoblèm kle yo dwe konsidere nan pwosesis lazè nan segondè-dansite tablo sikwi fleksib ak mikwo atravè perçage p>

The unique characteristics of flexible circuit board make it an alternative to rigid circuit board and traditional wiring scheme in many occasions. At the same time, it also promotes the development of many new fields. The fastest growing part of FPC is the internal connection line of computer hard disk drive (HDD). The magnetic head of the hard disk shall move back and forth on the rotating disk for scanning, and the flexible circuit can be used to replace the wire to realize the connection between the mobile magnetic head and the control circuit board. Hard disk manufacturers increase production and reduce assembly costs through a technology called “suspended flexible plate” (FOS). In addition, wireless suspension technology has better seismic resistance and can improve product reliability. Another high-density flexible circuit board used in hard disk is interposer flex, which is used between suspension and controller.

Dezyèm jaden k ap grandi nan FPC se nouvo anbalaj sikwi entegre. Sikwi fleksib yo te itilize nan nivo chip anbalaj (CSP), milti chip modil (MCM) ak chip sou tablo sikwi fleksib (COF). Pami yo, CSP sikwi entèn gen yon mache gwo, paske li ka itilize nan aparèy semi-conducteurs ak memwa flash, epi li lajman ki itilize nan kat PCMCIA, kondui disk, pèsonèl asistan dijital (PDAs), telefòn mobil, pager Kamera dijital ak kamera dijital. . Anplis de sa, ekspozisyon kristal likid (LCD), switch fim Polyester ak lank-jè katouch enprimant yo se lòt twa jaden aplikasyon kwasans segondè nan tablo sikwi segondè-dansite fleksib \

The market potential of flexible line technology in portable devices (such as mobile phones) is very large, which is very natural, because these devices require small volume and light weight to meet the needs of consumers; In addition, the latest applications of flexible technology include flat panel displays and medical devices, which can be used by designers to reduce the volume and weight of products such as hearing aids and human implants.

Gwo kwasans lan nan jaden ki anwo yo te mennen nan yon ogmantasyon nan pwodiksyon mondyal la nan tablo sikwi fleksib. Pou egzanp, volim lavant anyèl la nan disk difisil espere yo rive jwenn 345 milyon inite nan 2004, prèske de fwa sa yo ki an 1999, ak volim nan lavant nan telefòn mobil an 2005 se konsèvativman estime yo dwe 600 milyon inite. Ogmantasyon sa yo mennen nan yon ogmantasyon anyèl de 35% nan pwodiksyon an nan gwo dansite tablo sikwi fleksib, rive nan 3.5 milyon mèt kare pa 2002. Sa yo demann pwodiksyon segondè mande pou efikas ak pri ki ba-teknoloji pwosesis, ak teknoloji pwosesis lazè se youn nan yo .

Laser has three main functions in the manufacturing process of flexible circuit board: processing and forming (cutting and cutting), slicing and drilling. As a non-contact machining tool, laser can be used in a very small focus (100 ~ 500) μ m) High intensity light energy (650MW / mm2) is applied to the material. Such high energy can be used for cutting, drilling, marking, welding, marking and other processing. The processing speed and quality are related to the properties of the processed material and the laser characteristics used, such as wavelength, energy density, peak power, pulse width and frequency. The processing of flexible circuit board uses ultraviolet (UV) and far infrared (FIR) lasers. The former usually uses excimer or UV diode pumped solid-state (uv-dpss) lasers, while the latter generally uses sealed CO2 lasers div>

Teknoloji optik vektè itilize òdinatè pou kontwole glas la ekipe ak mèt koule ak lojisyèl CAD / CAM jenere koupe ak perçage grafik, epi li itilize sistèm lantiy telentrik pou asire ke lazè a klere vètikal sou sifas materyo a </ div>

Forage lazè pwosesis gen gwo presizyon ak aplikasyon lajè. Li se yon zouti ideyal pou fòme tablo sikwi fleksib. Kit lazè CO2 oswa lazè DPSS, materyèl la ka trete nan nenpòt fòm apre konsantre. Li tire gwo bout bwa a lazè konsantre nenpòt kote sou sifas la materyo pa enstale yon glas sou galvanomèt la, Lè sa a, pote soti òdinatè nimerik kontwòl (CNC) sou galvanomèt la lè l sèvi avèk vektè optik teknoloji, epi fè koupe grafik avèk èd nan lojisyèl CAD / CAM. Sa a “zouti mou” ka byen fasil kontwole lazè a nan tan reyèl lè se konsepsyon an chanje. Pa ajiste kontraksyon an limyè ak zouti koupe divès kalite, pwosesis lazè ka avèk presizyon repwodwi grafik yo ki konsepsyon, ki se yon lòt avantaj enpòtan.

Vector scanning can cut substrates such as polyimide film, cut out the whole circuit or remove an area on the circuit board, such as a slot or a block. In the process of processing and forming, the laser beam is always turned on when the mirror scans the whole processing surface, which is opposite to the drilling process. During drilling, the laser is turned on only after the mirror is fixed at each drilling position div>

seksyon

“Slicing” in jargon is the process of removing one layer of material from another with a laser. This process is more suitable for laser. The same vector scanning technology can be used to remove the dielectric and expose the conductive pad below. At this time, the high precision of laser processing once again reflects great benefits. Since FIR laser rays will be reflected by copper foil, CO2 laser is usually used here.

fè egzèsis twou

Malgre ke kèk kote toujou itilize perçage mekanik, Stamping oswa grave plasma yo fòme mikwo nan twou, perçage lazè se toujou mikwo ki pi lajman itilize nan twou fòme metòd nan tablo sikwi fleksib, sitou paske nan pwodiktivite segondè li yo, fò fleksibilite ak tan operasyon tan long .

Mekanik perçage ak Stamping adopte-wo presizyon Bits egzèsis ak mouri, ki ka fèt sou tablo a sikwi fleksib ak yon dyamèt prèske 250 μ M, men aparèy sa yo-wo presizyon yo trè chè epi yo gen yon lavi sèvis relativman kout. Akòz gwo-dansite tablo sikwi fleksib la, rapò ouvèti ki nesesè a se 250 μ M piti, kidonk perçage mekanik pa favorize.

Plasma etching can be used at 50 μ M thick polyimide film substrate with a size less than 100 μ M, but the equipment investment and process cost are quite high, and the maintenance cost of plasma etching process is also very high, especially the costs related to some chemical waste treatment and consumables. In addition, it takes quite a long time for plasma etching to make consistent and reliable micro vias when establishing a new process. The advantage of this process is high reliability. It is reported that the qualified rate of micro via is 98%. Therefore, plasma etching still has a certain market in medical and avionics equipment div>

In contrast, the fabrication of micro vias by laser is a simple and low-cost process. The investment of laser equipment is very low, and laser is a non-contact tool. Unlike mechanical drilling, there will be an expensive tool replacement cost. In addition, modern sealed CO2 and uv-dpss lasers are maintenance free, which can minimize downtime and greatly improve productivity.

Metòd la nan jenere mikro vias sou tablo sikwi fleksib se menm bagay la kòm sa yo ki sou PCB rijid, men kèk paramèt enpòtan nan lazè bezwen chanje akòz diferans lan nan substra ak epesè. CO2 sele ak lazer UV-dpss ka itilize menm teknoloji optik vektè tankou bòdi pou fè egzèsis dirèkteman sou tablo sikwi fleksib la. Sèl diferans lan se ke lojisyèl aplikasyon an perçage ap fèmen lazè a pandan optik la glas optik soti nan yon mikwo atravè yon lòt. Travès lazè a pa pral vire sou jiskaske li rive nan yon lòt pozisyon perçage. Yo nan lòd yo fè twou a pèpandikilè ak sifas la nan substrate nan tablo sikwi fleksib, gwo bout bwa a lazè dwe klere vètikal sou substra a tablo sikwi, ki ka reyalize lè l sèvi avèk yon sistèm lantiy telentrik ant glas la optik ak substra a (figi 2). ) div>

Holes drilled on Kapton using UV laser

CO2 laser can also use conformal mask technology to drill micro vias. When using this technology, the copper surface is used as a mask, the holes are etched on it by ordinary printing etching method, and then the CO2 laser beam is irradiated on the holes of the copper foil to remove the exposed dielectric materials.

Mikwo vias kapab fèt tou lè l sèvi avèk lazè excimer atravè metòd la nan pwojeksyon mask. Teknoloji sa a bezwen kat jeyografik imaj la nan yon mikwo atravè oswa mikwo antye atravè etalaj substra a, ak Lè sa a, gwo bout bwa a lazè excimer iradyasyon mask la kat imaj la mask nan sifas la substra, konsa tankou fè egzèsis twou a. Bon jan kalite a nan perçage lazè excimer se trè bon. Dezavantaj li yo se vitès ki ba ak pri segondè.

Seleksyon lazè byenke kalite lazè pou trete tablo sikwi fleksib se menm bagay la kòm sa pou trete PCB rijid, diferans lan nan materyèl ak epesè pral anpil afekte paramèt yo pwosesis ak vitès. Pafwa lazè excimer ak transverse eksite gaz (te) CO2 lazè ka itilize, men de metòd sa yo gen vitès dousman ak pri antretyen segondè, ki limite amelyorasyon nan pwodiktivite. Nan konparezon, CO2 ak UV-dpss lazè yo lajman itilize, vit ak pri ki ba, kidonk yo sitou itilize nan fabwikasyon ak pwosesis nan mikro vias nan tablo sikwi fleksib.

Different from gas flow CO2 laser, sealed CO2 laser（ http://www.auto-alt.cn ）The block release technology is adopted to limit the laser gas mixture to the laser cavity specified by two rectangular electrode plates. The laser cavity is sealed during the whole service life (usually about 2 ~ 3 years). The sealed laser cavity has compact structure and does not need air exchange. The laser head can work continuously for more than 25000 hours without maintenance. The biggest advantage of the sealing design is that it can generate fast pulses. For example, the block release laser can emit high-frequency (100kHz) pulses with a power peak of 1.5KW. With high frequency and high peak power, rapid machining can be carried out without any thermal degradation div>

Uv-dpss laser is a solid-state device that continuously sucks neodymium vanadate (Nd: YVO4) crystal rod with laser diode array. It generates pulse output by an acousto-optic Q-switch, and uses the third harmonic crystal generator to change the output of Nd: YVO4 laser from 1064nm & nbsp; The IR basic wavelength is reduced to 355 nm UV wavelength. Generally 355nm < / div >

Pouvwa pwodiksyon an mwayèn nan lazè UV-dpss nan 20kHz pousantaj repetisyon nominal batman kè se pi plis pase 3W div>

UV-dpss lazè

Tou de Dielectric ak kòb kwiv mete ka fasil absòbe UV-dpss lazè ak pwodiksyon longèdonn nan 355nm. UV-dpss lazè gen pi piti plas limyè ak pi ba pouvwa pwodiksyon pase lazè CO2. Nan pwosesis la nan pwosesis Dielectric, lazè UV-dpss anjeneral yo itilize pou ti gwosè (mwens pase 50%) μ m) Se poutèt sa, dyamèt la mwens pase 50 yo ta dwe trete sou substra a nan segondè-dansite tablo sikwi fleksib μ M mikwo atravè , lè l sèvi avèk lazè UV trè ideyal. Koulye a, gen yon lazè segondè-pouvwa UV-dpss, sa ki ka ogmante pwosesis la ak vitès perçage nan UV-dpss lazè div>

Avantaj nan lazè uv-dpss se ke lè foton UV-wo enèji li yo klere sou pifò kouch sifas ki pa metalik, yo ka dirèkteman kraze lyen an nan molekil, lis kwen an koupe ak pwosesis “frèt” litografi, ak minimize degre nan domaj tèmik ak boule. Se poutèt sa, UV mikwo koupe se apwopriye pou okazyon demann segondè kote pòs-tretman enposib oswa nesesè div>

CO2 lazè (altènativ Otomatik)

Sealed CO2 laser can emit a wavelength of 10.6 μ M or 9.4 μ M FIR laser, although both wavelengths are easy to be absorbed by dielectrics such as polyimide film substrate, the research shows that 9.4 μ The effect of M wavelength processing this kind of material is much better. Dielectric 9.4 μ The absorption coefficient of M wavelength is higher, which is better than 10.6 for drilling or cutting materials μ M wavelength fast. nine point four μ M laser not only has obvious advantages in drilling and cutting, but also has outstanding slicing effect. Therefore, the use of shorter wavelength laser can improve productivity and quality.

Generally speaking, fir wavelength is easily absorbed by dielectrics, but it will be reflected back by copper. Therefore, most CO2 lasers are used for dielectric processing, molding, slicing and delamination of dielectric substrate and laminate. Because the output power of CO2 laser is higher than that of DPSS laser, CO2 laser is used to process dielectric in most cases. CO2 laser and uv-dpss laser are often used together. For example, when drilling micro vias, first remove the copper layer with DPSS laser, and then quickly drill holes in the dielectric layer with CO2 laser until the next copper clad layer appears, and then repeat the process.

Because the wavelength of UV laser itself is very short, the light spot emitted by UV laser is finer than that of CO2 laser, but in some applications, the large-diameter light spot produced by CO2 laser is more useful than uv-dpss laser. For example, cut large area materials such as grooves and blocks or drill large holes (diameter greater than 50) μ m) It takes less time to process with CO2 laser. Generally speaking, the aperture ratio is 50 μ When m is large, CO2 laser processing is more appropriate, and the aperture is less than 50 μ M, the effect of uv-dpss laser is better.