Itumọ ti high-frequency PCB board

Igbimọ igbohunsafẹfẹ giga n tọka si igbimọ Circuit igbohunsafẹfẹ itanna pataki, ti a lo ni igbohunsafẹfẹ giga (o tobi ju 300 MHZ igbohunsafẹfẹ tabi igbi wa kere ju mita 1) ati makirowefu (ti o tobi ju igbohunsafẹfẹ 3 GHZ tabi igbi -omi jẹ kere ju awọn mita 0.1) ni aaye ti PCB, wa lori agbada microwave mimọ agbada agbelẹrọ lilo ọna iṣelọpọ ọkọ igbimọ alakikanju ti o wọpọ ti apakan ti ilana tabi lilo awọn ọna ṣiṣe pataki ati iṣelọpọ awọn igbimọ Circuit. Ni gbogbogbo, awọn igbimọ igbohunsafẹfẹ giga le ṣe asọye bi awọn igbimọ Circuit pẹlu awọn igbohunsafẹfẹ loke 1GHz.

With the rapid development of science and technology, more and more equipment design is in the microwave band (> 1GHZ) and even with the millimeter wave field (30GHZ) above the application, which also means that the frequency is higher and higher, the substrate of the circuit board requirements are also higher and higher. Fun apẹẹrẹ, awọn ohun elo sobusitireti nilo lati ni awọn ohun -ini itanna ti o tayọ, iduroṣinṣin kemikali to dara, pẹlu ilosoke ti igbohunsafẹfẹ ifihan agbara ni awọn ibeere pipadanu sobusitireti kere pupọ, nitorinaa pataki ti awo igbohunsafẹfẹ giga ti wa ni afihan.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Ọna ilana:

And epoxy resin/glass woven cloth (FR4) similar processing process, but the plate is more brittle, easy to break, drilling and gong plate drill nozzle and gong knife life is reduced by 20%.

2. PTFE (polytetrafluoroethylene) ohun elo

Ọna ilana:

1. Ṣiṣi ohun elo: fiimu aabo gbọdọ wa ni idaduro lati yago fun awọn eegun ati ifisinu

2. liluho:

2.1 use a new drill (standard 130), one piece stacked is the best, the presser foot pressure is 40psi

2.2 Aluminiomu dì bi awo ideri, lẹhinna lo awo 1mm ipon amine, mu awo PTFE pọ

2.3 Fẹ eruku lati inu iho pẹlu ibon afẹfẹ lẹhin liluho

2.4 Pẹlu ohun elo liluho iduroṣinṣin julọ, awọn aye liluho (ni ipilẹ, iho ti o kere ju, yiyara liluho lilu, fifuye Chip ti o kere, kere si oṣuwọn ipadabọ)

3. Isise iho

Itọju pilasima tabi iṣuu soda – itọju ifisilẹ naphthalene jẹ anfani si iṣelọpọ ti awọn pores

4. PTH rii idẹ

4.1 Lẹhin ti micro-etching (oṣuwọn micro-etching ti ni iṣakoso nipasẹ 20 micro-inches), awo naa jẹ lati inu silinda yiyọ epo ni fifa PTH

4.2 If necessary, go through the second PTH, just from the forecast? The cylinder began to enter the plate

5. The resistance welding

5.1 Pre-treatment: use acid washing plate instead of mechanical grinding plate

5.2 After pre-treatment, bake plate (90℃, 30min), brush green oil and cure

5.3 Three baking plates: one is 80℃, 100℃ and 150℃ for 30min each (if oil is found on the substrate surface, it can be reworked: wash off the green oil and reactivate it)

6. Gong board

Lay the white paper on the PTFE board circuit surface, and clamp it with fr-4 base plate or phenolic base plate with a thickness of 1.0mm and copper removal: As shown in the figure:

Kini awọn igbimọ igbohunsafẹfẹ giga ti PCB? PCB ga igbohunsafẹfẹ awo classification

Iwọn igbohunsafẹfẹ giga ati ohun elo dì iyara to gaju

Nigbati yiyan sobusitireti fun PCB fun awọn iyika igbohunsafẹfẹ giga, iṣaro pataki yẹ ki o fun awọn abuda iyatọ ti DK ohun elo ni awọn igbohunsafẹfẹ oriṣiriṣi. For the requirements of signal high-speed transmission or characteristic impedance control, DF and its performance under the conditions of frequency, temperature and humidity are mainly investigated.

Under the condition of frequency variation, the DK and DF values of general substrate materials change greatly. Paapa ni iwọn igbohunsafẹfẹ lati L MHz si L GHz, awọn iye DK ati DF wọn yipada diẹ sii han gedegbe. For example, the GENERAL epoxy – glass fiber substrate material (general FR-4) has a DK value of 4.7 at lMHz and a DK value of 4.19 at lGHz. Loke lGHz, iye DK rẹ yipada ni rọra. For example, under l0GHz, the DK value of FR-4 is 4.15. For substrate materials with high speed and high frequency characteristics, the DK value changes slightly. From lMHz to lGHz, the DK value mostly stays within 0.02 range. The DK value tends to decrease slightly at different frequencies from low to high.

Ifosiwewe pipadanu aisi -itanna (DF) ti ohun elo sobusitireti gbogbogbo tobi ju ti DK nitori ipa ti iyatọ igbohunsafẹfẹ (ni pataki ni sakani igbohunsafẹfẹ giga). Nitorinaa, nigba iṣiro awọn abuda igbohunsafẹfẹ giga ti ohun elo sobusitireti, o yẹ ki a dojukọ lori iyipada ti iye DF rẹ. Awọn ohun elo sobusitireti pẹlu iyara to ga ati awọn abuda igbohunsafẹfẹ giga ni o han gbangba yatọ si awọn ohun elo sobusitireti gbogbogbo ni awọn ofin ti awọn abuda iyatọ ni igbohunsafẹfẹ giga. Ọkan ni pe pẹlu iyipada igbohunsafẹfẹ, iye rẹ (DF) yipada pupọ diẹ. Omiiran jẹ iru si ohun elo sobusitireti gbogbogbo ni sakani iyatọ, ṣugbọn iye tirẹ (DF) jẹ kekere.

How to choose high frequency high speed plate

Aṣayan igbimọ PCB gbọdọ pade awọn ibeere apẹrẹ, iṣelọpọ ibi ati idiyele ti iwọntunwọnsi laarin. In short, the design requirements consist of two components: electrical and structural reliability. This is usually important when designing very high speed PCB boards (frequencies greater than GHz). For example, the fr-4 material commonly used today may not be applicable due to its large Df (Dielectricloss) at several GHz frequencies.

Kini awọn igbimọ igbohunsafẹfẹ giga ti PCB? PCB ga igbohunsafẹfẹ awo classification

For example, a 10Gb/S high-speed digital signal is a square wave, which can be regarded as a superposition of sinusoidal signals of different frequencies. Therefore, 10Gb/S contains many different frequency signals: 5Ghz fundamental signal, 3 order 15GHz, 5 order 25GHz, 7 order 35GHz signal, etc. Iduroṣinṣin ti ami oni -nọmba ati giga ti awọn oke ati isalẹ awọn ẹgbẹ jẹ kanna bi pipadanu kekere ati gbigbe ipalọlọ kekere ti microwave rf (apakan irẹpọ igbohunsafẹfẹ giga ti ami oni -nọmba de ẹgbẹ microwave). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

Kini awọn igbimọ igbohunsafẹfẹ giga ti PCB? PCB ga igbohunsafẹfẹ awo classification

In practical engineering operations, the selection of high-frequency plates seems simple, but there are still many factors to be considered. Through the introduction of this paper, AS a PCB design engineer or a high-speed project leader, I have a certain understanding of the characteristics and selection of plates. Loye awọn ohun -ini itanna, awọn ohun -ini igbona, igbẹkẹle, abbl. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

Awọn atẹle yoo ṣafihan awọn ifosiwewe akọkọ lati gbero ni yiyan awo ti o yẹ:

1, iṣelọpọ:

Bii iṣẹ titẹ pupọ, iṣẹ iwọn otutu, CAF/ resistance ooru ati lile ẹrọ (viscosity) (igbẹkẹle to dara), iwọn ina;

2, with the product matching performance (electrical, performance stability, etc.) :

Isonu kekere, iduroṣinṣin Dk/Df iduroṣinṣin, pipinka kekere, isodipupo iyipada kekere pẹlu igbohunsafẹfẹ ati agbegbe, ifarada kekere ti sisanra ohun elo ati akoonu roba (iṣakoso ikọlu ti o dara), ti okun waya ba gun, ro pe o jẹ ailagbara kekere ti idẹ. In addition, simulation is needed in the early stage of high-speed circuit design, and simulation results are the reference standard for design. “Imọ-ẹrọ Xingsen-Agilent (iyara to gaju/igbohunsafẹfẹ RADIO) yàrá apapọ” yanju iṣoro iṣẹ ti awọn abajade kikopa aiṣedeede ati awọn idanwo, ati ṣe nọmba nla ti kikopa ati idanwo gangan pipade-lupu, nipasẹ ọna alailẹgbẹ lati ṣaṣeyọri iduroṣinṣin ti kikopa ati wiwọn.

Kini awọn igbimọ igbohunsafẹfẹ giga ti PCB? PCB ga igbohunsafẹfẹ awo classification

3. Wiwa awọn ohun elo ni akoko:

Ọpọlọpọ iyipo rira awo-igbohunsafẹfẹ giga jẹ gigun pupọ, paapaa awọn oṣu 2-3; In addition to the conventional high frequency plate RO4350 has inventory, many high frequency plates need to be provided by customers. Therefore, high frequency plate and manufacturers need to communicate well in advance, as soon as possible;

4. Awọn idiyele idiyele:

Depending on the price sensitivity of the product, whether it is a consumer product, or a telecommunications, medical, industrial, military application;

5. Applicability of laws and regulations, etc.

Lati wa ni ibamu pẹlu awọn ilana ayika ti awọn orilẹ-ede oriṣiriṣi ati pade awọn ibeere ti RoHS ati halogen-ọfẹ.

Among the above factors, the running speed of high-speed digital circuit is the main factor to consider in PCB selection. The higher the circuit speed, the smaller the selected PCBDf value should be. Awo Circuit pẹlu alabọde ati pipadanu kekere yoo dara fun Circuit oni nọmba 10Gb/S; Awo pẹlu pipadanu kekere jẹ o dara fun Circuit oni nọmba 25Gb/s; Awọn panẹli pẹlu pipadanu kekere-kekere yoo gba yiyara, awọn iyika oni-nọmba ti o ni iyara ni awọn oṣuwọn ti 50Gb/s tabi ga julọ.

Lati ohun elo Df:

Df laarin 0.01 ~ 0.005 igbimọ Circuit ti o dara fun opin oke ti Circuit oni nọmba 10Gb/S;

Df laarin 0.005 ~ 0.003 igbimọ Circuit ti o dara fun opin oke ti Circuit oni nọmba 25Gb/S;

Awọn igbimọ Circuit pẹlu Df ko ju 0.0015 jẹ o dara fun 50Gb/S tabi awọn iyika oni nọmba iyara to ga julọ.

Awọn abọ iyara giga ti a lo nigbagbogbo jẹ:

1), Rogers: RO4003, RO3003, RO4350, RO5880, abbl

2), Taiyao TUC: Tuc862, 872SLK, 883, 933, abbl

3), Panasonic: Megtron4, Megtron6, abbl

4), Isola: FR408HR, IS620, IS680, abbl

5) Nelco: N4000-13, N4000-13EPSI, abbl

6), Dongguan Shengyi, Taizhou Wangling, Taixing Makirowefu, ati bẹbẹ lọ