Tanthauzo la high-frequency PCB board

Mkulu pafupipafupi bolodi amatanthauza makina amagetsi afupipafupi amagetsi, omwe amagwiritsidwa ntchito pafupipafupi (kuposa 300 MHZ pafupipafupi kapena kutalika kwake ndi ochepera 1 mita) ndi ma microwave (opitilira 3 GHZ pafupipafupi kapena kutalika kwake ndi ochepera 0.1 mita) m’munda wa PCB, ili pa microwave base copper clad yogwiritsa ntchito njira wamba zopangidwira zopangira board gawo la njirayi kapena kugwiritsa ntchito njira zakapangidwe kapadera ndikupanga ma board board. Mwambiri, ma board ofulumira kwambiri amatha kutanthauzidwa ngati mabwalo azizungulira omwe ali ndi mafupipafupi pamwamba pa 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. Mwachitsanzo, zida za gawo lapansi zimafunikira kukhala ndi magetsi abwino, kukhazikika kwamankhwala, ndikuwonjezereka kwamphamvu yamagetsi pazowonongeka za gawo lapansi ndizochepa kwambiri, chifukwa chake kufunikira kwa mbale yamafupipafupi kukuwonetsedwa.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Njira yopangira:

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) zakuthupi

Njira yopangira:

1. Kutsegula kwazinthu: Kanema woteteza ayenera kusungidwa kuti ateteze zokopa ndi mawonekedwe

2. Kubowola:

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

2.2 Aluminiyamu pepala ngati mbale yophimba, kenako gwiritsani ntchito 1mm wandiweyani amine mbale, imitsani mbale ya PTFE

2.3 Phulitsani fumbi mdzenje ndi mfuti yamlengalenga mutabowola

2.4 Ndi pakhola pobowola mosasunthika kwambiri, pobowola magawo (makamaka, dzenje laling’ono, liwiro lofikira, zing’onozing’ono za Chip, zocheperako ndi kubwerera)

3. Kukonzekera kwa dzenje

Chithandizo cha plasma kapena mankhwala a sodium-naphthalene activation ndi opindulitsa pakuwonjezera pores

4. PTH kumiza mkuwa

4.1 Pambuyo pochepetsa pang’ono (mulingo wazing’onozing’ono umayang’aniridwa ndi mainchesi 20), mbaleyo imadyetsedwa kuchokera kumphamvu yochotsa mafuta mu kukoka kwa 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:

Ndi matabwa PCB mkulu pafupipafupi ndi chiyani? PCB mkulu pafupipafupi mbale gulu

Kuthamanga kwapamwamba komanso mapepala othamanga kwambiri

Mukamasankha gawo la PCB pama circuits apamwamba, kulingalira kwapadera kuyenera kuperekedwa pamitundu yosiyana ya zinthu za DK pama frequency osiyanasiyana. 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. Makamaka pafupipafupi kuchokera ku L MHz mpaka L GHz, malingaliro awo a DK ndi DF amasintha kwambiri. 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. Pamwamba pa lGHz, mtengo wake wa DK umasintha pang’ono. 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.

The dielectric loss factor (DF) of the general substrate material is larger than that of DK due to the influence of frequency variation (especially in the high frequency range). Chifukwa chake, pofufuza momwe mafupipafupi amagwirira ntchito, tiyenera kuyang’ana pakusintha kwa mtengo wake wa DF. The substrate materials with high speed and high frequency characteristics are obviously different from the general substrate materials in terms of the variation characteristics at high frequency. One is that with the change of frequency, its (DF) value changes very little. Winawo ndi wofanana ndi gawo lonse lapansi lazinthu zosiyanasiyana, koma mtengo wake (DF) ndi wotsika.

How to choose high frequency high speed plate

Kusankhidwa kwa board ya PCB kuyenera kukwaniritsa zofunikira pakapangidwe, kupanga misa ndi mtengo wake pakati. 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.

Ndi matabwa PCB mkulu pafupipafupi ndi chiyani? PCB mkulu pafupipafupi mbale gulu

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. Umphumphu wa siginolo ya digito komanso kutsika kwa mapiri kumtunda ndi kutsika ndi chimodzimodzi ndi kutaya kocheperako komanso kufalikira kotsika kwa rf microwave (gawo lapafupipafupi la harmonic la chizindikiro cha digito limafika pagulu la microwave band). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

Ndi matabwa PCB mkulu pafupipafupi ndi chiyani? PCB mkulu pafupipafupi mbale gulu

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. Mvetsetsani zamagetsi, matenthedwe, kudalirika, ndi zina zambiri. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

Otsatirawa akuwunikiranso zifukwa zazikulu posankha mbale yoyenera:

1, kugulitsa:

Monga kugwira ntchito kochuluka, kutentha, CAF / kutentha kutentha komanso kulimba kwamakina (mamasukidwe akayendedwe) (kudalirika kwabwino), kuchuluka kwamoto;

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

Kutaya kochepa, magawo a Dk / Df okhazikika, kupezeka kotsika, koyefishienti yaying’ono yosinthasintha pafupipafupi komanso chilengedwe, kulolerana pang’ono kwakuthupi ndi mphira (kuyendetsa bwino kwa impedance), ngati waya uli wautali, ganizirani zojambulazo zazing’ono zamkuwa. In addition, simulation is needed in the early stage of high-speed circuit design, and simulation results are the reference standard for design. “Xingsen Technology – Agilent (othamanga kwambiri / ma RADIO pafupipafupi) labotale yolumikizana” yathetsa vuto la magwiridwe antchito pazotsatira zoyeserera zosagwirizana ndi mayeso, ndipo adachita zofanizira zambiri komanso kutsimikizira kwamayeso oyeserera, kudzera njira yapadera yokwaniritsira kusasinthasintha kwa kuyerekeza ndi kuyeza.

Ndi matabwa PCB mkulu pafupipafupi ndi chiyani? PCB mkulu pafupipafupi mbale gulu

3. Kupezeka kwa zinthu panthawi yake:

Many high-frequency plate procurement cycle is very long, even 2-3 months; 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. Zinthu zofunika:

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.

Kugwirizana ndi malamulo azachilengedwe m’maiko osiyanasiyana ndikukwaniritsa zofunikira za RoHS komanso zopanda halogen.

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. Mbale yoyenda ndi kutayika kwapakatikati komanso kotsika ndiyoyenera dera la digito la 10Gb / S; The plate with lower loss is suitable for 25Gb/s digital circuit; Mapanelo okhala ndi zotayika kwambiri amakhala ndi ma circuits othamanga kwambiri, othamanga kwambiri pamitengo ya 50Gb / s kapena kupitilira apo.

From the material Df:

Df pakati pa 0.01 ~ 0.005 board board yoyenerera malire apamwamba a 10Gb / S;

Df pakati pa 0.005 ~ 0.003 board board yoyenerera malire apamwamba a 25Gb / S;

Circuit boards with Df not more than 0.0015 are suitable for 50Gb/S or higher speed digital circuits.

Commonly used high-speed plates are:

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

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

3), Panasonic: Megtron4, Megtron6, etc

4), Isola: FR408HR, IS620, IS680, ndi zina

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

6), Dongguan Shengyi, Taizhou Wangling, Taixing mayikirowevu, etc.