Qeexitaanka high-frequency PCB board

Guddiga soo noqnoqda ee sare wuxuu loola jeedaa guddiga wareegga soo noqnoqda elektromagnetic -ga gaarka ah, oo loo isticmaalo soo noqnoqoshada sare (in ka badan 300 MHZ soo noqnoqoshada ama dhererka hirarka ayaa ka yar 1 mitir) iyo microwave (in ka badan 3 GHZ soo noqnoqoshada ama dhererka hirarka ayaa ka yar 0.1 mitir) PCB, wuxuu ku yaal makiinada microwave saldhigga naxaasiga ah iyadoo la adeegsanayo habka wax soo saarka guddiga wareegga caadiga ah ee qayb ka mid ah geeddi -socodka ama adeegsiga hababka wax -qabadka ee gaarka ah iyo soo -saarka guddiyada wareegga. Guud ahaan, looxyada aadka u soo noqnoqda waxaa lagu qeexi karaa guddiyada wareegga oo leh soo noqnoqosho ka sarreysa 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. Tusaale ahaan, alaabta substrate -ku waxay u baahan yihiin inay lahaadaan sifooyin koronto oo aad u fiican, xasilooni kiimiko oo wanaagsan, iyadoo kororka soo noqnoqoshada signalada korontada ee shuruudaha luminta substrate -ka ay aad u yar yihiin, sidaa darteed muhiimadda saxanka soo noqnoqoshada sare ayaa la muujiyey.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Habka Processing:

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) wax

Habka Processing:

1. Furitaanka maaddada: filim ilaalin ah waa in la hayaa si looga hortago xoqidda iyo soo -gelinta

2. Layliga:

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

2.2 Xaashida Aluminiumka oo ah saxan dabool leh, ka dibna isticmaal saxan amine cufan 1mm, adkee saxanka PTFE -ka

2.3 Boorka ha ku afuufo qori hawo ka dib qodista

2.4 Iyada oo leh xarkada qoditaanka ugu xasilloon, xuduudaha qodista (asal ahaan, godka yar, sida ugu dhakhsaha badan qodista qodista, culeyska Chip -ka yar, heerka soo -noqoshada yar)

3. Habaynta daloolka

Daaweynta Plasma ama daaweynta firfircoonaanta naphthalene waxay waxtar u leedahay biraha daloolada

4. PTH waxay ku dhejisaa naxaas

4.1 Ka-dib-u-xoqidda (heerka qallajinta micro-ga ayaa lagu xakameeyay 20 micro-inji), saxanka waxaa laga quudiyaa saliidda ka qaadaysa dhululuubka jiidista 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:

Waa maxay guddiyada soo noqnoqda ee PCB? PCB kala soocidda saxanka soo noqnoqoshada sare

Soo noqnoqoshada sare iyo wax xaashida xawaaraha sare leh

Markaad dooranayso substrate -ka PCB ee wareegyada soo noqnoqoshada sare, tixgelin gaar ah waa in la siiyaa astaamaha kala -duwanaanta ee maaddada DK ee soo noqnoqoshada kala duwan. 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. Gaar ahaan inta jeer ee u dhexaysa L MHz ilaa L GHz, qiimahooda DK iyo DF si cad bay isu beddelaan. 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. LGHz ka sarreeya, qiimaheeda DK si tartiib ah ayuu isu beddelaa. 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.

Qodobka luminta korontada (DF) ee maaddada guud ee substrate -ka ayaa ka weyn tan DK sababtuna tahay saamaynta kala duwanaanshaha soo noqnoqoshada (gaar ahaan xaddiga soo noqnoqoshada sare). Sidaa darteed, marka la qiimeynayo astaamaha soo noqnoqoshada sare ee maaddada substrate -ka, waa inaan diirada saarnaa isbeddelka qiimaheeda DF. Qalabka substrate -ka leh xawaaraha sare iyo astaamaha soo noqnoqoshada sare ayaa iska cad inay ka duwan yihiin agabyada substrate -ka guud ahaan marka la eego astaamaha kala duwanaanshaha ee soo noqnoqoshada sare. Mid waa marka la beddelo soo noqnoqoshada, qiimaheeda (DF) aad bay u yar tahay. Midda kale waxay la mid tahay agabka guud ee ku jira kala duwanaanshaha, laakiin qiimaheeda (DF) ayaa ka hooseeya.

How to choose high frequency high speed plate

Xulashada guddiga PCB waa inay buuxiyaan shuruudaha naqshadeynta, wax soo saarka ballaaran iyo qiimaha dheelitirka u dhexeeya. 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.

Waa maxay guddiyada soo noqnoqda ee PCB? PCB kala soocidda saxanka soo noqnoqoshada sare

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. Dhawrsanaanta signalada dhijitaalka ah iyo cidhiidhiga cidhifyada sare iyo kan hoose waxay la mid yihiin luminta hooseysa iyo gudbinta dhalanrog yar ee microwave rf (qaybta is -weydaarsiga aadka u sarreeya ee signalada dhijitaalka ah waxay gaarto kooxda microwave). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

Waa maxay guddiyada soo noqnoqda ee PCB? PCB kala soocidda saxanka soo noqnoqoshada sare

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. Fahmaan guryaha korontada, guryaha kuleylka, isku halaynta, iwm. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

Kuwa soo socda ayaa soo bandhigi doona qodobbada ugu waaweyn ee la tixgelinayo marka la dooranayo saxanka habboon:

1, wax -soo -saarka:

Sida waxqabadyo badan oo riixaya, waxqabadka heerkulka, CAF/ iska -caabbinta kulaylka iyo adkaanta farsamada (isku -kalsoonaanta), qiimeynta dabka;

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

Dhimasho hoose, xirmooyin Dk/Df oo deggan, kala -firidhnaan hooseeya, is -beddel yar oo is -beddel leh oo leh soo noqnoqosho iyo bay’ad, dulqaad yar oo dhumucda maaddada iyo waxyaabaha caagga ku jira (xakamaynta impedance wanaagsan), haddii siliggu dheer yahay, tixgeli biraha naxaasta oo aad u hooseeya. 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 (xawaare sare/soo noqnoqoshada RADIO) shaybaarka wadajirka ah” ayaa xalliyay dhibaatada waxqabadka natiijooyinka iyo tijaabooyinka jilitaanka ee aan is-waafaqsanayn, waxayna sameeyeen tiro badan oo jilitaan ah iyo tijaabinta dhabta ah ee xaqiijinta xir-xiran, iyada oo loo marayo hab gaar ah si loo gaaro joogtaynta jilid iyo cabbir.

Waa maxay guddiyada soo noqnoqda ee PCB? PCB kala soocidda saxanka soo noqnoqoshada sare

3. Helitaanka agabka oo waqtiyeysan:

Wareeg soo iibsi saxan oo aad u badan ayaa aad u dheer, xataa 2-3 bilood; 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. Qiyaasaha qiimaha:

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.

Inuu la jaanqaado xeerarka deegaanka ee dalal kala duwan oo buuxiyo shuruudaha RoHS iyo halogen-free.

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. Saxanka wareegga oo leh khasaare dhexdhexaad ah iyo mid hooseeya ayaa ku habboonaan doona wareegga dhijitaalka ah ee 10Gb/S; The plate with lower loss is suitable for 25Gb/s digital circuit; Guddiyada leh khasaare aad u hooseeya ayaa si dhakhso leh, xawaare sare leh oo wareegyo dhijitaal ah u dejin doona 50Gb/s ama ka sareeya.

From the material Df:

Df inta u dhaxaysa 0.01 ~ 0.005 guddi wareeg oo ku habboon xadka sare ee wareegga dhijitaalka ah ee 10Gb/S;

Df inta u dhaxaysa 0.005 ~ 0.003 guddi wareeg oo ku habboon xadka sare ee wareegga dhijitaalka ah ee 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, iwm

3), Panasonic: Megtron4, Megtron6, iwm

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

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

6), Dongguan Shengyi, Taizhou Wangling, Taixing Microwave, iwm