Incazelo ye high-frequency PCB board

Imvamisa yebhodi ephezulu isho ibhodi elikhethekile le-electromagnetic frequency circuit board, elisetshenziswa kumvamisa ophakeme (omkhulu kunemvamisa ye-300 MHZ noma i-wavelength ingaphansi kwemitha elingu-1) ne-microwave (enkulu kunemvamisa ye-3 GHZ noma i-wavelength ingaphansi kwamamitha ayi-0.1) emkhakheni we I-PCB, isembethe i-microwave base ithukile isebenzisa indlela ejwayelekile yokukhiqiza ibhodi yesifunda eyingxenye yenqubo noma ukusetshenziswa kwezindlela ezikhethekile zokucubungula nokukhiqizwa kwamabhodi wesifunda. Ngokuvamile, amabhodi wemvamisa ephezulu angachazwa njengamabhodi wesifunda anamafrikhwensi angaphezu kwe-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. Isibonelo, izinto ezisezingeni eliphansi zidinga ukuba nezakhiwo zikagesi ezinhle kakhulu, ukuqina kwamakhemikhali okuhle, ngokwanda kwemvamisa yesiginali yamandla kuzidingo zokulahleka kwe-substrate zincane kakhulu, ngakho-ke kuqokonyiswa ukubaluleka kwepuleti lemvamisa ephezulu.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Indlela yokucubungula:

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. Izinto ze-PTFE (polytetrafluoroethylene)

Indlela yokucubungula:

1. Ukuvulwa kwempahla: ifilimu evikelayo kufanele igcinwe ukuvimbela ukuklwebheka nokufakwa ngaphakathi

2. Ukuprakthiza:

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

2.2 Aluminium ishidi njengoba ikhava ipuleti, bese usebenzisa 1mm aminyene amine ipuleti, qinisa ipuleti PTFE

2.3 Vuthela uthuli emgodini ngesibhamu somoya ngemuva kokubhola

2.4 Ngomshini wokumba wokuzinza ozinzile kakhulu, imingcele yokubhola (ngokuyisisekelo, umgodi mncane, izinga lokubhola liyashesha, umthwalo omncane we-Chip, inani elincane lokubuyisa)

3. Ukucutshungulwa komgodi

Ukwelashwa kwe-Plasma noma ukwelashwa kokusebenzisa i-sodium-naphthalene kunenzuzo ekwenzeni metallization yama-pores

4. I-PTH cwilisa ithusi

4.1 Ngemuva kwe-micro-etching (isilinganiso se-micro-etching silawulwe ngama-intshi ama-20 amancane), ipuleti lifakwa kusuka kusilinda wokususa uwoyela ku-PTH donsa

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:

Yiziphi PCB imvamisa high amabhodi? PCB imvamisa high plate ngezigaba

Imvamisa ephezulu nezinto zeshidi elinejubane eliphezulu

Lapho ukhetha i-substrate ye-PCB yamasekethe amvamisa, ukucatshangelwa okukhethekile kufanele kunikezwe kuzimpawu zokuhluka kwezinto ezibonakalayo ze-DK kumaza ahlukahlukene. 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. Ikakhulu ebangeni lemvamisa kusuka ku-L MHz kuye ku-L GHz, amanani abo e-DK ne-DF aguquka ngokusobala. 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. Ngaphezulu kwe-lGHz, inani layo le-DK lishintsha ngobumnene. 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.

I-dielectric loss factor (DF) yezinto ezijwayelekile ze-substrate inkulu kunaleyo ye-DK ngenxa yethonya lokuhluka kwemvamisa (ikakhulukazi ebangeni lemvamisa ephezulu). Ngakho-ke, lapho sihlola izici zemvamisa ephezulu yento esezingeni eliphansi, kufanele sigxile ekuguqulweni kwenani laso le-DF. Izinto zokwakheka komhlaba ezinejubane eliphakeme kanye nezici zemvamisa ephezulu ngokusobala zihlukile ezintweni ezijwayelekile ze-substrate ngokuya ngezimpawu zokuhluka ebangeni eliphakeme. Okokuqala ukuthi ngokushintshwa kwemvamisa, inani lalo (DF) lishintsha kancane kakhulu. Enye iyafana nezinto ezijwayelekile ze-substrate ebangeni lokuhlukahluka, kepha inani lalo (DF) liphansi.

How to choose high frequency high speed plate

Ukukhethwa kwebhodi le-PCB kufanele kuhlangabezane nezidingo zokuklama, ukukhiqizwa kwesisindo kanye nezindleko zebhalansi phakathi. 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.

Yiziphi PCB imvamisa high amabhodi? PCB imvamisa high plate ngezigaba

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. Ubuqotho besiginali yedijithali kanye nokuqina kwamaphethelo aphezulu nangaphansi kuyafana nokulahleka okuphansi nokudluliswa kokuhlanekezelwa okuphansi kwe-rf microwave (ingxenye yemvamisa ephezulu ye-harmonic yesiginali yedijithali ifinyelela ku-microwave band). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

Yiziphi PCB imvamisa high amabhodi? PCB imvamisa high plate ngezigaba

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. Qonda izakhiwo zikagesi, izakhiwo ezishisayo, ukuthembeka, njll. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

Okulandelayo kuzokwethula izinto eziyinhloko ezizocatshangelwa ekukhetheni ipuleti efanelekile:

1, i-manufacturability:

Njengokusebenza kokucindezela okuningi, ukusebenza kwezinga lokushisa, ukumelana ne-CAF / ukushisa nobulukhuni bemishini (i-viscosity) (ukuthembeka okuhle), isilinganiso somlilo;

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

Ukulahleka okuphansi, imingcele eqinile ye-Dk / Df, ukusabalalisa okuphansi, ukushintsha okuncane kwe-coefficient ngemvamisa nemvelo, ukubekezelelana okuncane kobukhulu bezinto nokuqukethwe kwenjoloba (ukulawula okuhle kwe-impedance), uma ucingo lude, cabanga ngobucwebe obuphansi bethusi. In addition, simulation is needed in the early stage of high-speed circuit design, and simulation results are the reference standard for design. “I-Xingsen Technology – Agilent (ijubane eliphezulu / imvamisa yeRADIO) ilabhorethri ehlangene” ixazulule inkinga yokusebenza kwemiphumela yokulingisa engahambelani nokuhlolwa, futhi yenza inqwaba yokulingisa kanye nokuqinisekiswa kwangempela kokuhlolwa okuvaliwe, ngokusebenzisa indlela eyingqayizivele yokufeza ukuvumelana ukulingisa nokukala.

Yiziphi PCB imvamisa high amabhodi? PCB imvamisa high plate ngezigaba

3. Ukutholakala ngesikhathi kwezinto:

Imjikelezo eminingi yokuthengwa kwepuleti ephezulu kakhulu yinde kakhulu, ngisho nezinyanga ezingama-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;

Izici zezindleko:

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.

Ukuhambisana nemithetho yezemvelo yamazwe ahlukene futhi uhlangabezane nezimfuneko zeRoHS kanye ne-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. Ipuleti lesifunda elinokulahleka okuphakathi naphakathi lizolungela isekethe le-10Gb / S ledijithali; Ipuleti elinokulahleka okuphansi lilungele isekethe yedijithali engu-25Gb / s; Amaphaneli anokulahleka okuphansi kakhulu azokwamukela amasekhethi edijithali ashesha kakhulu, ngamazinga we-50Gb / s noma ngaphezulu.

Kusuka kokuqukethwe kwe-Df:

I-Df phakathi kwe-0.01 ~ 0.005 ibhodi lesifunda elifanele umkhawulo ophezulu wesekethe ye-10Gb / S;

I-Df phakathi kwe-0.005 ~ 0.003 ibhodi lesifunda elifanele umkhawulo ophezulu wesekethe ye-25Gb / S;

Amabhodi wesekethe ane-Df angadluli ku-0.0015 alungele ama-50Gb / S noma amasekethe edijithali aphezulu.

Amapuleti asheshayo asetshenziswa kakhulu yilezi:

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

2), iTaiyao TUC: Tuc862, 872SLK, 883, 933, njll

3), iPanasonic: Megtron4, Megtron6, njll

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

5) INelco: N4000-13, N4000-13EPSI, njll

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