Ma’anar high-frequency PCB board

Babban madaidaicin jirgi yana nufin hukumar keɓaɓɓiyar mitar wutar lantarki ta musamman, ana amfani da ita a cikin mitar (mafi girma fiye da 300 MHZ ko raƙuman ruwa bai wuce mita 1 ba) da microwave (mafi girma fiye da mita 3 GHZ ko raƙuman ruwa ƙasa da mita 0.1) a fagen PCB, yana kan madogarar microwave tushe jan ƙarfe ta amfani da hanyar keɓancewar katako na gama gari na wani ɓangaren aiwatarwa ko amfani da hanyoyin sarrafawa na musamman da kuma samar da allon kewaya. Gabaɗaya, ana iya ayyana allon allon mitar azaman allon kewaye tare da mitoci sama da 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. Misali, kayan substrate suna buƙatar samun ingantattun kaddarorin lantarki, kwanciyar hankali na sunadarai, tare da haɓaka mitar siginar wutar lantarki a cikin buƙatun asarar substrate ƙanana ne, don haka an nuna mahimmancin farantin farantin madaidaici.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Processing Hanyar:

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) abu

Processing Hanyar:

1. Buɗewar abu: dole ne a riƙe fim mai kariya don hana karcewa da shigar ciki

2. Rawa:

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

2.2 Takardar Aluminum kamar farantin murfi, sannan yi amfani da farantin amine mai kauri 1mm, ƙarfafa farantin PTFE

2.3 Ku busa ƙurar daga ramin da bindiga ta iska bayan hakowa

2.4 Tare da mafi tsayin hako mai hakowa, sigogi na hakowa (a zahiri, ƙaramin rami, saurin hakowa, ƙaramin ƙimar Chip, ƙaramin adadin dawowar)

3. Sarrafa rami

Maganin Plasma ko sodium – naphthalene kunna kunnawa yana da fa’ida ga ƙarfewar pores

4. PTH nutse tagulla

4.1 Bayan micro-etching (micro-etching rate an sarrafa ta micro-inci 20), ana ciyar da farantin daga mai cire silinda a cikin jan 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:

Menene allon mitar PCB? PCB high mita farantin rarrabuwa

High mita da high gudun takardar abu

Lokacin zaɓar substrate don PCB don madaidaiciyar madaidaiciya, yakamata a ba da kulawa ta musamman ga halayen bambancin kayan DK a mitoci daban -daban. 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. Musamman a cikin kewayon mita daga L MHz zuwa L GHz, ƙimar DK da DF sun canza a bayyane. 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. Sama da lGHz, ƙimar DK tana canzawa a hankali. 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.

Matsalar asarar dielectric (DF) na babban kayan maye ya fi na DK saboda tasirin bambancin mitar (musamman a cikin madaidaicin maɗaukaki). Sabili da haka, lokacin da ake kimanta halayen mitar babban kayan abu, yakamata mu mai da hankali kan canjin ƙimar DF. Kayan kayan da ke da saurin gudu da kuma halayen mitar a bayyane ya bambanta da kayan substrate na gabaɗaya dangane da halayen bambancin a babban mita. Oneaya shine tare da canjin mitar, ƙimarta (DF) tana canzawa kaɗan. Isayan yayi kama da kayan ƙaramin juzu’i a cikin kewayon bambancin, amma ƙimar sa (DF) tayi ƙasa.

How to choose high frequency high speed plate

Zaɓin hukumar PCB dole ne ya cika buƙatun ƙira, samar da taro da farashin daidaituwa tsakanin. 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.

Menene allon mitar PCB? PCB high mita farantin rarrabuwa

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. Amincin siginar dijital da tsinkayen saman da ƙananan gefuna iri ɗaya ne da ƙarancin asara da ƙarancin watsa murƙushewar rf microwave (babban haɗin jituwa na siginar dijital ya isa ga microwave band). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

Menene allon mitar PCB? PCB high mita farantin rarrabuwa

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. Fahimtar kayan lantarki, kaddarorin zafi, aminci, da sauransu. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

Mai zuwa zai gabatar da manyan abubuwan da za a yi la’akari da su yayin zaɓar farantin da ya dace:

1, kera:

Irin su aikin latsawa da yawa, aikin zafin jiki, CAF/ juriya mai zafi da taurin injin (danko) (ingantaccen abin dogaro), ƙimar wuta;

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

Ƙananan asara, tsayayyen sigogi na Dk/Df, ƙarancin watsawa, ƙaramin canjin coefficient tare da mita da muhalli, ƙaramin haƙuri na kauri da abun ciki na roba (kulawar rashin ƙarfi mai kyau), idan waya ta yi tsayi, yi la’akari da ƙarancin ƙarfi na jan ƙarfe. In addition, simulation is needed in the early stage of high-speed circuit design, and simulation results are the reference standard for design. “Fasahar Xingsen-Agilent (babban gudu/mitar RADIO) dakin gwaje-gwaje na hadin gwiwa” ya warware matsalar aikin sakamakon sakamako da gwaje-gwajen da ba su dace ba, kuma ya yi adadi mai yawa na kwaikwaiyo da ainihin gwajin rufe-madaidaicin gwaji, ta hanyar wata hanya ta musamman don cimma daidaiton kwaikwaiyo da aunawa.

Menene allon mitar PCB? PCB high mita farantin rarrabuwa

3. Samuwar kayan cikin lokaci:

Yawancin sake zagayowar sayan farantin madaidaiciya yana da tsayi sosai, har ma da watanni 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. Abubuwan ƙima:

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.

Don dacewa da ƙa’idodin muhalli na ƙasashe daban-daban kuma ya cika buƙatun RoHS da marasa 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. Farantin kewaye tare da matsakaici da ƙarancin asara zai dace da madaidaicin dijital 10Gb/S; The plate with lower loss is suitable for 25Gb/s digital circuit; Bangarorin da ke da ƙarancin asara za su karɓi da’irar dijital mai sauri da sauri a ƙimar 50Gb/s ko sama.

From the material Df:

Df tsakanin 0.01 ~ 0.005 allon kewaye wanda ya dace da iyakar babba na 10Gb/S dijital kewaye;

Df tsakanin 0.005 ~ 0.003 allon kewaye wanda ya dace da iyakar babba na 25Gb/S dijital kewaye;

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

Faranti masu saurin gudu da aka saba amfani da su sune:

1), Rogers: RO4003, RO3003, RO4350, RO5880, da sauransu

2), Taiyao TUC: Tuc862, 872SLK, 883, 933, da sauransu

3), Panasonic: Megtron4, Megtron6, da sauransu

4), Isola: FR408HR, IS620, IS680, da sauransu

5) Nelco: N4000-13, N4000-13EPSI, da sauransu

6), Dongguan Shengyi, Taizhou Wangling, Taixing Microwave, da sauransu