Ka wehewehe o high-frequency PCB board

ʻO ka papa alapine kiʻekiʻe e pili ana i ka papa kaapuni uila electromagnetic kūikawā, hoʻohana ʻia i ke alapine kiʻekiʻe (ʻoi aku ma mua o 300 MHZ pinepine a ʻoi paha ka lōʻihi o ka nalu ma lalo o 1 mika) a me ka hawewe (ʻoi aku ma mua o 3 GHZ pinepine a ʻoi paha ka lōʻihi o ka lōʻihi ma mua o 0.1 mika) i ke kahua o ʻO PCB, aia ma ka ipu keleawe kahua uila i hoʻohana ʻia me ka hoʻohana ʻana i ka papa hana kaapuni ʻoihana o kahi ʻāpana o ke kaʻina a i ʻole ka hoʻohana ʻana o nā ʻano hana kūikawā a me ka hana ʻana o nā papa kaapuni. Ma ke ʻano laulā, hiki ke wehewehe ʻia nā papa alapine kiʻekiʻe e like me nā papa kaapuni me nā alapine ma luna o 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. ʻO kahi laʻana, pono i nā mea substrate i nā pono uila maikaʻi, kūpaʻa kemika maikaʻi, me ka hoʻonui ʻana o ke alapine hōʻailona mana i nā koi pohō substrate he liʻiliʻi loa, no laila ua hōʻike ʻia ka mea nui o ka pā kiʻekiʻe pinepine.

Classification of PCB high frequency plate

1, at the end of the ceramic filled thermosetting material

Aaioee hana:

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) mea

Aaioee hana:

1. Wehe i nā mea: pono e mālama ʻia ke kiʻi ʻoniʻoni e pale ai i nā ʻalā a me ka nīnaninau

2. ka ʻepekema:

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

2.2 Pepa alumini e like me ka uhi uhi, a laila e hoʻohana i ka pā amine lahilahi 1mm, hoʻopaʻa i ka pā PTFE

2.3 Puhi i ka lepo mai ka lua me ka pū ea ma hope o ke kalai ʻana

2.4 Me ka rig wili paʻa loa, nā palena ʻeli (maʻamau, ʻo ka liʻiliʻi o ka puka, ʻo ka wikiwiki o ke ana o ka ʻeli, ʻo ka liʻiliʻi Chip, ʻo ka liʻiliʻi ka helu hoʻihoʻi)

3. Ka hana ʻana o ka lua

ʻO ka mālama Plasma a i ʻole ka sodium – maikaʻi ka hoʻomaʻamaʻa naphthalene i ka metallization o nā pores

4. Keleawe keleawe PTH

4.1 Ma hope o ka liʻiliʻi liʻiliʻi (ua kāohi ʻia ka helu micro-etching e 20 micro-inches), hānai ʻia ka pā mai ka aila e hemo nei i ka paukū i ka huki 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:

He aha nā papa alapine kiʻekiʻe PCB? Hoʻonohonoho papa kiʻekiʻe kiʻekiʻe PCB

ʻO ke alapine kiʻekiʻe a me ka pepa wikiwiki wikiwiki

Ke koho ʻana i ka substrate no PCB no nā kaapuni alapine kiʻekiʻe, pono e hāʻawi i ka noʻonoʻo kūikawā i nā ʻano loli o ka mea DK ma nā alapine like ʻole. 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. ʻOi loa i ke alapine alapine mai L MHz a L GHz, hoʻololi maopopo ʻia kā lākou DK a me DF mau waiwai. 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. Ma luna o lGHz, hoʻololi mālie kona waiwai DK. 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.

ʻO ke kumu pohō dielectric (DF) o nā mea substrate nui ka mea i ʻoi aku ma mua o DK ma muli o ka hopena o ka loli pinepine (ʻo ia hoʻi i ke kiʻekiʻena alapine kiʻekiʻe). No laila, ke loiloi i nā ʻano alapine kiʻekiʻe o kahi mea substrate, pono mākou e nānā i ka loli o kāna waiwai DF. ʻO nā mea substrate me ka wikiwiki a me nā ʻano kiʻekiʻe pinepine i maopopo he ʻokoʻa mai nā mea substrate āpau e pili ana i nā ʻano hoʻololi i ke alapine kiʻekiʻe. ʻO kekahi me ka loli o ke alapine, hoʻololi iki kona waiwai (DF). Ua like ka mea ʻē aʻe me nā mea substrate ākea i ka laulā o ka loli, akā ʻo kāna iho (DF) ke kumu haʻahaʻa.

How to choose high frequency high speed plate

Pono e koho i ka papa PCB i nā koina hoʻolālā, ka hana nui a me ke kumukūʻai o ke kaulike ma waena. 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.

He aha nā papa alapine kiʻekiʻe PCB? Hoʻonohonoho papa kiʻekiʻe kiʻekiʻe PCB

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. ʻO ke kūpaʻa o ka hōʻailona uila a me ke kiʻekiʻe o nā kihi luna a me lalo e like me ka hoʻohaʻahaʻa haʻahaʻa a me ka hoʻoliʻiliʻi haʻahaʻa o ka hawewe uila (ʻo ka ʻāpana kuʻikahi kiʻekiʻe o nā hōʻailona kikoʻī i hiki i ka band hawewe). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.

He aha nā papa alapine kiʻekiʻe PCB? Hoʻonohonoho papa kiʻekiʻe kiʻekiʻe PCB

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. Hoʻomaopopo i nā pono uila, nā waiwai wela, ka hilinaʻi, a pēlā aku. And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.

E hōʻike ka mea aʻe i nā kumu nui e noʻonoʻo ai i ke koho ʻana i ka pā kūpono.

1, hiki ke hana:

E like me nā hana kaomi pinepine, ka hana ʻana o ka wela, CAF / kūpaʻa wela a me ka paʻakikī mechanical (viscosity) (pono maikaʻi), helu ahi;

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

Ka nalowale haʻahaʻa, paʻa Dk / Df mau palena, hoʻolahalaha haʻahaʻa, coefficient hoʻololi liʻiliʻi me ke alapine a me ke kaiapuni, ka liʻiliʻi liʻiliʻi o ka mānoanoa o nā mea a me ka ʻikepili rubber (ka mana impedance maikaʻi), inā lōʻihi ka uea, e noʻonoʻo i ka pā keleawe haʻahaʻa. 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 (high speed / RADIO frequency) hoʻohui ʻia ke keʻena hoʻokolohua hui” i ka pilikia hana o nā hopena a me nā hoʻokolohua hoʻohālikelike kūlike ʻole, a hana i kahi helu nui o ka simulation a me ka hōʻoia maoli i ka hōʻoia o ka loop loop, ma o kahi hana kūikawā e hoʻokō i ka likelika o simulation a me ke ana.

He aha nā papa alapine kiʻekiʻe PCB? Hoʻonohonoho papa kiʻekiʻe kiʻekiʻe PCB

3. Loaʻa manawa kūpono o nā pono:

ʻOi aku ka lōʻihi o ke kūʻai ʻana o ka pā pinepine pinepine, ʻo 2-3 mau mahina paha; 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. Nā kumu kūʻai kumukūʻai:

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.

E kūlike me nā lula kaiapuni o nā ʻāina like ʻole a hoʻokō i nā koina o RoHS a me ka 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. E kūpono ka pā kaapuni me ka waena a me ka hoʻohaʻahaʻa no 10Gb / S uila uila; The plate with lower loss is suitable for 25Gb/s digital circuit; E hoʻopili nā panela me ka nalo haʻahaʻa-ʻoi loa i nā kaʻapuni uila wikiwiki wikiwiki kiʻekiʻe ma 50Gb / s a ​​ʻoi paha.

From the material Df:

Df ma waena o 0.01 ~ 0.005 papa kaapuni kūpono no ka palena kiʻekiʻe o 10Gb / S uila uila;

Df ma waena o 0.005 ~ 0.003 papa kaapuni kūpono no ka palena kiʻekiʻe o 25Gb / S uila uila;

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, a pēlā aku

2), Taiyao TUC: Tuc862, 872SLK, 883, 933, a pēlā aku

3), Panasonic: Megtron4, Megtron6, a pēlā aku

4), Isola: FR408HR, IS620, IS680, a pēlā aku

5) Nelco: N4000-13, N4000-13EPSI, a pēlā aku

6), Dongguan Shengyi, Taizhou Wangling, Taixing Microwave, a pēlā aku