The interconnect of circuit board system includes chip-to-circuit board, interconnect within PCB and interconnect between PCB and external devices. Ninu apẹrẹ RF, awọn abuda ti itanna ni aaye isopọ jẹ ọkan ninu awọn iṣoro akọkọ ti o dojuko nipasẹ apẹrẹ imọ -ẹrọ. Iwe yii ṣafihan awọn imuposi oriṣiriṣi ti awọn oriṣi mẹta ti o wa loke ti apẹrẹ asopọ asopọ, pẹlu awọn ọna fifi sori ẹrọ ẹrọ, ipinya ti okun ati awọn ọna lati dinku inductance asiwaju.

Awọn ami wa ti a ṣe apẹrẹ awọn igbimọ Circuit ti a tẹ pẹlu igbohunsafẹfẹ jijẹ. Bi awọn oṣuwọn data ti n tẹsiwaju lati pọ si, bandiwidi ti o nilo fun gbigbe data tun n ta aja igbohunsafẹfẹ ifihan si 1GHz tabi ga julọ. Imọ-ẹrọ ifihan agbara igbohunsafẹfẹ giga yii, botilẹjẹpe o kọja imọ-ẹrọ igbi millimeter (30GHz), ṣe pẹlu RF ati imọ-ẹrọ makirowefu kekere-kekere.

Awọn ọna apẹrẹ imọ -ẹrọ RF gbọdọ ni anfani lati mu awọn ipa aaye itanna ti o lagbara ti o jẹ ipilẹṣẹ ni igbagbogbo ni awọn igbohunsafẹfẹ giga. Awọn aaye itanna wọnyi le ṣe awọn ifihan agbara lori awọn laini ifihan ti o wa nitosi tabi awọn laini PCB, nfa crosstalk ti a ko fẹ (kikọlu ati ariwo lapapọ) ati ipalara iṣẹ ṣiṣe eto. Backloss jẹ pataki nipasẹ aiṣedeede ikọlu, eyiti o ni ipa kanna lori ifihan bi ariwo aropo ati kikọlu.

Pipadanu ipadabọ giga ni awọn ipa odi meji: 1. Ifihan ti o tan sẹhin si orisun ifihan yoo mu ariwo ti eto pọ si, ṣiṣe ni nira fun olugba lati ṣe iyatọ ariwo lati ami ifihan; 2. 2. Ifihan eyikeyi ti o farahan yoo ṣe ibajẹ didara ifihan naa ni pataki nitori apẹrẹ ti ifihan titẹ sii yipada.

Botilẹjẹpe awọn eto oni -nọmba jẹ ifarada ẹbi pupọ nitori wọn ṣe pẹlu awọn ami 1 ati 0 nikan, awọn harmonics ti ipilẹṣẹ nigbati pulusi ti nyara ni iyara to ga jẹ ki ifihan jẹ alailagbara ni awọn igbohunsafẹfẹ giga. Botilẹjẹpe atunse aṣiṣe siwaju le ṣe imukuro diẹ ninu awọn ipa odi, apakan ti bandiwidi eto ni a lo lati atagba data apọju, ti o yorisi ibajẹ iṣẹ. Ojutu ti o dara julọ ni lati ni awọn ipa RF ti o ṣe iranlọwọ kuku ju idinku lati iduroṣinṣin ifihan. A ṣe iṣeduro pe pipadanu ipadabọ lapapọ ni igbohunsafẹfẹ ti o ga julọ ti eto oni -nọmba kan (nigbagbogbo aaye data ti ko dara) jẹ -25dB, deede si VSWR ti 1.1.

Apẹrẹ PCB ni ero lati kere, yiyara ati din owo. For RF PCBS, high-speed signals sometimes limit the miniaturization of PCB designs. At present, the main method to solve the problem of cross-talk is ground management, spacing between wiring and reducing lead inductance. Ọna akọkọ lati dinku ipadabọ ipadabọ jẹ ibaamu ikọlu. Ọna yii pẹlu iṣakoso ti o munadoko ti awọn ohun elo idabobo ati ipinya ti awọn laini ifihan agbara ati awọn laini ilẹ, ni pataki laarin ipo ti laini ifihan ati ilẹ.

Nitori isopọpọ jẹ ọna asopọ ti ko lagbara julọ ninu pq Circuit, ni apẹrẹ RF, awọn ohun -ini itanna ti aaye isopọ jẹ iṣoro akọkọ ti nkọju si apẹrẹ imọ -ẹrọ, aaye asopọ kọọkan yẹ ki o ṣe iwadii ati awọn iṣoro to wa tẹlẹ yanju. Isopọ igbimọ Circuit pẹlu isọdọkan ọkọ-si-Circuit interconnection, isọdọkan PCB ati titẹ sii ifihan/isopọ iṣelọpọ laarin PCB ati awọn ẹrọ ita.

Interconnection between chip and PCB board

The PenTIum IV and high-speed chips containing a large number of input/output interconnects are already available. As for the chip itself, its performance is reliable, and the processing rate has been able to reach 1GHz. One of the most exciting aspects of the recent GHz Interconnect symposium (www.az.ww. Com) is that approaches to dealing with the ever-increasing volume and frequency of I/O are well known. The main problem of interconnect between chip and PCB is that the density of interconnect is too high. An innovative solution was presented that uses a local wireless transmitter inside the chip to transmit data to a nearby circuit board.

Boya tabi kii ṣe ojutu yii n ṣiṣẹ, o han fun awọn olukopa pe imọ -ẹrọ apẹrẹ IC jẹ ṣiwaju iwaju ti imọ -ẹrọ apẹrẹ PCB fun awọn ohun elo hf.

Isopọ PCB

Awọn imuposi ati awọn ọna fun apẹrẹ PCB hf jẹ bi atẹle:

1. A gbọdọ lo igun 45 ° fun igun laini gbigbe lati dinku ipadabọ ipadabọ (Ọpọtọ. 1);

2 iye idabobo igbagbogbo ni ibamu si ipele ti iṣakoso adaṣe iṣẹ ṣiṣe giga ti o muna ti o muna ti o ga julọ. Ọna yii jẹ anfani fun iṣakoso ti o munadoko ti aaye itanna laarin awọn ohun elo idabobo ati wiwakọ ti o wa nitosi.

3. Awọn alaye apẹrẹ PCB fun etching to peye yẹ ki o ni ilọsiwaju. Gbiyanju lati ṣalaye asise iwọn laini lapapọ ti +/- 0.0007 inches, ṣiṣakoso abẹrẹ ati awọn apakan agbelebu ti awọn apẹrẹ wiwu ati sisọ awọn ipo gbigbe ẹgbẹ odi. Isakoso gbogbogbo ti jiometirika (okun waya) ati awọn aaye ti a bo jẹ pataki lati koju awọn ipa awọ ti o ni ibatan si awọn igbohunsafẹfẹ makirowefu ati lati ṣe awọn alaye wọnyi.

4. Ifọwọkan tẹ ni awọn idari ti n jade. Yago fun lilo irinše pẹlu nyorisi. Fun awọn agbegbe igbohunsafẹfẹ giga, o dara julọ lati lo awọn paati ti a fi sori ilẹ.

5. Fun ifihan nipasẹ awọn iho, yago fun lilo ilana PTH lori awo ti o ni imọlara, nitori ilana yii le fa inductance asiwaju ni iho nipasẹ.

6. Pese lọpọlọpọ ilẹ fẹlẹfẹlẹ. Awọn iho ti a mọ ni a lo lati sopọ awọn fẹlẹfẹlẹ ilẹ wọnyi lati ṣe idiwọ awọn aaye itanna 3d lati ni ipa lori igbimọ Circuit.

7. Lati yan ti kii-electrolysis nickel plating tabi ilana imularada goolu, maṣe lo ọna fifẹ HASL. Ilẹ electroplated yii n pese ipa awọ ti o dara julọ fun awọn ṣiṣan igbohunsafẹfẹ giga (Nọmba 2). Ni afikun, wiwọ weldable ti o ga julọ nilo awọn itọsọna to kere, ṣe iranlọwọ lati dinku idoti ayika.

8. Layer resistance solder le se solder lẹẹ lati ti nṣàn. Sibẹsibẹ, nitori ailojuwọn ti sisanra ati iṣẹ idabobo aimọ, ibora ti gbogbo awo awo pẹlu ohun elo resistance solder yoo ja si iyipada nla ninu agbara itanna ni apẹrẹ microstrip. Generally, solder dam is used as solder resistance layer.

Ti o ko ba faramọ pẹlu awọn ọna wọnyi, kan si ẹlẹrọ apẹrẹ ti o ni iriri ti o ti ṣiṣẹ lori awọn igbimọ Circuit makirowefu fun ologun. O tun le jiroro pẹlu wọn kini ibiti idiyele ti o le mu. For example, it is more economical to use a copper-backed coplanar microstrip design than a strip design. Discuss this with them to get a better idea. Awọn onimọ -ẹrọ to dara le ma lo lati ronu nipa idiyele, ṣugbọn imọran wọn le wulo pupọ. Yoo jẹ iṣẹ igba pipẹ lati ṣe ikẹkọ awọn ẹlẹrọ ọdọ ti ko faramọ pẹlu awọn ipa RF ati pe ko ni iriri ni ṣiṣe pẹlu awọn ipa RF.

Ni afikun, awọn solusan miiran le gba, gẹgẹbi imudarasi awoṣe kọnputa lati ni anfani lati mu awọn ipa RF.

Isopọ PCB pẹlu awọn ẹrọ ita

A le ro bayi pe a ti yanju gbogbo awọn iṣoro iṣakoso ifihan lori ọkọ ati lori awọn isopọ ti awọn paati ọtọ. Nitorinaa bawo ni o ṣe yanju iṣoro titẹ sii/iṣoro ifihan lati igbimọ Circuit si okun waya ti n sopọ ẹrọ latọna jijin naa? Trompeter Electronics, an innovator in coaxial cable technology, is working on this problem and has made some important progress (Figure 3). Paapaa, wo aaye itanna ti o han ni Nọmba 4 ni isalẹ. Ni ọran yii, a ṣakoso iyipada lati microstrip si okun coaxial. Ninu awọn kebulu coaxial, awọn fẹlẹfẹlẹ ilẹ ti wa ni idapo ni awọn oruka ati ni aaye deede. Ni awọn microbelts, fẹlẹfẹlẹ ilẹ ni isalẹ laini ti n ṣiṣẹ. Eyi ṣafihan awọn ipa eti kan ti o nilo lati ni oye, asọtẹlẹ, ati gbero ni akoko apẹrẹ. Nitoribẹẹ, aiṣedeede yii tun le ja si ipadasẹhin ati pe o gbọdọ dinku lati yago fun ariwo ati kikọlu ifihan.

Isakoso ti iṣoro ikọlu inu kii ṣe iṣoro apẹrẹ ti o le foju pa. Ainilara naa bẹrẹ ni oke ti igbimọ Circuit, kọja nipasẹ apapọ asomọ si apapọ, ati pari ni okun coaxial. Nitori ikọlu yatọ pẹlu igbohunsafẹfẹ, ipo igbohunsafẹfẹ ti o ga julọ, iṣakoso imukuro ti o nira sii jẹ. Iṣoro ti lilo awọn igbohunsafẹfẹ giga lati gbe awọn ifihan agbara sori igbohunsafefe han lati jẹ iṣoro apẹrẹ akọkọ.

This paper summarizes

PCB platform technology needs continuous improvement to meet the requirements of IC designers. Hf signal management in PCB design and signal input/output management on PCB board need continuous improvement. Whatever exciting innovations are coming, I think bandwidth is going to get higher and higher, and using high frequency signals is going to be a prerequisite for that growth.