SU741140A1

SU741140A1 - Eddy-current transducer for testing ptinted-circuit boards

Info

Publication number: SU741140A1
Application number: SU782637172A
Authority: SU
Inventors: Владимир Федорович Данилюк; Вячеслав Андреевич Дергунов; Сергей Владимирович Еремин; Александр Валентинович Маклярский; Виктор Евгеньевич Соколов
Original assignee: Предприятие П/Я А-7555
Priority date: 1978-07-03
Filing date: 1978-07-03
Publication date: 1980-06-15

Description

Изобретение относится к средствам неразрушающего контроля материалов и изделий и может быть использовано в радиоэлектронной промышленности при производстве печатных плат. $The invention relates to non-destructive testing of materials and products and can be used in the electronics industry in the manufacture of printed circuit boards. $

Известно устройство для контроля качества электропроводящего покрытия на диэлектрической основе, содержащее наконечник и обмотки И . Внутри наконечника расположены два магнитопровода (возбуждающий и измерительный). Каждый магнитопровод имеет обойму с обмоткой и пару полюсов. Угол между полюсами магнитопроводов равен 90°. Связь между ₎₅полюсами возбуждающего и измерительного магнитопроводов осуществляется посредством электропроводного покрытия контролируемой платы при введении наконечника в отверстие. _χ A device for controlling the quality of an electrically conductive coating on a dielectric basis, containing a tip and windings And. Inside the tip are two magnetic cores (exciting and measuring). Each magnetic circuit has a holder with a winding and a pair of poles. The angle between the poles of the magnetic circuit is 90 °. The connection between the ₅ poles of the exciting and measuring magnetic circuits is carried out by means of an electrically conductive coating of the controlled board when the tip is inserted into the hole. _χ

Недостатком такого устройства является то, что оно неуниверсально, так как наконечник предназначен для контроля покрытий сквозных отверстий одного диа2 метра и не имеет' разъема для быстрой замены поврежденного наконечника.The disadvantage of this device is that it is not universal, since the tip is designed to control the coatings of the through holes of one diameter of 2 meters and does not have a connector for quickly replacing a damaged tip.

Наиболее близким техническим решением к изобретению является вихретоковый преобразователь для контроля качества металлизации отверстий печатных плат, содержащий цилиндрический корпус и размещенные на одном его конце стержень с возбуждающей и измерительными обмотками, витки которых расположены в плоскостях, параллельных образующей [2^ ·The closest technical solution to the invention is an eddy current transducer for controlling the metallization quality of holes in printed circuit boards, comprising a cylindrical body and a rod with exciting and measuring windings located at one end thereof, the turns of which are located in planes parallel to the generatrix [2 ^ ·

Производительность контроля этим вихретоковым преобразователем низка, так как много времени уходит на поиск отверстия на контролируемой плате диаметра, как у преобразователя, а также на совмещение оси отверстия контролируемой платы с осью магнитопровода и на замену стержня преобразователя.The monitoring performance of this eddy current transducer is low, since it takes a lot of time to search for the holes on the monitored diameter board, like for the transducer, as well as to combine the axis of the hole of the monitored circuit board with the axis of the magnetic circuit and to replace the transducer rod.

Целью изобретения является повышение производительности контроля.The aim of the invention is to increase the performance of the control.

Поставленная цель достигается тем, что стержень предлагаемого преобразователя выполнен ступенчатым, возбуждающие и измерительные обмотки размешены на ступенях стержня, а размеры каждой ступени выбраны из условия где - высота i -ой ступени преобразователя;The goal is achieved in that the rod of the proposed transducer is made stepwise, the exciting and measuring windings are placed on the steps of the rod, and the dimensions of each stage are selected from the conditions where is the height of the i-th stage of the transducer;

“ наибольшая толщина контролируемой платы с металлизацией;“The greatest thickness of the controlled board with metallization;

Гц - наружный диаметр обмотки i-ой ступени преобразователя;Hz - the outer diameter of the winding of the i-th stage of the Converter;

0Ц - диаметр металлизированного отверстия печатной платы; ^Δ^γγιαχ “ наибольший радиальный зазор между ступенью преобразователя и металлизированным отверс тием в плате;0C is the diameter of the metallized hole of the printed circuit board; ^Δ ^ γγιαχ “the largest radial clearance between the converter stage and the metallized hole in the board;

наименьший радиальный зазор ₂θ между ступенью преобразователя и металлизированным отверстием в плате.the smallest radial clearance ₂ θ between the converter stage and the metallized hole in the board.

На фиг. 1 изображен предлагаемый преобразователь , разрез; на фиг. 2 - измери- ₂₅тельная часть преобразователя, разрез; на фиг. 3 даны примеры установки преобразователя в сквозные отверстия печатнойIn FIG. 1 shows the proposed Converter, section; in FIG. 2 - measuring ₂₅ real part converter section; in FIG. 3 shows examples of installing the converter in the through holes of the printed

Наибольший радиаш..ный зазор между ступенью преобразователя и металлизированным отверстием в плате равен 0,15 мм, наименьший 0,01 мм. Из этого расчета размеры платы выбраны следующими:The largest radial clearance between the step of the converter and the metallized hole in the circuit board is 0.15 mm, the smallest 0.01 mm. From this calculation, the board sizes are selected as follows:

где Η-} ’ - высота -i -ой ступени преоб10 разователя;where Η-} ’is the height of the -i-th step of the converter;

^Ιΐΐαχ ~ ^наи®^опьшая толщина контролируемой платы с металлизацией;^ Ιΐΐαχ ~ ^nai ® the ^greater thickness of the controlled board with metallization;

Щ - наружный диаметр обмотки й-ой ступени преобразователя^ сЦ‘ - диаметр металлизированного отверстия печатной платы; наибольший радиальный зазор . между ступенью преобразователя и металлизированным отверстием в плате;Щ - outer diameter of the winding of the ith step of the converter ^ сЦ ‘- diameter of the metallized hole of the printed circuit board; largest radial clearance. between the stage of the converter and the metallized hole in the board;

наименьший радиальный зазор между ступенью преобразователя и металлизированным отверстием в плате.smallest radial clearance between the converter stage and the metallized hole in the board.

Предлагаемый преобразователь устанавливают в любое из множества контролируемых отверстий до упора одной из ступеней или его корпуса (см. фиг. 3) .The proposed Converter is installed in any of a variety of controlled holes until it stops one of the steps or its body (see Fig. 3).

платы разных диаметров.boards of different diameters.

Вихретоковый преобразователь содержит цилиндрический корпус 1, размещенный на конце корпуса ступенчатый стержень 2 с возбуждающими обмотками 3 и измерительными обмотками 4, витки которых ₃₅расположены в плоскостях, параллельных образующей.The eddy current transducer comprises a cylindrical housing 1, a step rod 2 located at the end of the housing with exciting windings 3 and measuring windings 4, the turns of which ₃₅ are located in planes parallel to the generatrix.

Корпус 1 выполнен из диэлектрического материала и предназначен для предох- · . ранения сменной измерительной части преобразоватепя, включающей в себя ступенчатый стержень 2, возбуждающие обмотки 3, измерительные обмотки 4 и розетку 5, от повреждения. В корпусе 1 установлены кнопка 6, пружина 7 и втулка- ₄₅фиксатор 8.The housing 1 is made of dielectric material and is intended for pre-protection. Injuries to the exchangeable measuring part of the converter, including a stepped rod 2, exciting windings 3, measuring windings 4 and socket 5, from damage. In the housing 1, a button 6, a spring 7 and a sleeve _{45, a} retainer 8 are installed.

Преобразователь работает следующим образом.The converter operates as follows.

Перед установкой преобразователя в металлизированное отверстие платы нажа- ₅θ тием кнопки 6 ступенчатый стержень 2 выходит из корпуса и под действием пружины 7 фиксируется его положение. В этом положении стержень вводится поочередно в контролируемые отверстия печат- ₅₅ной платы, и снимаемая с измерительных обмоток 4 ЭДС дает информацию на дефектоскоп о толщине или сплошности металлизированного покрытия отверстия.Before installing the inverter board metallized hole nazha- θ ₅ of a button 6 stepped rod 2 emerges from the housing and its position is fixed by the spring 7. In this position the rod is inserted alternately in the controlled holes ₅₅ printed matter hydrochloric board and removable from the measuring windings 4 EMF provides information on flaw on the thickness or continuity of the metallized coating orifice.

Claims

The invention relates to non-destructive testing of materials and products and can be used in the electronic industry in the manufacture of printed circuit boards. A device is known for monitoring the quality of an electrical coating on a dielectric substrate, comprising a tip and windings i. Inside the tip are two magnetic circuit (exciting and measuring). Each magnetic core has a ferrule with a winding and a pair of poles. The angle between the poles of the magnetic conductors is 9 °. The connection between the poles of the exciting and measuring magnetic circuits is carried out by means of an electrically conductive coating of the monitored board when the tip is inserted into the hole. The disadvantage of such a device is that it is non-universal, since the tip is designed to control coatings of through-holes of the same diameter and does not have a connector for quick replacement of a damaged tip. The closest technical solution to the invention is an eddy current transducer for controlling the quality of the metallization of the holes in printed circuit boards, the contents of a cylindrical body and a rod with excitation and measuring windings located at one end, the coils of which are located in planes parallel to the generator. The performance of the control with this eddy current transducer is low, since it takes a lot of time to search for a hole on a monitored diameter board like a transducer, as well as to align the hole axis of the monitored board with the axis of the magnetic circuit and to replace the transducer rod. The aim of the invention is to increase the productivity of the control. The goal is achieved by the fact that the rod of the proposed converter is made stepwise, the exciting and measuring windings are placed on the steps of the rod, and the dimensions of each stage are chosen from the condition vnax ma - Oi S 3r2 max - A - i - 2 min where C is the height of the converter stages; vnccn is the largest thickness of the controlled board with metalpiz & D is the outer diameter of the winding of the second transducer stage; (3 is the diameter of the metallized hole of the printed circuit board; the largest radial gap between the transducer stage and the metallized opening I tium in the board; hnv the smallest radial gap between the transducer stage and the metallized hole in the board. Fig. 1 shows the proposed transducer; 2 - the measuring part of the converter, a slit, and Fig. 3 gives examples of the installation of the converter into through-holes of a printed circuit board of different diameters. The eddy-current converter contains a cylindrical body. 1, a stepped rod 2 with excitation windings 3 and measuring windings 4, the coils of which are located in planes parallel to the generator, are located at the end of the housing. The housing 1 is made of dielectric material and is designed to protect the replaceable measuring part of the converter including the stepped rod 2, The ejecting windings 3, the measuring windings 4 and the socket 5 are damaged. In case 1, button 6, spring 7 and sleeve fixer 8 are installed. The conversion of the gel works as follows. Before installing the fixture into the metallized hole of the board by pressing button 6, the stepped rod 2 emerges from the housing and under the action of the spring 7 fixes its position. In this position, the rod is inserted alternately into the controlled holes of the printing rafts, and the emf gives information to the defectoscope about thickness or continuity of the metallized coating of the hole. 74 The largest radial gap between the transducer stage and the metallized hole in the board is 0.15 mm, the smallest is 0.01 mm. From this pa:; the size of the board is selected as follows: niax i max ° .5. .. where H j is the height of the i stage of the converter; max thickness of the controlled board with metallization; D is the outer diameter of the winding of the cii th transducer stage a is the diameter of the metallized opening of the printed circuit board; largest radial clearance. between the transducer stage and the metallized hole in the board; vnitt is the smallest radial clearance between the transducer stage and the metallized hole in the board. The proposed transducer is installed in any of the many controlled holes to stop. One of the steps or its body (see Fig. 3). Claims An eddy current transducer for controlling printed circuit boards comprising a cylindrical body and a rod with exciting and measuring windings located at one end thereof, the coils of which are located in planes paralle forming, characterized in that, in order to increase the control performance, the rod is stepped; The excitation and measuring windings are placed on the steps of the rod, and the dimensions of the steps are chosen from the conditions: -. tr, .. ,, where HJ is the height of the i -th stages of the converter; the maximum thickness of the controlled board; Q- is the outer diameter of the winding of the i -th stage npeo6pav3OBaTe-; di is the diameter of the metallized hole of the printed circuit board; the largest radial clearance between the transducer stage and the metallized hole in the board;