DE102019123193A1 - Field device of automation technology - Google Patents

Abstract

Field device of automation technology (1), comprising: - a housing (2) which encloses an interior (3), at least two chambers (7, 8) being formed in the interior; or actuator element (4) for setting and / or recording a process variable; - at least one electronic circuit (5) arranged in one of the two chambers for operating the sensor and / or actuator element (4); - at least one further electronic component (9) , which is arranged in the other chamber; - at least one circuit board (6) which is arranged in the interior (3) in such a way that the circuit board (6) separates the two chambers (7, 8) from one another; - at least one means ( 14), which, in conjunction with the at least one printed circuit board, is designed to create a hermetic seal between the two chambers.

Description

The invention relates to a field device in automation technology.

Field devices that are used in industrial systems are known from the prior art. Field devices are often used in process automation technology as well as in production automation technology. In principle, all devices that are used close to the process and that supply or process process-relevant information are referred to as field devices. Field devices are used to record and / or influence process variables. Measuring devices or sensors are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, etc. and record the corresponding process variables pressure, temperature, conductivity, pH value, level, flow, etc. Actuators are used to influence process variables. These are, for example, pumps or valves that can influence the flow of a liquid in a pipe or the fill level in a container. In addition to the aforementioned measuring devices and actuators, field devices also include remote I / Os, radio adapters or, in general, devices that are arranged on the field level.

A large number of such field devices are produced and sold by the Endress + Hauser Group.

Many field devices for process automation are exposed to different environmental influences, depending on where they are used. In different industrial areas, different influences are thus predominant, each of which requires different protective measures.

In order to do justice to the different prevailing conditions, it may be necessary to equip the housing with two separate chambers inside. These two chambers are in particular hermetically sealed so that the field device can be exposed to different climatic influences.

Such a climatic separation of the two chambers is usually achieved by means of a partition wall which extends inside through the housing.

The disadvantage of this is that the production of such a housing with an integrated partition wall requires increased manufacturing outlay, which in turn leads to increased costs. Furthermore, an electrical bushing must also be introduced into the partition during production.

The invention is therefore based on the object of showing a possibility of realizing a hermetic separation of two chambers in the interior of a field device housing, which can be manufactured as simply as possible and in particular also has lower costs.

The object is achieved according to the invention by the field devices of automation technology according to claim 1 and the method for producing a printed circuit board according to claim 9.

• - ein Gehäuse, welches einen Innenraum umschließt, wobei im Innenraum zumindest zwei Kammern ausgebildet sind;
• - ein am Gehäuse angeordnetes Sensor- und/oder Aktorelement zum Stellen und/oder Erfassen einer Prozessgröße;
• - zumindest eine in einer der beiden Kammern angeordnete elektronische Schaltung zum Betreiben des Sensor- und/oder Aktorelements;
• - zumindest eine weitere elektronische Komponente, die in der anderen Kammer angeordnet ist;
• - zumindest eine Leiterplatte, die derartig in dem Innenraum angeordnet ist, dass die Leiterplatte die zwei Kammern voneinander trennt;
• - zumindest ein Mittel, welches im Zusammenspiel mit der zumindest einen Leiterplatte dazu ausgebildet ist, eine hermetische Abdichtung zwischen den beiden Kammern zu erzeugen.

The field device according to the invention for automation technology comprises:

• a housing which encloses an interior space, at least two chambers being formed in the interior space;
• - A sensor and / or actuator element arranged on the housing for setting and / or detecting a process variable;
• - At least one electronic circuit arranged in one of the two chambers for operating the sensor and / or actuator element;
• - At least one further electronic component, which is arranged in the other chamber;
• - At least one printed circuit board which is arranged in the interior space in such a way that the printed circuit board separates the two chambers from one another;
• - At least one means which, in interaction with the at least one printed circuit board, is designed to produce a hermetic seal between the two chambers.

According to the invention, a field device in automation technology is proposed in which a hermetically sealed chamber separation is implemented with the aid of a printed circuit board. The actual housing consists of a single chamber inside, which is divided into two hermetically separated chambers with the help of the printed circuit board and a sealant. This form of separation has the advantage that the housing construction can be simplified so that the field device is easier to manufacture. Furthermore, by applying or introducing circuit elements onto the printed circuit board, the space required in the interior of the housing can be reduced, so that in turn costs can be minimized. For example, the circuit board can have circuit elements for EMC measures.

An advantageous embodiment of the field device according to the invention of automation technology provides that the at least one printed circuit board has at least one electrical feedthrough for having electrical connection of the electronic circuit and the further electronic component, the at least one electrical leadthrough being implemented by at least one internally metallized bore in a carrier material of the circuit board, and the internally metallized bore also being closed for hermetic sealing. In particular, the configuration can provide that the at least one internally metallized bore is sealed, preferably with copper. The copper is preferably introduced into the internally metallized hole while the printed circuit board is being printed.

A further advantageous embodiment of the field device according to the invention in automation technology provides that the at least one means comprises a seal, in particular an O-ring or a sealing cord, and the housing in the interior has a circumferential support surface on which the seal rests circumferentially. In particular, the embodiment can provide that the means further comprises a latching means, which is designed and arranged, preferably circumferentially on an inner wall of the housing, in such a way that the at least one circuit board can be clicked in at least at certain points and the at least one circuit board exerts such a pressure in the clicked-in state the seal applies so that the two chambers are hermetically separated from each other. Alternatively, the embodiment can provide that the means further comprises screws, and the circumferential bearing surface is designed to receive the screws at the thread end and wherein the circumferential bearing surface and the circumferential seal are designed so that the screws in an edge region between the circumferential seal and an inner wall of the housing are arranged circumferentially, preferably equidistantly, and the screws in the screwed-in state are guided through corresponding openings in the at least one circuit board and screwed to the support surface, so that the at least one circuit board applies such a pressure to the circumferential seal that the two chambers are hermetically separated from each other.

A further advantageous embodiment of the field device according to the invention in automation technology provides that the further electronic component comprises a connection block to which a two-wire and / or four-wire line coming from outside the housing can be connected.

A further advantageous embodiment of the field device according to the invention in automation technology provides that the at least one printed circuit board is arranged in the interior of the housing with a main plane in which it is formed, orthogonal to a longitudinal axis that extends through the interior of the housing.

• - Bereitstellen eines Trägermaterials einer Leiterplatte;
• - Einbringen von mindestens einer elektrischen Durchführung in Form einer innen metallisierten Bohrung in das Trägermaterial;
• - Vollständiges Verschließen der innen metallisierten Bohrung;
• - Einbringen der Leiterplatte in das Gehäuse des Feldgeräts, sodass in einem Innenraum des Gehäuses zwei Kammer ausgebildet werden;
• - Hermetisches Abdichten der zwei Kammern im Inneren des Gehäuses des Feldgeräts, wobei das hermetische Abdichten mit Hilfe eines Mittels im Zusammenspiel mit der zumindest einen Leiterplatte durchgeführt wird.

The invention further relates to a method for producing a field device in automation technology with the aid of a printed circuit board which is used for hermetic sealing between two chambers of a housing of the field device, having the following method steps:

• - Provision of a carrier material for a printed circuit board;
• - Introduction of at least one electrical feedthrough in the form of an internally metallized hole in the carrier material;
• - Complete sealing of the internally metallized bore;
• - Introducing the circuit board into the housing of the field device, so that two chambers are formed in an interior of the housing;
• Hermetic sealing of the two chambers in the interior of the housing of the field device, the hermetic sealing being carried out with the aid of an agent in interaction with the at least one printed circuit board.

An advantageous embodiment of the method according to the invention provides that the internally metallized bore is sealed, preferably when producing conductor tracks, particularly preferably with copper or a lacquer. By closing the internally metallized hole during the manufacturing process of the circuit board, in particular during the circuit board printing in which the conductor tracks are generated on the circuit board, the electrical feedthrough can be positioned as desired so that it can be individually adapted to the requirements. Furthermore, in the event that several electrical feedthroughs are provided, these can also be defined in the layout of the printed circuit board.

• 1: einen Querschnitt durch ein erfindungsgemäß ausgebildetes Feldgerät der Automatisierungstechnik.

The invention is explained in more detail with reference to the following drawing. It shows:

• 1 : a cross section through an inventive field device of automation technology.

1 shows a cross section through a schematically illustrated field device of automation technology embodied according to the invention 1 . The field device includes a housing 2 showing an interior 3rd having. The field device 1 further includes an on the housing 2 arranged sensor and / or actuator element 4th for setting and / or recording a process variable and associated sensor and / or actuator electronics 13th which is set up for this purpose, the sensor and / or actuator element 4th to operate.

The sensor and / or actuator electronics are used in particular 13th in addition, data in the form of measurement and / or control values with the sensor and / or actuator element 4th to communicate.

The sensor and / or actuator electronics 13th is with an electronic circuit 5 to operate the field device 1 connected. The electronic circuit 5 is set up to carry out the functions necessary to operate the field device. Such functions are in particular the further processing of the sensor and / or actuator electronics 13th originating data (raw measured values) in measured values that can be transmitted via a line, in particular a four-wire or two-wire line (e.g. 4-20 mA signals corresponding to the measured value), in the event that the field device detects a measured value. In the event that the field device provides a control value, the function includes, in particular, processing the data received from a control unit, for example PLC, 20 via the four-wire or two-wire line, into data corresponding to the sensor and / or actuator electronics.

To display measurement and / or control values, the field device has 1 a display 11 on which via a circuit for display control 10 is operated and controlled accordingly. The circuit for display control 10 can also be part of the electronic circuit 5 be. Alternatively, the circuit for display control 10 be designed as a separate circuit and connected to the electronic circuit for operating the field device in a data-conducting manner.

The electronic circuit 5 is in a first chamber in the interior 3rd of the housing 2 arranged. The first chamber 7th is through a circuit board 6th of one also in the interior 3rd of the housing 2 arranged second chamber 8th Cut. The circuit board 6th to separate the two chambers 7th , 8th can be part of the electronic circuit 5 be. Alternatively, the circuit board 6th belong to another electronic circuit.

In the in 1 illustrated embodiment is in the second chamber 8th a connection block 9 for connecting the four-wire or two-wire line 12th arranged. Via the four-wire or two-wire line 12th data, e.g. in the form of 4-20 mA signals with the control unit (PLC) 20th communicates.

So that the data between the one in the second chamber 7th , 8th arranged connection block 9 and the one in the first chamber 7th arranged electronic circuit 5 can be transmitted to operate the field device, the circuit board has an electrical feedthrough 15th on. The electrical implementation 15th comprises one in a substrate of the circuit board 6a realized inside metallized hole (via). The hole is metallized on the inside for a hermetic seal 16 locked. Closing is preferably done with copper. The copper is preferably used during the manufacturing process of the circuit board 6th introduced, for example during the printed circuit board.

The field device 1 further comprises a sealing means 14th , 17th , 18th , 19th , which interacts with the one circuit board 6th a hermetic seal between the two chambers 7th , 8th generated. The hermetic seal can be implemented in different ways.

In a first variant, the sealing means comprises a seal 14th and one on an inside of the housing 2 trained circumferential support surface 17th on which the seal 14th rests. The seal 14th can in particular comprise an O-ring or a sealing cord. According to the first variant, the sealing means further comprises a latching means 18th , for example in the form of a locking lug. The locking means 18th is such on the inside of the housing 2 arranged that the circuit board 6th between the locking lug 18th and allows the seal resting on the support surface to click into place and the printed circuit board, in the clicked-in state, exerts a pressure on the seal necessary for the hermetic seal 14th exercises. The locking means 18th can be made up of individual locking lugs on the inside of the housing 2 are arranged circumferentially or consist of a completely circumferential lip.

In a second variant, the sealing means comprises the seal in addition to the seal 14th and the support surface 17th also several screws 19th . According to the second variant, the seal 14th and the support surface 17th be designed so that the seal 14th , for example an O-ring or a sealing cord, offset inwards on the support surface 17th rests and the screws 19th in an edge area of the support surface 17a , which adjoins the housing inner wall, are arranged circumferentially. Preferably the screws are 19th arranged equidistantly. In 1 the first and second variants are shown by way of example, whereby either one or the other variant is usually implemented. Of course, a combination of both variants is also conceivable.

List of reference symbols

1

Field device of automation technology

2

casing

3

inner space

4th

Sensor and / or actuator element

5

Electronic circuit for operating the field device

6th

Circuit board

6a

Backing material of the printed circuit board

7th

First chamber

8th

Second chamber

9

Connection block for connecting a four-wire or two-wire line

10

Circuit for display control

11

Display

12th

Four-wire or two-wire line

13th

Sensor and / or actuator electronics

14th

Seal, e.g. O-ring or sealing cord

15th

Electrical feedthrough

16

Inside metallized hole (via)

16a

copper

17th

Circumferential support surface

17a

Edge area of the support surface

18th

Locking means

19th

Screws

20th

Control unit, e.g. PLC

E.

Level in which the circuit board is formed

L.

Longitudinal axis that extends through the interior of the housing

Claims (10)

Field device of automation technology (1), comprising: - A housing (2) which encloses an interior space (3), at least two chambers (7, 8) being formed in the interior space; - A sensor and / or actuator element (4) arranged on the housing (2) for setting and / or detecting a process variable; - At least one electronic circuit (5) arranged in one of the two chambers for operating the sensor and / or actuator element (4); - At least one further electronic component (9) which is arranged in the other chamber; - At least one circuit board (6) which is arranged in the interior (3) in such a way that the circuit board (6) separates the two chambers (7, 8) from one another; - At least one means (14) which, in interaction with the at least one printed circuit board, is designed to produce a hermetic seal between the two chambers. Field device Claim 1 , wherein the at least one circuit board (6) has at least one electrical leadthrough (15) for the electrical connection of the electronic circuit (5) and the further electronic component (9), the at least one electrical leadthrough (15) through at least one internally metallized bore (16) is realized in a carrier material (6a) of the printed circuit board (6), and furthermore the internally metallized bore (16) is closed for hermetic sealing. Field device according to the preceding claim, wherein the at least one internally metallized bore (16) is closed, preferably with copper (16a). Field device according to one of the preceding claims, wherein the at least one means comprises a seal (14), in particular an O-ring or a sealing cord, and wherein the housing (2) has a circumferential support surface (17) in the interior space (3), on which the seal (14) rests all around. Field device according to the preceding claim, wherein the means further comprises a latching means (18), which is formed and arranged, preferably circumferentially on an inner wall of the housing (2), in such a way that the at least one printed circuit board (6) can be clicked in at least at certain points and the at least a printed circuit board in the clicked-in state applies such a pressure to the seal (14) that the two chambers (7, 8) are hermetically separated from one another. Field device Claim 4 , wherein the means further comprises screws (19), and the circumferential bearing surface (17) is designed to receive the screws at the thread end and wherein the circumferential bearing surface (17) and the circumferential seal (14) are designed so that the screws ( 19) are arranged circumferentially, preferably equidistantly, in an edge area between the circumferential seal (14) and an inner wall of the housing (2) and the screws (19) are guided through corresponding openings in the at least one printed circuit board (6) and connected to the Support surface (17) are screwed so that the at least one printed circuit board (6) applies such a pressure to the circumferential seal (14) that the two chambers (7, 8) are hermetically separated from one another. Field device according to one of the preceding claims, wherein the further electronic component comprises a connection block (9) to which a two-wire and / or four-wire line (12) coming from outside the housing (2) can be connected. Field device according to one of the preceding claims, wherein the at least one printed circuit board (6) has a main plane (E) in which it is formed, orthogonal to a longitudinal axis (L) which extends through the interior (3) of the housing (2) , is arranged in the interior of the housing (2). A method for producing a field device in automation technology with the aid of a printed circuit board which is used for hermetic sealing between two chambers of a housing of the field device, comprising the following method steps: providing a carrier material for a printed circuit board; - Introduction of at least one electrical feedthrough in the form of an internally metallized hole in the carrier material; - Complete sealing of the internally metallized bore; - Introducing the circuit board into the housing of the field device, so that two chambers are formed in an interior of the housing; Hermetic sealing of the two chambers in the interior of the housing of the field device, the hermetic sealing being carried out with the aid of an agent in interaction with the at least one printed circuit board. Method according to the preceding claim, wherein the internally metallized bore is closed, preferably when producing conductor tracks, particularly preferably with copper or a lacquer.

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