DE102011004543A1 - Pulse resistor i.e. ohmic resistor, for dissipation of high voltage pulse in e.g. defibrillator, has thick-film arranged between contact members, where thickness of thick-film between contacts is specific value - Google Patents

Abstract

The resistor (100) has a thick-film (102) arranged between two contact members (112, 114) that are arranged in a transverse direction. A contact (104) is formed by the contact members at an outer side of the thick-film in a set of contact regions (134, 138) in electrical contact with one another. Another contact (106) is formed by the contact members that are in electrical contact with one another at the outer side of the thick-film in another set of contact regions (136, 140), where thickness of the thick-film between the contacts is 100 micrometer. An independent claim is also included for a method for manufacturing a pulse resistor and/or circuit board for an electrical or electronic device.

Description

The invention relates to a pulse resistor, a printed circuit board, which includes one or more pulse resistors, and an electrical or electronic device with a pulse resistance.

From the prior art, the use of pulse resistors to protect against pulse voltages is known. Such pulse resistors are realized in thick-film technology as discrete components in order to realize the material mass required for absorbing a high electrical pulse power in a thick-film resistor.

The invention is based on the object, an improved pulse resistance z. B. on a circuit board or other substrate, an electrical or electronic device and a method for producing a pulse resistor and / or a circuit board to create.

The object underlying the invention is achieved in each case with the features of the independent claims. Embodiments of the invention are indicated in the dependent claims.

According to embodiments of the invention, a pulse resistance is provided, which enables the derivation of a high voltage pulse. For this purpose, the pulse resistor has a thick film, in particular a thick film made of a conductive polymer. Suitable polymeric materials for this purpose are, for example, intrinsically Ken Gilleo: Polymer Thick Film. Van Nostrand Reinhold, New York 1996, chapter 2, pages 21 ff. known.

A "pulse resistance" is understood to mean in particular any arrangement which forms an ohmic resistance which is suitable for deriving a high-voltage pulse, in particular a so-called protective resistor.

To form the pulse resistance, the thick film is contacted by means of first and second contacts, which are arranged spaced apart in the direction of the longitudinal extent of the thick film. For example, the thick film extends in a striped manner between the first and second contacts.

Between the first and second contacts, a high voltage, for example, in an error, abut, so that a corresponding voltage pulse is dissipated through the thick film. In the process, the thick film will heat up for a short time, for example to approx. 170 ° C.

The first and second contacts are each formed by at least first and second contact elements, which are electrically contacted with each other outside the thick film. The first and second contact elements are each spaced apart in the transverse direction of the thick film, for example, one above the other or at an angle to one another. Between the first and second contact elements is the thick film.

Embodiments of the invention are particularly advantageous because they allow the realization of compact pulse resistors for receiving particularly high pulse powers in thick-film technology, which can be made in particular as an integral part of a printed circuit board. An inventive pulse resistor can be used as a discrete component or as an integral part of a printed circuit board or other electrical or electronic module in an electrical or electronic device by the discharge of high voltage pulses must be provided, such as in a residual current circuit breaker or a defibrillator.

According to one embodiment of the invention, the first contact elements are applied to a substrate, such as on a printed circuit board or an intermediate layer of a multilayer printed circuit board. On the substrate there is a thick film which extends in its longitudinal direction between the first contact elements and over the first contact elements. On the surface of the thick film, the second contact elements are arranged, for example, the respective first contact elements opposite each other.

The first contact elements protrude out of the thick layer and the second contact elements each extend over an edge of the thick layer up to the section of the first contact elements projecting out of the thick layer in order to contact each of them electrically.

For example, the first contact elements may be formed by a structured copper coating of the substrate, for example a printed circuit board or an intermediate layer. The thick film can then be applied to the substrate, such as by screen printing. The second contact elements are then printed onto the thick layer, for which purpose a suitable printing method is used, which makes it possible to print three-dimensional conductive structures. Suitable printing processes for this purpose are screen printing and tampo printing processes. As a result, a high-performance pulse resistance, in particular as an integral part of a high-performance pulse resistance can be particularly efficient, inexpensive and with low energy consumption realize single or multilayer printed circuit board ("printed circuit board").

According to one embodiment of the invention, several thick layers are applied one above the other so that a resulting thick layer with a particularly large layer thickness results (ultra-thick layer). After the application of each thick layer, second contact elements are printed in order to form an electrical connection with the respectively underlying second contact element. The first and second contacts then each consist of the first contact element and a plurality of second contact elements, wherein a second contact element is provided for each of the applied thick layers.

According to a further embodiment of the invention, the pulse resistance is formed by first and second substrates, between which the thick layer is located. On the first substrate are the first contact elements and on the second substrate are the second contact elements, which are each formed, for example, by structured copper layers of the first and second substrates. The electrical connection of the first and second contact elements of the first and second contacts is effected by vias, which bridge the gap between the first and second substrates.

This embodiment is particularly advantageous when the pulse resistance is realized as an integral part of a multilayer printed circuit board. The first and / or the second substrate may then be one of the intermediate layers of the printed circuit board.

In a further aspect, the invention relates to a method for producing a pulse resistor or a printed circuit board. The method comprises the following steps: structuring a printed circuit board blank to produce the first contact elements, applying the thick layer to the structured printed circuit board, applying the second contact elements to the thick layer and forming the electrical contact between the first and second contact elements of the first and second contacts.

Embodiments of the method according to the invention are particularly advantageous, since they can be carried out with a conventional guide plate production plant to produce printed circuit boards with integrated particularly powerful pulse resistors, the energy required for the production of a pulse resistance compared to the prior art (cermet thick-film resistor) is low ,

According to one embodiment of the invention, the application of the second contact elements by a printing process, which allows the realization of a three-dimensional conductive structure. For this purpose, suitable printing methods are, for example, screen printing or tampo printing method, wherein a conductive paste is printed.

According to one embodiment of the invention, the application of the thick film is carried out stepwise by several thick layers are applied to each other in successive process steps, so as to realize a resulting thick film of a particularly large layer thickness. Here, after the application of each thick layer, the step of applying the second contact elements is performed again, wherein in the second and each subsequent repetition of this step, the second contact elements are electrically connected to the second contact elements of the respective underlying thick film.

This has the advantage that the height difference to be bridged by the three-dimensional (3D) pressure of the second contact elements is only the layer thickness of a single thick layer and not the height difference to the first contact elements, which makes the 3D printing less expensive.

According to one embodiment of the invention, first and second substrates for producing the first contact elements are each structured. The first and second substrates may be, for example, intermediate layers of a printed circuit board or an outer layer of a printed circuit board and an intermediate layer.

For example, to produce a multilayer printed circuit board with one or more integrated pulse resistors, the procedure is such that two different printed circuit board layers are first patterned in order to realize the first and second contact elements. On a first of the structured printed circuit board layers, the thick film is then applied and dried. The second circuit board layer is a prepolymerized epoxy layer (prepreg) that has not yet fully cured. This is pressed onto the first printed circuit board layer, which consists of already hardened epoxy resin, in particular with a glass fiber reinforcement, in that the second contact elements penetrate into the dried thick layer and deform it plastically.

Embodiments of the invention are particularly advantageous because the production of a circuit board according to the invention can be carried out using a conventional manufacturing plant for the production of printed circuit boards. In particular, a conventional thickness of the patterned copper layer of 35 microns are chosen because despite this small compared to the thick layer of copper layer due to the second contact elements, a large effective contact area is formed on the first and second contacts, which approximates to one at the end portions of the thick film laminar current field with approximately homogeneous current density leads. This avoids local overheating (hot spots).

In the following, embodiments of the invention will be explained in more detail with reference to the drawings. Show it:

1 a top view of an embodiment of a pulse resistor according to the invention,

2 a sectional view of another embodiment along section AA of 1 .

3 a sectional view of another embodiment along section AA of 1 .

4 a sectional view of another embodiment of a pulse resistor according to the invention, which is integrated in a multilayer printed circuit board.

Elements of the following embodiments which correspond to each other are denoted by the same reference numerals.

The 1 shows a pulse resistance 100 with a thick layer 102 , The thick layer 102 consists of a conductive material, through which an ohmic resistance is formed. For example, the thick film is made of a conductive polymer. The thick layer preferably has a thickness of at least 60 μm, for example 70 μm or 100 μm, but may also be made substantially thicker.

The pulse resistance 100 has a first contact 104 and a second contact 106 for contacting the thick film 102 that are in your longitudinal direction 144 between the contacts 104 and 106 extends.

The contact 104 is through a lower contact element 108 and an upper contact element 110 educated. The contact elements 108 and 110 are transverse to the longitudinal direction 144 spaced apart, for example, opposite each other. In the embodiment considered here, the upper contact element 110 in the vertical direction above a portion of the lower contact element 108 arranged and covers this sub-area, with the sub-area under the thick film 102 located. The same applies to the lower contact element 112 and the upper contact element 114 of the contact 106 ,

Because the contacts 104 and 106 are each formed by two spaced-apart in the vertical direction contact elements, the effective contact surface of the contacts 104 and 106 , Which these with the respective end portions of the thick film 102 form, relatively large and extending over a large part or the entire cross section of the thick film 102 , Because of this, this is when dissipating an electrical pulse through the thick film 102 resulting electric flow field also at the end portions of the thick film 102 , where the electrical contact of the thick film 102 by means of the contacts 104 respectively. 106 takes place, approximately homogeneous, that is, the streamlines are approximately equidistant and parallel to each other. Because of this, the current density is over the cross section of the thick film 102 and thus the power density almost constant, so it can not come to local overheating.

The lower contact elements 108 and 112 can on a substrate 116 be arranged. At the substrate 116 it may be a carrier made of an epoxy resin, which may be glass fiber reinforced. In particular, it may be in the substrate 116 is a printed circuit board with a structured copper coating, wherein the structuring of the copper coating, the contact elements 108 and 112 be formed. In addition to the pulse resistance 100 can on the substrate 116 arranged further electrical or electronic components and with the pulse resistance 100 be interconnected.

According to one embodiment of the invention, the surface of the contact elements 108 and 112 coplanar to the surface of the substrate 116 , that is, it is at the contact elements 108 and 112 around flat structures. This is the case in particular when the contact elements 108 and 112 by structuring one on the substrate 116 be formed copper layer.

In contrast, it may be in the contact elements 110 and 114 to act three-dimensional conductive spatial structures, which are designed so that they both a surface of the thick film 102 in the respective end region cover as well as in each case a lateral edge of the thick film 102 for making a contact with the corresponding lower contact element in the vertical direction. A related embodiment is in the 2 along the section AA the 1 shown.

The upper contact element 110 here is designed so that it is in the left end area 118 the thick film 102 with the surface of the thick film 102 contacted, wherein the contact element 110 in this end area 118 in the embodiment considered here coplanar with the substrate 116 and the contact element 108 is.

The end area 118 the thick film 102 is by a flank area 120 completed in which the thick film 102 having an initially curved and then vertically downwardly extending edge. The upper contact element 110 is layered on this flank area 120 applied and extends toward the surface of the substrate 116 at least up to the height of the top of the contact element 108 , like in the 2 shown.

The upper contact element 114 at the other end of the thick film 102 is designed analogously. In other words, a first section of the contact element extends 114 in the end area 122 the thick film 102 coplanar to the substrate 116 and the surface of the contact element 112 , At the right end forms the thick film 102 in the flank area 124 one down to the substrate 116 falling edge along which the upper contact element 114 at least up to the height of the top of the contact element 112 runs.

The upper contact element 110 and the lower contact element 108 are electrically connected to each other so as to make a first contact at the left end of the thick film 102 to accomplish; Likewise, the upper contact element 114 and the lower contact element 112 electrically connected to each other so as to make a second contact at the right end of the thick film 102 to accomplish.

Due to the geometric shape of the first and second contacts, effective left and right contact surfaces for the thick film become 102 created, which in a wide range for an approximately homogeneous and laminar flow field of the through the thick film 102 flowing electric current, as by the in the 2 shown dashed lines shown.

The electrical connection of the lower contact element 108 and the upper contact element 110 occurs at a portion of the contact element 108 which is from the thick film 102 protrudes.

This section can be considered a track 126 be formed, which in a contact point 128 ends, the contact point 128 and the track 126 to the contact element 108 belong, form a unity with it and are coplanar with each other. The contact element 108 with the conductor track 126 and the contact point 128 are preferably formed by structuring one on the substrate 116 located copper layer having a thickness of, for example, 35 microns or 20 microns formed.

Characterized in that the upper contact element 110 along the left flank of the thick film 102 at least to the level of the surface of the contact element 108 extends, an electrical contact between the contact element 110 and the contact element 108 formed where the track 126 from the thick film 102 towards the contact point 128 emerges.

For this symmetrically the right contact is formed in the same way, wherein the lower contact element is a conductor track 130 that is from the thick film 102 stands out and in a contact point 132 ends.

The contact between the contact element 108 and the contact element 110 takes place in the contact area 134 , like in the 1 represented and on the opposite side, the contacting of the contact elements 112 and 114 in the contact area 136 , as also in the 1 shown.

The lower contact element 108 and or 112 may alternatively or additionally also at other locations from the thick film 102 stand out as in the 1 also shown so that the contact areas 138 respectively. 140 are formed, in which also takes place an electrical contacting of the respective lower and upper contact elements.

The 3 shows a further embodiment, which differs from the embodiment according to FIG 2 this distinguishes that the thick film 102 by two thick layers applied to each other 102 ' and 102 '' is formed.

This results in a thick layer with a particularly large layer thickness, since the layer thickness of the individual thick layers 102 ' and 102 '' add up.

In the end areas 118 respectively. 122 are on the surface of the upper thick film 102 '' in each case further upper contact elements 110 '' respectively. 114 '' formed, which also extend over the respective flank region away, wherein in the 3 only the left flank area 120 is shown in order to form an electrical contact with the respectively lower upper contact element, which in the 3 for the upper contact element 110 ' is shown as an example. The first contact 104 In this embodiment, therefore, by the contact element 108 as well as the upper contact elements 110 ' and 110 '' educated; The same applies to the second contact 106 passing through the lower contact element 112 as well as the upper contact elements 114 ' and 114 '' is formed.

For producing a pulse resistance 100 according to the embodiments of 2 or 3 The procedure is that first the substrate 116 is provided, which is coated with a copper layer. At the substrate 116 it may be, for example, a printed circuit board blank or the blank of a printed circuit board intermediate layer. The substrate 116 is then subjected to a structuring step to the contact elements 108 and 112 train. Subsequently, on the substrate 116 the thick film 102 applied, preferably by a printing process, such as by screen printing.

The thick layer 102 is thereby applied so that they are between the contact elements 108 and 112 and extends across them. After the thick film 102 is dried, in a further step, the upper contact elements 110 and 114 or in the embodiment of the 3 the upper contact elements 110 ' and 114 ' applied. This can be done by printing technology, such as by screen printing or tampo printing or another printing method, which allows the printing of a three-dimensional conductive structure. For the printing of the upper contact elements, for example, a conductive paste is used, such as a Silberleitpaste.

In the embodiment according to 3 then becomes the thick layer 102 '' printed on the then the other upper contact elements 110 '' respectively. 114 '' be printed.

The 4 shows an alternative embodiment of a pulse resistor according to the invention 100 , In this embodiment is opposite to the substrate 116 another substrate 142 arranged. The substrate 116 can as in the embodiments according to 1 to 3 be structured. The substrate 142 may have an identical structuring, that is, on the substrate 142 become a contact element 108 ' and a contact element 112 ' educated.

The contact elements 108 and 108 '' be outside the thick film 102 through a via 146 connected, which, for example, the opposing contact points 128 respectively. 128 ' the contact elements electrically connected to each other, so that thereby the contact 104 is formed. In a similar way can also contact 106 be formed. This embodiment is particularly advantageous, since the resulting electric flow field is particularly homogeneous, as in the 4 shown.

For producing the pulse resistance 100 in the embodiment according to 4 can be done so that first the copper-coated substrates 116 and 142 for the realization of the contact elements 108 and 112 respectively. 108 ' and 112 ' be structured. On the substrate 116 then becomes the thick film 102 applied and indeed as in the embodiment according to 2 the case is. The thick film is then dried.

Before curing the thick film becomes the substrate 142 with the contact elements 108 ' and 112 ' down direction on the substrate 116 pressed so that the contact elements 108 ' and 112 ' a little way into the thick layer 102 penetrate and plastically deform. Then the vias 146 . 148 between the substrates 116 and 142 made to the contact elements 108 and 108 ' on the one hand, and 112 and 112 ' on the other hand for the realization of the contacts 104 respectively. 106 electrically connect.

LIST OF REFERENCE NUMBERS

100

pulse resistance

102, 102 ', 102' '

thick film

104

Contact

106

Contact

108, 108 '

lower contact element

110, 110 ', 110' '

upper contact element

112, 112 '

lower contact element

114, 114 ', 114' '

upper contact element

116

substratum

118

end

120

flank area

122

end

124

flank area

126

conductor path

128

contact point

130

conductor path

132

contact point

134

contact area

136

contact area

138

contact area

140

contact area

142

substratum

144

longitudinal direction

146

Via

148

Via

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Ken Gilleo: Polymer Thick Film. Van Nostrand Reinhold, New York 1996, Chapter 2, pages 21 ff. [0005]

Claims (20)

Pulse resistance with a thick film ( 102 ), with a first contact ( 104 ) and a second contact ( 106 ) for electrically contacting the thick film, wherein the first contact and the second contact in a longitudinal direction ( 144 ) of the thick film are spaced apart, and wherein the first contact is first ( 108 ) and second ( 110 ) Has contact elements which are spaced from each other in a transverse direction of the thick film, and wherein the second contact is first ( 112 ) and second ( 114 ) Comprises contact elements which are spaced from each other in a transverse direction of the thick film, wherein the first and second contact elements of the first contact outside the thick film in at least one contact region ( 134 . 138 ) are electrically contacted with each other, wherein the first and second contact elements of the second contact outside of the thick film in at least one contact region ( 136 . 140 ) are electrically contacted with each other, wherein between the first and second contact elements, the thick film is located. Pulse resistor according to claim 1, wherein the first contact elements on a substrate ( 116 ) and the thick film is deposited on the substrate so as to extend over the first contact elements, the second contact elements being disposed on a surface of the thick film, the first contact elements protruding from the thick film and the second contact elements projecting over each other Flank ( 120 . 124 ) of the thick film extend to electrically contact each other with the respective first contact elements outside the thick film. Pulse resistor according to claim 2, wherein an end region ( 118 . 122 ) of the thick film by a flank region ( 120 . 124 ) is completed, in which the thick film has an initially curved and then vertically downwardly extending edge, wherein the upper contact element ( 110 . 114 ) is coated on the flank area in a layered manner and extends in the direction of the surface of the substrate at least to the level of the upper side of the lower contact element ( 108 . 112 ). Pulse resistor according to claim 2 or 3, wherein the electrical contacting of the second contact elements with the respective first contact elements in the plane of the first contact elements takes place. Pulse resistor according to claim 4, comprising a plurality of second contact elements, which are arranged one above the other, wherein an upper second contact element ( 110 '' . 114 '' ) extends over the edge of the thick film so far that with the underlying second contact element ( 110 ' . 114 ' ) an electrical contact is formed. Pulse resistor according to one of the preceding claims, wherein the substrate is a printed circuit board, in particular a printed circuit board made of epoxy resin, in particular a glass-fiber-reinforced printed circuit board. Pulse resistor according to one of the preceding claims, wherein the first contact elements are formed by a structured copper coating. Pulse resistor according to one of the preceding claims, wherein the second contact elements are each formed by a printed conductive three-dimensional structure. Pulse resistor according to one of the preceding claims, having first and second opposing substrates ( 116 . 142 ), wherein on the first substrate, the first contact elements ( 108 . 112 ) and on the second substrate, the second contact elements ( 108 ' . 112 ' ) are arranged, with a first Via ( 146 ) for electrically contacting the first and second contact elements of the first contact and with a second via (FIG. 148 ) for electrically contacting the first and second contact elements of the second contact, the vias extending outside the thick film between the first and second substrates. Pulse resistor according to one of the preceding claims, wherein the thickness of the thick film between the first and second contacts is more than 60 μm, preferably more than 70 μm, in particular more than 100 μm. Printed circuit board with at least one substrate, on which at least one pulse resistor according to one of the preceding claims is formed. Electrical or electronic device with a pulse resistor or a printed circuit board according to one of the preceding claims. Apparatus according to claim 12, which is a residual current circuit breaker, the residual current circuit breaker being designed to divert a fault current across the pulse resistor. Apparatus according to claim 12, which is a defibrillator and the pulse resistor is connected as a protective resistor to protect the operating personnel of the defibrillator against electric shock. Method for producing a pulse resistor and / or a printed circuit board for an electrical or electronic device according to one of the preceding claims, comprising the following steps: Structuring of a printed circuit board blank for producing the first contact elements ( 108 . 112 ), - application of the thick film ( 102 ) on the structured printed circuit board, - application of the second contact elements ( 110 . 114 ; 108 ' . 112 ' ) on the thick film and training the electrical contact ( 134 . 136 . 138 . 140 ) between the first and second contact elements of the first and second contacts. Method according to claim 15, wherein the second contact elements are arranged on the end regions ( 118 . 122 ) of the thick film are printed. The method of claim 16, wherein the printing of the second contact elements by screen printing or tampo printing of a conductive paste, in particular silver conductive paste, takes place. A method according to claim 16 or 17, wherein a further thick film ( 102 '' ) is applied, on the end regions of which further second contact elements ( 110 '' . 114 '' ) are printed so that the other second contact elements with the underlying second contact elements ( 110 ' . 114 ' ) are contacted electrically. A method according to claim 15, wherein a printed circuit board intermediate layer for producing the second contact elements ( 108 ' . 112 ' ) and wherein after drying and prior to curing of the thick film, the second contact elements are applied by pressing the printed circuit board intermediate layer so that the thick film plastically deforms. The method of claim 19, wherein the first and second contact elements of the first and second contacts are each connected by a via (FIG. 146 . 148 ), which runs outside the thick film.

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