METHOD FOR PRODUCING A PLURALITY OF RESISTANCE MODULAR UNITS OVER A CERAMIC SUBSTRATE

Abstract

A method of manufacturing resistor units that each comprise a carrier comprising resistor elements including ends with a respective first and second electrical terminal is disclosed. The method includes: a) providing a carrier plate; b) forming strips of a resistor material at the lower side of the carrier plate in a regular pattern such that a respective row of strips of the resistor material is formed along a longitudinal direction; c) forming a plurality of zones of an electrically conductive material at the lower side of the carrier plate in a regular pattern such that a respective row of zones of the electrically conductive material is formed along the longitudinal direction; and d) cutting through the carrier plate by regular transverse incisions, first longitudinal incisions, and second longitudinal incisions such that a respective resistor unit and a respective residual section are alternately formed along a transverse direction.

Claims

1. A method of manufacturing a plurality of resistor units that each comprise a carrier having a group of resistor elements each including ends provided with a respective first and second electrical terminal, the method comprising: a) providing a carrier plate that has an upper side and a lower side; b) forming a plurality of strips of a resistor material at the lower side of the carrier plate, that have a first end and a second end along a transverse direction, in a regular pattern such that a respective row of the resistor material is formed along a longitudinal direction that extends perpendicular to the transverse direction and such that a plurality of such rows are arranged next to one another in the transverse direction; c) forming a plurality of zones of an electrically conductive material at the lower side of the carrier plate, that have a first end, an intermediate region, and a second end along the transverse direction, in a regular pattern such that a respective row of zones of the electrically conductive material is formed along the longitudinal direction and such that a plurality of such rows are arranged next to one another in the transverse direction, wherein the rows of the resistor material and the rows of zones of the electrically conductive material are arranged alternately in the transverse direction, and wherein, with the exception of border regions of the carrier plate, the strips of the resistor material overlap the first end of a respective zone of the electrically conductive material at their first ends and overlap the second end of a respective zone of the electrically conductive material at their second ends; and d) cutting through the carrier plate by regular transverse incisions along the transverse direction, first longitudinal incisions along the longitudinal direction, and second longitudinal incisions along the longitudinal direction such that the transverse incisions extend between groups of strips of the resistor material that are associated with one another and that are adjacent to one another in the longitudinal direction, such that furthermore the first longitudinal incisions detach the first ends from the intermediate regions of zones of the electrically conductive material, and such that the second longitudinal incisions detach the second ends from the intermediate regions of a respective row of zones of the electrically conductive material such that a respective resistor unit and a respective residual section of the carrier plate are alternately formed along the transverse direction, said residual section including detached intermediate regions of a row of zones of the electrically conductive material.

2. The method according to claim 1, wherein the respective resistor unit formed by the cutting through of the carrier plate includes a section of the carrier plate that forms the carrier of the resistor unit; a group of strips of the resistor material that form the group of resistor elements of the resistor unit; a number of first ends of zones of the electrically conductive material that form the first electrical terminals of the resistor elements; and a number of second ends of zones of the electrically conductive material that forms the second electrical terminals.

3. The method according to claim 1, wherein mutual spacings of the transverse incisions and mutual spacings of the first and second longitudinal incisions are selected such that the respective formed resistor unit has a width of less than 0.6 mm and a length of less than 0.8 mm.

4. The method according to claim 1, wherein the group of strips of the resistor material comprises two strips of the resistor material.

5. The method according to claim 1, wherein the strips of the resistor material of the formed resistor unit are of equal size.

6. The method according to claim 1, wherein the strips of the resistor material of the formed resistor unit are of different sizes, in particular with a different width transversely to the extent of the strips of the resistor material between the first end and the second end.

7. The method according to claim 1, wherein the carrier plate comprises a ceramic substrate.

8. The method according to claim 1, wherein the resistor material and the electrically conductive material are only applied to the lower side of the carrier plate.

9. The method according to claim 1, wherein step b) of forming the plurality of strips of the resistor material comprises: applying a metal layer to the lower side of the carrier plate by cathode atomization; and local removal of the metal layer by vaporization.

10. The method according to claim 1, wherein step c) of forming the plurality of zones of the electrically conductive material comprises: printing the lower side of the carrier plate with an electrically conductive paste.

11. The method according to claim 1, wherein the cutting through of the carrier plate in step d) takes place by means of a laser beam.

12. The method according to claim 1, wherein the electrical resistance of a respective strip of the resistor material is measured before the cutting through of the carrier plate by the first and second longitudinal incisions, wherein contact probes are applied to that zone of the electrically conductive material that overlaps the first end of the respective first strip of the resistor material and to that zone of the electrically conductive material that overlaps the second end of the respective strip of the resistor material.

13. A resistor unit manufactured in accordance with the method according to claim 1, the resistor unit comprising a carrier, a group of resistor elements arranged at the lower side of the carrier, first electrical terminals that are connected to a respective first end of the resistor elements, and second electrical terminals that are connected to a respective second end of the resistor elements, wherein the resistor unit has a width of less than 0.6 mm and a length of less than 0.8 mm.

14. The method according to claim 3, wherein the width is in a range from approximately 0.3 mm to approximately 0.34 mm.

15. The method according to claim 3, wherein the length is in a range from approximately 0.54 mm to approximately 0.62 mm.

16. The resistor unit according to claim 13, wherein the width is in a range from approximately 0.3 mm to approximately 0.34 mm.

17. The resistor unit according to claim 13, wherein the length is in a range from approximately 0.54 mm to approximately 0.62 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The invention will be described in the following by way of example with reference to an advantageous embodiment and to the enclosed drawing. There are shown, schematically in each case,

[0033] FIG. 1 step a) of an embodiment of a method in accordance with the invention of manufacturing a plurality of resistor units;

[0034] FIG. 2 step b) of the embodiment of FIG. 1;

[0035] FIG. 3 step c) of the embodiment of FIG. 1;

[0036] FIG. 4 a function check of the embodiment of FIG. 1;

[0037] FIG. 5 step d) of the embodiment of FIG. 1; and

[0038] FIG. 6 the lower view of an embodiment of a resistor unit in accordance with the invention.

DETAILED DESCRIPTION

[0039] FIG. 1 shows a detail of a carrier plate 10 in accordance with step a) of an embodiment of a method in accordance with the invention of manufacturing a plurality of resistor units. The carrier plate 10 can be formed from a ceramic substrate that forms an electrically insulating carrier device for receiving a resistor material and an electrically conductive material. In FIG. 1, arrows and the letters “Q”, “L” designate a transverse direction Q and a longitudinal direction L orthogonal thereto. The transverse direction Q and the longitudinal direction L here define two reference directions that extend perpendicular to one another and do not necessarily designate a longitudinal shape of the carrier plate 10 or of the formed resistor units. The carrier plate 10 comprises an upper side 12 and a lower side 14 that is shown in a plan view in FIG. 1.

[0040] In step b) of the method in accordance with the invention that is shown in FIG. 2, a plurality of strips 16 of a resistor material are applied to the lower side 14 of the carrier plate 10 in a regular pattern. The strips 16 are arranged in rows 18 that extend in the longitudinal direction L and that are arranged next to one another with respect to the transverse direction Q. FIG. 2 here shows a detail of the carrier plate 10 in which sixteen strips 16 are arranged by way of example in four parallel rows 18. The arrangement of the strips 16 can be continued in accordance with the pattern shown in both of the directions Q and L orthogonal to one another. The strips 16 have a first end 20 and a second end 22 along the transverse direction Q. The application of the resistor material can take place, for example, by cathode atomization, so-called sputtering. This technique offers the advantage that the resistor material can be applied to the lower side 14 of the carrier plate 10 in a layer of uniform thickness and that layers of smaller thickness can also be produced. Other methods are, however, also conceivable to apply the resistor material to the carrier plate 10.

[0041] To only apply the resistor material to the carrier plate 10 at the positions of the strips 16, the resistor material can, for example, be applied to the carrier plate in continuous regions extending in parallel along the longitudinal direction L. A laser that removes or vaporizes resistor material at predefined spacings along the longitudinal direction L can be used to form the individual strips 16 (segmentation). A precise and exactly positioned arrangement of the strips 16 can be achieved by means of this method. Alternatively, the lower side 14 of the carrier plate 10 can, for example, be covered prior to the application of the resistor material by a mask, not shown, that has apertures at the position of the strips 16 and can, for example, be produced from plastic. After the application of the resistor material and the subsequent removal of the mask, a regular pattern of a plurality of strips 16 of the resistor material thus results on the carrier plate 10. However, other methods are also conceivable that can be applied alone or in combination with a mask to form the strips 16 of the resistor material precisely and simply and efficiently in this process on the carrier plate 10.

[0042] In the embodiment shown, the strips 16 of the resistor material are of equal size with respect to one another, i.e. the strips 16 of the resistor material have the same widths and lengths and the same thicknesses. The strips 16 of the resistor material accordingly have the same electrical resistance values. In other embodiments, the strips can have different sizes to thus produce strips 16 of the resistor material having different electrical resistance values. This can be achieved in a simple manner by a variation of the length of the strips along the longitudinal direction L.

[0043] FIG. 3 shows step c) of the method in accordance with the invention in which a plurality of zones 24 of an electrically conductive material are formed at the lower side 14 of the carrier plate 10. The zones 24 of the electrically conductive material are applied to the carrier plate 10 in a regular pattern, with the zones 24 of the electrically conductive material being arranged in a plurality of rows 26 that extend in the longitudinal direction L and are arranged next to one another with respect to the transverse direction Q. In this respect, the rows 26 of the zones 24 of the electrically conductive material extend in parallel with the rows 18 of the strips 16 of the resistor material and alternate with them in the transverse direction Q so that the plurality of rows 26 of the zones 24 of the electrically conductive material substantially correspond to the number of rows 18 of the strips 16 of the resistor material.

[0044] The zones 24 of the electrically conductive material have a respective first end 28, an intermediate region 30, and a second end 32 along the transverse direction Q, wherein, with the exception of at the marginal regions of the carrier plate 10, the strips 16 of the resistor material overlap the first end 28 of a respective zone 24 of the electrically conductive material at their first ends 20 and overlap the second end 32 of a respective zone 24 of the electrically conductive material at their second ends 22. The regular pattern of the zones 24 is coordinated with the regular pattern of the strips 16, and indeed such that a respective overlap region with a respective zone 24 is formed at each strip 16 at its first end 20 and an overlap region with a respective zone 24 is formed at its second end 22.

[0045] The zones 24 of the electrically conductive material can, for example, comprise a silver-palladium alloy. The zones 24 can be formed by application in the form of a paste, in particular by printing the lower side 14 of the carrier plate 10. The electrically conductive paste is for this purpose applied to a printing plate, not shown, in a regular pattern corresponding to a predefined arrangement of the zones 24. A plurality of zones 24 of the electrically conductive material can be efficiently produced in a printing process by means of this technique.

[0046] Step b) shown in FIG. 2 of forming the plurality of strips 16 of the resistor material and step c) shown in FIG. 3 of forming the plurality of zones 24 of the electrically conductive material can also be carried out in reverse order or simultaneously in part. The overlapping of the strips 16 of the resistor material with the zones 23 of the electrically conductive material can thus either take place such that the respective strip 16 of the resistor material partly covers the respective zones 24 of the electrically conductive material or such that the respective zones 24 of the electrically conductive material partly cover the respective strip 16 of the resistor material.

[0047] An optional step of checking the functionality and/or of characterizing the formed resistor units is shown in FIG. 4. For this purpose, contact probes 34, in particular Kelvin probes, are brought into contact with the zones 24 of the electrically conductive material and are associated with a respective strip 16 of the resistor material. Only the contact points of the contact probes 34 are illustrated in FIG. 4.

[0048] The contact probes 34 are applied at that zone 24 of the electrically conductive material that overlaps the first end 20 of the respective strip 16 of the resistor material and at that zone 24 of the electrically conductive material that overlaps the second end 22 of the respective strip 16 of the resistor material. In this respect, the contact probes 36 are configured to measure, for example by means of the Kelvin method, the electrical resistance of a respective strip 16 of the resistor material and thus the electrical resistance of the respective resistor element to be formed. Whether the resistance values are in a predefined range or whether deviations are present can then be determined from the measured values.

[0049] The application of the contact probes 34 at the respective zones 24 is facilitated by the carrying out of the function test after step c) of the method and before the cutting through of the carrier plate 10 in accordance with step d) since the surface of the intermediate regions 30 of the zones 24 is also available for this purpose at this point in time. At least one pair of contact probes 34 (one contact probe 34 each at the two sides of the respective strip 16) is required for the check of the strips 16 of the resistor material, with a plurality of pairs of contact probes 34 also being able to be used to test a plurality of strips 16 simultaneously.

[0050] FIG. 5 shows step d) of the method in accordance with the invention in which a plurality of resistor units 44 are separated from the carrier plate 10 occupied by rows 18 of strips 16 of the resistor material and by rows 26 of zones 24 of the electrically conductive material by a sequence of incisions. The sequence of incisions comprises transverse incisions 36 along the transverse direction Q, first longitudinal incisions 38 along the longitudinal direction L and second longitudinal incisions 40 along the longitudinal direction L.

[0051] The regular arrangement of the transverse incisions 36, of the first longitudinal incisions 38, and of the second longitudinal incisions 40 corresponds to the regular pattern of the strips 16 of the resistor material and to the regular pattern of the zones 24 of the electrically conductive material. The transverse incisions 36 here extend between groups 42 of strips 16 of the resistor material associated with one another and adjacent to one another in the longitudinal direction L. The groups 42 each comprise two strips 16 in the described embodiment. The groups 42 can, however, also comprise more strips 16 or only one strip 16. The number of strips 16 of the resistor material of the resistor units 44 can be changed by a simple adaptation of the incision spacings.

[0052] The first longitudinal incisions 38 detach the first ends 28 from the intermediate regions 30 of a respective row 26 of zones 24 of the electrically conductive material. In contrast, the second ends 32 are detached from the intermediate regions 30 of a respective row 26 of zones 24 of the electrically conductive material by the second longitudinal incisions 40. A respective resistor unit 44 and a respective residual section 46 of the carrier plate are thus alternately formed by the sequence of incisions 36, 38, 40 along the transverse direction Q. The respective residual section 46 comprises detached intermediate regions 30 of a row 26 of zones 24 of the electrically conductive material and is no longer required after the end of the manufacturing method.

[0053] It is understood that the transverse incisions 36, the first longitudinal incisions 38, and the second longitudinal incisions 40 are generally carried out in any desired order for the cutting through of the carrier plate 10. The cutting through of the carrier plate 10 can be carried out, for example, by means of a laser beam, which permits a precise and efficient structuring of the carrier plate 10 in one work process.

[0054] The strips 16 of the resistor material can generally have a longitudinal shape (in particular substantially rectangular), with the respective longitudinal axis of the strips 16 of the resistor material being able to be aligned along the longitudinal direction L or along the transverse direction Q. Alternatively to this, the strips 16 of the resistor material can, for example, also have a substantially square shape.

[0055] FIG. 6 shows by way of example in a lower view a resistor unit 44 of the plurality of resistor units that are generated by the steps a) to d) of the explained method. Each resistor unit 44 accordingly comprises a section of the carrier plate 10 that forms the carrier 48 of the resistor unit 44, a group 42 of strips 16 of the resistor material that form a group of resistor elements 50 of the resistor unit 44, a plurality of first ends 28 of zones 24 of the electrically conductive material that form first electrical terminals 52 of the resistor elements 50, and a plurality of second ends 32 of zones 24 of the electrically conductive material that form second electrical terminals 54 of the resistor elements 50. The first electrical terminals 52 are here connected to a respective first end of the resistor elements 50 and the second electrical terminals 54 are connected to a respective second end of the resistor elements 50. The resistor unit 44 is in particular suitable for an assembly and a contacting in a flip chip construction by the arrangement of the resistor elements 50 at the lower side of the carrier 48.

[0056] In the method, the mutual spacings of the transverse incisions 36 and the mutual spacings of the first and second longitudinal incisions 38, 40 are selected such that the resistor unit 44 has a width of less than 0.6 mm and a length of less than 0.8 mm, with the width in particular being able to be in a range from 0.3 mm to 0.34 mm and the length in particular being able to be in a range from 0.54 mm to 0.62 mm. Due to its small size, that can be achieved by the method in accordance with the invention, the resistor unit 44 can be used in electrical components or devices that require a particularly small and compact design of the resistor units.

REFERENCE NUMERAL LIST

[0057] 10 carrier plate [0058] 12 upper side [0059] 14 lower side [0060] 16 strips of the resistor material [0061] 18 rows of the strips 16 of the resistor material [0062] 20 first end of a strip 16 of the resistor material [0063] 22 second end of a strip 16 of the resistor material [0064] 24 zone of the electrically conductive material [0065] 26 row of the zones 24 of the electrically conductive material [0066] 28 first end of a zone 24 of the electrically conductive material [0067] 30 intermediate region of a zone 24 of the electrically conductive material [0068] 32 second end of a zone 24 of the electrically conductive material [0069] 34 contact probe [0070] 36 transverse incision [0071] 38 first longitudinal incision [0072] 40 second longitudinal incision [0073] 42 groups of adjacent strips [0074] 44 resistor unit [0075] 46 residual section [0076] 48 carrier [0077] 50 resistor element [0078] 52 first electrical terminal [0079] 54 second electrical terminal [0080] Q transverse direction [0081] L longitudinal direction