Component carrier having an ESD protective function and method for producing same

Patent metadata

Field	Value
Publication number	US-10490322-B2
Application number	US-201716064809-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jan 11, 2016
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A green film composed of varistor material laminated on a ceramic main body, which is provided with metallizations on both sides, and is sintered to form a varistor layer. A terminating electrode pair completes the arrangement and allows the varistor layer to be operated as a varistor. The upper second electrode pair can serve directly as a terminal contact for mounting an electrical component.

First claim

The invention claimed is:

1. A component carrier
comprising—a ceramic main body having electrical terminal pads on a first surface and a first electrode pair on a second surface, wherein electrical terminal pads and first electrode pair are connected to one another via plated-through holes,
comprising—a varistor layer laminated above the first electrode pair, and
comprising—a second electrode pair, which is applied above the varistor layer and is electrically connected in parallel with the first electrode pair,
wherein the varistor layer is laterally dimensioned such that it is circumferentially spaced apart from the edges of the component carrier,
wherein a passivation layer is arranged above the varistor layer and the second electrode pair such that the varistor layer is enclosed on all sides and completely between the ceramic main body, the second electrode pair and the passivation layer and only terminal contacts remain free of and not covered by the second electrode pair, and wherein the passivation layer includes glass or a polymer.

2. The component carrier according to claim 1 ,
wherein the second electrode pair comprises a solderable material or is provided with a solderable surface layer.

3. The component carrier according to claim 1 ,
wherein the main body comprises aluminum nitride.

4. The component carrier according to claim 1 ,
wherein at least the second electrode pair comprises a copper-containing material.

5. The component carrier according to claim 1 ,
wherein at least one internal electrode is arranged between first and second electrode pairs, said at least one internal electrode being embedded into the varistor layer and being electrically floating or electrically connected to a respective electrode of the first electrode pair.

6. A method for producing a component carrier comprising the following steps:
providing a monolithic ceramic main body,
providing plated-through holes through the main body,
printing electrical terminal pads on a first surface of the main body,
printing a first electrode pair on the second surface,
laminating a green film or a preformed stack of green films over the whole area above the first electrode pair on the ceramic main body, said green film being able to be converted into a varistor layer by sintering,
structuring the green film such that a circumferential marginal region of the second surface of the main body is also exposed besides an access to the first electrode pair,
sintering the green film and converting into the varistor layer,
printing a second electrode pair onto the varistor layer and the exposed region of the first electrode pair such that first and second electrode pairs are electrically interconnected and an overlap of an electrode of the first electrode pair with the opposite electrode of the second electrode pair jointly defines an active varistor region situated therebetween.

7. The method according to claim 6 ,
wherein one or a plurality of metallizations, selected from terminal pads, first electrode pair and second electrode pair, is produced by printing a paste containing Cu and glass portions, which has a solderable surface after firing.

8. The method according to claim 6 ,
wherein the laminated green film is structured with the aid of a laser.

9. The method according to claim 6 ,
wherein laminating the green film comprises laminating a prelaminated stack of a plurality of green films, wherein at least one internal electrode printed onto a green film is integrated in the stack.

10. The method according to claim 6 ,
wherein the internal electrode is printed in a structured fashion and does not extend over the entire varistor layer,
wherein the green film, after laminating, is structured by material removal such that at least one internal electrode intersects one of the exposed edges of the green film,
wherein, after printing the second electrode pair, one of the electrodes thereof electrically contacts the internal electrode.

11. The method according to claim 6 ,
wherein, after laminating the green film, before or after printing the second electrode pair, a passivation layer is applied and structured such that in the first case only the surface region provided for the second electrode pair remains free of the passivation layer,
or wherein in the second case the printed second electrode pair remains free only in a region in which solderable terminal contacts are subsequently produced by reinforcement of the second electrode pair.

12. The method according to claim 6 ,
wherein after laminating the green film, after printing the second electrode pair, a passivation layer is applied and structured,
wherein the printed second electrode pair remains free only in a region in which solderable terminal contacts are subsequently produced by reinforcement of the second electrode pair,
wherein the reinforcement is effected by electrodeposition of a solderable metal layer onto the exposed region of the second electrode pair.

13. The method according to claim 6 ,
wherein a large-area main body is provided which is able to be singulated into a multiplicity of component carriers,
wherein the large-area main body, after the completion of the second electrode pair or the solderable terminal contacts, is singulated into the multiplicity of component carriers by separation of the main body, wherein the separation of the main body is effected exclusively in the marginal region and at a distance from the respective edge of the varistor layer.

14. A method for producing a component carrier comprising the following steps:
providing a monolithic ceramic main body,
providing plated-through holes through the main body,
printing electrical terminal pads on a first surface of the main body,
printing a first electrode pair on the second surface,
laminating a green film or a preformed stack of green films over the whole area above the first electrode pair on the ceramic main body, said green film being able to be converted into a varistor layer by sintering,
structuring the green film such that a circumferential marginal region of the second surface of the main body is also exposed besides an access to the first electrode pair,
sintering the green film and converting into the varistor layer,
printing a second electrode pair onto the varistor layer and the exposed region of the first electrode pair such that first and second electrode pairs are electrically interconnected and an overlap of an electrode of the first electrode pair with the opposite electrode of the second electrode pair jointly defines an active varistor region situated therebetween,
wherein a passivation layer is applied such that the varistor layer is enclosed on all sides and completely between the ceramic main body, the second electrode pair and the passivation layer.

Assignees

• Epcos Ag

Inventors

• Brunner Sebastian
• Faistauer Christian
• Pudmich Günter
• Payr Edmund
• Wiesbauer Kurt

Classifications

• H01C1/14

  Terminals or tapping points specially adapted for resistors; Arrangements of terminals or tapping points on resistors · CPC title

• H01C17/281

  by thick film techniques · CPC title

• H01C7/1006 Primary

  Thick film varistors · CPC title

• H01C17/065

  by thick film techniques, e.g. serigraphy · CPC title

• H01C7/102

  Varistor boundary, e.g. surface layers (H01C7/12 takes precedence) · CPC title