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DE-102016100585-B4 - Carrier plate with protective function and manufacturing process

DE102016100585B4DE 102016100585 B4DE102016100585 B4DE 102016100585B4DE-102016100585-B4

Abstract

Carrier plate (TP) for an electrical component (BE) - with a mechanically stable base body (GK) which has external contacts (AK) on a bottom side (US) and connection surfaces (AF) for the component (BE) on a top side (OS), - with a recess (AN) in which an ESD protection element (SE) discrete from the base body (GK) is at least partially embedded, wherein the electrical connections of the protection element (SE) are accessible from the top (OS) or the bottom (US) of the base body (GK), - in which the protective element (SE) is mechanically firmly embedded in the recess (AN) of the base body (GK) by means of a connecting element (VM), wherein the connecting element (VM) does not fill all the spaces between the protective element (SE) and the outer walls of the recess (AN), - in which the electrical connections of the protective element (SE) are connected via a structured metallic layer (SM) to the contact surfaces (AF) on the top (OS) or the external contacts (AK) on the bottom (US).

Inventors

  • Christian Faistauer
  • Klaus-Dieter Aichholzer
  • Sebastian Brunner
  • Edmund Payr
  • Günther Pudmich

Assignees

  • TDK ELECTRONICS AG

Dates

Publication Date
20260513
Application Date
20160114

Claims (20)

  1. Carrier plate (TP) for an electrical component (BE) - with a mechanically stable base body (GK) having external contacts (AK) on a bottom surface (US) and connection surfaces (AF) for the component (BE) on a top surface (OS), - with a recess (AN) in which an ESD protection element (SE), discrete from the base body (GK), is at least partially embedded, wherein the electrical connections of the protection element (SE) are accessible from the top surface (OS) or the bottom surface (US) of the base body (GK), - wherein the protection element (SE) is mechanically firmly embedded in the recess (AN) of the base body (GK) by means of a connecting element (VM), wherein the connecting element (VM) does not fill all the spaces between the protection element (SE) and the outer walls of the recess (AN), - wherein the electrical connections of the protection element (SE) are connected to the connection surfaces (AF) on the top surface (OS) or the external contacts (AK) via a structured metallic layer (SM). are connected to the underside (US).
  2. Carrier plate (TP) according to Claim 1 , whereby the protective element (SE) is fastened in the recess (AN) at only a few points.
  3. Carrier plate (TP) according to one of the preceding claims, wherein the recess (AN) has a cross-section corresponding to the outer dimensions of the protective element (SE).
  4. Carrier plate (TP) according to one of the preceding claims, wherein the recess (AN) is provided in the underside (US) of the base body (GK) and the protective element (SE) is flush with the underside (US).
  5. Carrier plate (TP) according to one of the preceding claims, wherein the external contacts (AK) and the connection surfaces (AF) are electrically connected via vias (DK).
  6. Carrier plate (TP) according to one of the preceding claims, wherein the recess (AN) extends under the connection surfaces (AF).
  7. Carrier plate (TP) according to one of the preceding claims, wherein the base body (GK) is crystalline, ceramic, metallic or glassy.
  8. Carrier plate (TP) according to one of the preceding claims, wherein the depth of the recess is less than the thickness of the base body.
  9. Carrier plate (TP) according to one of the preceding claims, wherein the protection element (SE) is a varistor, a Zener diode, a TVS device or another non-linear element.
  10. Carrier plate (TP) according to one of the preceding claims, wherein the connecting element (VM) comprises a plastic or ceramic material, glass or a metal.
  11. Carrier plate (TP) according to one of the preceding claims, wherein the connecting means (VM) comprises a ceramic material, glass or a metal.
  12. Carrier plate (TP) according Claim 11 , wherein the connecting agent (VM) is a ceramic material, glass or a metal.
  13. Carrier plate (TP) according to one of the preceding claims, wherein an outwardly facing surface of the protective element (SE) is flush with a surface of the base body (GK), and wherein the structured metallic layer (SM) rests on the two flush surfaces.
  14. Carrier plate (TP) according to one of the preceding claims, wherein the base body (GK) has a multi-layer structure and a wiring level (SM) is present inside the base body (GK).
  15. Carrier plate (TP) according to one of the preceding claims, in which the recess (AN) is arranged between or below the connection surfaces (AF) for the component (BE), in which the protective element (SE) is recessed so deeply into the base body (GK) that the component (BE) can be applied at least partially over the protective element (SE).
  16. Carrier plate (TP) according to one of the preceding claims, wherein the recess (AN) is formed in the form of a trench that runs transversely over the base body (GK).
  17. Carrier plate (TP) according to one of the Claims 1 until 15 , in which the recess (AN) is enclosed laterally by the base body (GK), and in which the recess (AN) extends vertically through the entire base body (GK).
  18. Carrier plate (TP) according to one of the preceding claims, on which a plurality of component areas with connection surfaces (AF) and at least one recess (AN) are provided, wherein the carrier plate (TP) can be divided into individual carriers, on which each component area for one or more components (BE) is provided.
  19. Method for manufacturing a carrier plate (TP) for a component (BE), - in which a crystalline, ceramic, metallic, or glass substrate (GK) is provided, - in which a recess (AN) for receiving a protective element (SE) is created in a surface of the substrate (GK), - in which a protective element (SE) discrete to the substrate (GK) is at least partially arranged in the recess (AN) and mechanically fixed by means of a connecting element (VM), wherein the connecting element (VM) does not fill all the spaces between the protective element (SE) and the outer walls of the recess (AN), - in which, after fixing the protective element (SE) in the recess (AN) and before applying a structured metallic layer (SM), the protective element (SE) is ground down from a top side until the top side of the protective element (SE) is flush with the top side (OS) of the substrate (GK), - in which a surface of the substrate (GK) is a structured metallic layer (SM) is produced on top of the base body (GK) and the protective element (SE), - in which electrical connection surfaces (AF) for the component (BE) are formed on the top surface (OS) of the base body (GK), - in which the structured metallic layer (SM) overlaps with electrical connections of the protective element (SE) and the connection surfaces (AF) and electrically connects them, or in which the structured metallic layer (SM) forms the connection surfaces (AF) and is structured in such a way that it overlaps one of the electrical connections of the protective element (SE) in each case.
  20. Method according to the preceding claim, wherein the protective element (SE) is fastened in the recess (AN) only at a few points.

Description

The application concerns a carrier plate with a protective function for an electrical component and a low overall height. Varistors can be used to protect sensitive equipment, components, and networks against ESD (Electrostatic Discharge). These are non-linear components whose resistance drops sharply when a certain applied voltage is exceeded. Varistors are therefore suitable for safely dissipating overvoltage pulses. They are made of a zinc oxide ceramic with a granular structure. Varistors are difficult to integrate into multilayer ceramics and are therefore usually used as discrete components. Discrete varistors, on the other hand, have primarily geometric advantages; for example, they can be manufactured very thin. However, this increases the risk of breakage for the panels. Discrete components with varistor function or, more generally, with ESD protection function are soldered directly onto a ceramic substrate, a leadframe, a circuit board or a printed circuit board and electrically connected to the component to be protected. It is also possible to integrate such protective elements into a laminate during its production. Furthermore, it is possible to position the protective element in a recess of the substrate, carrier board, or laminate in such a way that it is adjacent to other electrically conductive structures intended for connection with further components. While this results in a low component height, it requires sufficient assembly area. It is also possible to use a varistor ceramic as a component substrate and to integrate the protective function into the substrate. From the US 2007 / 0 075 323 A1 An arrangement is known in which an LED is mounted on a carrier serving as a heat sink. A varistor element is arranged in a recess of the heat sink. From the US 7 528 422 B2 An LED is known that is arranged in a recess of a substrate. There, the LED is connected to an ESD protection component. From the JP H01- 99 227 A A hybrid integrated circuit structure is known, for which questions of heat dissipation are discussed. The US 2014 / 0 301 054 A1 shows an arrangement in which a Zener diode is potted with a resin to serve as an electrical protection element in the base of a printed circuit board. The US 2011 / 0 001 215 A1 discloses a method for applying an electrical component to a suitable substrate. Other carrier devices for electrical components can be found, for example, in the printed materials. DE 10 2012 212 320 A1 or AT 503 718 A2 known. The object of the present invention is to further improve the integration of a protective function or a protective element into an electrical component. This problem is solved by a carrier plate having the features of claim 1. Advantageous embodiments of the invention and a method for manufacturing a carrier plate can be found in further claims. A carrier plate is proposed that has a mechanically stable base body, similar to those commonly found in known carrier plates. External contacts are provided on the underside of the base body, and connection surfaces for the component are provided on the top side. According to the invention, a recess is provided for the placement of an ESD protection element, in which the ESD element is at least partially embedded. The electrical connections of the protection element are accessible from the top or bottom of the base body. In an alternative embodiment, the protection element is electrically contacted at the bottom of the recess. The electrical connection between the protection element and the component can then be made via vias running through the base body. This makes it possible to bring the corresponding connections to the surface of the base body via vias. The protective element is mechanically fixed in the recess by means of a connecting device. The fixing can be made at only a few points. The protective element is electrically connected to the connection surfaces on the top or the external contacts on the underside of the base body via a structured metallic layer. Such a carrier plate has the advantage that the protective element can be embedded in the base body without significant technical effort. The fastener can be selected to serve solely for the mechanical fixation of the protective element in the recess. Preferably, a fastener is chosen that is compatible with subsequent process techniques, particularly for the later mounting of a component onto the connection surfaces, especially by soldering. The bonding agent thus functions like an adhesive, passing through a liquid or viscous phase at least once before or during the fixing of the protective element in the recess. The bonding agent does not fill all remaining gaps between the protective element and the outer walls of the recess. It is sufficient to fix the protective element in the recess with the bonding agent, which can be achieved by fastening it at just a few points. By at least partially embedding the protective element in the base body, the overa