Housing with a Cavity for a Mechanically-Sensitive Electronic Component and Method for Production

• US 20090127697A1
• Filed: 09/29/2006
• Published: 05/21/2009
• Est. Priority Date: 10/20/2005
• Status: Abandoned Application

• Current Assignee: Epcos AG (TDK Corporation)
• Original Assignee: Epcos AG (TDK Corporation)
• Inventors: Pahl, Wolfgang
• Application Number:
  US12/090,529
• Publication Number:
  US 20090127697A1
• Time in Patent Office: Days
• US Class Current: 257/698
• CPC Class Codes: B81B 7/0054 between other parts not provided for in B81B7/0048 - B81B7/0051
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

An element includes a hollow space for a mechanically sensitive electrical element. The element includes a first housing part and a second housing part rigidly connected to the first housing part via joint surfaces. The element also includes connection surfaces on a base of a recess in the first housing the first housing part being covered by the second housing part to form an enclosed hollow space.

Claims

1. A device having a hollow space for a mechanically sensitive electrical element, the device comprising:

a first housing part; and

a second housing part rigidly connected to the first housing part via joint surfaces, and

connection surfaces on a base of a recess in the first housing part the first housing part being covered by the second housing part to form an enclosed a hollow space, wherein

the mechanically sensitive electrical element comprises a chip having contact surfaces on a surface, and

the mechanically sensitive electrical element is suspended in the hollow space by electrically conductive mountings configured to deform elastically or plastically, the electrically conductive mountings connecting at least one of the contact surfaces to at least one of the connection surfaces.

2. The device of claim 1, wherein the mountings have an expansion reserve and are configured to elastically or plastically absorb tensile and compressive stresses.

3. The device of claim 1, wherein the mountings have a non-linear profile and are bent, angled or slotted.

4. The device of claim 1, wherein the chip comprises electrical contact surfaces on a surface configured to electrically and mechanically connect the chip to the electrically conductive mountings.

5. The device of claim 1, further comprising plated through-holes electrically connecting the connection surfaces to solderable contacts on an outer side of a housing part.

6. Thee device of claim 1, wherein:

the mountings have first and second regions and a longitudinal extent parallel to the base of at least one of the housing parts between first and second regions,

the mountings are each connected by the first region to the electrical connection surfaces on the base,

the mountings each extend toward the second region above the base,

the element is connected by contact surfaces to the second region to form an air gap between the base and the second region.

7. The device of claim 6, wherein the base of the housing part comprises a multi-layer circuit board, comprising plated through-holes that connect the connection surfaces to solderable contacts on the opposite surface.

8. The device of claim 1, wherein the housing part with the recess comprises:

a base plate;

a frame extending above the base plate, and

the second housing part comprises a flat cover layer on the frame.

9. The device of claim 8, wherein the base plate comprises connection surfaces, plated through-holes, and solderable contacts.

10. The device of claim 8, wherein at least a surface of the frame comprises a metal.

11. The device of claim 9, wherein base plate and second housing part each include, one or more of ceramic, LTCC, HTCC, glass, silicon, plastic, liquid-crystalline polymer, a conductor plate laminate, or another circuit carrier.

12. The device of claim 8, wherein the cover layer and base plate are composed of the same material.

13. The device of claim 8, wherein the frame comprises a metallized surface area toward the hollow space.

14. The device of claim 13, wherein the base plate comprises a metallized plate in a peripheral region within the frame, having the metallization that extends continuously from the peripheral region past the inner side of the frame and past the top side of the frame forming a joint surface.

15. The device of claim 8, wherein the cover layer comprises a metal foil or a plastic film coated with metal.

16. The device of claim 1, wherein one of the first and second housing parts comprises a base plate and includes the connection surfaces, plated through-holes, and solderable contacts, wherein the housing part with the recess comprises a metallic cap on the base plate.

17. The device of claim 1, wherein the first and second housing parts are connected at the joint surfaces by glass solder, solder, an adhesive layer, or directly through welding.

18. The device of claim 1, wherein the element comprises a SAW chip, a BAW chip, or a MEMS element.

19. The device of claim 1, wherein the element comprises a frequency-precise or frequency-determining element and includes a resonator in MEMS, SAW, or BAW technology.

20. The device of claim 1, wherein a total number of mountings is greater than a total number of electrical connections and the additional mountings are configured to provide a purely mechanical connection between the element and housing part.

21. The element of claim 1, further comprising a mechanically rigid connection between the element and one of the first and second housing parts, the connection having a cross section that is small relative to the surface area of the element chip.

22. The device of claim 1, wherein the hollow space comprises a hermetically encapsulated space having no organic materials in the interior of the encapsulated space.

23. The device of claim 1, wherein the device consists essentially of materials having a melting point greater than or equal to 260 C.

24. A method for producing a device with a hollow space for a mechanically sensitive electrical element, the method comprising:

preparing a first housing part and a second housing part such that the first and second housing parts match each other at joint surfaces and are shaped so that a hollow space is enclosed between the first and second housing surfaces when the first and second housing parts are connected at the joint surfaces, and

forming solderable contacts on an outside of the first housing part.

connecting the solderable contacts by plated through-holes to contact surfaces on a base of the first housing part facing the hollow space,

applying and structuring a sacrificial layer on the base of the first housing part,

applying a structured metal layer to form mountings the mountings having a first region connected to the contact surfaces and a second region remote from the first region on the structured sacrificial layer,

placing and connecting an element to the second regions of the mountings, and

removing the sacrificial layer form an air gap between the second region of the mountings connected to the element and the base of the first housing part.

25. The method of claim 24, further comprising:

placing the second housing part on the first housing part; and

producing a tight connection between the first and second housing parts.

26. The method of claim 24, wherein:

preparing the first housing part comprises forming a plurality of recesses in a first large surface area housing part wafer;

preparing the second housing part comprises providing a second large surface area housing part;

applying the structured metal layer to form the mountings comprises generating the mountings for all of the plurality of recesses in the first large surface area housing part wafer in a common processing step,

placing and connecting the element to the second regions of the mountings comprises inserting elements into the plurality of recesses of the first housing part wafer and attaching the elements to the mountings,

and the method further comprises connecting the first housing part wafer to the second large surface area housing part enclosing the elements in the recesses, and

separating the connected housing part and housing part wafer into components with individual or with groups of hermetically enclosed elements.

27. The method of claim 24, further comprising installing the elements in an intermediary step in the alignment with the reverse side opposite electrical contact surfaces on an auxiliary carrier, and

removing the auxiliary carrier after connecting the elements to the mountings.

28. The method of claim 24, further comprising applying structured metallization layers on the surfaces of the housing part wafer or elements as mountings.

29. The method of claim 24, further comprising reinforcing the mountings by a polymer layer, above or below the mountings.

30. The method of claim 24, further comprising, after the placement and connection of the elements to the mountings and before the placement of the second housing part, electrically testing the element and based on a result of the testing, performing a trimming process to modify properties of the element by depositing or removing material.

31. The method of claim 24, wherein the sacrificial layer comprises an organic layer configured to decompose thermally without forming a solid residue.

32. The method of claim 24, further comprising performing a soldering or bonding process to connect the elements to the first housing part by means of the mountings.

33. The method of claim 24, further comprising:

generating the sacrificial layer and mountings above the front side of the element carrying the contact surfaces,

placing the elements with the sacrificial layer and mountings on the connection surfaces, and

removing the sacrificial layer to form an air gap between the ends of the mountings connected to the element and the base of the first housing part.

34. The method of claim 24, further comprising suspending two or more equivalent or different elements on mountings in the same hollow space in a housing part.