Module comprising a MEMS component mounted without subjecting same to stress
A model is specified in which a MEMS component is connected to the carrier in a stress-free fashion over a large temperature range. For this purpose, a mechanical connection comprises a compensation structure which bridges a horizontal offset of mounting points by means of a horizontal shoulder and the thermal expansion coefficient of which is suitably selected.
1. An electric module, comprising
a carrier having a first thermal expansion coefficient K 1 , a first mounting point and a second mounting point,
a MEMS component with MEMS structures, a second thermal expansion coefficient K 2 ≠K 1 , a first mounting point and a second mounting point,
a first mechanical connection between the first mounting point of the carrier and the first mounting point of the component,
a second mechanical connection between the second mounting point of the carrier and the second mounting point of the component with a compensation structure with a thermal expansion coefficient K k ,
wherein
the mounting points on the MEMS component are spaced apart by a horizontal distance d 1 and the mounting points on the carrier are spaced apart by a horizontal distance d 2 ,
the values for d 1 and d 2 are selected such that in the case of a change in the temperature the compensation structure compensates the different changes in length of d 1 and d 2 , and in the case of different temperatures the MEMS component is connected in a stress-free fashion to the carrier, and
wherein
the compensation structure bridges the distance Δd=d 2 −d 1 along the connecting direction between the two second mounting points, and
the equation d 2 =d 1 (K K −K 1 )/(K K −K 2 ) is satisfied.
2. The module according to claim 1 , wherein K K
is either larger than the larger of the two values K 1 and K 2 :K K >max (K 1 , K 2 ) or
smaller than the smaller of the two values K 1 and K 2 :K K <min (K 1 , K 2 ).
3. The module according to claim 1 , wherein the compensation structure comprises a horizontal section which is arranged on or above the carrier.
4. The module according to claim 1 , additionally comprising one or more additional compensation structures which connect additional mounting points of the carrier to additional mounting points of the MEMS component.
5. The module according to claim 1 , wherein the first mechanical connection comprises a compensation structure which, together with the other compensation structures, compensates the different changes in length of the carrier and MEMS component in the case of a change in temperature.
6. The module according to claim 1 , in which at least one compensation structure forms an electrical connection between the carrier and MEMS component.
7. The module according to claim 1 , wherein the carrier comprises a ceramic material or an organic circuit board material.
8. The module according to claim 7 , wherein the carrier has a plurality of dielectric layers between which structured metallization layers are arranged.
9. The module according to claim 1 , wherein the MEMS component comprises a body made of a semiconductor material.
10. The module according to claim 1 , wherein at least one compensation structure comprises a metal.
11. The module according to claim 1 , wherein all the compensation structures are arranged radially symmetrically about a center.
12. The module according to claim 1 , wherein at least one compensation structure is connected to a plurality of mounting points on the carrier and/or to a plurality of mounting points on the MEMS component.
13. The module according to claim 1 , wherein the MEMS component has a body with a height ≤700 μm and with a side length between 0.3 mm and 5 mm.
14. A microphone comprising a module according to claim 1 , wherein the MEMS component is an electro-acoustic transducer.
15. The microphone according to claim 14 wherein
the module has three or more compensation structures which are arranged in a rotationally symmetrical fashion about a center, and
the electro-acoustic transducer comprises a sound input in the center.
16. The microphone according to claim 14 , wherein the compensation structure is provided for mounting the MEMS component elastically.
17. An electric module, comprising
a carrier having a first thermal expansion coefficient K 1 , a first mounting point and a second mounting point,
a MEMS component with MEMS structures, a second thermal expansion coefficient K 2 ≠K 1 , a first mounting point and a second mounting point,
a first mechanical connection between the first mounting point of the carrier and the first mounting point of the component,
a second mechanical connection between the second mounting point of the carrier and the second mounting point of the component with a compensation structure with a thermal expansion coefficient K k ,
wherein
the mounting points on the MEMS component are spaced apart by a horizontal distance d 1 and the mounting points on the carrier are spaced apart by a horizontal distance d 2 ,
the values for d 1 and d 2 are selected such that in the case of a change in the temperature the compensation structure compensates the different changes in length of d 1 and d 2 , and in the case of different temperatures the MEMS component is connected in a stress-free fashion to the carrier, and
wherein K K
is either larger than the larger of the two values K 1 and K 2 :K K >max (K 1 , K 2 ) or
smaller than the smaller of the two values K 1 and K 2 :K K <min (K 1 , K 2 ).
18. The module according to claim 17 , wherein the MEMS component is an electro-acoustic transducer.
19. The module according to claim 18 wherein
the module has three or more compensation structures which are arranged in a rotationally symmetrical fashion about a center, and
the electro-acoustic transducer comprises a sound input in the center.
20. The module according to claim 18 , wherein the compensation structure is provided for mounting the MEMS component elastically.