MEMS Package

Abstract

A package includes a base structure, which has an electrically isolating material and/or an electrically conductive contact structure, an electronic component, which is embedded in the base structure or is arranged on the base structure, a microelectromechanical system (MEMS) component, and a cover structure, which is mounted on the base structure for at least partially covering the MEMS component.

Claims

1. A package comprising: a base structure, which has an electrically isolating material and/or an electrically conductive contact structure; an electronic component, which is embedded in the base structure or is arranged on the base structure; a microelectromechanical system (MEMS) component; and a cover structure, which is mounted on the base structure for at least partially covering the MEMS component.

2. The package according to claim 1, wherein the base structure is configured as a conductor board or as a section thereof.

3. The package according to claim 1, wherein the cover structure is selected from a group, which consists of: a casting compound, a die cast component, a metal cap, and a further electrically isolating material having a further electrically conductive contact structure, a conductor board, a printed circuit board, or a section thereof.

4. The package according to claim 1, wherein the electrically isolating material is selected from a group, which consists of: resin, bismaleimide-triazine resin, glass fibres, prepreg material, polyimide, a liquid crystal polymer, epoxy-based build-up film, and FR4 material.

5. The package according to claim 1, wherein the electronic component is configured for functionally cooperating with the MEMS component.

6. The package according to claim 1, wherein the MEMS component is formed as one of the group, which consists of: a sensor, an actuator, a loudspeaker, a balanced armature receiver, a microphone, an autofocus component, a two-dimensional scanner, a haptic actuator, a pressure sensor, a micropump, an adjustable lens, an adjustable wavelength-selective filter, and a fluid sensor.

7. The package according to claim 1, wherein the electronic component is a semiconductor integrated circuit.

8. The package according to claim 1, wherein at least a portion of surfaces at the side of the electronic component is covered with material of the base structure.

9. The package according to claim 1, wherein at least one of the group, which consists of: the base structure and the cover structure, has: at least a via hole for providing a fluid connection between the MEMS component and an environment of the packaged, and/or a surface structuring for influencing acoustic waves.

10. (canceled)

11. The package according to claim 1, wherein the MEMS component is arranged in a cavity, which is confined between the base structure and the cover structure.

12. The package according to claim 1, wherein the cover structure has at least one of the group, which consists of: an EMI protection device, an ESD protection device, at least one solder pad, and a feature for adapting acoustic waves.

13. The package according to claim 1, further having bonding material at a mounting site between the base structure and the cover structure.

14. The package according to claim 13, wherein the bonding material is configured for providing both a mechanical connection and an electrical coupling between the base structure and the cover structure.

15. The package according to claim 1, wherein at least a portion of the electrically conductive contact structure is configured for electrically coupling the electronic component with the MEMS component.

16. The package according to claim 1, wherein the MEMS component is mounted on the base structure and/or on the cover structure.

17. A method for manufacturing packages, the method comprising: embedding an electronic component in, or arranging the electronic component on a base structure, which has an electrically isolating material and/or an electrically conductive contact structure; mounting a microelectromechanical system (MEMS) component at the base structure; and at least partially covering the MEMS component with a cover structure, which is mounted at the base structure.

18. The method according to claim 17, the method further comprising: embedding at least one further electronic component in, or arranging the at least one further electronic component on, a base master structure, wherein the base structure forms a portion of the base master structure; mounting at least one further MEMS component at the base master structure; at least partially covering the at least one further MEMS component with a cover master structure, which is mounted at the base master structure, wherein the cover structure forms a portion of the cover master structure.

19. The method according to claim 17, further comprising: singularizing of the arrangement of the base master structure having the electronic components and the mounted MEMS components and the cover master structure, in order to thereby obtain a plurality of packages, each of which comprises a base structure, an electronic component, a MEMS component and a cover structure.

20. The method according to claim 17, wherein the electronic components and the MEMS components are distributed two-dimensionally across the base master structure and the cover master structure.

21. An assembly, comprising: a base master structure, which has an electrically isolating material and/or an electrically conductive contact structure; a plurality of electronic components, which are embedded in the base master structure, or are arranged on the base master structure; a plurality of MEMS components at the base master structure; a cover master structure, which is mounted at the base master structure and at least partially covers the MEMS components, in order to thus define individual cavities for each one of the MEMS components between a respective section of the base master structure and a respective section of the cover master structure.

Description

BRIEF DESCRIPTION DRAWINGS

[0033] Exemplary embodiment examples of the present invention are described hereinafter with reference to the following figures.

[0034] FIG. 1 shows a cross-sectional view of a package according to an exemplary embodiment example of the invention.

[0035] FIG. 2 shows a cross-sectional view of a package according to another exemplary embodiment example of the invention.

[0036] FIG. 3 shows a cross-sectional view of a package according to still another exemplary embodiment example of the invention.

[0037] FIG. 4 shows another view of the package according to FIG. 3.

[0038] FIG. 5 shows a cover master structure according to an exemplary embodiment example of the invention.

[0039] FIG. 6 shows a base master structure according to an exemplary embodiment example of the invention.

[0040] FIG. 7 shows a schematic view for illustrating individual processes during a method for manufacturing packages according to an exemplary embodiment example of the invention.

[0041] FIG. 8 shows a base master structure according to another exemplary embodiment example of the invention.

[0042] FIG. 9 shows a schematic view for illustrating individual processes according to a method for manufacturing packages according to another exemplary embodiment example of the invention.

[0043] FIG. 10 shows a cover master structure according to another exemplary embodiment example of the invention.

[0044] FIG. 11 shows a cross-sectional view of an assembly according to another exemplary embodiment example of the invention.

[0045] FIG. 12 shows a cross-sectional view of a package according to another exemplary embodiment example of the invention.

[0046] FIG. 13 and FIG. 14 show cross-sectional views of packages according to other exemplary embodiment examples of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0047] Same or similar components in different figures are provided with same reference numerals.

[0048] Before exemplary embodiment examples of the invention are described with reference to the figures, some general aspects of the invention shall still be explained:

[0049] According to an exemplary embodiment example, a PCB-based packaging architecture for MEMS components (in particular MEMS sensors or MEMS actuators) may be provided.

[0050] According to an exemplary embodiment example of the invention, one semiconductor chip or plural semiconductor chips, or other electronic components, may be arranged on a substrate (which is also referred to as base master structure) in a format of stripes (or streaks, bands). Thereby, mechanisms such as die attach, flipchipping (i.e. a back side arrangement of electronic chips on the substrate), wirebonding (i.e. the provision of bond wires for contacting electronic chips) can be applied, in order to possibly accomplish desired electrical and mechanical connections. A second stripe (which may also be referred to as cover master structure), which may consist of an arrangement of cavities corresponding to the MEMS components and/or electronic chips, may be oriented suitably (or fittingly) to the first stripe and is attached to the latter. This procedure may be effected by using bond material (for example, an adhesive, epoxy material, etc.). The bond material may be attached on the substrate stripe (i.e. the base master structure) in a suitable manner, for example, by means of dispersing, stamping, printing, etc. Alternatively or in addition, it may be possible to attach such bond material using the mentioned or other methods on the cover master structure. After both stripes or master structures have been connected with one another, the individual packages may be singularized.

[0051] In order to possibly allow a pressure wave or a sound wave to reach the MEMS component, one via hole or plural via holes may be provided in one or both of the master structures. This architecture may enable a bottom access of the pressure or sound waves, if the via hole is arranged between solder pads of the base master structure, or may be a port on the top, if the via hole is provided at the cover master structure. Preferably, the via hole may be provided to be non-flush with a membrane of the MEMS component, in order to possibly exclude a damage of the same by the influence of a mechanical load through the via hole. A package having a via hole on the top may have a smaller footprint, whereas a via hole at the bottom may show a higher sensitivity due to its higher back volume. The port must not be in a straight line, but may have a desired and thus also more complex shape, and may be guided, for example, through a PCB.

[0052] At least one of the semiconductor chips and/or at least passive component may also be embedded in one of the master structures, in order to possibly reduce the package dimensions and to possibly improve the electrical performance.

[0053] If a hermetic connection is manufactured between the MEMS component (in particular the sensor element of the same) and the via hole (in order to make impossible an external access, which might damage other parts of the system), the assembly and/or the package may be realized with fluid sensors.

[0054] When providing membrane-based MEMS components, it may be advantageous to enclose them as far as possible, in order to possibly mechanically protect the movable element, however, without decoupling the membranes from the air connection, via which they may sense a sensor signal. This may for example be achieved by a PCB as a cover master structure or by a metal cap.

[0055] According to an exemplary embodiment example, the manufacturing effort may be kept low, in particular if two PCBs are used as master structures. It may thus be possible to reduce the risk of a misalignment (which may lead to a reduction of the yield) and to increase the production speed.

[0056] It may be possible to functionalize the cover master structure and/or to structure it, for example to enable passively filtering. This may be an additional advantage to the simplified mounting and the lower NRE (non-recurring engineering) costs.

[0057] When providing a via hole in one of the master structures, a (preferably smaller) via hole may also be provided in the respective other master structure, in order to possibly accomplish a pressure balance.

[0058] A cavity provided around an MEMS component (for example for the example of a loudspeaker as MEMS component) may ideally be as close as possible to a shape of a hemisphere, in order to possibly disable sound reflections, which would negatively influence the performance of the package. Such a hemispherical cavity may be achieved, for example, by drilling or milling using a spherical bit.

[0059] It may also be possible, in addition to the electronic chip, to integrate one or plural passive components (for example, an ohmic resistance, a capacitor or an electrically conductive and thermally conductive block, for example a copper block) in the base structure.

[0060] FIG. 1 shows a cross-sectional view of a package 100 according to an exemplary embodiment example of the invention. The package 100 according to FIG. 1 may be configured as a loudspeaker.

[0061] The package 100 may comprise a base structure 102 in the form of a section and/or a portion of a printed circuit board, which may comprise FR4 as an electrically isolating material and may comprise copper structures provided partially in and partially on the electrically isolating material as an electrically conductive contact structure 110. The electrically conductive contact structure 110 may have both structured electrically conductive layers (see reference numeral 122) and also vertical through-connections, so-called vias (see reference numeral 124). An electronic chip 104, which may be configured as an ASIC, may be embedded in the base structure 102, but could alternatively also be surface-mounted to the base structure 102, and may serve as a controller IC. According to FIG. 1, the surfaces at the side (or lateral surfaces) and also the mutually opposite upper and lower main surfaces of the electronic chip 102 may be covered with material of the base structure 102.

[0062] A microelectromechanical system (MEMS) component 106 may be surface-mounted on the base structure 102 and may be coupled electrically conductively to the electronic chip 104 by means of the electrically conductive contact structure 110 and by means of a bonding wire 120, such that electrical signals can propagate between the electronic chip 104 and the MEMS component 106. In other embodiment examples, in which the electronic chip 104 may be mounted in a flip chip configuration, the bond wire 120 may be omitted and the electrical coupling of the flip chip mounted electronic chip 104 may be effected by means of solder balls.

[0063] A cap-type cover structure 108, which may be formed as a section or a portion of a further printed circuit board (PCB) in the embodiment example, may be mounted on the base structure 102, so as to possibly cover the MEMS component 106. This means, that also the cover structure 108 may comprise dielectric material (in particular FR4) and an electrically conductive contact structure 110 made of copper, in correspondence to the base structure 102. Alternatively, the cover structure 108 may also be formed, for example, as a metal cap or as a casting compound.

[0064] In the present case, the electronic chip 104 may be configured for controlling the MEMS component 106. This means, that the electronic chip 104 of the MEMS component 106, which may be formed as a loudspeaker, transmits electrical signals that may be indicative for an audio content to be reproduced, on the basis of which a swingable membrane 160 of the MEMS component 106 may be excited to [perform] oscillations (or swings). Thus, acoustical waves may be generated, which can be emitted into the environment through one of via holes 112 provided in an outer casing of the package 100.

[0065] Both the base structure 102 and also the cover structure 108 may have a respective via hole 112 for providing an air connection between the MEMS component 106 and an environment of the package 100, through which [via hole] a sound connection may be formed between an interior and an outside of the package 100. An outer region of the via hole 112, which may be formed in the base structure 102, may be provided with a chamfer section 154, in order to possibly improve the propagation properties of the acoustical waves between an interior and an outside of the package 100.

[0066] The MEMS component 106 may be arranged distance-afflicted in a cavity 114 and/or in an opening of the cover structure 108 (which may be produced, for example, by means of etching the PCB structure), which [cavity or opening] may be confined between the base structure 102 and the cover structure 108. In this way, it may be ensured that the membrane 160 of the MEMS component 106 may be freely swingable (or capable to oscillate).

[0067] The package 100 may have electrically conductive bond material 116 (for example metallic solder material) at a mounting site between the base structure 102 and the cover structure 108. Since this electrically conductive bond material 116 may contact the electrically conductive contact structures 110 of the base structure 102 and of the cover structure 108 on both sides (i.e. on the top side and on the bottom side) and may connect them with one another, an electrically conductive connection may be established also between the base structure 102 and the cover structure 108 by means of the bond material 116.

[0068] In FIG. 1, a package 100 can be recognized, in which the MEMS component 106 may be formed as an MEMS loudspeaker. In the case of an embodiment as a MEMS loudspeaker, the electronic chip 104 may provide control signals to the loudspeaker in the form of the MEMS component 106 via the electrically conductive contact structure 110, which control signals may be converted to sound by a piezoelectric membrane 160 of the MEMS component 106. This sound may exit, through one of the via holes 110, into an environment, where it may be audible.

[0069] A similar configuration may also serve as an MEMS microphone. In the case of an embodiment as a microphone, acoustical waves would propagate from the environment through one or both of the via holes 112 into the cavity 114 and may excite the piezoelectric membrane 160 to [perform] oscillations. Thus, corresponding electrical signals would be produced at the MEMS component 106, which [signals] could be transmitted to the electronic chip 104 and could thus be further processed.

[0070] By the burying of the electronic chip 104 in the base structure 102, a vertical arrangement of the electronic chip and the MEMS structure 106 may be enabled, which may lead to a compact configuration in the height direction. In addition, a low constructional height may be achieved also by the provision of plate-shaped PCBs as a basis for the base structure 102 and the cover structure 108. By arranging the electronic chip 104 and the MEMS component 106 approximately vertically on top of one another, a compact configuration may be enabled also in a lateral direction.

[0071] At a bottom side of the package 100 according to FIG. 1, the latter can be mounted to a substrate, for example, to a printed circuit board (not shown).

[0072] FIG. 2 shows a cross-sectional view of a package 100 according to another exemplary embodiment example of the invention. The package 100 according to FIG. 2 may be configured as a balanced armature receiver.

[0073] The package 100 according to FIG. 2 may differ from the package 100 according to FIG. 1 in that according to FIG. 2, the larger one of the two via holes 112 (a so-called ventilation hole) may be arranged laterally (or at a side) and not at a bottom side of the base structure 102. In this way, a mounting of the bottom side of the package 100 at a substrate (not shown) may be possible without the air connection of the MEMS component 106 being impeded thereby. A ventilation air channel, which may be constituted by the lower via hole 112, may thus be oriented partially parallel to the membrane 160 of the MEMS component 106.

[0074] FIG. 3 shows a cross-sectional view of a package 100 according to another exemplary embodiment example of the invention. The package 100 according to FIG. 3 may be configured partially as a balanced armature receiver.

[0075] The package 100 according to FIG. 3 may differ from the packages 100 according to FIG. 1 and/or FIG. 2 in that according to FIG. 3 there may be provided a step-shaped bottom side. The lower via hole 112 may be arranged in one region of the step, while another region of the step may be free for mounting the package 100 to a substrate.

[0076] FIG. 4 shows a cross-sectional view of the package 100, and how this is mounted to a substrate 400 by means of bond material 402. In the embodiment example shown, the substrate 400 may be embodied as a printed circuit board (PCB) and may have an electrically isolating core 404 and an electrically conductive wiring 406, by means of which the substrate 400 may be electrically coupled with the package 100. Thus, FIG. 4 shows a receiver on a PCB.

[0077] FIG. 5 shows a cover master structure 500 according to an exemplary embodiment example of the invention.

[0078] The cover master structure 500 may be formed on a printed circuit board. A plurality of active cover sections 502 may be arranged in the form (or shape) of a matrix, i.e. in rows and columns, on the shown main surface of the cover master structure 500. Inactive areas 504 may be provided between the active cover sections 502. FIG. 5 shows furthermore that each one of the active cover sections 502 may have in turn a plurality of cover structures 108 arranged in rows and columns. These may be embodied such as it has been described with references to FIG. 1 to FIG. 3. The cavities 104, which may be provided to this end, may be produced by means of etching, for example. In summary, FIG. 5 shows that the cover master structure 500 shown there may be well suitable for a batch-wise production of packages 100 according to exemplary embodiment examples.

[0079] FIG. 6 shows a base master structure 600 according to an exemplary embodiment example of the invention.

[0080] In the base master structure 600, package formation sections 602 may be arranged in rows and columns, and may thus be separated by inactive sections 604. Furthermore in FIG. 6, one of the package formation sections 602 is shown in an enlarged representation, in which it can be seen, that a plurality of base structures 102 may be formed in rows and columns, hence in the form of a matrix. These may be formed such as it has been shown according to FIGS. 1 to 3.

[0081] In order to manufacture a plurality of packages 100 in a batch-wise manner, the cover master structure 500 according to FIG. 5 can be attached to the base master structure 600 according to FIG. 6 by means of an adhesive compound (not shown) and another bond material. Subsequently, a singularization of the thus obtained assembly (see reference numeral 1100 in FIG. 11) may be performed, in order to possibly separate the individual packages 100 from one another.

[0082] FIG. 7 shows a schematic view of processes during a method for manufacturing packages 100 according to an exemplary embodiment example of the invention.

[0083] As is illustrated by means of the reference numeral 702, the MEMS component 106 may be attached to a top side of the base structure 102 by means of die bonding, such that a mechanical attachment may be enabled simultaneously, and such that an electrical contacting to the electronic chip 104, which may be provided buried in the base structure 102, may be prepared. Such as is shown by means of the reference numeral 704, a bond wire 120 can be attached to the MEMS component 106 by means of wire bonding, in order to possibly electrically couple the latter with the electronic chip 104. As is shown by means of the reference numeral 708, a cavity 114 may be formed in the cover structures 108. Subsequently, a batch-wise connection between a base master structure 600 and a cover master structure 500, or a connection between a base structure 102 that may have been singularized already and a cover structure 108 that may have been singularized already may be performed, in order to possibly produce the package 100 shown in FIG. 7. Subsequently, a singularizing to individual packages may be performed in the case of a batch-wise processing.

[0084] FIG. 8, FIG. 9 and FIG. 10 show a very similar procedure as in FIG. 5 to FIG. 7, wherein FIG. 8 may correspond to FIG. 6, FIG. 9 may correspond to FIG. 7 and FIG. 10 may correspond to FIG. 5. The difference between the embodiment examples of FIG. 8 to FIG. 10 in comparison with the embodiment examples of FIG. 5 to FIG. 7 may be that different base structures 102 and different cover structures 108 may be implemented. According to FIG. 8 to FIG. 10, a respective MEMS component 106 may be arranged directly above the electronic chip 104, instead of being arranged laterally shifted as according to FIG. 5 to FIG. 7.

[0085] FIG. 11 shows a cross-sectional view of an assembly 1100 according to an exemplary embodiment example of the invention.

[0086] The assembly 1100 may comprise a base master structure 600; a plurality of electronic chips 104, which may be embedded in the base master structure 600; a plurality of MEMS components 106, which may be arranged on the base master structure 600; and a cover master structure 500, which may be mounted to and/or on the base master structure 600, and which may cover the MEMS components 106. Thus, individual cavities 114 may be defined for each one of the MEMS components 106 between a respective section of the base master structure 600 and a respective section of the cover master structure 500.

[0087] In the assembly 1100 shown in FIG. 11, a singularization into packages 100 may be effected by separating the individual packages 100 from one another along separation lines or cutting lines 1102 (for example by means of sawing, laser cutting or etching).

[0088] FIG. 12 shows a cross-sectional view of a package 100 according to another exemplary embodiment example of the invention.

[0089] According to FIG. 12, the electronic chip 104 may be formed as a CCD (charge coupled device) and may detect electromagnetic radiation. The electronic chip 104 of the CCD type may be embedded in the base structure 102, wherein an upper surface of the CCD chip may be exposed with respect to the base structure 102, in order to possibly be sensitive for electromagnetic radiation. The electronic chip 104 may cooperate with an electrically movable lens by means of an electrically conductive contact structure 110, wherein the lens as an MEMS component 106 may be arranged above the electronic chip 104, in order to possibly serve as an adjustable optical element for influencing the electromagnetic radiation that may be detected by means of the CCD. In the embodiment example according to FIG. 12, at least a section of the cover structure 108 above the MEMS component 106 and the electronic chip 104 may be optically transparent, or the cover structure 108 should have a via hole 112, which may allow light to propagate into the cavity 114.

[0090] FIG. 13 and FIG. 14 show cross-sectional views of packages 100 according to other exemplary embodiment examples of the invention.

[0091] The package 100 shown in FIG. 13 may be formed as a balanced armature receiver (BAR) having a double-sided configuration. This means that a base structure 102 having an embedded electronic component 104 may be populated (or fitted with components) on each of its two opposing main surfaces with a respective MEMS component 106, which in turn may be covered by means of a respective cover structure 108. In addition, a membrane 1300 may cover an exposed surface of the respective MEMS component 106. The membrane 1300 may be manufactured, for example, from silicon, or from another polymer material. In this way, a compact design (or configuration) can be combined with a high level of functionality. FIG. 13 shows furthermore a housing 1302 (for example made of metal or of plastics), which may serve as a guide for sound waves, and which may have a sound access opening 1304.

[0092] The package 100 shown in FIG. 14 may be formed as a balanced armature receiver (BAR) having a single-sided configuration. This means that a base structure 102 having an embedded electronic component 104 may be populated with an MEMS component 106 only on one of its two opposing main surfaces, which MEMS component 106 may in turn be covered by means of a membrane 1300 and may be enclosed by a cover structure 108. According to FIG. 14 too, there may be provided a housing 1302, which may be configured according to FIG. 13.

[0093] As a supplement, it is to be noted that “comprising” or “having” may not exclude other elements or steps, and that “a” or “an” may not exclude a plurality. Furthermore, it should be noted that features or steps, which have been described with reference to one of the embodiment examples above, may be used also in combination with other features or steps of other embodiment examples described above. Reference numerals in the claims may not to be construed as limitations.