CN101459866B - MEMS microphone module and manufacturing method - Google Patents

Abstract

The invention discloses a micro-electromechanical microphone module and a manufacturing method, wherein the thickness and the size of a transparent temporary cover plate temporarily arranged in the existing plastic packaging structure are allocated, after the mold forming process of a plastic protective body, the adhesiveness between the temporary cover plate and the back surface of a micro-electromechanical sound wave sensing chip is reduced by UV light irradiation, then after the temporary cover plate is removed, the left space is the main back sound cavity volume source of the micro-electromechanical microphone, and finally, a label piece covers the upper part of the plastic protective body so as to define the whole back sound cavity volume and form a closed back sound cavity volume. The volume of the rear sound cavity in the manufacturing method is the area of the whole micro-electromechanical microphone chip, and the volume of the rear sound cavity can be defined.

Description

MEMS microphone module and manufacturing method

technical field

The present invention relates to a micro-electro-mechanical (MEMS) microphone module and a manufacturing method thereof, in particular to a micro-electro-mechanical microphone module with increased volume of a rear acoustic cavity and a manufacturing method thereof.

Background technique

In terms of integrated circuit device products equipped with microphones, the demand for MEMS microphones tends to expand. For example, the current global mobile phone manufacturers tend to equip a microphone for the camera function in addition to the microphone required for calls, in order to meet the convenience of practical use. Designs in this area are gradually appearing in portable audio and digital camera products using microhard drives or flash memories. Therefore, MEMS microphones may have a considerable market share in the above-mentioned application fields in the future.

The MEMS microphone is not only thin in thickness and small in size, but also can be surface-mounted by reflow soldering (solder reflow), which can effectively reduce assembly costs. Therefore, in the face of the demand for small size and low cost of mobile phones, electromechanical microphones are gradually occupying the market of the original electric condenser microphone (ECM, Electric Condenser Microphone). Its power consumption is about 1/3 of that of condenser microphones. For mobile phones with limited power storage, the advantage of power saving is also a significant driving force for MEMS microphones to replace condenser microphones.

Please refer to FIG. 1A to FIG. 1B , the US Patent Publication No. US20050185812 is used at the relative position of the carrier substrate 11 and the central vibrating membrane 13 of the micro-electromechanical microphone chip 12 to hollow out and not penetrate the carrier substrate. 11 to define the volume of the rear acoustic cavity 14 of the microphone package. In addition, the carrier base material of the printed circuit board that cooperates with the plywood bonding process is interlayered in the middle of the plywood, and the form of the hole 15 is used for interlayer bonding and The area of the interlayer hole 15 overlaps with the hollowed-out area of the carrier substrate 11 to serve as an extension of the rear acoustic cavity volume 14 and achieve the purpose of enlarging the rear acoustic cavity volume 14 . From the perspective of general MEMS microphone module design, the chip size of a general MEMS microphone is about 2.0×2.0mm, and the diameter area of the acoustic vibration sensing film is about 1.0mm, and a 0.2-0.3mm-thick carrying substrate material, the thickness of the possible interlayer cavity in the middle is about 0.07mm. In the structure of the above-mentioned patent, the volume of the acoustic cavity behind it is on the supporting substrate, and the diameter area of the acoustic vibration induction film extends downward and does not penetrate the supporting substrate. . Generally speaking, in the splint lamination process of the actual load-bearing substrate, the thickness of the holes in the middle layer is not easy to control to make it uniform, and the depth that can be extended under the diameter area of the acoustic vibration induction film is determined by the thickness of the load-bearing substrate. Restricted, the space it can form is limited.

Contents of the invention

The invention provides a micro-electromechanical microphone module, comprising: a carrier base material with an acoustic wave injection hole; a micro-electromechanical microphone chip with an acoustic wave sensing mechanism area, the acoustic wave sensing mechanism area is fixed on the carrier base material as an acoustic wave sensor measuring unit; a plastic body covers all devices above the carrier substrate except the upper surface of the MEMS microphone chip, and forms the external structural main body of the MEMS microphone module; and a label is bonded to the outer surface of the plastic body , as the rear cavity volume.

In the present invention, the sound wave injection hole of the supporting substrate is a vertical through hole or a stepped through hole.

In the present invention, the tag part further includes at least one circular, polygonal or other irregular-shaped through hole at the area corresponding to the lower MEMS microphone chip.

In the present invention, the through holes of the label are arranged in an array or staggered array radiation distribution or random distribution; and the diameter of a single through hole of the label or the diameter of the long side is less than or equal to the side length of the micro-electromechanical microphone chip; the label The location of the single through hole can be at the geometric center or at any position corresponding to the range of the MEMS microphone chip below.

The present invention provides a manufacturing method of a micro-electro-mechanical microphone chip assembly, the steps of which include: providing a micro-electro-mechanical microphone silicon chip having a plurality of micro-electro-mechanical microphone chips, which has a plurality of chip division and cutting lines, an active surface and a back surface; Use a UV adhesive to attach a transparent temporary cover to the center of the back of the micro-electromechanical microphone silicon chip; form a plurality of grooves on the upper surface of the temporary cover, and correspond to each chip division and cutting line; fill a sacrificial material in the Groove space; forming a plurality of sacrificial layers by exposure and development process; and cutting grooves to form a plurality of microelectromechanical microphone chip components, so that the temporary cover plate of each microelectromechanical microphone chip component forms a rear acoustic cavity cover plate, and around A replacement layer of sacrificial material remains.

The present invention provides a manufacturing method of a micro-electro-mechanical microphone module, which includes: providing a carrier substrate, which has a plurality of units of pads and a plurality of corresponding sound wave injection holes, and then fixing and electrically coupling the above-mentioned micro-electro-mechanical microphone chip The micro-electromechanical microphone chip assembly and the integrated circuit device used in the component process are placed on the carrier substrate; a plastic body is formed in the packaging mold to cover the integrated circuit device, and surround the electromechanical microphone chip assembly and the side of the rear acoustic cavity cover; Remove the replacement layer around the rear acoustic cavity cover; remove the rear acoustic cavity cover to form a space for the volume of the rear resonance cavity; join a label on the outer surface of the plastic body to form a closed rear with the space where the original front and rear acoustic cavity cover is located the volume of the resonant cavity; and cutting the carrier substrate and the plastic body to form a single MEMS microphone module.

The beneficial effects of the present invention are: the volume of the final rear acoustic cavity in the present invention can be determined by the thickness of the temporary cover plate in the manufacturing process, and the increase in thickness can be determined easily and clearly, which is different from the existing The present invention has relative advantages in terms of the thickness uniformity design of the interlayer holes of the supporting substrate that cannot exceed the design limit of the thickness of the supporting substrate in the prior art and cannot be fully controlled by the prior art. On the other hand, since the extended base of the volume of the rear acoustic cavity of the present invention is the size of the entire microelectromechanical microphone chip, the volume of the rear acoustic cavity of the microelectromechanical microphone module can be increased more efficiently.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

1A to FIG. 1B are schematic diagrams of micro-electromechanical microphone modules with enlarged rear acoustic cavity volume in the prior art;

2A to 2E are schematic structural flow diagrams of an embodiment of the manufacturing method of the micro-electromechanical microphone chip assembly of the present invention;

3A to 3F are schematic structural flow diagrams of an embodiment of a manufacturing method of a micro-electromechanical microphone module of the present invention;

Fig. 4 shows the cross-sectional view of the embodiment of the micro-electromechanical microphone module of the present invention;

Fig. 5 shows the cross-sectional view of the through-hole embodiment of the label part of the embodiment of Fig. 4;

Figure 6 is a cross-sectional view of another embodiment of the MEMS microphone module of the present invention; and

FIG. 7 is a cross-sectional view of a third embodiment of the MEMS microphone module of the present invention.

Among them, reference signs

11 Carrying substrate

12 microelectromechanical microphone chips

13 shock film

14 Rear cavity volume

15 holes

20 microelectromechanical microphone chip components

21 electromechanical microphone silicon wafer

211 active side

212 back

22 microelectromechanical microphone chips

2201 chip upper surface

2202 chip lower surface

221 Acoustic Sensing Mechanism Area

222 pits

23UV adhesive

24 Temporary cover

241 Rear acoustic chamber cover

25 grooves

26 sacrificial material

261 replacement layer

30 load-bearing substrate

301 welding pad

302 sonic injection hole

31 integrated circuit devices

32 bottom filler

40 plastic body

Resonant cavity volume after 50

60, 60a, 60b labels

601a, 601b Bottom concave hole

602 top surface

61 through holes

62 label notes

70 MEMS microphone module

detailed description

In order to have a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed descriptions are provided in conjunction with the embodiments.

Please refer to FIG. 2A to FIG. 2E , which are schematic structural flow diagrams of an embodiment of the manufacturing method of the MEMS microphone chip assembly of the present invention. The manufacturing method steps of the microelectromechanical microphone chip assembly 20 include: providing a microelectromechanical microphone silicon chip 21 with a plurality of microelectromechanical microphone chips 22, which has an active surface 211 and a back surface 212; The transparent temporary cover 24 is at the center of the back 212 of the MEMS silicon wafer 21 (as shown in FIG. 2A ); on the upper surface of the temporary cover 24, a plurality of grooves 25 are formed corresponding to the periphery of each MEMS microphone chip (as shown in FIG. 2B ). Then fill a sacrificial material 26 in the trench 25 space (as shown in Figure 2C); use exposure and development process to make the sacrificial material 26 form a plurality of sacrificial layers; and cut the trench 25 to form a plurality of micro-electromechanical microphone chip components 20 (as Fig. 2D and Fig. 2E), the cutting width of its cutting knife should be less than the width of each groove 25, so that the rear acoustic cavity cover plate 241 that the temporary cover plate 24 of each microelectromechanical microphone chip assembly 20 forms The replacement layer 261 made of the sacrificial material 26 remains in the surrounding area.

The above-mentioned MEMS microphone chip assembly 20 disclosed in FIG. 2E has a structure comprising: a MEMS microphone chip 22, which has a chip upper surface 2201 and a chip lower surface 2202, and the chip upper surface 2201 has an acoustic wave sensing mechanism area 221. The acoustic wave sensing part has a cavity structure with a cavity 222 on the lower surface 2202 of the chip; and a rear acoustic cavity cover plate assembly, which includes a rear acoustic cavity cover plate 241 and a replacement layer 261, and the replacement layer 261 surrounds the Around the rear acoustic cavity cover 241, the rear acoustic cavity cover assembly is combined with the chip lower surface 2202 of the micro-electromechanical microphone chip 22, and defines a sound wave sensing part with the acoustic wave sensing mechanism area 221 and the micro-electromechanical microphone chip 22. enclosed space.

Please continue to refer to FIG. 3A to FIG. 3F , which are schematic structural flow diagrams of an embodiment of the manufacturing method of the MEMS microphone module of the present invention. It uses the above-mentioned micro-electromechanical microphone chip assembly 20, fixes it on a carrier substrate 30 having a plurality of unit pads 301 and a plurality of corresponding sound wave injection holes 302, and also fixes the integrated circuit device 31 used in conjunction with it ; The upper surface 2201 of the chip of the MEMS microphone chip assembly 20 and the integrated circuit device 31 are electrically coupled to the carrier substrate 30, and the method of the electrical coupling can be carried out by applying flip chip bonding and underfill glue technology; in the packaging mold ( Not shown in the figure) to form a protective plastic body 40 to cover the integrated circuit device 31 and to surround the electromechanical microphone chip assembly 20 and the side area of the rear acoustic cavity cover 241; the replacement around the rear acoustic cavity cover 241 is removed using an etching process Layer 261; irradiating UV light to reduce the viscosity of the temporary cover UV adhesive 23 to remove the rear acoustic cavity cover 241 to form a space for the rear resonance cavity volume 50; bonding a label 60 on the outer surface of the plastic body 40 , forming a closed rear resonant cavity volume 50 with the space where the original front and rear acoustic cavity cover plate 241 is located; and cutting the carrier substrate 30 and the plastic body 40 to form a single MEMS microphone module 70 .

In the above-mentioned embodiment, the upper surface of the label member 60 further includes forming a label note 62, and the label note 62 uses laser, printing, corrosion, stamping, printing or transfer process; The jointing method of the outer surface of the adhesive adopts adhesive heating fusion or heating hardening process; the material of the label part 60 is selected from the group consisting of pure metal, pure non-metal and composite materials.

In the above embodiment, the position of the outer surface of the plastic body 40 may be higher than the lower surface 2202 of the MEMS microphone chip 22 , and the plastic body 40 is formed by integral resin transfer molding or liquid dispensing method of damming/filling.

Please refer to FIG. 4 which is a cross-sectional view of an embodiment of the MEMS microphone module of the present invention. Its structure includes: a carrier substrate 30 has a plurality of welding pads 301 and sound wave injection holes 302, and the sound wave injection holes 302 can be vertical through holes or stepped through holes; After bonding, fill in primer to make it bonded on the carrier substrate 30. The upper surface 2201 of the chip has an acoustic wave sensing mechanism area 221, and the chip lower surface 2202 on the other side of the sensing mechanism area 221 has a The cavity 222, the cavity 222 corresponds to the position of the sound wave injection hole 302, as the sound wave sensing unit; a plastic body 40 covers all the devices (including the integrated circuit device 31) above the above-mentioned carrier substrate 30, but does not include micro The chip lower surface 2202 of the electromechanical microphone chip 22 forms the main body of the external structure of the microelectromechanical microphone module 70 ;

In the above-mentioned embodiment, the tag 60 further includes at least one through hole 61 (as shown in FIG. 5 ) at the range corresponding to the MEMS microphone chip 22 below, and the diameter or long side diameter of the single through hole 61 of the tag 60 is less than Or equal to the side length of the micro-electromechanical microphone chip 22, the through holes 61 can be circular, polygonal or other irregular shapes, and the arrangement can be in an array or staggered array radiation distribution or random distribution.

Please refer to FIG. 6 . Compared with the above-mentioned embodiment in FIG. 4 , the label 60a has a bottom concave hole 601a. When the label 60a is attached to the top surface of the plastic body 40, the bottom concave hole 601a corresponds to The position of the acoustic wave sensing mechanism area 221 .

Please continue to refer to shown in Figure 7, another embodiment of the microelectromechanical microphone module, its structure includes: a carrier substrate 30 with a plurality of welding pads 301 and sound wave injection holes 302, a microelectromechanical microphone chip 22 with its chip The upper surface 2201 is fixed on the carrier substrate 30 by flip-chip bonding and filled with primer. The micro-electromechanical microphone chip 22 has an acoustic wave sensing mechanism area 221 and has a cavity on the other side of the acoustic wave sensing mechanism area 221. 222, used as the acoustic wave sensing unit, a tag 60b, which is fixed on the chip lower surface 2202 of the MEMS microphone chip 22, the tag 60b has a bottom concave hole 601b, and its bottom concave hole 601b is facing the acoustic wave sensing mechanism area 221, and a plastic body 40, which covers all devices above the surface of the carrier substrate 30 and exposes the top surface 602 of the label member 60b.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the scope of protection of the appended claims of the present invention.

Claims (15)

1. an electric microphone module for microcomputer, is characterized in that, this electric microphone module for microcomputer comprises:

One supporting substrate, it has multiple weld pad and a sound wave hand-hole;

One MEMS microphone chip, it has a chip upper surface and a chip lower surface, this chip upper surface chip bonding is in this supporting substrate, and this chip upper surface has a sound wave senses machine-processed district, and relative to the chip lower surface that this sound wave senses machine-processed district opposite side, there is a depression, using as sound wave sensing cell;

One plastic body, all devices in top of its coated supporting substrate except this chip lower surface of this MEMS microphone chip, and form the formal structure main body of this electric microphone module for microcomputer; And

One tab member, the outer surface bonding of itself and this plastic body, using as rear resonant cavity volume;

Wherein, this microphone chip is positioned at directly over sound wave hand-hole, and the corresponding sound wave hand-hole of this depression.

2. electric microphone module for microcomputer according to claim 1, is characterized in that, this tab member has more a bottom recess and senses machine-processed district corresponding to this sound wave.

3. electric microphone module for microcomputer according to claim 1, is characterized in that, this tab member more comprises at least one through hole at the scope place of this MEMS microphone chip of corresponding below.

4. electric microphone module for microcomputer according to claim 3, is characterized in that, this through hole of this tab member is circular, polygon or other are irregularly shaped.

5. electric microphone module for microcomputer according to claim 3, is characterized in that, this through hole of this tab member be arranged as Arbitrary distribution.

6. electric microphone module for microcomputer according to claim 3, is characterized in that, the diameter of the single through hole of this tab member or long limit diameter are less than or equal to the length of side of this MEMS microphone chip.

7. electric microphone module for microcomputer according to claim 3, is characterized in that, the position of the single through hole of this tab member can in the geometric center of the scope of this MEMS microphone chip of corresponding below.

8. an electric microphone module for microcomputer, is characterized in that, this electric microphone module for microcomputer comprises:

One supporting substrate, it has multiple weld pad and a sound wave hand-hole;

One MEMS microphone chip, it has a chip upper surface and a chip lower surface, this chip upper surface chip bonding is in this supporting substrate, and this chip upper surface has a sound wave senses machine-processed district, and sense machine-processed district opposite side chip lower surface relative to this sound wave there is a depression, using as sound wave sensing cell;

One tab member, it is fixedly arranged on this chip lower surface of this MEMS microphone chip to comprise a top surface and a lower surface, and this tab member has a bottom recess and is aligned with this sound wave and senses machine-processed district; And

One plastic body, all devices in top of its this supporting substrate coated and expose this top surface of this tab member, wherein fit between this tab member and this plastic body completely;

Wherein, this microphone chip is positioned at directly over sound wave hand-hole, and the corresponding sound wave hand-hole of this depression.

9. a MEMS microphone chip assembly, is characterized in that, comprises:

One MEMS microphone chip, it has a chip upper surface and a chip lower surface, and this chip upper surface has a sound wave sensing parts, this chip lower surface has a pothole structure; And

One hybrid rear operatic tunes cover plate assembly, operatic tunes cover plate and a displacement layer after it comprises one, and this displacement layer is looped around this rear operatic tunes cover plate surrounding, this hybrid rear operatic tunes cover plate assembly is combined with this chip lower surface of this MEMS microphone chip, and defines an enclosure space with this sound wave sensing parts and this microphone chip.

10. a manufacture method for MEMS microphone chip assembly, is characterized in that, its step comprises:

There is provided a micro-electro-mechanical microphone silicon chip chip with multiple MEMS microphone chip, it has many chip separation lines of cut, an active surface and a back side;

A transparent interim cover plate is close in this center, back side of this micro-electro-mechanical microphone silicon chip chip with a UV stalemate agent;

Form many grooves in this interim cover plate upper surface, this groove corresponds to this chip separation line of cut of each this micro-electro-mechanical microphone silicon chip;

Fill up an expendable material in this groove space;

Use exposure imaging technique, make this expendable material form many sacrifice layers; And

Cut this groove to form multiple MEMS microphone chip assembly, its cutting width is less than the width of each this groove, operatic tunes cover plate after making this interim cover plate of each this MEMS microphone chip assembly form one, and leave in this rear operatic tunes cover plate surrounding displacement layer formed by this expendable material.

The manufacture method of 11. 1 kinds of electric microphone module for microcomputer, is characterized in that, comprises:

There is provided a supporting substrate, it has the weld pad of multiple unit and multiple corresponding sound wave hand-hole;

One MEMS microphone chip assembly is provided, this MEMS microphone chip assembly comprises a MEMS microphone chip and a hybrid rear operatic tunes cover plate assembly, this MEMS microphone chip has a chip upper surface and a chip lower surface, this chip upper surface has a sound wave sensing parts, this chip lower surface has a pothole structure, operatic tunes cover plate and a displacement layer after this hybrid rear operatic tunes cover plate assembly comprises one, and this displacement layer is looped around this rear operatic tunes cover plate surrounding, this hybrid rear operatic tunes cover plate assembly is combined by UV stalemate agent with this chip lower surface of this MEMS microphone chip, and define an enclosure space with this sound wave sensing parts and this microphone chip,

Application chip bonding and bottom filler technique fix and this chip upper surface of this MEMS microphone chip assembly of electric property coupling and at least one integrated circuit (IC)-components on this supporting substrate;

Plastic body is formed with this integrated circuit (IC)-components coated in encapsulating mould, and around the side of this dynamo-electric microphone chip assembly and its this rear operatic tunes cover plate;

Remove the displacement layer of this rear operatic tunes cover plate surrounding;

Irradiate the viscosity that UV light reduces this UV stalemate agent, to remove the space that this rear operatic tunes cover plate forms resonant cavity volume after;

Engage a tab member in this plastic body outer surface, make to form a closed rear resonant cavity volume with the space at this rear operatic tunes cover plate place original, wherein fit completely between this tab member and this plastic body; And

Cut this supporting substrate and this plastic body forms single electric microphone module for microcomputer.

The manufacture method of 12. electric microphone module for microcomputer according to claim 11, is characterized in that, this tab member upper surface more comprises and forms label annotation, and this label annotation uses radium-shine, printing, burn into punch die, printing or transfer printing process.

The manufacture method of 13. electric microphone module for microcomputer according to claim 11, is characterized in that, the juncture of the outer surface of this tab member lower surface and this plastic body adopts viscose glue heat fusion or heat hardening technique.

The manufacture method of 14. electric microphone module for microcomputer according to claim 11, is characterized in that, the cohort that this tab member composition material is selected from simple metal, pure nonmetal and composite material forms.

The manufacture method of 15. electric microphone module for microcomputer according to claim 11, is characterized in that, this plastic body liquid dotting glue method that is shaping with one resin transfer or box dam/filling is formed.