MEMS package, MEMS microphone, method of manufacturing the MEMS package and method of manufacturing the MEMS microphone
10785576 ยท 2020-09-22
Assignee
Inventors
Cpc classification
B81C1/00309
PERFORMING OPERATIONS; TRANSPORTING
H04R1/04
ELECTRICITY
B81B2201/0257
PERFORMING OPERATIONS; TRANSPORTING
B81B2207/012
PERFORMING OPERATIONS; TRANSPORTING
B81B7/0061
PERFORMING OPERATIONS; TRANSPORTING
International classification
B81C1/00
PERFORMING OPERATIONS; TRANSPORTING
B81B7/00
PERFORMING OPERATIONS; TRANSPORTING
H04R31/00
ELECTRICITY
H04R1/04
ELECTRICITY
Abstract
A MEMS package has a MEMS chip, a package substrate, a dammed-seal part. The MEMS chip has an element substrate which a movable element is formed, the package substrate has a sound hole. The dammed-seal part has an annular dam-member which is formed on the element substrate so as to surround the movable element, and a gel member. The MEMS chip is mounted on the package substrate so that the movable element opposes to the sound hole. The gel member is formed by hardening of gel which is applied on the annular dam-member from outside so as to surround the annular dam-member.
Claims
1. A MEMS package comprising: a MEMS chip; a package substrate which the MEMS chip is adhered; and a dammed-seal part, wherein the MEMS chip comprises an element substrate which a movable element is formed, wherein the package substrate comprises a sound hole, wherein the dammed-seal part comprises an annular dam-member which is formed on the element substrate so as to surround the movable element, and a gel member, wherein the MEMS chip is mounted on the package substrate so that the movable element opposes to the sound hole, wherein the gel member is formed by hardening of gel which is applied on the annular dam-member from outside so as to surround the annular dam-member, wherein the annular dam-member is formed on an opposing surface, opposing to the package substrate, of the element substrate, wherein the opposing surface has an arrangement part, for the gel member, which is arranged in the outside than the annular dam-member, wherein the gel member is formed on the arrangement part, and the gel member has a gel-outside surface which is not contact with the annular dam-member, wherein the gel-outside surface is an exposed surface.
2. The MEMS package according to claim 1, wherein the dammed-seal part is formed so as to seal the part between the MEMS chip and the package substrate, and so as to surround the sound hole.
3. A MEMS package comprising: a MEMS chip; a package substrate which the MEMS chip is adhered; and a dammed-seal part, wherein the MEMS chip comprises an element substrate which a movable element is formed, wherein the package substrate comprises a sound hole, wherein the dammed-seal part comprises an annular dam-member which is formed on the element substrate so as to surround the movable element, and a gel member, wherein the MEMS chip is mounted on the package substrate so that the movable element opposes to the sound hole, wherein the gel member is formed by hardening of gel which is applied on the annular dam-member from outside so as to surround the annular dam-member, wherein the annular dam-member comprises a dam outer end surface, which is along with an opposing surface, of the element substrate, opposing to package substrate, a dam base surface, which is in contact with the opposing surface, a pair of dam slopes, which connects the dam outer end surface and the dam base surface, and a variable width structure in which the width gradually increases toward the dam base surface from the dam outer end surface.
4. The MEMS package according to claim 3, wherein the gel member is in contact with both the dam outer end surface of the annular dam-member and an outer dam slope, arranged outside, of the pair of the dam slopes, and the gel member enters a dam space being formed between the dam outer end surface and the package substrate.
5. A MEMS microphone comprising: a MEMS package; and a cap which wraps the MEMS package, wherein the MEMS package comprises a MEMS chip, a package substrate which the MEMS chip is adhered, and a dammed-seal part, wherein the MEMS chip comprises an element substrate which a movable element is formed, wherein the package substrate comprises a sound hole, wherein the dammed-seal part comprises an annular dam-member which is formed on the element substrate so as to surround the movable element, and a gel member, wherein the MEMS chip is mounted on the package substrate so that the movable element opposes to the sound hole, wherein the gel member is formed by hardening of gel which is applied on the annular dam-member from outside so as to surround the annular dam-member, wherein the annular dam-member is formed on an opposing surface, opposing to the package substrate, of the element substrate, wherein the opposing surface has an arrangement part, for the gel member, which is arranged in the outside than the annular dam-member, wherein the gel member is formed on the arrangement part, and the gel member has a gel-outside surface which is not contact with the annular dam-member, wherein the gel-outside surface is an exposed surface.
6. The MEMS microphone according to claim 5, wherein the dammed-seal part is formed so as to seal the part between the MEMS chip and the package substrate, and so as to surround the sound hole, wherein the MEMS microphone further comprising a front volume, which is surround by the movable element of the element substrate and the package substrate.
7. A MEMS microphone comprising: a MEMS package; and a cap which wraps the MEMS package, wherein the MEMS package comprises a MEMS chip, a package substrate which the MEMS chip is adhered, and a dammed-seal part, wherein the MEMS chip comprises an element substrate which a movable element is formed, wherein the package substrate comprises a sound hole, wherein the dammed-seal part comprises an annular dam-member which is formed on the element substrate so as to surround the movable element, and a gel member, wherein the MEMS chip is mounted on the package substrate so that the movable element opposes to the sound hole, wherein the gel member is formed by hardening of gel which is applied on the annular dam-member from outside so as to surround the annular dam-member, wherein the annular dam-member comprises a dam outer end surface, which is along with an opposing surface, of the element substrate, opposing to package substrate, a dam base surface, which is in contact with the opposing surface, a pair of dam slopes, which connects the dam outer end surface and the dam base surface, and a variable width structure in which the width gradually increases toward the dam base surface from the dam outer end surface, wherein the gel member is in contact with both the dam outer end surface of the annular dam-member and an outer dam slope, arranged outside, of the pair of the dam slopes, and the gel member enters a dam space being formed between the dam outer end surface and the package substrate.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE EMBODIMENTS
(21) In the following, embodiments of the present invention will be described with reference to the drawings. Note that the same components will be referred to with the same numerals or letters, while omitting their overlapping descriptions.
(22) (Structure of the MEMS Package, MEMS Microphone)
(23) To begin with, the structure of a MEMS package 1, a MEMS microphone 100, according to the embodiment of the present invention will be explained with reference to
(24) Here,
(25) As illustrated in
(26) The MEMS package 1 has a MEMS chip 10, a package substrate 20, which the MEMS chip 10 is adhered, bonding bumps 4, a dammed-seal part 30 and an ASIC package 91. The MEMS chip 10 and an ASIC 92 are mounted on the package substrate 20 by the FCB, in the MEMS package 1.
(27) The MEMS chip 10 has an element substrate 2 which a membrane 3, as a movable element, is formed. The MEMS chip 10 is used as the microphone of capacitance-type. The element substrate 2 is a substrate formed in a rectangular-shape in a plan view, as illustrated in
(28) The membrane 3 is vibration film formed approximately in a circular-shape, and it is a thin-film made of an inorganic metal such as SiO.sub.2, SiN or the like.
(29) The bonding bumps 4 are solder bumps made of solder. As illustrated in
(30) The package substrate 20 is a board like member made of such as silicon, ceramic or the like (or PCB: Printed Circuit Board). The electrode pads 21 and electrode pads 12 are formed on the package surface 20a of the package substrate 20. The package substrate 20 has a sound hole 20b, the electrode pads 21 are arranged so as to surround the sound hole 20b. The MEMS chip 10 is mounted on the part, of the package surface 20a, which the electrode pads 21 are formed, so that the membrane 3 opposes to the sound hole 20b, the ASIC 92 is mounted on the part which the electrode pads 12 are formed.
(31) In the MEMS package 1 and the MEMS microphone 100, the later-described dammed-seal part 30 is formed to be adhered to the opposing surface 2a of the MEMS chip 10 so as to surround the membrane 3. Further, the dammed-seal part 30 is also formed to be adhered to package surface 20a of the package substrate 20, so as to surround the sound hole 20b. The MEMS package 1 and the MEMS microphone 100 have the bottom-seal structure with the dammed-seal part 30. Further, the dammed-seal part 30 is arranged in the outside than the all bonding bumps 4, the dammed-seal part 30 is formed so as to surround the all bonding bumps 4.
(32) The ASIC package 91 has the ASIC 92, and bonding bumps 93. The ASIC 92, for example, is an integral circuit which amplifies an output signal of the MEMS chip 10 (an integral circuit which outputs displacement of a capacitance as displacement of the voltage in the MEMS chip 10). Electrode pads 14 are formed lower side of the ASIC 92. The electrode pads 14 are connected to the electrode pads 12 of the package surface 20a by the bonding bumps 93.
(33) The cap 99 covers the MEMS package 1. The cap 99 is adhered to the package surface 20a with not illustrated adhesive (or by soldering). The MEMS package 1 is accommodated inside the cap 99.
(34) The cap 99 has a top surface 99E and a cap side-surface 99D. The top surface 99E is a part which is formed so as to oppose to the package substrate 20. The cap side-surface 99D is a part which is formed on the peripheral part of the top surface 99E. The cap side-surface 99D surrounds the top surface 99E, and it is adhered to the package substrate 20.
(35) (Dammed-Seal Part)
(36) Subsequently, the dammed-seal part 30 will be explained with reference to
(37) The dammed-seal part 30 has an annular structure, which surrounds the whole of the membrane 3, as illustrated in detail in
(38) The dammed-seal part 30 has a plurality of (four, in
(39) Then, as illustrated in
(40) The annular dam-member 25 is formed on the opposing surface 2a so as to surround the whole of the membrane 3, and further so as to surround the all bonding bumps 4.
(41) The annular dam-member 25 has a dam outer end surface 25a, which is along with the opposing surface 2a, a dam base surface 25b, which is in contact with the opposing surface 2a, a pair of dam slopes 25s, which connects the dam outer end surface 25a and the dam base surface 25b. Then, the annular dam-member 25 has a variable width structure in which the width (the width means a width along with the opposing surface 2a) gradually increases toward the dam base surface 25b from the dam outer end surface 25a.
(42) Then, the annular dam-member 25 has an outer dam slope 25sa, which is arranged in the outside being distant from the membrane 3, and an inner dam slope 25sb, which is arranged in the inside being close to the membrane 3, as the pair of dam slopes 25s.
(43) The gel member 26 is a member formed by hardening of gel which is applied on the annular dam-member 25. Gel is obtained by a hardening of colloidal solution into semisolid or solid. As described later, gel, having fluidity, is applied on the annular dam-member 25 in a step of manufacturing the MEMS package 1. After that, the gel becomes solid condition by fluidity loss caused by hardening, thereby the gel member 26 is formed.
(44) The gel member 26 is in contact with both the dam outer end surface 25a and the outer dam slope 25sa. Further, the gel member 26 enters a later-described dam space 27, and the gel member 26 is in also contact with the package surface 20a of the package substrate 20. The annular dam-member 25 has a fixed structure which the form does not change. The gel member 26 is in contact with the annular dam-member 25, as described-above, and it is supported by the annular dam-member 25, thereby the gel member 26 is formed.
(45) As illustrated in
(46) Then, as illustrated in detail in
(47) (Method of Manufacturing the MEMS Package 1, MEMS Microphone 100)
(48) Subsequently, the method of manufacturing the MEMS package 1 and the MEMS microphone 100, having the above-described structures, will be explained with reference to
(49) In the method of manufacturing the MEMS package 1, the method of manufacturing the MEMS microphone 100, the above-described MEMS chip 10, the ASIC 92 and the package substrate 20 which the MEMS chip 10 and the ASIC 92 are adhered. The MEMS chip 10 is manufactured with the MEMS wafer 40, illustrated in
(50) The MEMS wafer 40 is formed with a semiconductor wafer. As illustrated in
(51) As illustrated in
(52) Then, an annular dam-member forming step, a MEMS chip manufacturing step, a mounting step, a gel member forming step and a panel cutting step are included in the method of manufacturing the MEMS package 1, the method of manufacturing the MEMS microphone 100. A cap mounting step is further included in the method of manufacturing the MEMS microphone 100. At first, the annular dam-member forming step is performed.
(53) (Annular Dam-Member Forming Step)
(54) In the annular dam-member forming step, the above-described annular dam-members 25 are formed. The annular dam-members 25 are formed on dam expected areas 41r of the respective MEMS regions 41, about the MEMS wafer 40. As illustrated in
(55) A dam layer forming step is included in the annular dam-member forming step. In the dam layer forming step, a dam layer is formed by an ink application and an ink hardening. In the ink application, ink is applied on the wafer (MEMS wafer 40, in this embodiment) by the ink jet system. In the ink hardening, ink, applied by the ink application, is hardened.
(56) In the dam layer forming step, for example, the dam layer is formed on the dam expected area 41r using a printing hardening device 78, illustrated in
(57) Then, when the printing hardening device 78 is used, minute ink drops 79a are discharged from the printing head 78a, and they are applied on the dam expected area 41r. Further, UV light irradiation 78d, by the light irradiation device 78b, is performed, works with the application of the ink drops 79a. Then, hardening the ink drops 79a is performed, thereby a hardened ink layer 79b is formed on the dam expected area 41r. The dam layer is formed from the hardened ink layer 79b.
(58) In the method of manufacturing the MEMS package 1, the method of manufacturing the MEMS microphone 100, the above-described dam layer forming step is performed repeatedly, thereby a laminated dam layer is formed. The laminated dam layer is formed by laminating the dam layer.
(59) The dam layer is formed by the above-described ink application and the ink hardening, after that the ink application and the ink hardening are performed again. Thereby another dam layer is formed on the dam layer which has been formed. Thereby, the laminated dam layer is formed.
(60) For example, as illustrated in
(61) In the method of manufacturing the MEMS package 1, the method of manufacturing the MEMS microphone 100, the above-described laminated dam layer 35 is formed, as the annular dam-member 25. Because the laminated dam layer 35 is formed as the annular dam-member 25, the annular dam-member 25 is formed in the predetermined thickness.
(62) As described above, the annular dam-member forming step is performed, thereby, as illustrated in
(63) (MEMS Chip Manufacturing Step)
(64) Subsequently, the MEMS chip manufacturing step is performed. In the MEMS chip manufacturing step, the dam-MEMS wafer 40X is divided along with the scribe lines 42, thereby the dam-MEMS wafer 40X is cut into the respective MEMS regions 41. A dam-MEMS chip 10E is manufactured from each of the MEMS regions 41 (see
(65) (Mounting Step)
(66) Next, the mounting step is performed. In the mounting step, as illustrated in
(67) At this time, as illustrated in
(68) (Gel Member Forming Step)
(69) Subsequently, the gel member forming step is performed. In the gel member forming step, the gel members 26 are formed.
(70) As described-above, the annular dam-members 25 are formed on the dam-MEMS chips 10E. Therefore, in the gel member forming step, as illustrated in
(71) At this time, the dam spaces 27 are secured between the dam outer end surfaces 25a of the annular dam-members 25 and the surfaces 141a. Therefore, as illustrated in
(72) (Cap Mounting Step)
(73) After that, the cap mounting step is performed. In the cap mounting step, the caps 99 are mounted on the respective package regions 141 of the package-panel 140.
(74) (Panel Cutting Step)
(75) After that, the panel cutting step is performed. In the panel cutting step, the package-panel 140, which the MEMS chips 10 (the dam-MEMS chips 10E) and the ASICs 92 are mounted, is cut along with the divided lines 142 to be divided into the respective package regions 141. Then, the package-panel 140 is divided into a plurality of the package regions 141. The MEMS package 1 and the MEMS microphone 100 are manufactured together with the package substrate 20 from each of the package regions 141.
(76) (Operation and Effect of the MEMS Package, MEMS Microphone)
(77) As mentioned above, the MEMS package 1 and the MEMS microphone 100 have the dammed-seal part 30. The dammed-seal part 30 has the annular dam-member 25 and the gel member 26, the gel member 26 is formed by hardening of gel which is applied on the annular dam-member 25 from outside.
(78) Further, the gel member 26 is adhered to the opposing surface 2a so as to surround the whole of the membrane 3, and it also adhered to the package surface 20a so as to surround the whole of the sound hole 20b. Namely, the dammed-seal part 30 is a seal part which surrounds the sound hole 20b. The gel member 26 is formed by fluidity loss of gel caused by hardening. Then, gel having fluidity must to be applied on the MEMS chip 10 so that the gel member 26 is formed.
(79) However, when gel having fluidity is applied on the opposing surface 2a of the MEMS chip 10, the gel is adhered to the membrane 3, thereby the membrane 3 is likely to be damaged. It is extremely difficult that the seal part, surrounds the membrane 3 and the sound hole 20b, is formed certainly with only gel having fluidity.
(80) Then, in the MEMS package 1 and MEMS microphone 100, the annular dam-member 25 is formed on the opposing surface 2a so as to surround the membrane 3. Gel having fluidity is applied on the annular dam-member 25, the gel member 26 is formed by hardening of the gel.
(81) In this case, the formation of gel, having fluidity, is maintained by the annular dam-member 25, having fixed structure. Because the gel member 26 is formed by hardening of gel, the dammed-seal part 30, which the annular dam-member 25 and the gel member 26 are united to one body, is obtained, at the moment when the gel member 26 is formed. Therefore, the seal part, which is adhered closely to the MEMS chip 10 and the package substrate 20, is manufactured certainly, from gel having fluidity. Therefore, the MEMS package 1 and the MEMS microphone 100 are able to be manufactured certainly.
(82) Then, because the dammed-seal part 30 is formed so as to surround the all bonding bumps 4, the front volume is never narrowed by the dammed-seal part 30. Therefore, the MEMS package 1 and MEMS microphone 100 has a structure which the acoustic characteristic is not lowered.
(83) Further, the annular dam-member 25 has the variable width structure. In the mounting step, the dam-MEMS chip 10E is mounted so that the annular dam-member 25 faces to the package substrate 20 side and the annular dam-member 25 surround the sound hole 20b. Therefore, when the gel is applied to the annular dam-member 25 (the MEMS chip 10 is arranged as illustrated in
(84) Accordingly, gel having fluidity is kept certainly, outflow of gel is surely prevented. Further, the gel member 26 is united closely with the annular dam-member 25 to form the dammed-seal part 30.
(85) Further, the annular dam-member 25 is formed by performing the dam layer forming step repeatedly. Therefore, when the number of times for performing the dam layer forming step is changed, the size of the annular dam-member 25 is changed. Therefore, the annular dam-members, having various forms, are formed by the annular dam-member forming step. Further, because the dam layer is formed by the ink application and the ink hardening, the annular dam-member 25, having precise and minute form, is formed.
(86) The type double back-plate, having two not illustrated thin-films which are called back-plate are arranged in the upper side and the lower side of the membrane 3, is explained exemplarily in the embodiment. The present invention is also applicable to the type single back-plate, having one back-plate is arranged in the one side of the membrane 3.
(87) This invention is not limited to the foregoing embodiments but various changes and modifications of its components may be made without departing from the scope of the present invention. Besides, it is clear that various embodiments and modified examples of the present invention can be carried out on the basis of the foregoing explanation. Therefore, the present invention can be carried out in modes other than the above-mentioned best modes within the scope equivalent to the following claims.