CN111422826B

CN111422826B - Method for manufacturing sensor

Info

Publication number: CN111422826B
Application number: CN202010527133.XA
Authority: CN
Inventors: 党茂强; 解士翔
Original assignee: Weifang Goertek Microelectronics Co Ltd
Current assignee: Weifang Goertek Microelectronics Co Ltd
Priority date: 2020-06-11
Filing date: 2020-06-11
Publication date: 2020-10-20
Anticipated expiration: 2040-06-11
Also published as: CN111422826A; WO2021249124A1

Abstract

The invention discloses a manufacturing method of a sensor, which comprises the following steps: providing a first PCB, a second PCB and a third PCB, wherein the first PCB comprises a plurality of top plate units, the second PCB comprises a plurality of surrounding plate units, and the third PCB comprises a plurality of bottom plate units; respectively installing the first PCB and the third PCB on two sides of the second PCB to form a sensor assembly; each coaming unit is correspondingly connected with one top plate unit and one bottom plate unit so as to form a plurality of sensor units on the sensor aggregate; and separating the sensor unit from the sensor assembly to obtain a plurality of sensors. Therefore, the mass production of the MEMS sensor with the three layers of PCB boards as the packaging shell can be realized.

Description

Method for manufacturing sensor

Technical Field

The invention relates to the technical field of sensor production, in particular to a manufacturing method of a sensor.

Background

A MEMS (micro electro mechanical system) sensor is a device that converts an external signal (such as vibration, light, or pressure) into an electrical signal through a sensor chip, and in the device, a package is required in order to protect a fragile chip and reduce external interference, etc.

In a related design, a package is formed by three layers of PCB boards, that is, the package includes a surrounding board, and a bottom board and a top board respectively disposed at two ends of the surrounding board, the bottom board and the top board respectively seal openings at two ends of the surrounding board, and the surrounding board, the bottom board and the top board are all PCB boards. Therefore, the three layers of PCB boards are used as the packaging shell, the performance of the MEMS sensor can be improved, and the MEMS sensor is convenient to be connected with an external circuit.

However, the package is not easy to realize mass production, so in order to realize mass production of the MEMS sensor in the art, another package structure is designed, that is, the package structure includes a metal housing with an opening at one end and a bottom plate for sealing the opening of the metal housing, so that the metal housing can be realized in mass production by adopting a stamping forming method, thereby realizing mass production of the MEMS sensor. However, the metal shell is used as the packaging shell of the sensor, which is not beneficial to improving the performance of the MEMS sensor, for example, the sensor chip and the sound hole can only be arranged on the bottom plate.

Therefore, a method for mass production of MEMS sensors using a three-layer PCB as a package is desired.

Technical solution

The invention mainly aims to provide a manufacturing method of a sensor, aiming at realizing the mass production of MEMS sensors which adopt three layers of PCB boards as packaging shells.

In order to achieve the above object, the present invention provides a method for manufacturing a sensor, where the sensor includes a package casing, the package casing includes a surrounding plate, and a top plate and a bottom plate respectively disposed at two ends of the surrounding plate, where the two ends of the surrounding plate are respectively provided with a first connection structure and a second connection structure, the first connection structure connects one end of the surrounding plate with the top plate, the second connection structure connects the other end of the surrounding plate with the bottom plate, and the widths of the first connection structure and the second connection structure are both greater than or equal to 0.1 mm and less than or equal to 0.3 mm;

the manufacturing method of the sensor comprises the following steps:

s100, providing a first PCB (printed circuit board), a second PCB and a third PCB, wherein the first PCB comprises a plurality of top plate units, the second PCB comprises a plurality of enclosing plate units, the third PCB comprises a plurality of bottom plate units, a first connecting structure and a second connecting structure are arranged on the second PCB, and the first connecting structure and the second connecting structure are respectively arranged on two side surfaces of the second PCB of each enclosing plate unit;

s200, respectively installing the first PCB and the third PCB on two sides of the second PCB to form a sensor assembly; each enclosing plate unit is correspondingly connected with one top plate unit on one side of the second PCB through the first connecting structure, and is correspondingly connected with one bottom plate unit on the other side of the second PCB through the second connecting structure, so that a plurality of sensor units are formed on the sensor assembly; and

s300, separating the sensor unit from the sensor assembly to obtain a plurality of sensors.

Optionally, the step S200 of mounting the first PCB and the third PCB on two sides of the second PCB respectively to form a sensor assembly includes:

s210, attaching the second PCB to the first PCB, and enabling one end of each enclosing plate unit to be connected with one top plate unit through the first connecting structure; and

s240, the first PCB and the second PCB are attached to the third PCB together, and the other end of each enclosing plate unit is connected with one bottom plate unit through the second connecting structure.

Optionally, the first connecting structure is a first solder ring;

the step S210 of attaching the second PCB to the first PCB includes:

s212, applying solder paste to each of the top plate units on the first PCB; and

and S213, attaching the second PCB to the first PCB, wherein the solder paste on each top plate unit is connected with the top plate unit and the first welding ring of the enclosing plate unit corresponding to the top plate unit.

Optionally, in the step S210 of attaching the second PCB to the first PCB, the first PCB is laid flat, and the second PCB is attached to the upper surface of the first PCB from above the first PCB.

Optionally, the second connecting structure is a second solder ring;

the step S240 of attaching the first PCB and the second PCB to the third PCB together includes:

s243, coating solder paste on each bottom plate unit on the third PCB; and

and S244, attaching the first PCB and the second PCB together to the third PCB, wherein the solder paste on each bottom plate unit is connected with the bottom plate unit and the second welding ring of the surrounding plate unit corresponding to the bottom plate unit.

Optionally, the first solder ring includes a copper layer disposed on a side surface of the second PCB, a nickel layer disposed on a surface of the copper layer, and a gold layer disposed on a surface of the nickel layer, and the nickel layer is disposed between the copper layer and the gold layer.

Optionally, the thickness of the first solder ring is greater than or equal to 20 microns; and/or the presence of a gas in the gas,

the thickness of the nickel layer is greater than or equal to 3 micrometers and less than or equal to 8 micrometers; and/or the presence of a gas in the gas,

the thickness of the gold layer is greater than or equal to 0.08 micrometers and less than or equal to 12 micrometers.

Optionally, before the step S210 of attaching the second PCB to the first PCB, the method for manufacturing the sensor further includes:

s20a, attaching MEMS sensor chips to the first PCB, wherein each top plate unit is attached with one MEMS sensor chip;

alternatively, the first and second electrodes may be,

after the step S210 of attaching the second PCB to the first PCB and before the step S240 of attaching the first PCB and the second PCB together to the third PCB, the method for manufacturing a sensor further includes:

s22a, attaching MEMS sensor chips to the first PCB, wherein each top plate unit is attached with one MEMS sensor chip.

s20b, attaching ASIC chips to the first PCB, wherein each top plate unit is attached with one ASIC chip;

alternatively, the first and second electrodes may be,

s22b, attaching ASIC chips to the first PCB, wherein each top plate unit is attached with one ASIC chip;

alternatively, the first and second electrodes may be,

before the step S240 of attaching the first PCB and the second PCB to the third PCB, the method for manufacturing a sensor further includes:

s300, pasting the ASIC chips on the third PCB, wherein one ASIC chip is pasted on each bottom plate unit.

s250, attaching the second PCB to the third PCB, and enabling one end of each enclosing plate unit to be connected with one bottom plate unit through the second connecting structure; and

and the third PCB and the second PCB are attached to the first PCB together, and the other end of each enclosing plate unit is connected with one top plate unit through the first connecting structure.

Optionally, the sensor unit is separated from the sensor aggregate by means of cutting.

Optionally, a metal shielding layer is arranged on an inner wall surface of the boarding unit.

Optionally, an insulating layer is disposed on an inner side surface of the metal shielding layer.

Optionally, the thickness of the insulating layer is greater than or equal to 6 micrometers and less than or equal to 20 micrometers; and/or the presence of a gas in the gas,

the thickness of the metal shielding layer 21 is greater than or equal to 10 micrometers.

Optionally, a distance between two adjacent sensor units is greater than or equal to 0.2 mm and less than or equal to 0.6 mm.

Optionally, the number of sensor units is greater than or equal to 150 and less than or equal to 1000.

Optionally, the amount of solder paste used in each of the sensor manufacturing processes is greater than or equal to 0.06 grams and less than or equal to 2 grams.

Optionally, the overall thickness of the sensor assembly is less than or equal to 1.5 millimeters.

According to the invention, the first PCB and the third PCB are respectively arranged on two sides of the second PCB, so that a sensor assembly with a plurality of sensor units can be formed, and a plurality of sensors are separated from the sensor assembly. Therefore, the mass production of the MEMS sensor with the three layers of PCB boards as the packaging shell can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic block flow diagram of one embodiment of a method of manufacturing a sensor of the present invention;

FIG. 2 is a schematic assembly flow diagram of a method of manufacturing the sensor of FIG. 1;

FIG. 3 is a schematic assembly flow diagram of a first embodiment of a method of manufacturing a sensor according to the present invention;

FIG. 4 is a schematic assembly flow diagram of a third embodiment of a method of manufacturing a sensor according to the present invention;

FIG. 5 is a schematic front view of the second PCB shown in FIG. 1;

FIG. 6 is a schematic diagram of a reverse structure of the second PCB shown in FIG. 5;

FIG. 7 is a schematic diagram of the sensor of FIG. 1;

FIG. 8 is a schematic front view of the shroud of FIG. 7;

FIG. 9 is a schematic view of the back panel of FIG. 8 in an inverted configuration;

fig. 10 is a schematic cross-sectional view of the shroud of fig. 7.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Sensor with a sensor element	27	Second solder ring
10	Top board	30	Base plate
				11	Sound hole	200	First PCB board
20	Boarding board	10a	Top plate unit
				21	Metal shielding layer	300	Second PCB board
22	Insulating layer	310	Second pair of knife marks
				23	Solder resist isolation layer	20a	Boarding unit
24	Electrical connector	400	Third PCB board
				25	First welding ring	30a	Floor unit
26	Resin isolation layer	500	Sensor assembly

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Modes for carrying out the invention

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that if the description of "first", "second", etc. is provided in the embodiment of the present invention, the description of "first", "second", etc. is only for descriptive purposes and is not to be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B" including either scheme A, or scheme B, or a scheme in which both A and B are satisfied.

The invention provides a manufacturing method of a sensor.

As shown in fig. 1 to 10, the sensor 100 includes a package, and a MEMS sensor chip and an ASIC chip disposed in the package, where the package includes a surrounding plate 20, and a top plate 10 and a bottom plate 30 respectively disposed at two ends of the surrounding plate 20, where two ends of the surrounding plate 20 respectively have an opening, and the top plate 10 and the bottom plate 30 are respectively used for sealing the openings at two ends of the surrounding plate 20. Specifically, the top plate 10, the surrounding plate 20 and the bottom plate 30 are all PCB boards.

The sensor is an MEMS sensor, and specifically can be an MEMS microphone, an MEMS pressure sensor or the like; correspondingly, the MEMS sensor chip may specifically be a MEMS microphone chip, or a MEMS pressure sensor chip, or the like. The following description will be given taking the MEMS microphone as an example of the sensor.

Specifically, a first connecting structure and a second connecting structure are respectively arranged at two ends of the enclosing plate 20, the first connecting structure connects one end of the enclosing plate 20 with the top plate 10, and the second connecting structure connects the other end of the enclosing plate 20 with the bottom plate 30. In this manner, the connection of the fence 20 to the top plate 10 or the fence 20 to the bottom plate 30 can be facilitated by the connection structure (first connection structure, second connection structure).

In an embodiment, the first connecting structure may be configured as a solder ring, so that the enclosure plate 20 and the top plate 10 may be soldered by solder paste. Of course, the first connecting structure may also be a plurality of welding sheets/portions annularly distributed at one end of the enclosing plate, so that the enclosing plate 20 and the top plate 10 may also be welded by solder paste. Of course, the first connecting structure may also be provided as a ring-shaped electrical connector, so that the enclosure plate 20 and the top plate 10 may be connected by conductive adhesive. It is understood that the structural form of the second connecting structure is the same as that of the first connecting structure, and therefore, a detailed description thereof is not required. Also, the first connecting structure and the second connecting structure are solder rings, but the invention is not limited thereto.

Further, the widths of the first connecting structure and the second connecting structure are both greater than or equal to 0.1 millimeter and less than or equal to 0.3 millimeter.

It will be understood that the width of the first attachment formation is the length of the first attachment formation in the direction of the thickness of the panel wall of the enclosure. Such as: when the first connecting structure is a welding ring, the width of the first connecting structure is the width of the welding ring; when the first connecting structure is a plurality of welding sheets/parts which are annularly distributed at one end of the enclosing plate, the width of the first connecting structure refers to the width of an annular structure formed by the plurality of welding sheets/parts; when the first connecting structure is a ring-shaped electric connector, the width of the first connecting structure refers to the width of the ring-shaped electric connector; and so on. Similarly, the width of the second connecting structure also refers to the length of the first connecting structure in the thickness direction of the wall of the enclosing plate.

It can be understood that if the first connecting structure and the second connecting structure are too narrow, the first connecting structure and the second connecting structure may be difficult to process and may have poor firmness after connection. If the widths of the first connection structure and the second connection structure are too wide, the size of the sensor 100 may be affected; and for the welding ring, when the solder paste is scratched, the amount of the solder paste is large, thereby affecting the flatness of the product.

Optionally, the widths of the first connecting structure and the second connecting structure are greater than or equal to 0.12 mm and less than or equal to 0.28 mm, such as 0.15, 0.18, 0.2, 0.22, 0.25, 0.27 mm, and the like.

Based on the above structure of the sensor 100, in an embodiment of the present invention, as shown in fig. 1 to 3, a manufacturing method of the sensor 100 includes:

step S100, providing a first PCB 200, a second PCB 300 and a third PCB 400, wherein the first PCB comprises a plurality of top plate units 10a, the second PCB 300 comprises a plurality of surrounding plate units 20a, and the third PCB 400 comprises a plurality of bottom plate units 30 a. And the second PCB is provided with a first connection structure and a second connection structure, and each of the surrounding plate units 20a is provided with one of the first connection structure and one of the second connection structure at both side surfaces of the second PCB 300.

Wherein, it is understood that each top plate unit 10a is used for forming the top plate 10 of one sensor, each enclosure unit 20a is used for forming the enclosure 20 of one sensor, and each bottom plate unit 30a is used for forming the bottom plate 30 of one sensor; in other words, each top plate unit 10a is a top plate 10 of one sensor 100, each enclosure unit 20a is an enclosure 20 of one sensor 100, and each bottom plate unit 30a is a bottom plate 30 of one sensor 100, the bottom plate 30 being used for connecting with an external circuit board.

Specifically, the plurality of top plate units 10a are arranged in an array, the plurality of surrounding plate units 20a are also arranged in an array, and the plurality of bottom plate units 30a are also arranged in an array; and the array arrangement modes of the three are the same.

Wherein, each top plate unit 10a is provided with a sound hole 11 (if the sensor is a MEMS pressure sensor, the sound hole 11 is a pressure transmission hole correspondingly).

Specifically, the ceiling unit 10a may be circular or square (square or rectangular), and the shape of the enclosure unit 20a and the bottom unit 30a is adapted to the shape of the ceiling unit 10 a.

Step S200, respectively mounting the first PCB 200 and the third PCB 400 on two sides of the second PCB 300 to form a sensor assembly 500; and each of the enclosure units 20a is correspondingly connected with one of the top plate units 10a at one side of the second PCB 300 through the first connection structure, and is correspondingly connected with one of the bottom plate units 30a at the other side of the second PCB 300 through the second connection structure, so as to respectively seal openings at two ends of the enclosure unit 20a, thereby forming a plurality of sensor units on the sensor assembly 500.

Here, it is understood that each sensor unit is a sensor 100, which includes a surrounding unit 20a, and a top plate unit 10a and a bottom plate unit 30a respectively provided at both ends of the surrounding unit 20 a.

And a step S300 of separating the sensor units from the sensor assembly 500 to obtain a plurality of sensors 100.

The present invention can form a sensor assembly 500 having a plurality of sensor units by mounting the first PCB 200 and the third PCB 400 on both sides of the second PCB 300, respectively, so that a plurality of sensors 100 can be separated from the sensor assembly 500. In this way, mass production of the sensor 100 using the three-layer PCB board as the package can be realized.

Moreover, the connecting structures (the first connecting structure and the second connecting structure) are arranged at the two ends of the enclosing plate, so that the enclosing plate 20 and the top plate 10 or the enclosing plate 20 and the bottom plate 30 can be conveniently connected, and the connecting strength is favorably improved.

In a specific embodiment, there are various ways to mount the first PCB 200 and the third PCB 400 on two sides of the second PCB 300 respectively to form the sensor assembly 500, and specifically, it can be understood that in the present invention, the second PCB 300 is a surrounding plate assembly, the first PCB 200 is a top plate assembly, and the third PCB 400 is a bottom plate assembly; therefore, the scheme of the invention can be as follows: firstly, mounting a coaming aggregate on a top plate aggregate, and then mounting the coaming aggregate and a bottom plate aggregate together; or the coaming aggregate is installed on the bottom plate aggregate and then is installed on the top plate aggregate; the following examples are given for illustration.

In the first embodiment of the present invention, as shown in fig. 3, the step S200 of mounting the first PCB 200 and the third PCB 400 on both sides of the second PCB 300, respectively, to form a sensor assembly 500 includes:

step S210, attaching the second PCB 300 to the first PCB 200, and connecting one end of each enclosure unit 20a to a top plate unit 10a through a first connecting structure.

And step S240, attaching the first PCB 200 and the second PCB 300 to a third PCB 400, and connecting the other end of each enclosure unit 20a to a bottom plate unit 30a through a second connection structure.

In this way, the first PCB 200 and the third PCB 400 are disposed at both sides of the second PCB 300, and each of the enclosure units 20a is connected with one of the top plate units 10a and one of the bottom plate units 30a, respectively, so as to form a plurality of sensor units on the sensor assembly 500.

In an exemplary embodiment, the first connecting structure and the second connecting structure are generally solder rings, and the first PCB 200 is attached to the second PCB 300 by solder paste, and the third PCB 400 is attached to the second PCB 300 by solder paste, wherein the attaching steps will be described in detail below with reference to the structure of the sensor 100.

Thus, the second PCB 300 is attached to the first PCB 200, and then the first PCB 200 and the second PCB 300 are attached to the third PCB 400, thereby effectively preventing solder paste from flowing into the inner wall of the enclosure unit 20 a.

Specifically, as shown in fig. 8, the first connecting structure is a first solder ring 25.

Wherein, the width of the first welding ring 25 is greater than or equal to 0.1 mm and less than or equal to 0.3 mm.

It will be appreciated that if the first solder ring 25 is too narrow, the first solder ring 25 will be difficult to process and will have poor strength after bonding. If the first solder ring 25 is too wide, the size of the sensor 100 may be affected; and when the solder paste is scratched, the amount of the solder paste is large, thereby affecting the flatness of the product.

Optionally, the width of the first solder ring 25 is greater than or equal to 0.12 mm and less than or equal to 0.28 mm, such as 0.15, 0.18, 0.2, 0.22, 0.25, 0.27 mm, etc.

Further, the first solder ring 25 includes a copper layer disposed on the side of the second PCB 300, a nickel layer disposed on the surface of the copper layer, and a gold layer disposed on the surface of the nickel layer, wherein the nickel layer is disposed between the copper layer and the gold layer. In this manner, the weldability of the first solder ring 25 can be improved.

Specifically, the copper layer is formed by a process of coating copper on the surface.

Specifically, the nickel layer is an electroplated layer, and the gold layer is an electroplated layer.

Further, the copper layer has a thickness greater than or equal to 20 microns. It is understood that if the copper layer is thin, the copper layer is difficult to process and has poor firmness after soldering.

Further, the thickness of the nickel layer is greater than or equal to 2 micrometers and less than or equal to 10 micrometers. It can be understood that if the nickel layer is thinner, it is not favorable for improving the weldability of the first solder ring 25; if the nickel layer is thick, the cost increases.

Specifically, the thickness of the nickel layer is greater than or equal to 3 micrometers and less than or equal to 8 micrometers. For example, the nickel layer may be selected to have a thickness of 4 microns, 5 microns, 6 microns, 7 microns, and the like.

Further, the thickness of the gold layer is greater than or equal to 0.05 micrometers and less than or equal to 15 micrometers. It can be understood that if the thickness of the gold layer is relatively thin, it is not favorable for improving the weldability of the first solder ring 25; if the thickness of the gold layer is thick, the cost increases.

Specifically, the thickness of the gold layer is greater than or equal to 0.08 micrometers and less than or equal to 12 micrometers. For example, the gold layer may be selected to have a thickness of 0.09 microns, 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, and the like.

Specifically, as shown in fig. 9, the second connecting structure is a second solder ring 27. The structure of the second solder ring 27 is (substantially) the same as that of the first solder ring 25, and it also includes a copper layer disposed on the side of the second PCB 300, a nickel layer disposed on the surface of the copper layer, and a gold layer disposed on the surface of the nickel layer, and the specific structural limitations thereof are not repeated herein.

Specifically, the second PCB 300 is further provided with an electrical connector 24, and the electrical connector 24 is embedded in each enclosure unit 20 a. Optionally, the electrical connector 24 is an annular cylindrical structure.

Further, the step S210 of attaching the second PCB 300 to the first PCB 200 includes:

step S212, applying solder paste to each of the top plate units 10a on the first PCB 200.

Wherein, each of the top plate units 10a on the first PCB 200 is provided with a first annular coating region, and in step S212, solder paste is applied to the first annular coating region. Optionally, solder paste is applied over the first annular coating region to ensure bond strength.

Wherein, be equipped with first pad in the first annular coating district.

And step S213, attaching the second PCB 300 to the first PCB 200, and connecting the top plate unit 10a and the first solder ring 25 of the surrounding plate unit 20a corresponding to the top plate unit 10a with solder paste on each top plate unit 10 a.

In this embodiment, specifically, in step S212, solder paste is scribed on each of the top plate units 10 a. In step S213, specifically, the solder paste solders the first solder ring 25 and the first pad together at the soldering temperature.

In this way, the first solder ring 25 and the first solder pad are soldered by solder paste to connect the top plate unit 10a and the corresponding enclosure unit 20a, so that not only the top plate unit 10a and the enclosure unit 20a can be fixedly connected, but also the top plate unit 10a and the enclosure unit 20a can be electrically connected.

Further, in the step S210 of attaching the second PCB 300 to the first PCB 200, the first PCB 200 is disposed flatly, and the second PCB 300 is attached to the upper surface of the first PCB 200 from above the first PCB 200. Thus, solder paste can be prevented from flowing around the first PCB 200.

Specifically, a first positioning hole is formed in the first PCB 200, and a second positioning hole is formed in the second PCB 300.

Specifically, before step S212, step S210 of attaching the second PCB 300 to the first PCB 200 further includes:

step S211, fixing the first PCB 200 on a mounting table, and inserting a positioning pin on the mounting table into a first positioning hole.

Specifically, the first PCB 200 is placed above the mounting table, the first positioning hole is aligned with the positioning pin of the mounting table, and then the first PCB 200 is moved downward, so that the positioning pin is inserted into the first positioning hole, so as to guide the first PCB 200 to move toward the mounting table, so that the first PCB 200 is fixed on the mounting table.

Specifically, the specific process of step S213 is: the second PCB 300 is placed above the first PCB 200 such that the second positioning hole is aligned with the positioning pin of the mounting table, and then the second PCB 300 is moved downward such that the positioning pin is inserted into the second positioning hole to guide the second PCB 300 to move toward the first PCB 200, so that the second PCB 300 is mounted on the first PCB 200.

Thus, the first positioning hole and the second positioning hole are correspondingly arranged, so that each top plate unit 10a corresponds to one enclosing plate unit 20a, and accurate positioning is realized.

In some embodiments, in order to prevent the solder paste from being scattered and improve the connection effect, a first annular barrier wall is provided at the periphery of each ceiling unit 10a, the first annular barrier wall being located inside the inner wall surface of the enclosure unit, and the first annular barrier wall may be used to form a first annular coating region. It is understood that the first annular barrier wall may form a first coating groove between the adjacent ceiling units 10 a. In step S212, the solder paste may be coated in the first coating groove, so that the width of the first coating groove is adjusted to ensure the connection strength and prevent the solder paste from being dispersed, reduce the amount of the solder paste as much as possible, and allow for the separation of the sensor units. Moreover, the first annular blocking wall can also block solder (such as soldering tin and the like) during welding so as to prevent the solder from splashing into the packaging shell to pollute the internal chip. In this embodiment, the first annular blocking wall may be formed integrally with the ceiling unit 10a or may be formed separately and connected to the surface of the ceiling unit 10 a.

Specifically, in order to improve the shielding effect of the package, a metal shielding layer 21 is further provided on the inner wall surface of each enclosure unit 20a, and the metal shielding layer 21 is grounded.

Optionally, the metal shielding layer 21 is a copper foil layer.

Specifically, the thickness of the metal shielding layer 21 is greater than or equal to 10 micrometers. Thus, the shielding effect is ensured/improved.

In a further design, in order to avoid solder entering the package during soldering, an insulating layer 22 is provided on the inner wall surface of each enclosure unit 20a to block the solder during soldering.

Specifically, the metal shielding layer 21 is provided between the insulating layer 22 and the inner wall surface of the enclosure unit 20a, that is, the insulating layer 22 is provided on the inner side surface of the metal shielding layer 21.

Wherein the insulating layer 22 is optionally an electrophoretic layer.

Specifically, the thickness of the insulating layer 22 is greater than or equal to 6 micrometers, and less than or equal to 20 micrometers, for example, it may be 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, 15 micrometers, 16 micrometers, 17 micrometers, 18 micrometers, 19 micrometers, or the like.

Specifically, the manufacturing process of the second PCB 300 generally includes:

1) holes are formed in the PCB, and each enclosure unit 20a is provided with an inner cavity through hole and a metalized through hole formed in the side wall of the enclosure unit 20 a.

2) A metal shield layer 21 is formed on an inner wall surface (i.e., an inner wall surface of the cavity through-hole) of each of the apron units 20 a.

3) An electrical connector 24 is formed within the metallized via. In some embodiments, the electrical connector 24 is in an annular column shape, and a resin isolation layer 26 may be further filled in the metalized through hole, that is, a resin plug hole structure is formed, so that no bubbles remain inside the metalized through hole. Optionally, the electrical connector 24 has a sidewall thickness greater than or equal to 12 microns.

4) An insulating layer 22 is formed inside the metal shield layer 21.

5) The first solder ring 25 and the second solder ring 27 are formed on both sides of the PCB panel, respectively.

6) A solder resist isolation layer 23, such as a layer of green oil, is formed on the surface of the sheet material.

Further, as shown in fig. 3, the step S240 of attaching the first PCB 200 and the second PCB 300 to the third PCB 400 includes:

step S243, solder paste is applied to each of the chassis units 30a on the third PCB 400.

A second annular coating area is provided on each of the bottom plate units 30a of the third PCB 400, and in step S243, solder paste is applied to the second annular coating area. Optionally, solder paste is applied over the second annular coating region to ensure bond strength.

And a second bonding pad is arranged in the second annular coating area.

And step S244, attaching the first PCB 200 and the second PCB 300 together to the third PCB 400, and connecting the solder paste on each bottom plate unit 30a to the second solder ring 27 of the bottom plate unit 30a and the enclosure unit 20a corresponding to the bottom plate unit 30 a.

Specifically, in step S243, solder paste is scribed on each of the base plate units 30 a. In step S244, specifically, solder paste bonds the second solder ring 27 and the second pad together at the bonding temperature.

In some embodiments, in order to prevent the solder paste from being scattered and improve the connection effect, a second annular barrier wall is provided at the periphery of each of the chassis units 30a, the second annular barrier wall being located inside the inner wall surface of the enclosure unit, and the second annular barrier wall may be used to form a second annular coating region. It is understood that the second annular barrier wall may form a second coating groove between the adjacent floor units 30 a. In step S243, the solder paste may be coated in the second coating groove, so that the width of the second coating groove is adjusted to ensure the connection strength and prevent the solder paste from being dispersed, reduce the amount of the solder paste as much as possible, and allow for the separation of the sensor units. Moreover, the second annular blocking wall can also block solder (such as soldering tin and the like) during welding so as to prevent the solder from splashing into the packaging shell to pollute the internal chip. In some embodiments, the second annular blocking wall may be integrally formed with the base unit 30a, or may be formed separately from the surface of the base unit 30 a.

Further, in step S240 of attaching the first PCB 200 and the second PCB 300 to a third PCB 400, the third PCB 400 is horizontally disposed, and the first PCB 200 and the second PCB 300 are attached to an upper surface of the third PCB 400 from above the third PCB 400.

Specifically, a third positioning hole is formed in the third PCB 400.

Specifically, before step S243, step S240 of attaching the first PCB 200 and the second PCB 300 to the third PCB 400 further includes:

step S241, the first PCB 200 and the second PCB 300 are removed from the mounting table together.

Step S242, fixing the third PCB 400 on the mounting table, and inserting the positioning pin on the mounting table into the third positioning hole.

Specifically, the third PCB 400 is placed above the mounting table, and the third positioning hole is aligned with the positioning pin of the mounting table, and then the third PCB 400 is moved downward, so that the positioning pin is inserted into the third positioning hole, so as to guide the third PCB 400 to move toward the mounting table, so that the third PCB 400 is fixed on the mounting table.

Specifically, the specific process of step S244 is: placing the first PCB 200 and the second PCB 300 above a third PCB 400, wherein the first PCB 200 is located above the second PCB 300, and the first positioning hole and the second positioning hole are aligned with the positioning pin of the mounting table; and then, the first PCB 200 and the second PCB 300 are moved downward together, so that the positioning pins are inserted into the first positioning holes and the second positioning holes to guide the first PCB 200 and the second PCB 300 to move downward together, so that the first PCB 200 and the second PCB 300 are attached to the third PCB 400 together.

Thus, the first positioning hole, the second positioning hole and the third positioning hole can be correspondingly arranged, so that each enclosing plate unit 20a can correspond to a top plate unit 10a and a bottom plate unit 30 a.

In addition, the first PCB 200 and the third PCB 400 are respectively mounted on both sides of the second PCB 300 in this manner, so that solder paste can be effectively prevented from being scattered.

Of course, in other embodiments, the first PCB 200 and the second PCB 300 may be directly mounted on the second PCB above the third PCB 400 without being taken off from the mounting table.

In a specific embodiment, the MEMS sensor chip is typically provided on the TOP plate 10 to form a pseudo TOP structure, thereby improving the performance of the MEMS sensor chip.

Before the step S210 of attaching the second PCB 300 to the first PCB 200, the method further includes:

step S20a, attaching the MEMS sensor chip to the first PCB 200, and attaching one MEMS sensor chip to each of the top plate units 10 a.

Therefore, before the second PCB 300 is attached to the first PCB 200, the MEMS sensor chip is attached to the first PCB 200, and the MEMS sensor chip can be attached to the first PCB 200 by using a surface-mount technology, so that the difficulty of the attachment process of the MEMS sensor chip can be reduced, and the cost can be reduced.

Of course, after the second PCB 300 is attached to the first PCB 200, the MEMS sensor chip may be attached to the first PCB 200, that is, after the step S210 of attaching the second PCB 300 to the first PCB 200 and before the step S240 of attaching the first PCB 200 and the second PCB 300 together to the third PCB 400, the method for manufacturing the sensor further includes:

step S22a, attaching the MEMS sensor chip to the first PCB 200, and attaching one MEMS sensor chip to each of the top plate units 10 a.

Thus, when the second PCB 300 is attached to the first PCB 200, the MEMS sensor chip can be prevented from being contaminated by the spattered solder (e.g., solder).

Specifically, in an embodiment of the sensor 100, the ASIC chip is also disposed on the top plate 10, and therefore, in the first embodiment of the present invention, the manufacturing method of the sensor 100 further includes the following steps, before the step S210 of attaching the second PCB 300 to the first PCB 200, of:

step S20b, the ASIC chip is mounted on the first PCB 200, and one ASIC chip is mounted on each top plate unit 10 a.

In the present invention, the order of step S20a and step S20b is not limited, and step S20a may precede step S20, or step S20b may precede step S20.

Of course, after the second PCB 300 is mounted on the first PCB 200, the ASIC chip may be mounted on the first PCB 200, that is, after the step S210 of mounting the second PCB 300 on the first PCB 200 and before the step S240 of mounting the first PCB 200 and the second PCB 300 on the third PCB 400, the method for manufacturing the sensor further includes:

step S22b, attach an ASIC chip to the first PCB 200, and each top plate unit 10a is attached with an ASIC chip.

Thus, it is possible to prevent the ASIC chip from being contaminated by the spattered solder (e.g., solder) when the second PCB 300 is mounted on the first PCB 200.

In the present invention, the order of step S22a and step S22b is not limited, and step S22a may precede step S22 b.

It should be noted that, based on the above examples, the steps for mounting the MEMS sensor chip and the ASIC chip can be combined as follows: step S20a and step S20b, step S20a and step S22b, step S20b and step S22a, and step S22a and step S22 b.

Specifically, in another embodiment of the sensor 100, the ASIC chip is disposed on the bottom plate 30. In view of this, the present invention further provides a second embodiment, in which the method for manufacturing the sensor 100 further includes, before the step S240 of attaching the first PCB 200 and the second PCB 300 to the third PCB 400, the steps of:

step S300, mounting an ASIC chip on the third PCB 400, and mounting an ASIC chip on each bottom plate unit 30 a.

It should be noted that in the second embodiment of the present invention, the steps for mounting the MEMS sensor chip and the ASIC chip can be combined as follows: step S20a and step S300 (not shown), and step S22a and step S300 (not shown).

In other embodiments of the present invention, the first PCB 200 and the third PCB 400 may be mounted on both sides of the second PCB 300 by other methods to form the sensor assembly 500.

As in the third embodiment of the present invention, as shown in fig. 4, the step S200 of mounting the first PCB 200 and the third PCB 400 on both sides of the second PCB 300, respectively, to form the sensor assembly 500 includes:

step S250, attaching the second PCB 300 to a third PCB 400, and connecting one end of each enclosure unit 20a to a bottom plate unit 30a through a second connection structure; and

step S260, the third PCB 400 and the second PCB 300 are attached to the first PCB 200, and the other end of each enclosure unit 10a is connected to a top plate unit 10a through a first connection structure.

In the third embodiment of the present invention, specifically, the step S250 includes:

step S251, the third PCB 400 is fixed on a mounting table, and a positioning pin on the mounting table is inserted into a third positioning hole.

Step S252, solder paste is applied to each of the bottom plate units 30a on the third PCB 400.

Specifically, solder paste may be applied to the second annular coating region.

Step S253 is to attach the second PCB 300 to the third PCB 400, and the solder paste on each bottom plate unit 30a connects the bottom plate unit 30a and the second solder ring 27 of the surrounding plate unit 20a corresponding to the bottom plate unit 30 a.

Specifically, the second PCB 300 is placed above the third PCB 400, the second positioning hole is aligned with the positioning pin of the mounting table, and then the second PCB 300 is moved downward, so that the positioning pin is inserted into the second positioning hole, so as to guide the second PCB 300 to move toward the third PCB 400, so that the second PCB 300 is mounted on the third PCB 400.

In the third embodiment of the present invention, specifically, the step S260 includes:

step S261, removing the third PCB 400 and the second PCB 300 from the mounting table together.

Step S262, fixing the first PCB 200 on the mounting table, and inserting the positioning pin on the mounting table into the first positioning hole.

Step S263, solder paste is applied to each top plate unit 10a on the first PCB 200.

Specifically, solder paste may be applied to the first annular application region.

Step S264, placing the third PCB 400 and the second PCB 300 above the first PCB 200, wherein the third PCB 400 is located on the upper side of the second PCB 300, and aligning the third positioning hole and the second positioning hole with the positioning pin of the mounting table; then, the third PCB 400 and the second PCB 300 are moved downward together, so that the positioning pins are inserted into the third positioning holes and the second positioning holes to guide the third PCB 400 and the second PCB 300 to move downward together, so that the third PCB 400 and the second PCB 300 are attached to the first PCB 200 together, and the solder paste on each top plate unit 10a connects the top plate unit 10a and the first solder ring 25 of the enclosure unit 20a corresponding to the top plate unit 10 a.

Specifically, regarding the mounting of the MEMS sensor chip and the ASIC chip, before step S250, the ASIC chip may be mounted on the third PCB 400, and one ASIC chip is mounted on each bottom plate unit 30 a; alternatively, after step S250 and before step S260, the ASIC chip is mounted on the third PCB 400, and one ASIC chip is mounted on each chassis unit 30 a; alternatively, before step S260, the ASIC chip is mounted on the first PCB 200, and one ASIC chip is mounted on each top plate unit 10 a.

The MEMS sensor chips may be mounted on the first PCB board 200 before step S260, and one MEMS sensor chip is mounted on each top plate unit 10 a.

For other details in the third embodiment of the present invention, reference may be made to the first and second embodiments of the present invention, which need not be described in detail herein.

In a specific embodiment, the sensor units may be separated from the sensor assembly 500 by cutting to obtain a plurality of sensors 100.

Specifically, step S300 includes: the sensor units are separated from the sensor assembly 500 by cutting to obtain a plurality of sensors 100. Specifically, the sensor assembly 500 may be cut by a dicing saw to separate the sensor units.

Specifically, the step S300 specifically includes:

step S310, fixing the sensor assembly 500 and the steel ring by using the positioning pins, with the sensor assembly 500 being located inside the steel ring, and then laying a UV film on one side of the sensor assembly 500 and the steel ring to fix the sensor assembly 500 on the steel ring through the UV film.

Step S320, dicing the sensor assembly 500 on the steel ring to separate the sensor units from the sensor assembly 500, so as to obtain a plurality of sensors 100.

Step S330, tearing off the UV film on the sensor 100.

Wherein, the sensor assembly 500 is provided with a tool setting mark to improve the cutting precision. Specifically, a first pair of knife marks, a second pair of knife marks 310, and a third pair of knife marks are provided at the same positions of the first PCB 200, the second PCB 300, and the third PCB 400, respectively, to form a pair of knife marks on the sensor assembly 500.

In this embodiment, a plurality of the sensor units are arranged in a rectangular or square shape, wherein a plurality of the tool setting marks are provided, wherein a part of the tool setting marks are located at four corners of the rectangular or square shape in which the plurality of sensor units are arranged, and a part of the tool setting marks are located on sides of the rectangular or square shape in which the plurality of sensor units are arranged.

As shown in fig. 5 and 6, for the second PCB, a plurality of enclosure units 20a are arranged in a rectangular or square shape, and a plurality of second pair of blade marks 310 are provided, wherein a part of the second pair of blade marks are located at four corners of the rectangular or square shape in which the plurality of enclosure units 20a are arranged, and a part of the second pair of blade marks are located on sides of the rectangular or square shape in which the plurality of enclosure units 20a are arranged.

Wherein, the tool setting mark can be a cross mark.

Here, in step S310, a UV film is generally laid on the surface of the first PCB 200, so that the UV film can also protect the sound hole 11. However, if the UV film is laid on the surface of the third PCB 400, a protective film is further attached to the surface of the first PCB 200 to protect the sound hole 11; or a protective film may be attached only at the sound hole 11 of each ceiling plate unit 10 a.

Further, the distance between two adjacent sensor units is greater than or equal to 0.2 mm. It can be understood that if the distance between two adjacent sensor units is too small, cutting is not facilitated.

Further, the distance between two adjacent sensor units is less than or equal to 0.6 mm. It can be understood that if the distance between two adjacent sensor units is too large, the arrangement of the sensor units is too thin, so that the production efficiency is not improved, and waste is caused.

Optionally, a distance between two adjacent sensor units is greater than or equal to 0.28 mm and less than or equal to 0.5 mm.

Optionally, a distance between two adjacent sensor units is greater than or equal to 0.32 mm and less than or equal to 0.4 mm.

In a specific embodiment, the distance between two adjacent sensor units may be 0.34 mm, 0.35 mm, 0.36 mm, 0.38 mm, 0.4 mm, etc.

Specifically, the width of the sensor assembly 500 is greater than or equal to 50 mm and less than or equal to 200 mm. The length of the sensor assembly 500 is greater than or equal to 50 mm and less than or equal to 200 mm. Accordingly, the width of the second PCB 300 is greater than or equal to 50 mm and less than or equal to 200 mm. The length of the second PCB 300 is greater than or equal to 50 mm and less than or equal to 200 mm.

Further, the number of sensor units is greater than or equal to 150 and less than or equal to 2400. That is, the number of the top plate units 10a on the first PCB 200 is greater than or equal to 150 and less than or equal to 2400, the number of the shroud plate units 20a on the second PCB 300 is greater than or equal to 150 and less than or equal to 2400, and the number of the bottom plate units 30a on the third PCB 400 is greater than or equal to 150 and less than or equal to 2400.

It can be understood that if the number of sensor units on each sensor assembly 500 is too small, the layout will be too small, thereby affecting the efficiency and cost; if the number of the sensor units on each sensor assembly 500 is too large, the layout may be too large, which may affect the flatness and position of the PCB, resulting in low process yield and difficulty in transporting the PCB.

Optionally, the number of sensor units is greater than or equal to 300 and less than or equal to 2000. Wherein, the number of the sensor units can be 400, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1500, 1600, 1800 and the like.

Further, during the manufacturing process of each sensor 100, the amount of solder paste is greater than or equal to 0.06 grams and less than or equal to 2 grams. It can be understood that if the consumption of the solder paste is too large, not only waste is caused, but also the solder paste is easy to splash during welding; if the amount of the solder paste is too small, the soldering strength cannot be ensured. It is understood that the amount of solder paste used is also influenced by the size of the sensor assembly 500 and the arrangement density of the sensor units.

Alternatively, the amount of solder paste is greater than or equal to 0.1 grams and less than or equal to 1.2 grams, such as 0.2 grams, 0.3 grams, 0.4 grams, 0.5 grams, 0.6 grams, 0.7 grams, 0.8 grams, 0.9 grams, 1 gram, 1.1 grams, and the like.

Further, the overall thickness of the sensor assembly 500 is less than or equal to 1.5 mm. It is understood that if the entire thickness of the sensor assembly 500 is too thick, it is disadvantageous to miniaturize the sensor.

Optionally, the overall thickness of the sensor assembly 500 is less than or equal to 1.2 millimeters.

Wherein, the thickness of the second PCB board is 0.65 +/-0.03 mm.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The manufacturing method of the sensor is characterized in that the sensor comprises a packaging shell, the packaging shell comprises a surrounding plate, a top plate and a bottom plate, the top plate and the bottom plate are respectively arranged at two ends of the surrounding plate, a first connecting structure and a second connecting structure are respectively arranged at two ends of the surrounding plate, the first connecting structure is connected with one end of the surrounding plate and the top plate, the second connecting structure is connected with the other end of the surrounding plate and the bottom plate, and the widths of the first connecting structure and the second connecting structure are both larger than or equal to 0.1 mm and smaller than or equal to 0.3 mm;

the manufacturing method of the sensor comprises the following steps:

s100, providing a first PCB (printed circuit board), a second PCB and a third PCB, wherein the first PCB comprises a plurality of top plate units, the second PCB comprises a plurality of enclosing plate units, the third PCB comprises a plurality of bottom plate units, a first connecting structure and a second connecting structure are arranged on the second PCB, and the first connecting structure and the second connecting structure are respectively arranged on two side surfaces of the second PCB of each enclosing plate unit; the second connecting structure is a second welding ring, the second welding ring comprises a copper layer arranged on the side face of the second PCB, a nickel layer arranged on the surface of the copper layer and a gold layer arranged on the surface of the nickel layer, and the nickel layer is arranged between the copper layer and the gold layer; the thickness of the copper layer of the second solder ring is greater than or equal to 20 microns; the thickness of the nickel layer of the second welding ring is greater than or equal to 3 micrometers and less than or equal to 8 micrometers; the thickness of the gold layer of the second welding ring is greater than or equal to 0.08 micrometer and less than or equal to 12 micrometers;

2. The method of manufacturing a sensor according to claim 1, wherein the step S200 of mounting the first PCB and the third PCB on both sides of the second PCB, respectively, to form a sensor assembly includes:

3. The method of manufacturing a sensor of claim 2, wherein the first connecting structure is a first solder ring;

the step S210 of attaching the second PCB to the first PCB includes:

4. The method for manufacturing a sensor according to claim 3, wherein in the step S210 of attaching the second PCB to the first PCB, the first PCB is laid flat and the second PCB is attached to an upper surface of the first PCB from above the first PCB.

5. The method for manufacturing a sensor according to claim 2, wherein the step S240 of attaching the first PCB together with the second PCB to the third PCB includes:

s243, coating solder paste on each bottom plate unit on the third PCB; and

6. The method of manufacturing a sensor according to claim 3, wherein the first solder ring includes a copper layer provided on a side surface of the second PCB, a nickel layer provided on a surface of the copper layer, and a gold layer provided on a surface of the nickel layer, and the nickel layer is provided between the copper layer and the gold layer.

7. The method of manufacturing a sensor according to claim 6, wherein the thickness of the copper layer of the first solder ring is greater than or equal to 20 micrometers; and/or the presence of a gas in the gas,

the thickness of the nickel layer of the first welding ring is more than or equal to 3 micrometers and less than or equal to 8 micrometers; and/or the presence of a gas in the gas,

the thickness of the gold layer of the first solder ring is greater than or equal to 0.08 micrometer and less than or equal to 12 micrometers.

8. The method for manufacturing a sensor according to claim 2, wherein before the step S210 of attaching the second PCB to the first PCB, the method for manufacturing a sensor further comprises:

alternatively, the first and second electrodes may be,

9. The method of manufacturing a sensor according to claim 8, wherein before the step S210 of attaching the second PCB to the first PCB, the method of manufacturing a sensor further comprises:

alternatively, the first and second electrodes may be,

10. The method of manufacturing a sensor according to claim 1, wherein the step S200 of mounting the first PCB and the third PCB on both sides of the second PCB, respectively, to form a sensor assembly includes:

11. The method of manufacturing a sensor according to any one of claims 1 to 10, wherein the sensor unit is separated from the sensor aggregate by cutting.

12. The method of manufacturing a sensor according to any one of claims 1 to 10, wherein a metal shield layer is provided on an inner wall surface of the apron unit.

13. The method of manufacturing a sensor according to claim 12, wherein an inner side surface of the metal shield layer is provided with an insulating layer.

14. The method of manufacturing a sensor according to claim 13, wherein the insulating layer has a thickness of 6 micrometers or more and 20 micrometers or less; and/or the presence of a gas in the gas,

the thickness of the metal shielding layer is greater than or equal to 10 microns.

15. The method of manufacturing a sensor according to any one of claims 1 to 10, wherein a distance between two adjacent sensor units is greater than or equal to 0.2 mm and less than or equal to 0.6 mm.

16. The method of manufacturing a sensor according to any one of claims 2 to 10, wherein the number of the sensor units is 150 or more and 1000 or less.

17. The method of claim 16, wherein the amount of solder paste used in each sensor manufacturing process is greater than or equal to 0.06 grams and less than or equal to 2 grams.

18. The method of manufacturing a sensor according to any one of claims 1 to 10, wherein the entire thickness of the sensor assembly is 1.5 mm or less.