CN207456650U - Pressure sensor - Google Patents

Abstract

The utility model is related to a kind of pressure sensor, the pressure sensor includes：Substrate；Host cavity, in the substrate, including bottom wall and side wall；Sense body, it is suspended in the host cavity, there is deep trouth between the sensing body and the host cavity side wall, between the sensing body and host cavity bottom wall there is the first cavity connected with the deep trouth, and be fixedly connected between the sensing body and host cavity side wall by being located at the overarm in the deep trouth；The sensing body includes：Semiconductor layer, the second closed cavity positioned at the dielectric layer of the semiconductor layer surface, in the dielectric layer to semiconductor layer, the device layer for covering the dielectric layer and the second cavity, the device layer surface have pressure drag item.Above-mentioned pressure sensor has strain relief, and reliability is high.

Description

Pressure sensor

Technical field

The utility model is related to microelectromechanical systems field more particularly to a kind of pressure sensors.

Background technology

MEMS (microelectromechanical systems) technology is a fast-developing in recent years new and high technology, it is using advanced half Conductor manufacturing process is, it can be achieved that the batch micro operations of MEMS device, and compared with corresponding traditional devices, MEMS device is in volume, work( Consumption and has comparable advantage at weight in price.

Pressure sensor is one of product for occurring and applying earliest in MEMS, is widely used in consumer electronics, medical treatment neck The fields such as domain, automotive electronics, such as electronic sphygmomanometer, tire gauge, altimeter, weather forecast meter, automobile inlet manifold sensor Deng.It is several pressure resistance type, condenser type and piezoelectric type etc. can be divided into according to operation principle.Wherein, piezoresistive pressure sensor has output The advantages that signal is big, subsequent processing is simple and is suitble to produce in enormous quantities.But the pressure-sensitive film thickness of piezoresistance sensor is uniform Property and uniformity be a key index, currently used pressure-sensitive film manufacturing process is using the back side of the alkaline solution from silicon chip Anisotropic etch is carried out, pressure-sensitive film is formed in front while back of the body chamber so as to be formed at the back side of silicon chip.This kind of method is not It can guarantee uniformity and uniformity of the pressure-sensitive film thickness in piece between piece, pressure sensitive film size is big.Another kind is more often adopted at present Method is electrochemical corrosion, and what this method can obtain making pressure drag on it is lightly doped pressure-sensitive film, but this kind of method Potentiostat costly need to be added, and is not corroded using the fixture protection front of special designing with applying voltage to silicon chip Front, so on the one hand improve equipment cost, on the other hand also increase the complexity of technique so that production efficiency is very It is low.

In addition, it is sensitive that piezoresistive principles, which determine that pressure-sensitive film changes introduced stress for encapsulation and external environment, 's.When chip is in encapsulation, assembling process, the stress of generation will be transferred to pressure-sensitive film by substrate, will cause device performance It drifts about, and the impact brought will also influence the reliability and robustness of product, this is that piezoresistive transducer is urgently to be resolved hurrily Problem.

It is, therefore, desirable to provide a kind of new pressure sensor, uniformity is good, and performance is more excellent.

Utility model content

Technical problem to be solved in the utility model is to provide a kind of pressure sensor.

To solve the above-mentioned problems, the utility model provides a kind of pressure sensor, which is characterized in that including：Substrate； Host cavity, in the substrate, including bottom wall and side wall；Sense body, be suspended in the host cavity, the sensing body Between the host cavity side wall there is deep trouth, have what is connected with the deep trouth between the sensing body and host cavity bottom wall First cavity, and be fixedly connected between the sensing body and host cavity side wall by being located at the overarm in the deep trouth；It is described Sensing body includes：Semiconductor layer, positioned at the dielectric layer of the semiconductor layer surface, in the dielectric layer to semiconductor layer The second closed cavity, the device layer of the covering dielectric layer and the second cavity, the device layer surface has pressure drag item.

Optionally, the sensing body bottom portion has the pillar of net distribution towards the surface of host cavity bottom wall.

Optionally, the centre of the overarm connection sensing body and the host cavity opposing sidewalls；Or institute Edge extension of the overarm along sensing body is stated, one end is connected to sensing body apex angle, and the other end is connected in host cavity side wall Center portion position.

Optionally, the overarm includes：The bending beam of the apex angle and host cavity side wall of connection sensing body.

Optionally, the overarm quantity is two or more, is symmetrically distributed between sensing body and host cavity side wall.

Optionally, further include：Dedicated IC chip, the positive and substrate bottom of the dedicated IC chip Portion bonds；Substrate is bonded with the dedicated IC chip back side；The substrate surface of the host cavity periphery has the first weldering Disk, the dedicated IC chip front have the second pad, and first pad and the second pad pass through wire bonding.

Optionally, further include：Dedicated IC chip, the back side of the dedicated IC chip and the substrate bottom Portion bonds；Substrate, the substrate front side are connected with the dedicated IC chip front by Flip Chip Bond Technique；The collecting The substrate surface of chamber periphery has the first pad, and the substrate front side has the 3rd pad, first pad and the 3rd pad Between pass through wire bonding.

Optionally, further include：Cap layer, the cap layer have at least one stomata, and the cap layer is accommodated with being located at The substrate surface of chamber periphery is connected by bonded layer, covers the substrate and sensing body；Encapsulating material layer covers the substrate Periphery, dedicated IC chip and substrate.

Optionally, further include：Metal shell, the metal shell include top and side wall, and at the top of the metal shell With stomata；The metal shell sidewall bottom bonds to form body structure with the substrate edges, and the substrate and sensing are originally Body is located in the metal shell.

The pressure sensor of the utility model, using SOI (silicon in dielectric substrate) technology, has on the basis of traditional silicon piece One sensing body, is suspended on host cavity, and is connected to by overarm on peripheral connecting portion, avoids stress and is passed by substrate It is delivered on stress sensitive film so that device performance shifts.Also, the thickness for the device layer that SOI technology is formed determines pressure The sensitivity of force snesor.It is thick since the device layer in the pressure sensor of the utility model after grinding wafer by forming Spend easily controllable, uniformity is higher, and size can accomplish very little, and simple for process, and production efficiency is high；And it may insure big During batch production, the uniformity and uniformity of the device layer between different pressures sensor are higher.

Further, sensing has several pillars below body, can play position-limiting action, prevents product in encapsulation, assembling Or the moment impact brought in transportational process has been more than that the maximum hung oneself from a beam meets with stresses, and improves the robustness of product.

In order to enable pressure sensor easily senses the variation of ambient air pressure, the utility model additionally provides a variety of Encapsulating structure.Encapsulation stress can be introduced in encapsulation process, when stress is transferred to the periphery of pressure sensing chip even from packaging body Socket part is connected since sensing body is to suspend, and by overarm with periphery connecting portion, when extraneous stress is transferred in overarm, It hangs oneself from a beam relatively soft, stress can be absorbed, and play the role of stress release, improve the robustness of product.

Description of the drawings

Fig. 1 is the flow diagram of the manufacturing method of the pressure sensor of specific embodiment of the present invention；

Fig. 2 to Figure 24 is the structure diagram of the manufacturing process of the pressure sensor of specific embodiment of the present invention.

Specific embodiment

The specific embodiment of pressure sensor provided by the utility model and its manufacturing method is done below in conjunction with the accompanying drawings It is described in detail.

It please refers to Fig.1, is the flow diagram of the pressure sensor manufacturing method of the utility model.

The pressure sensor manufacturing method of the utility model includes the following steps：

Step S11：Substrate is provided, the substrate has first surface and second surface.The substrate can be monocrystalline silicon Wafer or other semiconductor crystal wafers.

Step S12：Etch the substrate, formed in the substrate deep hole and positioned at the deep hole bottom first Cavity.

Step S13：Semiconductor layer is epitaxially formed in the substrate first surface, the semiconductor layer covers the deep hole.

Step S14：Dielectric layer is formed in the semiconductor layer surface；

Step S15：It etches inside the dielectric layer to the semiconductor layer, forms the second cavity, second cavity is wide Degree is less than the first cavity；

Step S16：Bond together to form the device layer of the covering semiconductor layer and the second cavity and positioned at device layer surface Pressure drag item, seal second cavity；

Step S17：It etches device layer, dielectric layer and the semiconductor layer of the second cavity periphery, is formed and described the The deep trouth of one cavity connection and the overarm in the deep trouth, the deep trouth and the first cavity form host cavity, are suspended in Part of semiconductor layer, dielectric layer, the second cavity and device layer in the host cavity form sensing body, the overarm connection The sensing body and host cavity side wall.

Please refer to Fig.2 the structure of the manufacturing process to the pressure sensor that Figure 24 is one specific embodiment of the utility model Schematic diagram.

It please refers to Fig.2, substrate 101 is provided, the substrate 101 includes first surface 101a and second surface 101b.The tool In body embodiment, the substrate 101 is monocrystalline silicon wafer crystal.

It please refers to Fig.3, the first mask layer 102 with the first mask pattern 103 is formed on the first surface 101a. The manufacturing method of first mask layer 102 includes：Using low-pressure chemical vapor deposition, plasma activated chemical vapour deposition or heat The techniques such as oxidation are formed on the first surface 101a after mask layer 102, then using photoetching and wet etching work Skill or photoetching and dry etch process removal part mask layer, form the first mask pattern 103.The specific embodiment party In formula, the material of first mask layer 102 is silica, in other specific embodiments of the utility model, described the The material of one mask layer 102 can also be the dielectric materials such as silicon nitride, carborundum, silicon oxynitride, can be answered for single-layer or multi-layer Close structure.

It please refers to Fig.4, is mask with first mask layer 102, etch the substrate 101, the shape in the substrate 101 Into deep hole 104.In the specific embodiment, using anisotropic etch process, such as deep reactive ion silicon etching (DRIE) work Skill etches the substrate 101 and obtains several deep holes 104, and the cross-sectional shape of the deep hole 104 can be rectangle, circle, five sides Shape, hexagon or other polygons.The size of the deep hole 104 can be determined according to technique and design requirement.The deep hole 104 Depth be generally tens microns.

Fig. 5 is refer to, continues to etch the substrate 101, forms the first cavity 105 positioned at 104 bottom of deep hole.Tool Body, using anisotropy rot etching technique, such as using potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) alkaline solution It injects in several deep holes 104, the substrate 101 is corroded, so as to interior by the connection of several 104 bottoms of deep hole in substrate 101 To form the first cavity 105.In this step, first cavity 105 is being formed simultaneously, above the first cavity 105 Substrate forms netted pillar 106.The positions and dimensions scope of first cavity 105 has the first mask pattern 103 to determine.It is described The depth of pillar 106 is usually tens microns, and the pillar 106 in the follow-up process, plays position-limiting action, prevents product from sealing The moment impact brought during dress, assembling shipping are defeated is more than that the maximum for the cantilever beam or folded beam being subsequently formed meets with stresses, Improve the robustness of product.

In other specific embodiments of the utility model, first cavity 105 and pillar 106 can also be used and done Method etching technics such as deep reactive ion silicon etching (DRIE) technique, and passes through suitable technological parameter and obtains.

In other specific embodiments of the utility model, can also by adjusting etching substrate 101 etching parameters, The removal so that pillar 106 at 105 top of the first cavity is also etched simultaneously.

Fig. 6 is refer to, first mask layer 102 is removed, is then epitaxially formed in the 101 first surface 101a of substrate Semiconductive thin film 107, the semiconductive thin film 107 cover the deep hole 104.Dry etching or wet etching work may be employed Skill such as removes first mask layer 102, then with being used on the first surface 101a of substrate 101 with buffered hydrofluoric acid (BOE) Epitaxy technique covers semiconductive thin film 107, and the specific semiconductive thin film 107 can be monocrystalline silicon thin film.The semiconductor Film 107 covers several deep holes 104, and the first cavity 105 becomes a seal cavity at this time.Since the semiconductive thin film 107 exists 104 Epitaxial growth of deep hole, 107 surface of semiconductive thin film have several recess 108 so that the semiconductive thin film 107 Surface irregularity.

Fig. 7 is refer to, 107 depression in the surface 108 of semiconductive thin film is removed using semiconductor grinding technique, is formed flat Smooth semiconductor layer 109, the thickness of the semiconductor layer 109 are less than the thickness of semiconductive thin film 107.

Fig. 8 is refer to, dielectric layer 110 is formed on 109 surface of semiconductor layer, etches the dielectric layer 110 to described Inside semiconductor layer 109, the second cavity 111 is formed, 111 width of the second cavity is less than the width of the first cavity 105.Specifically , it, can be on flat 109 surface of semiconductor layer, using low-pressure chemical vapor deposition (LPCVD) work in the specific embodiment The techniques such as skill, plasma activated chemical vapour deposition (PECVD) technique, thermal oxide are formed described on 109 surface of semiconductor layer Dielectric layer 110.In the specific embodiment, the material of the dielectric layer 110 is silica；Other in the utility model are specific In embodiment, the material of the dielectric layer 110 can also be the insulating dielectric materials such as silicon nitride, silicon oxynitride.Described in etching Dielectric layer 110 forms an opening, then continues etching semiconductor layer 109 along the opening, forms the second cavity of certain depth 111, and form a step 110-1 in 111 surrounding of the second cavity.The depth of second cavity 111 can be according to etching condition control System, but do not connected with first cavity 105.And the width of second cavity 111 is less than the width of the first cavity 105, with Just enough spaces are left in 111 surrounding of the second cavity to be used for carrying out subsequent bonding.

Fig. 9 is refer to, the device layer 113 for covering 110 and second cavity 111 of dielectric layer is formed, makes second chamber Body 111 seals.The forming method of the device layer 113 is specific as follows：One wafer is provided, and in the 110 surface shape of dielectric layer Into silicon-oxidation silicon bonding, after the wafer covering and the second cavity 111, and sealing is formed；The good wafer of para-linkage is ground Mill, forms the device layer 113 of suitable thickness, and the thickness of the device layer 113 is far below the thickness of wafer, and the thickness is according to treating The range and Calculation of Sensitivity of the pressure sensor of formation obtain.Structure described in Fig. 9 uses SOI on the basis of traditional wafer (silicon in dielectric substrate) technology, wherein, the thickness of device layer 113 determines the sensitivity of pressure sensor.Due to the device For layer 113 by the way that being formed after grinding wafer, thickness is easily controllable, and uniformity is higher, size can accomplish very little, and technique letter Single, production efficiency is high；And it may insure during mass production, the device layer 113 between different pressures sensor Uniformity and uniformity it is higher.

0 is please referred to Fig.1, makes pressure drag item 114 on 113 surface of device layer, ion may be employed in the pressure drag item 114 Injection is formed.In addition, form barrier layer and passivation layer (not shown) on 113 surface of device layer.In addition, in device layer 113 Surface also formed some for electric connection metal layer (not shown), the first pad (not shown) and first be bonded Layer 115, same material may be employed in the metal layer and the first bonded layer 115, is formed simultaneously, such as metal Al or Au etc..

1 is please referred to Fig.1, etches device layer 113, dielectric layer 110 and the semiconductor layer of 111 periphery of the second cavity 109, form the deep trouth 116 connected with first cavity 105 and the overarm in the deep trouth 116, the deep trouth 116 Host cavity, part of semiconductor layer 109, dielectric layer 110, the second chamber being suspended in the host cavity are formed with the first cavity 105 Body 111 and device layer 113 form sensing body 114-1, the overarm connection sensing body 114-1 and host cavity side Wall.Specifically, in the 113 surface spin coating photoresist of device layer and exposure imaging (not shown), using deep reactive ion Silicon etching process is etched according to the mask pattern after exposure imaging, forms the deep trouth 116 connected with the first cavity 105.Deep trouth 116 It is enclosed with the first cavity 105 and sets the sensing body 114-1 to form MEMS sensor and peripheral connecting portion 114-2.So far, shape Into pressure sensing chip.

2A is please referred to Fig.1, is the schematic top plan view of the pressure sensor of one specific embodiment of the utility model in Figure 11. Sensing body 114-1 is attached by the 114-3 and periphery connecting portion 114-2 that hangs oneself from a beam, the pressure drag item of 111 top of the second cavity (not shown) is connected by metal connecting line (not shown), and by overarm 114-3, being connected to sensing body 114- On 1 metal pad 117.The 114-3 that hangs oneself from a beam is located at the centre of sensing body 114-1 one sides, can also be located at sensing body At four corner positions of 114-1.First bonded layer 115 makes a circle outside deep trouth 116, and positioned at peripheral connecting portion 114- On 2.

When having stress when on pressure sensor, stress will be by substrate transfer to device layer 113, due to sensing It is separated between body 114-1 and other positions, such as peripheral connecting portion 114-2, and is suspended in host cavity, passes through overarm 114-3 connections, stress will not be coupled, and are not transferred on the device layer of sensing body 114-1, therefore played stress release Effect.

2B is please referred to Fig.1, is the schematic top plan view of the pressure sensor of another specific embodiment of the utility model.In order to Further improve the effect of stress release and improve the robustness of product, except the overarm 114-3 that is used to support and connects up it Outside, on tetra- angles of sensing body 114-1, four bending beams 118 are also formed, since bending beam 118 is relatively soft, work as assembling product Or when receiving external force collision, reliability can be greatly improved.It, can not also shape in other specific embodiments of the utility model Into the overarm 114-3, and only the sensing body 114-1 and peripheral connecting portion 114-2 are connected by bending beam 118.

2C is please referred to Fig.1, is the schematic top plan view of the pressure sensor of another specific embodiment of the utility model.It is described The overarm sensed between body 114-1 and peripheral connecting portion 114-2 is long beam 119, and one end of long beam 119 is with sensing body 114- 1 angle connection, the other end is connected with the centre on periphery connecting portion 114-2 one side, since long beam 119 is long, because This hardness is softer, while stress release, can also promote the robustness of product.

Further, 2D is please referred to Fig.1, two long beam 119 can be made, it is symmetrically placed, while stress release, into One step promotes the robustness of product, reliability higher.

In other specific embodiments of the utility model, the sensing body 114-1 and peripheral connecting portion 114-2 it Between more than two symmetrical overarms can be set, to improve the reliability of stress release effect and product.

After pressure sensor is formed, specific embodiment of the present utility model is furthermore provided to the pressure The method that sensing element is packaged.

In a specific embodiment of the utility model, formed pressure sense die chip architecture as shown in figure 11 it Afterwards, formed and have leachy cap layer, there is the second bonded layer on the fringe region of the cap layer；By the cap layer and institute Device layer is stated by first bonded layer, the bonding connection of the second bonded layer, the method for forming the cap layer please refers to Fig.1 3 To Figure 15 B.

3 are please referred to Fig.1, a wafer 121 is provided, the second bonded layer 123, second bonded layer 123 are made in upper surface Material is aluminium, such as aluminium, gold, germanium or other metal materials.Second bonded layer, 123 position (refer to the first bonded layer 113 Figure 11) position corresponds to；Then using deep plough groove etched technique, thin deep trouth 122 is etched, thin deep trouth 122 can be one, also may be used To be multiple；Thin deep trouth 122 can be evenly distributed on the center of wafer 121 or any away from center Position.

4 are please referred to Fig.1, the wafer 121 that will be processed in the chip and Figure 13 in Figure 11 passes through 115 He of the first bonded layer Second bonded layer 123 is bonded together.

5A is please referred to Fig.1, wafer 121 is thinned using chemical mechanical milling tech, exposes stria 122-2.The stria The depth of 122-2 is less than thin deep trouth 122, and collectively forms a cap layer 121-1 with stomata with bonding position.The stomata As stria 122-2.Stomata 122-2 is located at the center of wafer 121, just opposite with the device layer 113 of sensing bodies top, It can be 1, or multiple.Stomata 122-2 is used to communicate with atmospheric environment.

5B is please referred to Fig.1, external foreign matter falls into the device layer 113 of sensing bodies top by stomata 122-2 in order to prevent On, stomata 122-2 can also be made with making a circle outside wafer 121, can equally complete the effect with air intercommunication.

After cap layer 121-1 is formed, 6 are please referred to Fig.1, an application-specific integrated circuit (ASIC) chip 124 and base are provided Plate 125,124 front of dedicated IC chip have the second pad；By the front of the dedicated IC chip 124 It is bonded with the second surface of the substrate 101 by an adhesion layer (not shown)；By the dedicated IC chip 124 The back side is bonded with substrate 125；By the second pad on the first pad of pressure sense die on piece and dedicated IC chip 124 (not shown) is bonded by lead 126.The substrate 125 can be printed circuit board (PCB) or other organic composite multilayer bases Plate；The lead 126 is gold thread.

Referring now to Figure 17, using injection molding process, an encapsulating material 127 is covered into the outer of cap layer 121-1 Enclose, lead 126, with integrated circuit (ASIC) chip 124 and substrate 125.The edge of encapsulating material 127 and cap layer 121-1 are neat It is flat.This encapsulating material 127 is resin, and the encapsulating material 127 had both protected the first pad, the second pad and lead 126, and also protected Entire pressure sensor chip has been protected not to be destroyed.In addition, encapsulation stress can be introduced in encapsulation process, because of the uniqueness of chip therefore Strain relief, cap layer 121-1, periphery connecting portion 114-2 and the substrate being transferred to when stress from packaging body on chip 101, final stress always collects peripheral connecting portion 114-2.Since sensing body 114-1 is to suspend, and by overarm and outside It encloses connecting portion 114-2 to be connected, when extraneous stress is transferred in overarm, overarm is relatively soft, and stress can be absorbed, and play stress release Effect, improve the robustness of product.

Please refer to Fig.1 8 to Figure 20 the utility model also provide another specific embodiment formed pressure sensing chip and Pressure sensing chip is packaged to form pressure sensor.

8 are please referred to Fig.1, box dam 128 is formed on 113 surface of device layer, the box dam 128 is hard resin, then shape again Into the deep trouth 116 connected with the first cavity 105.116 and first cavity 105 of deep trouth, which encloses, sets the sense to form MEMS sensor Answer body 114-1 and peripheral connecting portion 114-2.

9 are please referred to Fig.1, pressure sensing chip shown in Figure 18 and 124 front of dedicated IC chip is viscous by one layer Attached layer bonding, application-specific integrated circuit 124 is bonded with substrate 125, by the first pad of pressure sense die on piece and special integrated electricity The second pad (not shown) on road chip 124 is bonded by lead 126；Then using injection molding process, by an envelope Package material 127 covers 128 periphery of box dam, lead 126, dedicated IC chip 124 and substrate 125.Encapsulating material 127 Surface is flushed with 128 top of box dam.

0 is please referred to Fig.2, the cap layer with stomata is formed in the superstructure of Figure 19.In the specific embodiment, the lid Cap layers are the hard material 130 with stomata 129, and the hard material 130 is resin material, shown in hard material 130 and Figure 19 Structure is by high-temperature laminating or is bonded.The hard material 130 with stomata 129 is to protect the sensing body of chip The device layer 113 on surface is not contaminated.Equally, the stomata 129 can be one, or it is multiple, hard can be located at The center of material 130 can also be located at the surrounding of hard material 130, and the effect of the stomata 129 is to be in communication with the outside, Convenient for sensing ambient pressure environment.

Please refer to Fig.2 1 to Figure 22 for another specific embodiment of the utility model pressure sensing chip is packaged with The method for forming pressure sensor.

1 is please referred to Fig.2, by the pressure sensor chip shown in Figure 13 of formation with dedicated IC chip 124 just Face is bonded by one layer of adhesion layer (not shown), and the back side and the substrate 125 of dedicated IC chip 124 bond, described Substrate 125 can be printed circuit board (PCB) or other organic composite multilager base plates.The first pad on pressure sensor chip with The second pad on application-specific integrated circuit is bound into line lead 126, and the lead 126 is gold thread.

2 are please referred to Fig.2, in one adhesion material (not shown) of the periphery of substrate 125 coating, such as silica gel or tin cream, then Improve to a metal shell 132 with stomata 131, the position of the adhesion material and the adhesion locations one of metal shell 132 It causes.The stomata 131 is used for and atmosphere, and stomata has prevented foreign matter from falling into, shadow away from directly over pressure sensor chip Ring properties of product.

Please refer to Fig.2 3 to Figure 24, for another specific embodiment of the utility model pressure sensing chip is packaged with The method for forming pressure sensor.

3 are please referred to Fig.2, flip chip bonding (Flip-Chip) technique is used to dedicated IC chip 124, specifically, special Soldered ball 133 is grown up to by plating on the front pad of IC chip 124, then by dedicated IC chip 124 Soldered ball 133 is welded to substrate 125 by Reflow Soldering.Then again by pressure sensor chip shown in Figure 13 and the special integrated electricity The back side of road chip 124 is bonded by a floor adhesion layer.There is the 3rd pad (not shown), pressure on the substrate 125 First pad 117 of sensor core on piece is bound with the 3rd pad on substrate 125 into line lead 134, and the lead 134 is gold Line.

4 are please referred to Fig.2, make a circle one adhesion material of coating outside substrate 125, such as silica gel or tin cream, then covers one Metal shell 132 with stomata 131, the position of the adhesion material are consistent with the adhesion locations of metal shell 132.The stomata 131 are used for and atmosphere, and stomata has prevented foreign matter from falling into, influenced properties of product away from directly over pressure sensor chip. In other specific embodiments of the utility model, can also further it be encapsulated using injection molding process.

In above-mentioned specific embodiment, using SOI (silicon in dielectric substrate) technology on the basis of traditional silicon piece, a sense is prepared Body is answered, is suspended on host cavity, and is connected to by overarm on peripheral connecting portion, stress is avoided and is transferred to by substrate On stress sensitive film so that device performance shifts.

Further, when preparing the first cavity, several pillars are formed, position-limiting action can be played, prevent product encapsulation, The moment impact brought in assembling or transportational process has been more than that the maximum of overarm meets with stresses, and improves the robustness of product.

In order to enable pressure sensor easily senses the variation of ambient air pressure, the specific embodiment party of the utility model Formula further discloses a variety of method for packing.Encapsulation stress can be introduced in encapsulation process, when stress is transferred to periphery even from packaging body Socket part is connected since sensing body is to suspend, and by overarm with periphery connecting portion, when extraneous stress is transferred in overarm, It hangs oneself from a beam relatively soft, stress can be absorbed, and play the role of stress release, improve the robustness of product.

Specific embodiment of the present utility model also provides the pressure sensor that a kind of above method is formed.

1 is please referred to Fig.1, is the structure diagram of the pressure sensor of one specific embodiment of the utility model.

In the specific embodiment, the pressure sensor includes a pressure sensing chip, the pressure sensing chip bag It includes：Substrate, including substrate 101, semiconductor layer 109, dielectric layer 110 and device layer 113；Host cavity, in the substrate, Including bottom wall and side wall；Sense body 114-1, be suspended in the host cavity, the sensing body 114-1 and the host cavity Between side wall there is deep trouth 116, have what is connected with the deep trouth 116 between the sensing body 114-1 and host cavity bottom wall First cavity 105, and consolidated between the sensing body 114-1 and host cavity side wall by being located at the overarm in the deep trouth 116 Fixed connection；The sensing body 114-1 includes：Part of semiconductor layer 109, the dielectric layer positioned at 109 surface of semiconductor layer 110th, the second closed cavity 111 in the dielectric layer 110 to semiconductor layer 109, the covering dielectric layer 110 and the The device layer 113 of two cavitys 111, the device layer surface have pressure drag item 114 so that at the top of the sensing body 114-1 Device layer 113 is used as pressure sensitive film.

Further, the sensing body 114-1 bottoms have the pillar of net distribution towards the surface of host cavity bottom wall 106, the pillar 106 is used as position limiting structure, prevents that the moment impact that product is brought in encapsulation, assembling or transportational process is more than The maximum of overarm meets with stresses, and improves the robustness of product.

2A to Figure 12 D is please referred to Fig.1, is structure shown in Figure 11 of formation in specific embodiment of the present utility model Schematic top plan view.

2A is please referred to Fig.1, in a detailed embodiment, is led between the sensing body 114-1 and host cavity side wall Cross the center of overarm 114-3 connections, the overarm 114-3 connections sensing body 114-1 and the host cavity opposing sidewalls Position.

2B is please referred to Fig.1, in another specific embodiment, is further included：The apex angle of connection sensing body 114-1 and collecting The bending beam 118 of chamber side wall.

2C is please referred to Fig.1, in another specific embodiment, the overarm 119 is long beam, along sensing body 114-1's Edge extends, and one end is connected to sensing body 114-1 apex angles, and the other end is connected to the centre of host cavity side wall.

2D is please referred to Fig.1, in another specific embodiment, tool is symmetrical there are two overarm 119.

In other specific embodiments of the utility model, the overarm quantity is two or more, can be outstanding for other Girder construction is symmetrically distributed between sensing body and host cavity side wall.

Specific embodiment of the present utility model also provides the pressure sensor with package casing.

7 are please referred to Fig.1, is the pressure sensor in specific embodiment with package casing, inside package casing Pressure sense die chip architecture be described in detail in above-mentioned specific embodiment, therefore not to repeat here.The pressure sense die Piece includes the cap layer 121-1 with stomata 122-2, and connection is bonded with the top device layer periphery of pressure sensing chip；It is special IC chip 124, the substrate bottom of the positive and pressure sensing chip of the dedicated IC chip 124 are glued Knot；Substrate 125 is bonded with 124 back side of dedicated IC chip；The lining of the host cavity periphery of the pressure sensing chip Bottom surface has the first pad, and 124 front of dedicated IC chip has the second pad, first pad and second Pad passes through wire bonding.Further include encapsulating material 127, overburden pressure sensing chip periphery, lead 126 and special integrated electricity Road chip 124, substrate 125.

0 is please referred to Fig.2, in another specific embodiment, the peripheral connection surface of the pressure sensing chip is formed There are box dam 128,127 overburden pressure sensing chip of encapsulating material periphery, lead 126 and dedicated IC chip 124, substrate 125；The hard material 130 with stomata 129 is further included as cap layer, covers the encapsulating material 127 and pressure sensing Chip.

2 are please referred to Fig.2, in another specific embodiment, is further included：Metal shell 132, the metal shell 132 wrap Top and side wall are included, and 132 top of the metal shell has stomata 131；132 sidewall bottom of metal shell and the base 125 edge of plate bonds to form body structure, and the pressure sensing chip substrate and sensing body are located at the metal shell 132 It is interior.

4 are please referred to Fig.2, in another specific embodiment, the substrate bottom of the pressure sensing chip is integrated with special The back side of circuit chip 124 bonds；124 front of the dedicated IC chip by Flip Chip Bond Technique formed soldered ball 133 with The front connection of substrate 125；The substrate front side has the 3rd pad, first pad on the pressure sensing chip surface and the It is bonded between three pads by lead 134；Top has the sidewall bottom of the metal shell 132 of stomata 131 and the substrate 125 Edge bonds to form body structure, and the pressure sensing chip substrate and sensing body are located in the metal shell 132.

The above is only the preferred embodiment of the utility model, it is noted that for the common skill of the art Art personnel on the premise of the utility model principle is not departed from, can also make several improvements and modifications, these improvements and modifications Also it should be regarded as the scope of protection of the utility model.

Claims (9)

1. a kind of pressure sensor, which is characterized in that including：

Substrate；

Host cavity, in the substrate, including bottom wall and side wall；

Sense body, be suspended in the host cavity, there is deep trouth between the sensing body and the host cavity side wall, it is described There is the first cavity connected with the deep trouth, and the sensing body and host cavity side between sensing body and host cavity bottom wall It is fixedly connected between wall by being located at the overarm in the deep trouth；

The sensing body includes：Semiconductor layer, positioned at the dielectric layer of the semiconductor layer surface, through the dielectric layer to half The device layer of the second closed cavity, the covering dielectric layer and the second cavity in conductor layer, the device layer surface have Pressure drag item.

2. pressure sensor according to claim 1, which is characterized in that described to sense body bottom portion towards host cavity bottom wall Surface have net distribution pillar.

3. pressure sensor according to claim 1, which is characterized in that the overarm connection sensing body and described The centre of host cavity opposing sidewalls；Or edge extension of the overarm along sensing body, one end is connected to sensing body Apex angle, the other end are connected to the centre of host cavity side wall.

4. pressure sensor according to claim 1, which is characterized in that the overarm includes：The top of connection sensing body Angle and the bending beam of host cavity side wall.

5. pressure sensor according to claim 1, which is characterized in that the overarm quantity is two or more, symmetrical point It is distributed between sensing body and host cavity side wall.

6. pressure sensor according to claim 1, which is characterized in that further include：Dedicated IC chip, it is described special With the positive and substrate bottom adhesive of IC chip；Substrate is bonded with the dedicated IC chip back side；Institute Stating the substrate surface of host cavity periphery has the first pad, and the dedicated IC chip front has the second pad, described First pad and the second pad pass through wire bonding.

7. pressure sensor according to claim 1, which is characterized in that further include：Dedicated IC chip, it is described special The back side and the substrate bottom adhesive with IC chip；Substrate, the substrate front side and the application-specific integrated circuit core Piece front is connected by Flip Chip Bond Technique；The substrate surface of the host cavity periphery has the first pad, the substrate front side tool There is the 3rd pad, pass through wire bonding between first pad and the 3rd pad.

8. the pressure sensor according to claim 6 or 7, which is characterized in that further include：Cap layer, the cap layer tool There is at least one stomata, the cap layer is connected with the substrate surface positioned at host cavity periphery by bonded layer, covers the lining Bottom and sensing body；Encapsulating material layer covers its periphery, dedicated IC chip and substrate.

9. the pressure sensor according to claim 6 or 7, which is characterized in that further include：Metal shell, outside the metal Shell includes top and side wall, and has stomata at the top of the metal shell；The metal shell sidewall bottom and the substrate side Edge bonds to form body structure, and the substrate and sensing body are located in the metal shell.