KR102194070B1 - Pressure sensor with modular semi-hermetic structure - Google Patents

Abstract

According to the present invention, a pressure sensor comprises: a sensor fixing unit having a pressure transfer pipe transferring pressure; and a pressure sensor positioned on one surface of the sensor fixing unit to come in contact with one end of the pressure transfer pipe. The sensor fixing unit is provided with an accommodation groove to accommodate the sensor, and an auxiliary accommodation groove to include a portion of the accommodation groove to rapidly increase the bond strength of the pressure sensor. Accordingly, the pressure sensor can detect an accurate pressure value in an environment where vibration or high temperature, corrosion, etc. can occur without exhibiting hysteresis, and have a strong tolerance to a medium having a pressure of an imperfect property which occurs in fuel such as diesel or gasoline.

Description

Pressure sensor with modular semi-hermetic structure

The present invention relates to a pressure sensor having a modularized semi-hermetic structure, and in detail, a sensor fixing part exposed to the inside of a housing and having a pressure transfer pipe for transmitting pressure, and the pressure on one surface of the sensor fixing part. Including a pressure sensor positioned to be in contact with one end of the delivery pipe, wherein the sensor fixing portion is further provided with a receiving groove for receiving the sensor and an auxiliary receiving groove for including a part of the receiving groove, so that the bonding strength of the pressure sensor It relates to a pressure sensor that can increase dramatically.

Based on the semiconductor integrated circuit manufacturing technology, MEMS (Micro Electro Mechanical) integrates on one chip by simultaneously manufacturing micro-mechanical structures for detecting various physical quantities and electronic circuits for changing, amplifying, and correcting various physical quantities into electrical signals. Systems) technology has been rapidly developed and commercialized in the automotive industry with the advantage of minimizing cost along with miniaturization, weight reduction, multifunctionality, and high performance of the sensor. In particular, the semiconductor pressure sensor was first commercialized in the MAP (Manifold Absolute Pressure) sensor for engine control, and is currently used in tire pressure sensors and tank fuel pressure sensors.

The pressure sensor manufactured using the semiconductor process is made of silicon (ceramic) having high fatigue strength as a structure, so it has very high stability against external load or thermal deformation.

In the case of a general ceramic type pressure sensor, a circular sensor chip made of ceramic and an internal O-ring that may be provided around the sensor to prevent internal leakage, an external O-ring to prevent leakage from the outside, a printed circuit board, a housing, and Includes a connector. However, if the sensor chip is located inside the sensor housing and the fuel cell system is not driven and is exposed to low-temperature external pressure for a long time, moisture may condense between the sensor chip and the housing, or freeze, resulting in damage to the diaphragm of the sensor. . Further, in the sensor according to the conventional structure, as two or more fastening points in which leakage may occur are formed, the airtightness of the sensor is inevitably lowered.

In addition, there are various methods such as anodic bonding, fusion bonding, frit glass bonding, epoxy bonding, etc. to package the ceramic type pressure sensor, but each has problems such as compatibility, whether hermetic sealing, and whether a batch process is applied. In particular, in the case of epoxy bonding, a polymer of epoxies is used as an intermediate bonding medium, which has the advantage of being able to perform a low-temperature process.However, this method is not hermetic and is manufactured by aging effects over time. Since the characteristics of the swaying movement (drift) characteristics, there is an urgent need to study the level bonding technology of such a pressure sensor.

Republic of Korea Patent Publication No. 10-2008-0102510 (November 26, 2008)

The present invention is conceived to solve the above-described problem, and is exposed to the inside of the housing, and a sensor fixing portion having a pressure transmission pipe for transmitting pressure is formed, and one end of the pressure transmission pipe is in contact with one surface of the sensor fixing portion. Including a pressure sensor positioned, wherein the sensor fixing portion is further provided with a receiving groove for accommodating the sensor, and an auxiliary receiving groove for including a portion of the receiving groove, thereby dramatically increasing the bonding strength of the pressure sensor. It is intended to provide a pressure sensor having a modular semi-hermetic structure.

The present invention relates to a pressure sensor having a modularized semi-hermetic structure.

One aspect of the present invention,

A cover having one or more lead holes formed thereon and having a coupling protrusion on a lower side of the sidewall;

A housing which forms a space by being fitted with the coupling jaws of the cover through irregularities on the inner surface, and having a first pressure transmission pipe communicating with the outside on a lower surface thereof;

A substrate provided on a lower surface of the space of the housing and having a receiving hole penetrating through the upper and lower surfaces;

A sensor fixing part inserted into the receiving hole of the substrate, positioned between the bottom surface of the housing and the bottom surface of the substrate, and having a second pressure transmission tube formed therein in a longitudinal direction to communicate with the first pressure transmission tube;

A pressure sensor positioned on one surface of the sensor fixing part to contact one end of the pressure transfer pipe;

One or a plurality of linear leads having one end in contact with the lower surface of the space of the housing and the other end passing through the lead hole and protruding out of the space; And

A lead support part positioned on the upper surface of the substrate to fix the lead;

It relates to a pressure sensor having a modularized semi-hermetic structure comprising a.

In the present invention, the sensor fixing unit,

A pressure sensor receiving groove formed to be recessed in a hexahedral shape on an upper surface and receiving a pressure sensor therein; And

A pressure sensor auxiliary receiving groove formed by depressing the inner side so as to be bent at a predetermined radius around an inner side height direction edge of the pressure sensor receiving groove;

Further comprising,

A bottom surface of the pressure sensor receiving groove is characterized in that it communicates with the second pressure transmission pipe.

In addition, the pressure sensor receiving groove and the pressure sensor may be bonded with one or more of a metal adhesive and an organic adhesive.

In the present invention, the housing is provided with an extension part extending in the direction of formation of the first pressure transmission pipe on the lower surface, and one or more protruding jaws and O-ring receiving grooves are formed alternately on the outer surface of the extension part. do.

In the present invention, the pressure sensor may be electrically connected to the substrate through wire bonding, and the lead may pass through the substrate and contact the lower surface of the space of the housing.

In addition, the sensor fixing part may be made of any one or a plurality of metals selected from copper alloy (brass), aluminum, nickel, tin, palladium, tantalum, and zinc.

The pressure sensor according to the present invention includes a sensor fixing part on which a pressure transmission pipe for transmitting pressure is formed, and a pressure sensor positioned on one surface of the sensor fixing part so as to contact one end of the pressure transmission pipe, wherein the sensor fixing part A receiving groove for accommodating the sensor and an auxiliary receiving groove for including a portion of the receiving groove may be further provided, so that the bonding strength of the pressure sensor may be dramatically increased.

In particular, when forming the receiving groove for receiving and protecting the sensor, the pressure sensor processes the auxiliary receiving groove around the four corners formed in the same direction as the processing direction of the receiving groove, but the auxiliary receiving groove is preceded by the receiving groove. By forming, it is possible to easily determine the application position of the adhesive, and the application process is also easy. In addition, the sensor can detect an accurate pressure value in an environment where vibration, high temperature, corrosion, etc. may occur without showing a hysteresis phenomenon, and for a medium having an incomplete characteristic pressure generated in fuel such as diesel or gasoline. Can have strong tolerance.

1 is a perspective view of a pressure sensor according to the present invention.
2 is a plan view (a) and a cross-sectional view (b) of the pressure sensor according to the present invention.
3 and 4 show that the substrate, the pressure sensor, the lead and the lead support are combined in the present invention.
5 is a cross-sectional view of (a) and a cross-sectional view of the sensor fixing part to which the pressure sensor is bonded and the substrate are combined.
6 shows a process of forming the sensor fixing part in the pressure sensor according to the present invention.
7 shows that the substrate is bonded to the sensor fixing part in the pressure sensor according to the present invention.

Hereinafter, a pressure sensor having a modularized semi-hermetic structure according to the present invention will be described in more detail with reference to Examples and Comparative Examples. However, specific examples introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art.

Accordingly, the present invention is not limited to the specific examples presented below and may be embodied in other forms, and the specific examples presented below are only described to clarify the spirit of the present invention, and the present invention is not limited thereto.

At this time, unless there are other definitions in the technical and scientific terms used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, and unnecessarily obscure the subject matter of the present invention in the following description. Description of possible known functions and configurations will be omitted.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

In addition, the drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Also, throughout the specification, the same reference numerals indicate the same elements.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

In describing the constituent elements of the present invention, terms such as first, second, A, B, (a), (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but another component between each component It should be understood that elements may be “connected”, “coupled” or “connected”.

The pressure sensor having a modularized semi-hermetic structure according to the present invention may be fastened to a pressure measurement object to measure the pressure of a fluid flowing from the pressure measurement object, and signal the measured pressure and transmit it to the outside. To this end, the pressure sensor may include various components, such as a sensor element for directly measuring pressure, a case for protecting the sensor element, and a transmission means for transmitting pressure to the sensor element.

In more detail, a housing 100 for accommodating a pressure sensor (sensor element, 500) therein as shown in FIG. 1, a cover 200, a sensor fixing part 400 for fixing the sensor by combining with the housing, and the sensor It may include a substrate 300 for changing the signal measured through the electrical signal, and a lead 600 for connecting the substrate and an external device (e.g., an ECU (Electronic Control Unit), a power supply unit, etc.).

In the pressure sensor having the above configuration, when the fluid introduced through the first pressure transfer pipe and the second pressure transfer pipe formed in the housing and the sensor fixing part applies pressure to the pressure sensor, the diaphragm located above the pressure sensor is deformed. The resistance value of the strain gauge changes. The change in micro-resistance generated by the pressure is converted into an electrical signal and output, and the electrical signal is transmitted to an external device such as an electronic control device through the lead.

In the present invention, the housing 100 is opened on one side as shown in FIG. 2 and has a space of a certain size therein, but a first pressure transmission tube 110 communicating with the outside is formed on the bottom of the housing body 120 Thus, it is possible to transmit external pressure by communicating with the second pressure transmission pipe of the sensor fixing unit to be described later, and may include a side wall 130 formed by protruding the outer surface of the housing body in the longitudinal direction.

As described above, the housing has a space having a predetermined size therein in a cylindrical shape with an open surface as described above, and includes a housing body having an inner surface to accommodate a substrate, and a sidewall forming an inner space together with the inner surface. In this case, as described above, the sidewall may be further formed with unevenness so as to be coupled with the coupling jaws of the cover to be described later.

In more detail, the housing may have an unevenness 140 formed on an inner surface or a bottom surface of the end of the sidewall so as to be fitted with the coupling protrusion 220 of the cover. As the irregularities are formed, a space for accommodating the coupling jaws of the cover is formed between the irregularities and the bottom surface of the housing, thereby increasing the contact area between the cover and the housing so that the fluid becomes a contact surface between the housing and the cover. Invasion can be prevented.

In addition, as described above, the housing has a first pressure transfer tube communicating with a second pressure transfer tube formed in the longitudinal direction of the sensor fixing unit to be described later, and the first pressure transfer tube is formed inside the lower surface of the housing body. An extension portion 150 formed to extend in the longitudinal direction may be further provided. At this time, one or a plurality of protruding jaws and O-ring receiving grooves are formed alternately on the outer surface of the extension part to more strongly combine with the fuel tank, and at the same time to prevent the intrusion of fluid, and at the same time, the outer circumferential surface of the extension part It may be provided to contact the inner peripheral surface of the connection.

To this end, one or more protruding jaws 151 and O-ring receiving grooves 152 may be alternately formed on an outer surface of the extension part.

The protruding jaw may be in the form of a screw (thread) that can be coupled through rotation for close coupling with the connection part, and in addition, a protruding jaw (supporting jaw) of a general shape that can be combined with other devices through fitting coupling. If so, the shape is not limited.

The O-ring receiving groove is to further increase adhesion between the outer circumferential surface of the extension part and the inner circumferential surface of the connection part of the external device to prevent unnecessary injection of fluid, and may accommodate the O-ring 153, which is a type of sealing member.

Since the O-ring has a ring shape, it is seated so as to surround the outer circumferential surface of the O-ring receiving groove, thereby sealing the periphery of the extension and increasing frictional force between the extension and the external device.

The O-ring is provided to block unnecessary injection or outflow of fluid, and it is preferable to use a material that can completely block the coupling gap of the above components, has an elastic recovery power over a certain amount, and has excellent heat resistance and corrosion resistance. Examples of such materials include silicone rubber (VMQ), fluorosilicone rubber (FVMQ), fluoroelastomer (FKM), ethylene-propylene-diene monomer rubber (EPDM), and nitrile-butadiene rubber (NBR), and the like, Among these, it is preferable to use silicone rubber or fluorosilicone rubber.

The housing may be formed of an appropriate metal material capable of having heat resistance and impact resistance, and examples thereof include copper alloy, aluminum, nickel, tin and zinc, and in addition to these, stainless steel, copper, bronze , Chromium, titanium, and other metals or alloys thereof may be included.

In the present invention, the cover 200 is combined with the housing to form a space for accommodating a pressure sensor, a substrate, a lead, etc., and a lead hole 210 formed in one or more on the upper surface as shown in FIG. Similar to the housing, including a side wall formed by extending an outer surface in the longitudinal direction, and a coupling jaw 220 formed to protrude from the outer circumferential surface of the side wall to seal the space by fitting with the unevenness and space of the housing described above. It features.

In the present invention, the lead hole 210 is formed to expose the lead 600 to be described later to the outside of the space, and the lead exposed to the outside through the lead hole may be directly connected to an external device such as power. To this end, a coupling means such as a protruding jaw and a coupling groove may be further provided around the lead hole so that the connection part of the external device can be inserted or connected by fitting.

The coupling jaw 220 is formed to protrude from the outer peripheral surface of the end of the side wall formed by extending the outer peripheral surface of the cover in the longitudinal direction, precisely in the direction opposite to the exposure direction of the lead, and is fitted with the unevenness and space of the housing. And can be fixed.

The cover may form a space in which a side wall of the cover is formed and an opposite surface thereof is opened through coupling with the housing. The space formed by the cover is combined with the space of the housing to form a space for accommodating the lead support 700, the substrate 300, and the sensor 500, which will be described later.

In addition, as described above, the coupling protrusion 220 is formed on the outer circumferential surface of the sidewall, thereby increasing the contact area with the housing and preventing fluid from entering the space of the housing. However, the coupling between the housing and the cover may rely only on fitting, but for more reliable sealing, the space between the housing and the cover may be filled with an adhesive or the like.

The cover is not limited in material. However, since heat resistance, pressure resistance, and impact resistance must be maintained, it is preferable to manufacture using a material that can satisfy the above properties. Fibers containing glass fibers in any one or more polymer resins selected from, for example, polyolefin, polyamide, polyacrylic, polyurethane, polyimide, polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate of these materials It may be made of reinforced plastic, more preferably polyamide as a polymer resin, of which fiber-reinforced plastics containing glass fibers in polyamide 6,6 are of high rigidity and high resistance to fluid, abrasion resistance, It is preferable because it has high dimensional stability and adhesion, and has excellent heat deflection temperature.

In the present invention, the substrate, specifically, a printed circuit board (300), is electrically connected to the pressure sensor through a wire, and serves to convert a resistance change formed through pressure into an electric signal.

More specifically, the printed circuit board is formed such that the receiving hole 310 penetrates the upper and lower surfaces so that one surface of the sensor fixing part is exposed to the space of the housing by penetrating the sensor fixing part as shown in FIG. A wire for electrically connecting to a pressure sensor provided on one side of the fixing unit, a through hole filled with a conductive adhesive so that the lead can be electrically connected while passing through the lead may be provided.

At this time, the printed circuit board has a coupling jaw and an outer circumferential surface in direct contact with the second receiving hole among the inner circumferential surfaces of the receiving hole and the outer circumferential surfaces of the sensor fixing unit, similar to bolts and nuts in order to more closely couple with the sensor fixing unit. As the coupling groove is formed and the sensor fixing part is rotated and coupled, screw coupling may be performed.

As described above, the through-hole may be fixed by passing through the lead 600 and filled with a conductive adhesive so as to be electrically connected to the lead. In this case, the conductive adhesive is not limited in the present invention, but may be an epoxy containing conductive metal particles such as iron or copper.

The through hole may be formed according to the number of leads. In this case, the lead penetrates the substrate and contacts the bottom surface of the metal housing, so that the substrate, the lead, and the housing may all be electrically connected.

In addition, a buffer member (not shown) may be further provided between the substrate and the housing. When a small pressure is applied from the outside, the buffer member may elastically deform and absorb it, thereby maintaining the bonding between the substrate and the housing, and absorbing the shock transmitted to the substrate.

In the present invention, the substrate is not limited to a material and a forming method. Specifically, a wafer made of silicon oxide forming a substrate and a p-type semiconductor layer formed on the surface of the wafer into which boron is implanted may be printed in a pattern form. When the p-type semiconductor layer forms a plurality of layers, the p-type semiconductor layer An insulating layer made of a silicon oxide material may be further provided between the semiconductor layers.

In the present invention, the sensor fixing part 400 is located in the inner space formed by the housing and the cover to accommodate and fix the pressure sensor, and is inserted into the receiving hole of the substrate as shown in FIGS. It is located between the bottom surface and the bottom surface of the substrate, and a second pressure transmission pipe 411 is formed in the longitudinal direction so as to penetrate through one surface and the other surface to communicate with the first pressure transmission pipe 110 of the above-described housing. Pressure can be transmitted.

In this case, a coupling means (not shown) may be further provided on an inner circumferential surface of the receiving hole and an outer circumferential surface of the sensor fixing unit in order to further increase the coupling force between the receiving hole and the sensor fixing unit and the bottom surface of the housing. The coupling means is not limited in the present invention, and as an example, there are irregularities (steps), magnets, adhesive layers, etc., which can be fitted, and various coupling means commonly applicable in the art may be exemplified.

Referring to FIG. 5, the bonding of the sensor fixing part and the pressure sensor will be described in more detail, and the upper surface of the sensor fixing part is formed to be recessed in a hexahedral shape, and a pressure sensor receiving groove 420 for accommodating the pressure sensor therein and A pressure sensor auxiliary receiving groove 430 formed by depressing the inner surface so as to be bent at a predetermined radius around the inner side height direction edge of the pressure sensor receiving groove may be formed.

That is, the sensor fixing part forms a receiving groove for accommodating the pressure sensor on the upper surface to protect the pressure sensor, and when the sensor fixing part is viewed in the longitudinal direction from the upper surface, the shape of the receiving groove is changed from the square to the square. You can make the circle centered around the four corners merged.

At this time, it is preferable that the sensor fixing part cuts the auxiliary receiving groove before the receiving groove, and then cuts the receiving groove accordingly.

Referring to Figure 6 to describe in more detail the bonding method of the pressure sensor in the present invention, including the method of cutting the receiving groove,

a) determining a vertex of the rectangle by drawing a rectangular virtual line (V) on the upper surface of the sensor fixing unit;

b) forming an auxiliary receiving groove 430 by cutting the upper surface of the sensor fixing part into a cylindrical shape in the longitudinal direction with the center of the vertex;

c) forming a receiving groove 420 by cutting the upper surface of the sensor fixing part into a hexahedron in a longitudinal direction around the square; And

d) applying an adhesive to the bottom of the receiving groove, fixing a pressure sensor on the adhesive and curing it;

It may include.

In the present invention, step a) is the first step of forming the receiving groove for placing the pressure sensor on the upper surface of the sensor fixing part, and is a step of drawing a virtual line in a rectangular shape to determine a vertex. At this time, the square may be set as a general asymmetric square, but it is preferable to set it as a left-right symmetric square such as a rectangle or a square, and the second in the square so that the receiving groove communicates with the second pressure transmission pipe 411 It is desirable to set the pressure transmission pipe so that it is located.

Next, as in step b), the upper surface of the sensor fixing part centered on the square vertex is cut into a cylindrical shape in the longitudinal direction to form an auxiliary receiving groove.

5 and 6, the auxiliary receiving groove 430 formed through step b) is a virtual structure set through step a) when viewed longitudinally from the upper surface of the sensor fixing unit. It may have a circle shape centered on each vertex among the squares. That is, through the step b), four auxiliary receiving grooves are formed around the vertices of the square.

At this time, the auxiliary receiving groove may have the same depth as the receiving groove to be described later as shown in FIG. 5, and has a cylindrical shape centered on the vertex of the square as described above, so of course, the auxiliary receiving groove and the receiving groove are combined. In this case, the portion in which the auxiliary receiving groove is formed replaces the edge formed in the etching direction of the receiving groove.

In general, in order to accommodate the square pressure sensor, the receiving groove must also be processed into a hexahedral shape. The problem is that most of the milling equipment forming grooves must be processed by rotating a special type of drill such as a long edge cutter, and even in this case, there is a problem that the center must be continuously moved when the cutter is rotated. In addition, even in this processing, there is a problem that the accuracy of the receiving groove is deteriorated because it is difficult to obtain a flat and straight edge due to the limitation of the processing method.

In addition, when the pressure sensor is placed on the adhesive and pressure is applied after applying the adhesive to the receiving groove, the bonding area is widened in such a way that the adhesive spreads widely between the receiving groove and the pressure sensor, so that the bonding is performed. Problems can arise.

For example, if the amount of adhesive applied is too large, of course, the adhesive spreads more widely when pressure is applied. Therefore, if the adhesive spreading area is excessively expanded, it spreads to the pressure transfer pipe, affecting the pressure transfer to the pressure sensor. Measurement accuracy may decrease. In addition, if the amount of adhesive is not completely the same when applying the adhesive to several places, the amount of spreading of the adhesive is different even if the pressure applied to the pressure sensor is constant, so between the surface of the receiving groove where the pressure transfer tube is formed and the pressure sensor. This may also affect the measurement accuracy of the pressure sensor, as the width of may not be constant.

In order to solve the above problems, the present invention does not first form a receiving groove for accommodating a pressure sensor, but first sets a rectangular virtual line having the same size as the receiving groove, and then centers the vertex of the virtual line. After forming the auxiliary receiving groove, it is characterized in that the receiving groove is formed by processing along the virtual line.

In this case, it is easy to determine the location and shape of the receiving groove by simply forming the auxiliary receiving groove first, so it is easy to process it with accurate dimensions, and when forming the receiving groove, the edge in the direction to be etched is replaced with the auxiliary receiving groove. Therefore, there is no need to apply a special type of drill or processing method, and processing cost can be reduced. In addition, as shown in (d) of FIG. 6, the application position or amount of the adhesive can be determined according to the position of the auxiliary receiving groove, so that the bonding position of the pressure sensor can be more precisely. Here, as shown in FIG. 7, when the adhesive is applied to the auxiliary receiving groove, simply by adjusting the application position or amount of the adhesive, the adhesive does not spread to the second pressure transfer pipe, and the adhesive is easily adhered to the edge of the pressure sensor. It is possible to increase the adhesive strength between the sensor fixing part and the pressure sensor.

In the present invention, the auxiliary receiving groove does not limit the size or depth of the diameter, but is preferably set in consideration of the ratio of the width of the receiving groove to be described later. Specifically, the diameter (A) of the auxiliary receiving groove is preferably a ratio (A/B) of 0.1 to 0.5 with the width (B) of the receiving groove. If A/B does not satisfy the above range, the bonding process of the pressure sensor may become difficult, or it may be difficult to maintain a constant bonding strength between the pressure sensor and the receiving groove. In addition, the depth may be 0.1 to 1 mm, but the present invention is not limited thereto.

In the present invention, the auxiliary receiving groove is not limited to a molding method. For example, there are drilling processing, laser processing, electric discharge processing, electron beam processing, grinding stone particle processing, press processing, and the like, among which laser processing is most preferable.

Next, a step of cutting the virtual line (V), which is a hexahedron connecting the center of the auxiliary receiving groove formed through step b), to form the receiving groove connected to the auxiliary receiving groove.

As the receiving groove is formed to be connected to the auxiliary receiving groove through the step c), the edge to be formed in the cutting direction of the receiving groove is replaced by the auxiliary receiving groove as described above. Through this, the receiving groove can be precisely formed in a desired place, and the adhesive strength and pressure measurement accuracy of the sensor can be improved by simply determining the application location of the adhesive and the bonding location of the pressure sensor.

It is preferable to process the upper surface on which the pressure transmission pipe is formed so that the receiving groove communicates with the second pressure transmission pipe 411 to be described later, and the processing method may be applied to the processing method of the auxiliary receiving groove described above.

In addition, the size of the receiving groove is not limited. For example, the width of the receiving groove (the distance between the corners facing each other based on the square of the upper surface) may be 0.5 to 2 mm, the depth may be 0.1 to 1 mm, but the depth of the auxiliary receiving groove within the above range It is better to form the same as.

Next, as in step d), an adhesive is applied to the bottom surface of the receiving groove where the pressure sensor will be located, and then the pressure sensor is fixed on the adhesive and cured.

In this case, the adhesive may be formed in a thin film form, and it is preferable that the adhesive is a metal having good properties of fire resistance, conductivity, and wetness. In this case, when the structure when the pressure sensor is bonded to the sensor fixing part is viewed in the longitudinal direction, the pressure sensor may be stacked in the order of the pressure sensor-glass (glass film)-metal film from the top.

To explain step d) in more detail, first, after designing an integrated circuit on the upper surface of the silicon wafer forming the pressure sensor, chemical resistance, conductivity, and wettability are applied to the lower surface by using evaporation or sputtering. This excellent metal film (first film) is formed. The pressure sensor is manufactured by removing the mask for designing the integrated circuit or etching the upper surface on which the mask pattern is formed, and then forming a second layer of the same material as the first layer on the bottom of the receiving groove, It can be formed by aligning the first film and the second film so that they are in contact with each other and then heating the first film and the second film at a melting temperature.

In the present invention, the metal film as described above may include gold, titanium, chromium, tungsten, nickel, copper, platinum, tin, germanium, silicon, antimony, etc., and these may be used alone or in combination of two or more. . More preferably, alloys such as tin-gold-copper, gold-tin alloy, gold-germanium-antimony alloy, and gold-silicon alloy having a composition capable of eutectic bonding that can immediately form a metal foil on the surface of a silicon substrate It is better to use.

The eutectic bonding is a method of bonding by heating an adhesive made of a metal material.General metal does not change directly from solid to liquid when heated, but changes to liquid through a slush state. The longer it lasts and as the slush state progresses in many parts, it acts as a factor that lowers the bonding strength. In Utetic, when the metals constituting the alloy are adjusted at a certain ratio, the heated metal does not go through a slush state, but changes directly from the lowest melting point to a liquid state, thereby increasing the bonding strength.

When heating the metal foil, the heating temperature is preferably in the range of 350 to 450°C. In the above temperature range, metal films made of uthetic material formed on the bonding surface of the temperature sensor and the bottom surface of the receiving groove, respectively, are melted so that a silicon wafer used as a pressure sensor and a sensor fixing part made of silicon (glass) may be bonded to each other. .

However, in the present invention, a bonding method using a metal adhesive to fix the pressure sensor is exemplified, but in some cases, an organic adhesive may be used instead of the metal adhesive. At this time, the organic adhesive is preferably excellent in heat resistance and weather resistance and less dimensional change.For example, one or more of thermosetting resins such as epoxy, melamine, phenol, unsaturated polyester, urea, resorcinol, etc. Can include.

When the pressure sensor is bonded to the sensor fixing unit as described above, since it has a much higher bonding strength than the conventional solder die bonding method, the pressure inside the housing changes or the size of the pressure transmitted through the pressure transfer tube suddenly increases. Even if it increases, it is desirable to maintain a constant adhesive force between the pressure sensor and the sensor fixing part.

In addition, as described above, the sensor fixing part may further include a second pressure transmission pipe 411 formed in the longitudinal direction so as to penetrate through one surface and the other surface.

The second pressure transmission pipe is for supplying fluid into the housing by communicating with the first pressure transmission pipe 110 of the housing through a portion formed on the other surface, and one surface from the other surface of the sensor fixing unit as shown in FIG. It is characterized in that it is formed so that the diameter becomes narrower as it goes.

The sensor fixing part is not limited in material, but is preferably made of a metal material in order to minimize the difference in the coefficient of thermal expansion from the above-described metal adhesive, etc., and to secure heat resistance and corrosion resistance, for example, copper alloy, aluminum, nickel, Tin, palladium, tantalum, zinc, and the like. At this time, the metal is preferably used alone or two or more, and it is most preferable to use a copper alloy in terms of weather resistance and heat resistance.

In the present invention, the pressure sensor 500 is located to be buried in the receiving groove formed on the upper surface of the sensor fixing unit as described above to be protected from fluid or external shocks (heat, pressure, other physical shocks), and through the wire It is electrically connected to the substrate to perform a function of transmitting an electrical signal according to a pressure change.

The pressure sensor (pressure sensor) is connected to a diaphragm having a piezo resistance effect such as single crystal silicon, and a plurality of semiconductor strain gauges (resistances) are formed on the diaphragm, and a connection circuit connected to the semiconductor strain gauge , An integrated circuit such as an amplifying circuit and an operation processing circuit for increasing the output from the circuit may be included. In addition, the pressure sensor may be electrically connected to the substrate through the above-described wire.

When explaining the operation method of the pressure sensor, first, when the diaphragm is deformed by the pressure transmitted through the pressure transmission pipe, the resistance disposed on the surface is also deformed. In this case, the resistance value of the surface also changes according to the shape deformation, and an electric signal generated by the change in resistance may be transmitted to the substrate through a pressure sensor.

In the present invention, the type of the pressure sensor is not limited. The pressure sensor is classified as a method of converting the stress generated in the diaphragm into an electrical signal, and the conversion method includes a change in the natural frequency of the vibrator, a method using a surface acoustic wave, a piezoresistive type and a capacitance type, etc. Among these, it is preferable to apply a piezoresistive type or a capacitance type.

In the piezoresistive type, a piezoresistive body capable of measuring a change in pressure is formed between two layers of silicon substrates, and when the substrate is deformed by pressure, the pressure of the piezoresistive body is measured to measure the pressure. Such a piezoresistive type has a strong change in pressure measured according to temperature and poor circuit compatibility, but has advantages of a simple structure and process, and a simple circuit.

The capacitive type is provided with electrodes separated by a certain distance so as to face each other, and when the distance between the electrodes changes due to external pressure, the capacitance between the electrodes also changes, and the change in capacitance is changed into an electric signal and measured. to be. The capacitive type has a precise and complex structure and poor responsiveness, but is relatively less affected by temperature and can detect minute changes.

In the present invention, the pressure sensor can be manufactured by designing an integrated circuit on the upper surface of a silicon wafer and then etching it as described above. In this case, the silicon wafer is formed integrally on the lower glass substrate in terms of securing insulation. In order to improve the adhesion between the glass substrate and the sensor fixing unit, the glass substrate and the sensor fixing unit are Join up and down.

In the present invention, the lead 600 is a type of connection terminal for sending a signal transmitted to the substrate to an external device and supplying power to the substrate, etc., and penetrates the housing as shown in FIGS. 3 and 4 It may be electrically connected to the housing, the substrate, the pressure sensor, etc. by contacting the bottom of the inner space.

The lead is connected vertically to the bottom of the inner space of the housing, and at this time, it may be fixed by a conductive adhesive or welding. In addition, in order to stably maintain an electrical contact state between the lead and the substrate or the housing, a certain portion is located in the inner space of the housing in a curved shape, but may have elasticity in a direction perpendicular to the substrate and the housing.

Meanwhile, the number of the leads is not limited, but it is preferable that the lead is provided as three separate leads for external input/output (Vout), for supplying a driving voltage (Vcc), and for grounding (GND) as shown in FIG. 1.

The lead is not limited in its material, but is preferably made of a material having conductivity similar to the housing. Examples of the above materials include copper alloy, aluminum, nickel, tin, and zinc, and these may be used alone or in the form of two or more alloys.

The lead support part 700 is supported on the upper surface of the substrate as shown in FIGS. 3 and 4 and includes a coupling member or the like to guide and fix the plurality of leads described above, and may be located on the upper surface of the substrate within the housing. .

The lead support part is basically supported on the upper surface of the substrate as shown in FIG. 4 and may have various lengths and shapes depending on the shape and position of the lead. In particular, the upper surface may contact a curved portion of the outer peripheral surface of the lead. It can be maintained so that the electrical connection between the lead and the substrate is not broken even by impact.

The lead support portion does not limit the fixing method or shape of the lead. As an example, the lead support portion may further include a protrusion on the bottom so as to be fitted with a coupling groove formed on the substrate, and the lead support portion and the substrate are coupled using an adhesive without having to have a protrusion or coupling groove. You may.

In addition, the lead support portion may further include one or more gripping means 710 on the side as shown in FIG. 4 to fix the lead. The gripping means is provided on the side to accommodate a portion of the outer circumferential surface of the lead by fitting with the lead, and by fixing the lead more firmly, it is possible to prevent disconnection of electrical connection that may occur due to impact.

In the present invention, the material of the lead support portion is not limited, but, similar to the cover, it is preferable to use a polymer material that satisfies heat resistance, impact resistance, and insulation. For example, a glass fiber is mixed with one or more polymer resins selected from polyolefin, polyamide, polyacrylic, polyurethane, polyimide, polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate. Fiber-reinforced plastics may be mentioned, and in addition, various materials satisfying the above physical properties may be used.

As described above, the pressure sensor according to the present invention includes a sensor fixing part on which a pressure transmission pipe for transmitting pressure is formed, and a pressure sensor positioned on one surface of the sensor fixing part to contact one end of the pressure transmission pipe, The sensor fixing portion is further provided with a receiving groove for accommodating the sensor and an auxiliary receiving groove for including a part of the receiving groove, thereby dramatically increasing the bonding strength of the pressure sensor.

Through this, the pressure sensor can detect an accurate pressure value in an environment where vibration, high temperature, corrosion, etc. may occur without showing a hysteresis phenomenon, and a medium having an incomplete characteristic pressure generated in fuel such as diesel or gasoline Can have a strong resistance to

As described above, various embodiments of the present invention have been presented and described, but the present invention is not necessarily limited thereto, and those of ordinary skill in the art to which the present invention pertains, within the scope of the technical spirit of the present invention. It will be easy to see that branch substitutions, modifications and changes are possible.

100: housing
110: first pressure transmission pipe
120: housing body
130: side wall
140: irregularities
150: extension
151: protruding jaw
152: O-ring receiving groove
153: O-ring
200: cover
210: lead hole
220: combined jaw
300: substrate
310: accommodation hall
400: sensor fixing unit
411: second pressure transmission pipe
420: receiving groove
430: auxiliary receiving groove
500: pressure sensor
600: lead
700: lead support
710: holding means
Ad: adhesive
V: virtual line

Claims (7)

A cover having one or more lead holes formed thereon and having a coupling protrusion on a lower side of the sidewall;
A housing which forms a space by being fitted with the coupling jaws of the cover through irregularities on the inner surface, and having a first pressure transmission pipe communicating with the outside on a lower surface thereof;
A substrate provided on a lower surface of the space of the housing and having a receiving hole penetrating through the upper and lower surfaces;
A sensor fixing unit inserted into the receiving hole of the substrate, positioned between the bottom surface of the housing and the bottom surface of the substrate, and having a second pressure transmission tube formed therein in a longitudinal direction so as to communicate with the first pressure transmission tube;
A pressure sensor positioned on one surface of the sensor fixing part to contact one end of the second pressure transfer pipe;
One or a plurality of linear leads having one end in contact with the lower surface of the space of the housing and the other end passing through the lead hole and protruding out of the space; And
A lead support part positioned on the upper surface of the substrate to fix the lead;
Including,
The sensor fixing unit,
A pressure sensor receiving groove formed to be recessed in a hexahedral shape on an upper surface and receiving a pressure sensor therein; And
Four pressure sensor auxiliary receiving grooves formed by depressing the inner surface to be bent at a predetermined radius around the inner side height direction edge of the pressure sensor receiving groove;
It further includes,
The bottom surface of the pressure sensor receiving groove is in communication with the second pressure transmission pipe,
The pressure sensor receiving groove and the pressure sensor auxiliary receiving groove have a modularized semi-hermetic structure, characterized in that the depression depth is the same.
delete The method of claim 1,
The pressure sensor receiving groove and the pressure sensor is a pressure sensor having a modular semi-hermetic structure, characterized in that bonding with any one or a plurality of adhesives of a metal adhesive and an organic adhesive.
The method of claim 1,
The housing,
An extension portion extending in the direction of formation of the first pressure transmission pipe is provided on the lower surface thereof,
A pressure sensor with a modular semi-hermetic structure, characterized in that one or a plurality of protruding jaws and O-ring receiving grooves are alternately formed on an outer surface of the extension part.
The method of claim 1,
The pressure sensor is a pressure sensor having a modularized semi-hermetic structure, characterized in that the electrical connection to the substrate through wire bonding.
The method of claim 1,
The pressure sensor having a modularized semi-hermetic structure, wherein the lead penetrates the substrate and contacts a lower surface of the space of the housing.
The method of claim 1,
The sensor fixing part is a pressure sensor having a modular semi-hermetic structure, characterized in that made of any one or a plurality of metals selected from copper alloy, aluminum, nickel, tin, palladium, tantalum and zinc.

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