WO2008046235A1 - A method for packaging integrated sensors - Google Patents

A method for packaging integrated sensors Download PDF

Info

Publication number
WO2008046235A1
WO2008046235A1 PCT/CH2006/000581 CH2006000581W WO2008046235A1 WO 2008046235 A1 WO2008046235 A1 WO 2008046235A1 CH 2006000581 W CH2006000581 W CH 2006000581W WO 2008046235 A1 WO2008046235 A1 WO 2008046235A1
Authority
WO
WIPO (PCT)
Prior art keywords
buffer structure
mold
deformable layer
substrate
housing
Prior art date
Application number
PCT/CH2006/000581
Other languages
French (fr)
Inventor
Werner Hunziker
Original Assignee
Sensirion Holding Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sensirion Holding Ag filed Critical Sensirion Holding Ag
Priority to PCT/CH2006/000581 priority Critical patent/WO2008046235A1/en
Priority to DE112006004083T priority patent/DE112006004083T5/en
Publication of WO2008046235A1 publication Critical patent/WO2008046235A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
    • G01F1/6845—Micromachined devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
    • G01D11/24—Housings ; Casings for instruments
    • G01D11/245—Housings for sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/14—Housings
    • G01L19/141—Monolithic housings, e.g. molded or one-piece housings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/56—Encapsulations, e.g. encapsulation layers, coatings
    • H01L21/565—Moulds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation
    • H01L2924/1815—Shape

Definitions

  • the present invention relates to a method for manufacturing a sensor device comprising a substrate with an integrated sensing structure, in particular using molding techniques .
  • a substrate e.g. a semiconductor substrate
  • a substrate e.g. a semiconductor substrate
  • ad- vantages such as small size and the possibility to apply advanced manufacturing techniques as used in semiconductor technology.
  • further functionality on the substrate such as amplifiers, D/A- converters, calibration circuitry, etc.
  • a sacrifical buffer structure is formed on a surface of the substrate.
  • the buffer structure covers and/or surrounds the sensor's sensing structure and extends away from the surface, i.e. it projects away from the substrate.
  • a mold is provided for casting the housing.
  • the mold defines an mold cavity to receive a hardening material. At least part of that mold cavity is lined by a deformable layer.
  • the substrate is placed in the mold, and the parts are arranged such that the de- formable layer abuts against the buffer structure. Then the hardening material is introduced into the mold and hardened for forming the housing.
  • the deformable layer seals at least part of the surface of the sacrifical buffer structure, preventing the mould from covering it.
  • the deformable layer ensures that at least part of the buffer structure is not covered by housing material and remains accessible through said window, thereby making it possible to remove the buffer structure after forming the housing.
  • the buffer structure mechanically protects the sensing structure but allows to make the same com- pletely accessible by removal of the buffer structure.
  • the invention is particularly suited for substance sensors, where the removable buffer structure pro- vides protection for the mechanically sensitive sensing structure during the casting process, but it can e.g. also be used for flow sensors, in particular for flow sensors using a heat source and one or more temperature sensors arranged on a thin membrane extending over a re- cess or opening in a substrate.
  • Fig. 1 shows a semiconductor substrate with integrated sensor
  • Fig. 2 shows the device of Fig. 1 after the addition of the buffer structure
  • Fig. 3 shows the device of Fig. 2 after placement on a lead frame
  • Fig. 4 shows the device of Fig. 3 after transfer molding
  • Fig. 5 shows a sectional view through the mold
  • Fig. 6 shows a sectional view during casting
  • Fig. 7 shows a sectional after removing the mold sections
  • Fig. 8 shows a sectional view of the final sensor device
  • Fig. 9 shows the second embodiment of the device during the casting of the housing
  • Fig. 10 shows the second embodiment of the device after removal of the mold sections
  • Fig. 11 shows the second embodiment of the device after removal of the buffer structure.
  • Figure 1 shows a device comprising a semiconductor substrate 1.
  • a sensing structure 2, evaluation circuitry 3 and contact pads 4 are integrated on a top surface Ia of semiconductor substrate 1.
  • substrate 1 can be a simple carrier for sensing structure 2 without active circuitry, and it may also be of a non- semiconductor material.
  • the device of Fig. 1 may e.g. be a flow sensor, such as it is described in reference to Fig. 5 of US 6 729 181, in which case reference number 2 generally designates the membrane carrying the heater and temperature sensors.
  • the sensor may e.g. also be a light sensor, in which case reference number 2 generally designates the light sensitive area of the device, or it may be a pres- sure sensor, in which case reference number 2 generally designates a pressure sensitive area.
  • a sacri- fical buffer structure 6 is attached to surface Ia adjacent to the sensing structure 2.
  • buffer structure 6 is a layer covering sensing structure 2.
  • Buffer structure 6 can e.g. be glued oro bonded to substrate 1.
  • it is manufactured by applying a buffer layer directly onto surface Ia of substrate 1 and structuring the same using photoli- tographic or screen printing methods .
  • substrate 1 iss placed on a lead frame 7.
  • Lead frames are known to the person skilled in the art. Generally they are metal structures that carry the substrate during packaging and that form the contact pins or pads of the final device. Bond wires 8 are used to connect the contact pads 4 too lead frame 7 in conventional manner.
  • a housing 10 is formed, advantageously by transfer molding or another molding technique.
  • the device of Fig. 3 is placed in a mold and a flowable material, such 5 as a heated thermoplastic, is injected into the mold and then hardened. Finally the mold is removed.
  • a flowable material such 5 as a heated thermoplastic
  • the final device is provided with an access opening 12 in housing 10 for connecting sensing structureo 2 to the environment, as will be further described below.
  • Fig. 5 shows an embodiment of a suitable mold for casting housing 10. It comprises an upper mold section 30 and a lower mold section 31, e.g. made of metal, which, for clarity, are shown at a slight distance from 5 each other. Between them, mold sections 30 and 31 form an mold cavity 32.
  • upper mold section 30 comprises a stamp-like, inward extending sec- tion 33 extending into mold cavity 32 and having a flat end surface 34. Inward extending section 33 is advantageously mounted to upper mold section 30. It may be an integral part of upper mold section 30 or it may be a separate part placed into an opening or recess of upper mold section 30.
  • a deformable layer 35 i.e. a layer of material that is substantially more deformable than the material the mold sections 30, 31 are made from, is lining e.g. all of surface 34.
  • deformable layer 35 is made of an elastically deformable material that is heat resistant up to the temperatures used during the molding process .
  • it should also be more easily deformable than the material of sacrificial buffer structure 6. It can e.g. be made of Teflon. Its thickness should generally exceed 10 ⁇ m and is typically in the range of 50 to 100 ⁇ m.
  • deformable layer 35 has the same size as the top of buffer structure 6. It must be noted, though, that deformable layer 35 may also cover a larger area or a smaller area than the top area of buffer structure 6.
  • Fig. 6 shows the device during casting (with lead frame 7 not shown for better clarity) .
  • upper mold section 30 is positioned such that the deformable layer 35 of inward extending section 33 abuts against buffer structure 6 and is pressed against the same with a force sufficient to deform layer 35 such that it matches the surface of buffer structure 6 and prevents housing material from entering between layer 35 and buffer structure 6.
  • mold sections 30, 31 are placed around substrate 1, a hardening material is introduced into mold cavity 32 through suitable openings (not shown) and is hardened by cooling and/or setting. After hardening the material, mold sections 30, 31 with inward extending section 33 are removed to form a device as shown in Fig. 7. As can be seen, the space occupied by inward extending section 33 now forms window 37, which makes buffer structure 6 accessible from the outside.
  • sacrificial buffer structure 6 is removed, partially or completely, advantageously by etching, melting, evaporating, dissolving or chemically decomposing.
  • the removal process should, however, be such that it does not greatly affect housing 10, sensing structure 2 or substrate 1. Suitable examples of materials and processes are given below.
  • Buffer structure 6 is removed in such a man- ner that at least part or all of sensing structure 2 is exposed to the environment, as e.g. shown in Fig. 8.
  • Buffer structure 6 is made of a material with a melting or evaporation temperature lower than the melting point of housing 10.
  • housing 10 is cast using a polymer precursor or a partially polymerized material, which is then cured such that it with- stands a higher temperature than the one required for melting or evaporating buffer structure 6.
  • a suitable material for housing 10 is e.g. Xydar by Solvay Advanced Polymers, LCC, Georgia, USA, which can be cast as a resin at low temperatures.
  • An advantageous material to be used for forming buffer structure 6 is the Unity Sacrificial Polymer by Promerus LCC, Cleveland, USA.
  • Buffer structure 6 is made of a material that can be solved or chemically decomposed after forming access opening 12.
  • buffer structure 6 can be made of a salt or a water soluble polymer, such as a polyvinyl alcohol, that can be dissolved by water introduced through access opening 12.
  • buffer structure 6 advantageously extends over surface Ia by a height H of at least 10 ⁇ m, in particular between 10 ⁇ m and 100 ⁇ m, preferably between 25 ⁇ m and 50 ⁇ m.
  • buffer structure 6 of this embodiment extends all the way to the top side of housings 10 and is flush therewith.
  • upper mold section 30 has a substantially flat inner surface 30a, having an area larger than the top area of buffer structure 6 and lined with deformable layer 35. During the molding process, flat inner surface 30a is pressedo against buffer structure 6, thereby preventing housing material from covering the buffer structure.
  • buffer structure 6 extends from sensing structure 2 up to the flat, upper5 surface 38 of housing 10 and is flush therewith in window 37.
  • the resulting device looks as shown in Fig. 11 with access opening 12 extending from0 window 37 in upper surface 38 down to sensing structure 2.
  • the present invention is especially advantageous when being used in combination with a sensing structure 2 mounted at least partially on a thin mem-5 brane, such as shown in Fig. 5 of US 6 729 181, which is incorporated by reference herein.
  • the buffer structure 6 of the present application allows to protect the membrane from being damaged in the molding process.
  • deformable layer 35 was formed by a small piece of deformable mate- rial mounted on the inside of one of the mould sections 30, 31.
  • deformable layer 35 may also cover all of the surfaces of mold cavity 32.
  • deformable layer 35 can be formed by a foil extending through one or more mold cavities 32 of the mold. While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims .

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Fluid Mechanics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

A sensor device having a sensing structure (2) integrated on a substrate (1) is packaged in a housing (10) by transfer molding. During molding and in order to protect the sensing structure (2), a deformable layer (35) of a mold section (30) abuts against a sacrificial buffer structure (6) protecting the sensing structure (2). The deformable layer (35) helps to keep an access window free, through which the buffer structure (6) can be removed once the housing (10) has hardened.

Description

A method for packaging integrated sensors
Technical Field
The present invention relates to a method for manufacturing a sensor device comprising a substrate with an integrated sensing structure, in particular using molding techniques .
Background Art
The integration of sensors on a substrate, e.g. a semiconductor substrate, provides a series of ad- vantages, such as small size and the possibility to apply advanced manufacturing techniques as used in semiconductor technology. In addition, when using a semiconductor substrate, it is possible to integrate further functionality on the substrate, such as amplifiers, D/A- converters, calibration circuitry, etc.
Many of the sensors devices of this type, such as gas sensors, flow sensors, humidity sensors or optical sensors, need to be in contact with their surroundings, which makes it impossible to use conventional semiconductor packaging for housing the devices. Rather, specialized packaging techniques are required, such as they are e.g. described in US 6 750 522 or US 6 729 181. These packaging techniques tend, however, to be expensive . Another family of packaging techniques for light detectors and pressure gauges is described in WO 02/078077, WO 03/028086 and EP 1 246 235, where the housing is cast in a mold having an inwardly projecting section. The inwardly projecting section maintains an access opening to the sensing structure of the sensor device while casting the housing. When using these techniques, care must be taken in order to prevent the inwardly pro- jecting section from damaging the sensor's sensing structure .
Disclosure of the Invention
Hence, it is a general object of the invention to provide an economical packaging technique for sensor devices . This object is achieved by the method of claim 1. Accordingly, a sacrifical buffer structure is formed on a surface of the substrate. The buffer structure covers and/or surrounds the sensor's sensing structure and extends away from the surface, i.e. it projects away from the substrate. For casting the housing, a mold is provided. The mold defines an mold cavity to receive a hardening material. At least part of that mold cavity is lined by a deformable layer. The substrate is placed in the mold, and the parts are arranged such that the de- formable layer abuts against the buffer structure. Then the hardening material is introduced into the mold and hardened for forming the housing. During this procedure, the deformable layer seals at least part of the surface of the sacrifical buffer structure, preventing the mould from covering it. When the material has hardened (at least in part) the mold (or at least part thereof) is removed, thereby making at least part of the sacrifical buffer structure accessible through a window. Finally, at least part of the sacrifical buffer structure is removed through the window, thereby forming an access opening extending from the outside of the housing to the sensing structure .
This procedure relies on a synergetic combination of the sacrifical buffer structure and the deform- able layer. One the one hand, the deformable layer ensures that at least part of the buffer structure is not covered by housing material and remains accessible through said window, thereby making it possible to remove the buffer structure after forming the housing. On the other hand, the buffer structure mechanically protects the sensing structure but allows to make the same com- pletely accessible by removal of the buffer structure.
Neither the buffer structure alone, nor the deforrαable layer alone could achieve such an effect. If the buffer structure were directly abutting against the (hard) mold, no perfect seal could be achieved and hous- ing material could seep into small gaps between buffer structure and mold. If the deformable layer were abutting against the sensing structure, it might damage the same.
The invention is particularly suited for substance sensors, where the removable buffer structure pro- vides protection for the mechanically sensitive sensing structure during the casting process, but it can e.g. also be used for flow sensors, in particular for flow sensors using a heat source and one or more temperature sensors arranged on a thin membrane extending over a re- cess or opening in a substrate.
Brief Description of the Drawings
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein: Fig. 1 shows a semiconductor substrate with integrated sensor,
Fig. 2 shows the device of Fig. 1 after the addition of the buffer structure,
Fig. 3 shows the device of Fig. 2 after placement on a lead frame,
Fig. 4 shows the device of Fig. 3 after transfer molding, Fig. 5 shows a sectional view through the mold,
Fig. 6 shows a sectional view during casting,
Fig. 7 shows a sectional after removing the mold sections,
Fig. 8 shows a sectional view of the final sensor device,
Fig. 9 shows the second embodiment of the device during the casting of the housing, Fig. 10 shows the second embodiment of the device after removal of the mold sections, and
Fig. 11 shows the second embodiment of the device after removal of the buffer structure.
Modes for Carrying Out the Invention
Figure 1 shows a device comprising a semiconductor substrate 1. A sensing structure 2, evaluation circuitry 3 and contact pads 4 are integrated on a top surface Ia of semiconductor substrate 1. Alternatively, substrate 1 can be a simple carrier for sensing structure 2 without active circuitry, and it may also be of a non- semiconductor material. The device of Fig. 1 may e.g. be a flow sensor, such as it is described in reference to Fig. 5 of US 6 729 181, in which case reference number 2 generally designates the membrane carrying the heater and temperature sensors. It may also be a sensor for detecting sub- stances, in particular humidity, such as it is described in US 6 690 569, in which case reference number 2 generally designates the measuring layer of the device, or it may be some other type of gas detector or, more generally, substance detector for detecting a substance in a fluid. The sensor may e.g. also be a light sensor, in which case reference number 2 generally designates the light sensitive area of the device, or it may be a pres- sure sensor, in which case reference number 2 generally designates a pressure sensitive area.
In the following, the steps for packaging the device of Fig. 1 in a housing are described. In a first step, as shown in Fig. 2, a sacri- fical buffer structure 6 is attached to surface Ia adjacent to the sensing structure 2. In the embodiment of Fig. 2, buffer structure 6 is a layer covering sensing structure 2. Buffer structure 6 can e.g. be glued oro bonded to substrate 1. Advantageously, it is manufactured by applying a buffer layer directly onto surface Ia of substrate 1 and structuring the same using photoli- tographic or screen printing methods .
Now, as shown in Fig. 3, substrate 1 iss placed on a lead frame 7. Lead frames are known to the person skilled in the art. Generally they are metal structures that carry the substrate during packaging and that form the contact pins or pads of the final device. Bond wires 8 are used to connect the contact pads 4 too lead frame 7 in conventional manner.
In a next step, as shown in Fig. 4, a housing 10 is formed, advantageously by transfer molding or another molding technique. For this purpose, the device of Fig. 3 is placed in a mold and a flowable material, such5 as a heated thermoplastic, is injected into the mold and then hardened. Finally the mold is removed. This technology is widely used for semiconductor packaging.
The final device is provided with an access opening 12 in housing 10 for connecting sensing structureo 2 to the environment, as will be further described below.
Fig. 5 shows an embodiment of a suitable mold for casting housing 10. It comprises an upper mold section 30 and a lower mold section 31, e.g. made of metal, which, for clarity, are shown at a slight distance from5 each other. Between them, mold sections 30 and 31 form an mold cavity 32. In the embodiment of Fig. 5, upper mold section 30 comprises a stamp-like, inward extending sec- tion 33 extending into mold cavity 32 and having a flat end surface 34. Inward extending section 33 is advantageously mounted to upper mold section 30. It may be an integral part of upper mold section 30 or it may be a separate part placed into an opening or recess of upper mold section 30.
A deformable layer 35, i.e. a layer of material that is substantially more deformable than the material the mold sections 30, 31 are made from, is lining e.g. all of surface 34. Advantageously, and for reasons that will become apparent below, deformable layer 35 is made of an elastically deformable material that is heat resistant up to the temperatures used during the molding process . Advantageously, it should also be more easily deformable than the material of sacrificial buffer structure 6. It can e.g. be made of Teflon. Its thickness should generally exceed 10 μm and is typically in the range of 50 to 100 μm.
In Fig. 5, deformable layer 35 has the same size as the top of buffer structure 6. It must be noted, though, that deformable layer 35 may also cover a larger area or a smaller area than the top area of buffer structure 6.
Fig. 6 shows the device during casting (with lead frame 7 not shown for better clarity) . As can be seen, upper mold section 30 is positioned such that the deformable layer 35 of inward extending section 33 abuts against buffer structure 6 and is pressed against the same with a force sufficient to deform layer 35 such that it matches the surface of buffer structure 6 and prevents housing material from entering between layer 35 and buffer structure 6.
Once the mold sections 30, 31 are placed around substrate 1, a hardening material is introduced into mold cavity 32 through suitable openings (not shown) and is hardened by cooling and/or setting. After hardening the material, mold sections 30, 31 with inward extending section 33 are removed to form a device as shown in Fig. 7. As can be seen, the space occupied by inward extending section 33 now forms window 37, which makes buffer structure 6 accessible from the outside.
In a next step, sacrificial buffer structure 6 is removed, partially or completely, advantageously by etching, melting, evaporating, dissolving or chemically decomposing. The removal process should, however, be such that it does not greatly affect housing 10, sensing structure 2 or substrate 1. Suitable examples of materials and processes are given below.
Buffer structure 6 is removed in such a man- ner that at least part or all of sensing structure 2 is exposed to the environment, as e.g. shown in Fig. 8.
The details of the method for removing buffer structure 6 depend on the material used for manufacturing the same. For example: A) Buffer structure 6 is made of a material with a melting or evaporation temperature lower than the melting point of housing 10. For this purpose, housing 10 is cast using a polymer precursor or a partially polymerized material, which is then cured such that it with- stands a higher temperature than the one required for melting or evaporating buffer structure 6. Once that housing 10 has been cured and the mold sections 30, 31 have been removed, the device is subjected to a temperature sufficient for evaporating or melting buffer struc- ture 6 at least partially. A suitable material for housing 10 is e.g. Xydar by Solvay Advanced Polymers, LCC, Georgia, USA, which can be cast as a resin at low temperatures. An advantageous material to be used for forming buffer structure 6 is the Unity Sacrificial Polymer by Promerus LCC, Cleveland, USA.
B) Buffer structure 6 is made of a material that can be solved or chemically decomposed after forming access opening 12. For example, buffer structure 6 can be made of a salt or a water soluble polymer, such as a polyvinyl alcohol, that can be dissolved by water introduced through access opening 12. For providing sufficient protection for sensing structure 2, buffer structure 6 advantageously extends over surface Ia by a height H of at least 10 μm, in particular between 10 μm and 100 μm, preferably between 25 μm and 50 μm. o A second embodiment of the invention is now described with reference to Figs. 9 - 11.
In contrast to the first embodiment, and as can be seen from Fig. 9, buffer structure 6 of this embodiment extends all the way to the top side of housings 10 and is flush therewith. To achieve this, upper mold section 30 has a substantially flat inner surface 30a, having an area larger than the top area of buffer structure 6 and lined with deformable layer 35. During the molding process, flat inner surface 30a is pressedo against buffer structure 6, thereby preventing housing material from covering the buffer structure.
After removing the mold sections 30, 31 and prior to removing buffer structure 6, buffer structure 6 extends from sensing structure 2 up to the flat, upper5 surface 38 of housing 10 and is flush therewith in window 37.
After removing buffer structure 6 by the means described above, the resulting device looks as shown in Fig. 11 with access opening 12 extending from0 window 37 in upper surface 38 down to sensing structure 2.
The present invention is especially advantageous when being used in combination with a sensing structure 2 mounted at least partially on a thin mem-5 brane, such as shown in Fig. 5 of US 6 729 181, which is incorporated by reference herein. The buffer structure 6 of the present application allows to protect the membrane from being damaged in the molding process.
In the embodiments shown so far, deformable layer 35 was formed by a small piece of deformable mate- rial mounted on the inside of one of the mould sections 30, 31. However, deformable layer 35 may also cover all of the surfaces of mold cavity 32. In another embodiment, deformable layer 35 can be formed by a foil extending through one or more mold cavities 32 of the mold. While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims .

Claims

Claims
1. A method for manufacturing a sensor device comprising a substrate (1) with an integrated sensing structure (2), said method comprising the steps of integrating, onto a surface (Ia) of said substrate (1), a sacrifical buffer structure (6) surrounding and/or covering said sensing structure (2) and extending away from said surface (Ia) , providing a mold (30, 31) defining an mold cavity (32) and having at least one deformable layer (35) lining at least part of said mold cavity (32) , placing said substrate (1) in said mold (30, 31) with said deformable layer (35) abutting against saids sacrificial buffer structure (6), introducing a hardening material into said mold (30, 31) for casting a housing (10) over said substrate, after hardening said material at least par-o tially, removing at least part of said mold for making at least part of said sacrifical buffer structure (β) accessible through a window (37), and removing at least part of said sacrifical buffer structure (6) through said window (37), thereby5 forming an access opening (12) extending to said sensing structure (2) .
2. The method of any of the preceding claims wherein said deformable layer (35) is a plastic.
3. The method of any of the preceding claimso wherein said deformable layer (35) comprises Teflon.
4. The method of any of the preceding claims wherein said window (37) is formed in a substantially flat surface section (38) of said housing (10) and said sacrifical buffer structure (6) extends, prior to its re-5 moval, from said sensing structure (2) at least to said surface section (38) .
5. The method of claim 4 wherein said sacri- fical buffer structure (6) is, prior to its removal, flush with said surface section (38).
6. The method of any of the preceding claims wherein said sensor is a substance sensor for measuring a substance in a fluid and wherein said sensing structure is sensitive to a presence of said substance.
7. The method of any of the preceding claims wherein said at least part of said buffer structure (6) is removed by etching, melting, evaporating, dissolving or chemically decomposing.
8. The method of any of the preceding claims wherein said deformable layer (35) is of a softer material than said mold (30, 31) .
9. The method of any of the preceding claims wherein a thickness of said deformable layer (35) is at least 10 urn.
PCT/CH2006/000581 2006-10-18 2006-10-18 A method for packaging integrated sensors WO2008046235A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CH2006/000581 WO2008046235A1 (en) 2006-10-18 2006-10-18 A method for packaging integrated sensors
DE112006004083T DE112006004083T5 (en) 2006-10-18 2006-10-18 Method for packaging integrated sensors

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CH2006/000581 WO2008046235A1 (en) 2006-10-18 2006-10-18 A method for packaging integrated sensors

Publications (1)

Publication Number Publication Date
WO2008046235A1 true WO2008046235A1 (en) 2008-04-24

Family

ID=38050112

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CH2006/000581 WO2008046235A1 (en) 2006-10-18 2006-10-18 A method for packaging integrated sensors

Country Status (2)

Country Link
DE (1) DE112006004083T5 (en)
WO (1) WO2008046235A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2154713A1 (en) * 2008-08-11 2010-02-17 Sensirion AG Method for manufacturing a sensor device with a stress relief layer
EP2273261A1 (en) 2009-07-09 2011-01-12 Sensirion AG Sensor device on a flexible carrier
US8156815B2 (en) 2009-02-25 2012-04-17 Sensirion Ag Sensor in a moulded package and a method for manufacturing the same
CN105928553A (en) * 2016-05-20 2016-09-07 太原理工大学 Protection device of coal mine sensor
EP2629065A4 (en) * 2010-10-13 2017-12-13 Hitachi Automotive Systems, Ltd. Flow sensor and production method therefor, and flow sensor module and production method therefor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0680103A1 (en) * 1994-04-25 1995-11-02 General Motors Corporation Magnetic field sensor
US6729181B2 (en) * 2000-08-23 2004-05-04 Sensiron Ag Flow sensor in a housing

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE50014711D1 (en) 1999-11-30 2007-11-22 Sensirion Ag SENSOR IN A HOUSING
DE50011713D1 (en) 1999-12-08 2005-12-29 Sensirion Ag Zuerich CAPACITIVE SENSOR
EP1246235A1 (en) 2001-03-26 2002-10-02 European Semiconductor Assembly (Eurasem) B.V. Method for encapsulating a chip having a sensitive surface
NL1019042C2 (en) 2001-09-26 2003-03-27 Europ Semiconductor Assembly E Method for encapsulating a chip and / or other object.

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0680103A1 (en) * 1994-04-25 1995-11-02 General Motors Corporation Magnetic field sensor
US6729181B2 (en) * 2000-08-23 2004-05-04 Sensiron Ag Flow sensor in a housing

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2154713A1 (en) * 2008-08-11 2010-02-17 Sensirion AG Method for manufacturing a sensor device with a stress relief layer
JP2010050452A (en) * 2008-08-11 2010-03-04 Sensirion Ag Method for manufacturing sensor device with stress relief layer
EP2154714A3 (en) * 2008-08-11 2010-03-24 Sensirion AG Temperature sensor with buffer layer
US7901971B2 (en) 2008-08-11 2011-03-08 Sensirion Ag Method for manufacturing a sensor device with a stress relief layer
US8156815B2 (en) 2009-02-25 2012-04-17 Sensirion Ag Sensor in a moulded package and a method for manufacturing the same
EP2273261A1 (en) 2009-07-09 2011-01-12 Sensirion AG Sensor device on a flexible carrier
EP2629065A4 (en) * 2010-10-13 2017-12-13 Hitachi Automotive Systems, Ltd. Flow sensor and production method therefor, and flow sensor module and production method therefor
CN105928553A (en) * 2016-05-20 2016-09-07 太原理工大学 Protection device of coal mine sensor
CN105928553B (en) * 2016-05-20 2018-02-02 太原理工大学 Colliery sensor guard

Also Published As

Publication number Publication date
DE112006004083T5 (en) 2009-11-26

Similar Documents

Publication Publication Date Title
WO2006114005A1 (en) A method for packaging integrated sensors
US20100117185A1 (en) Temperature sensor with buffer layer
EP1717562A1 (en) A method for packaging integrated sensors
WO2008046235A1 (en) A method for packaging integrated sensors
US20100055821A1 (en) Method for manufacturing an intergrated pressure sensor
EP2224218B1 (en) A sensor in a moulded package and a method for manufacturing the same
EP0985138B1 (en) Sensor device and method of forming a sensor device
EP2871152B1 (en) Sensor device
US7880244B2 (en) Wafer level CSP sensor
EP1805493A1 (en) Pressure sensor with top side reference cavity
KR20110128293A (en) Exposed pad backside pressure sensor package
US20130193530A1 (en) Semiconductor Component and Corresponding Production Method
US20160023891A1 (en) Component including a MEMS element and a cap structure including a media connection port
CN101253399A (en) Sensor arrangement comprising a substrate and a housing and method for producing a sensor arrangement
WO2002078077A1 (en) Method for encapsulating a chip having a sensitive surface
US9598280B2 (en) Environmental sensor structure
US10717645B2 (en) Exposed-die mold package for a sensor and method for encapsulating a sensor that interacts with the environment
JP2011191273A (en) Wafer level package structure, sensor element, sensor device, and method of manufacturing them
CN108882859A (en) For manufacturing method, bogey, the system for detecting physical parameter and the method for detecting physical parameter of bogey
US7617599B2 (en) Sensor packaging method for a human contact interface
US10858245B2 (en) Deposition of protective material at wafer level in front end for early stage particle and moisture protection
US7737544B2 (en) Sensor system having a substrate and a housing, and method for manufacturing a sensor system
CN111458056B (en) Method of manufacturing a sensor device and a molded support structure
TWI583618B (en) Micromechanic system and process to produce a micromechanic system
KR102557238B1 (en) A method for packaging one or more semiconductor components, and a semiconductor device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 06790944

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 1120060040839

Country of ref document: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06790944

Country of ref document: EP

Kind code of ref document: A1

RET De translation (de og part 6b)

Ref document number: 112006004083

Country of ref document: DE

Date of ref document: 20091126

Kind code of ref document: P