Thermal sensing package

Abstract

The application discloses a heat sensing package. The heat sensing package comprises a package frame defining a receiving space, an integrated circuit chip, a heat sensing element, a heat conductive insulating glue and a cover plate. The integrated circuit chip is arranged in the receiving space. The heat sensing element is stacked on the integrated circuit chip and electrically connected to the integrated circuit chip. At least a part of the heat conductive insulating glue is filled in a gap between the heat sensing element and the integrated circuit chip. The cover plate is combined with the package frame to close the receiving space. The heat sensing package provided by the application effectively reduces the volume after packaging.

Description

TECHNICAL FIELD

[0001] The present application relates to a sensing element package, in particular to a thermal sensing package. BACKGROUND

[0002] Infrared temperature sensors can be used to absorb thermal radiation (infrared rays) generated by an object to be measured to obtain the temperature of the object to be measured, and are widely used in devices such as ear thermometers, proximity sensors, or thermal imagers. However, miniaturization is an inevitable trend in the market. Therefore, how to improve the structure design to reduce the package size while not affecting the measurement accuracy under the limited manufacturing cost is one of the important issues to be solved in this industry. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a thermal sensing package that effectively reduces the volume after packaging.

[0004] To solve the above problems, the technical solution adopted by the present application is to provide a thermal sensing package, which includes a packaging frame defining a receiving space, an integrated circuit chip, a thermal sensing element, and a cover plate. The integrated circuit chip is arranged in the receiving space and includes a plurality of first connection pads. The thermal sensing element is stacked on the integrated circuit chip and connected to the integrated circuit chip. The cover plate is combined with the packaging frame.

[0005] One of the beneficial effects of the present application is that the thermal sensing package provided by the present application arranges the thermal sensing element and the integrated circuit chip in the thickness direction of the base of the packaging frame, thereby reducing the size of the packaging frame, reducing the size of the integrated circuit chip and the thermal sensing element, and improving the integration of the package.

[0006] For a further understanding of the features and technical contents of the present application, please refer to the following detailed description of the present application and the accompanying drawings. However, the provided drawings are only used for reference and illustration, and are not used to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 FIG. 1 is a perspective view of a thermal sensing package according to a first embodiment of the present application.

[0008] Figure 2 FIG. 2 is a top view of the thermal sensing package according to the first embodiment of the present application.

[0009] Figure 3 FIG. 3 is a sectional view of III-III of the thermal sensing package according to the first embodiment of the present application. Figure 2

[0010] Figure 4A FIG. 4 is a perspective exploded view of a thermal sensing element according to an embodiment of the present application. FIG. 4 is a perspective exploded view of a thermal sensing element according to an embodiment of the present application.

[0011] Figure 4B This is a partial cross-sectional schematic diagram of a thermoelectric stack layer according to an embodiment of the present invention.

[0012] Figures 5 to 8 This is a cross-sectional schematic diagram of the thermal sensing package in the manufacturing process according to the first embodiment of the present invention.

[0013] Figure 9A This is a three-dimensional schematic diagram of the thermal sensing package according to the second embodiment of the present invention.

[0014] Figure 9B This is a cross-sectional schematic diagram of the thermal sensing package according to the second embodiment of the present invention.

[0015] Figure 10 This is a cross-sectional schematic diagram of the thermal sensing package according to the third embodiment of the present invention.

[0016] Figure 11 This is a top view schematic diagram of the thermal sensing package according to the fourth embodiment of the present invention.

[0017] Figure 12 for Figure 11 A schematic diagram of the cross-section XII-XII.

[0018] Figure 13 This is a partial schematic diagram of a thermal sensing element according to another embodiment of the present invention. Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of the "thermal sensing packaging" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention. In addition, the term "or" used herein should be interpreted to include, depending on the actual situation, any combination of any one or more of the associated listed items.

[0020] [First Embodiment]

[0021] See Figures 1 to 3 The figures show a perspective view, a top view, and a cross-sectional view of the thermal sensing package according to the first embodiment of the present invention. The first embodiment of the present invention provides a thermal sensing package M1, which includes: a package frame 1, an integrated circuit chip 2, a thermal sensing element 3, a cover plate 4, and a thermally conductive insulating adhesive 5.

[0022] The package frame 1 can define a receiving space H1 and an opening (not labeled). The package frame 1 of the present embodiment includes a base 10 and a surrounding side frame 11. The base 10 can be a flat plate or have a recessed or stepped structure. When the base 10 has a recess, the recess can be used to accommodate the integrated circuit chip 2, and the depth of the recess is equal to or slightly lower than the integrated circuit chip 2. The base 10 with a recess helps to miniaturize the overall structure. In one embodiment, the base 10 can be a multi-layer circuit board. The surrounding side frame 11 is disposed on the base 10 and cooperates with the base 10 to define the aforementioned receiving space H1. That is, the surrounding side frame 11 protrudes from the base 10 and surrounds the integrated circuit chip 2 and the thermal sensing element 3. In the present embodiment, the base 10 and the surrounding side frame 11 are integrally formed. That is, the materials constituting the base 10 and the surrounding side frame 11 are the same, for example, ceramic, but the present application is not limited thereto.

[0023] Please refer to Figure 2 and Figure 3 The package frame 1 further includes a plurality of internal contacts 12 and a plurality of external contacts 13. The plurality of internal contacts 12 are located in the receiving space H1 and on the base 10. When the base 10 is a flat plate, the internal contacts 12 are disposed on the surface of the flat plate. When the base 10 has a recessed or stepped structure, the internal contacts 12 are preferably located on the top surface of the recess or the stepped structure, i.e., the position where the surrounding side frame 11 is connected. Further, the height of the top surface of the base 10 is similar to the height of the upper surface 2s of the integrated circuit chip 22 located in the recess or the stepped structure, so that the wire bonding distance can be further reduced, and the stress can be reduced to avoid wire breakage. However, the present application is not limited thereto. In the present embodiment, the plurality of external contacts 13 are located on the bottom side of the package frame 1, i.e., disposed on the bottom surface 100 of the base 10. In this way, the thermal sensing package M1 can be assembled on another circuit board (not shown) through the plurality of external contacts 13. However, in the present application, the positions of the plurality of external contacts 13 are not limited to the aforementioned examples.

[0024] It should be noted that a plurality of lines (not shown) can be formed in advance in the base 10 or the surrounding side frame 11 of the package frame 1, so that each internal contact 12 of the package frame 1 can be electrically connected to at least one corresponding external contact 13.

[0025] Please refer to Figure 2 and Figure 3The integrated circuit chip 2 is located within the accommodating space H1 and disposed on the substrate 10. The integrated circuit chip 2 is an application-specific integrated circuit (ASIC) chip, which can be used to receive and process signals detected by the thermal sensing element 3, such as voltage signals. Furthermore, the integrated circuit chip 2 can calculate the temperature of an object based on the received signals. In this embodiment, the integrated circuit chip 2 includes a plurality of first connection pads 21 and a plurality of second connection pads 22, both disposed on the upper surface 2s of the integrated circuit chip 2. The plurality of first connection pads 21 are positioned corresponding to the thermal sensing element 3, thereby electrically connecting the integrated circuit chip 2 to the thermal sensing element 3. In this embodiment, the plurality of first connection pads 21 are located below the thermal sensing element 3. Additionally, the integrated circuit chip 2 can be electrically connected to the package frame 1 via the plurality of second connection pads 22. Furthermore, the thermal sensing package M1 further includes a plurality of wires 6, each wire 6 connecting a corresponding second connection pad 22 to a corresponding internal contact 12. In other words, the multiple second connection pads 22 are electrically connected to the multiple internal contacts 12 of the package frame 1 through multiple wires 6. Furthermore, the multiple second connection pads 22 located on the upper surface 2s of the integrated circuit chip 2 are at similar or flush height with the multiple internal contacts 12 located on the top surface of the substrate 10, which can shorten the wire bonding distance and avoid wire breakage.

[0026] In this embodiment, the thermal sensing element 3 is stacked on the integrated circuit chip 2 and is located together with the integrated circuit chip 2 within the accommodating space H1 to receive thermal radiation entering through the opening. In this embodiment, the thermal sensing element 3 can be an infrared thermopile sensor, but the present invention is not limited thereto. Accordingly, the thermal sensing element 3 of this embodiment has a thermal absorption surface 3a, a bottom surface 3b opposite to the thermal absorption surface 3a, and a side surface 3c connecting the thermal absorption surface 3a and the bottom surface 3b. Furthermore, the material constituting the thermal absorption surface 3a of the thermal sensing element 3 is an infrared absorbing material, which can be used to receive the thermal radiation of the object under test.

[0027] Please refer to the following: Figure 2 , Figure 4A ,in Figure 4A This is a perspective view of a thermal sensing element according to one embodiment of the present invention. The thermal sensing element 3 includes an infrared radiation absorbing layer L1, a thermopile layer L2, a protective layer L3, and a plurality of pads 31 ( Figure 4A (Examples are shown below).

[0028] The infrared radiation absorption layer L1 can be used to absorb thermal radiation, and the aforementioned heat absorption surface 3a is the surface of the infrared radiation absorption layer L1. The infrared radiation absorption layer L1 has an absorption rate of greater than 90% for infrared light. In an embodiment, the infrared radiation absorption layer L1 can absorb radiation with a wavelength range of 250 nm to 22.5 μm. In addition, the material of the infrared radiation absorption layer L1 can not only absorb infrared light but also be flexible.

[0029] The thermoelectric layer L2 is located between the infrared radiation absorption layer L1 and the protective layer L3. Please refer to Figure 4A and Figure 4B , wherein Figure 4B is a partial cross-sectional view of the thermoelectric layer of an embodiment of the present application. As Figure 4A shown, the thermoelectric layer L2 includes thermocouples 30 distributed within a sensing range 3R and connected in series with each other. As Figure 4B shown, each thermocouple 30 includes a hot junction 301, a cold junction 302, a first pin group 303, and a second pin group 304. In this embodiment, the hot junction 301 is closer to the heat absorption surface 3a, and the cold junction 302 is closer to the bottom surface 3b. The hot junction 301 of one thermocouple 30 is connected in series with the cold junction 302 of an adjacent thermocouple 30 through at least the first pin group 303 or the second pin group 304. In this embodiment, the first pin group 303 and the second pin group 304 can each include a plurality of nanowire clusters. The material of the nanowire clusters of the first pin group 303 is different from the material of the nanowire clusters of the second pin group 304. The plurality of thermocouples 30 connected in series or in parallel with each other can form a thermoelectric pile, which can convert the temperature difference sensed by the plurality of hot junctions 301 and the plurality of cold junctions 302 into a voltage signal or a current signal.

[0030] Please refer to Figure 3 and Figure 4A , the protective layer L3 of the thermal sensing element 3 is located on the bottom side of the thermal sensing element 3 together with the plurality of contact pads 31. As Figure 4A shown, the protective layer L3 covers the plurality of thermocouples 30 within the sensing range 3R, but does not cover the plurality of contact pads 31. That is, the plurality of contact pads 31 are exposed on the bottom surface 3b of the thermal sensing element 3 and are respectively arranged close to the four corners of the thermal sensing element 3. The number and position of the contact pads 31 can be adjusted according to the type of the thermal sensing element 3, and the present application is not limited. It should be noted that two of the contact pads 31 are electrically connected to the thermoelectric pile as signal output terminals of the thermoelectric pile.

[0031] Please refer to Figure 3The heat sensing element 3 is disposed on the integrated circuit chip 2 with the bottom surface 3b facing the integrated circuit chip 2. Specifically, the plurality of contact pads 31 of the heat sensing element 3 are respectively electrically connected to the plurality of first connection pads 21 of the integrated circuit chip 2. Further, the plurality of contact pads 31 of the heat sensing element 3 are respectively connected to the plurality of first connection pads 21 through the plurality of conductive pastes P1. In an embodiment, the conductive pastes P1 can be silver paste, which can reduce the process difficulty and cost.

[0032] In addition, it should be noted that, in the heat sensing package M1 provided by the embodiment of the present application, the heat sensing element 3 is stacked on the integrated circuit chip 2, rather than being disposed on the substrate 10 side by side with the integrated circuit chip 2. That is, the heat sensing element 3 and the integrated circuit chip 2 are arranged along the thickness direction of the substrate 10, and thus the size of the substrate 10 of the package frame 1 can be reduced, thereby reducing the overall volume of the heat sensing package M1.

[0033] As described above, after the infrared radiation absorbing layer L1 of the heat sensing element 3 absorbs the heat radiation generated by the object to be measured, the temperature of the infrared radiation absorbing layer L1 rises, causing a temperature difference between the hot junction 301 and the cold junction 302 of the plurality of thermocouples 30, thereby generating a voltage signal. The aforementioned voltage signal can be output to the integrated circuit chip 2 through the two contact pads 31. After receiving and processing the voltage signal, the integrated circuit chip 2 can calculate the temperature of the object to be measured according to a lookup table or a formula.

[0034] In the embodiment, a gap is defined between the bottom surface 3b of the heat sensing element 3 and the integrated circuit chip 2. When the heat sensing element 3 is an infrared thermopile sensing element, if the gap between the heat sensing element 3 and the integrated circuit chip 2 is air, the temperature of the bottom surface 3b of the heat sensing element 3 can be non-uniform, or there can be a large difference between the temperature of the bottom surface 3b of the heat sensing element 3 and the temperature of the integrated circuit chip 2, thereby affecting the measurement accuracy of the heat sensing element 3.

[0035] Please refer to Figure 3In the present embodiment, the thermal sensing package M1 further comprises a thermally conductive and insulating adhesive 5 located in the accommodation space H1. The thermally conductive and insulating adhesive 5 has good thermal conductivity, and at least a portion of the thermally conductive and insulating adhesive 5 fills the gap between the thermal sensing element 3 and the integrated circuit chip 2 to form a so-called underfill. In addition to effectively increasing the bonding strength of the bonding pads of the above two, the thermally conductive and insulating adhesive 5 can also make the temperature of the bottom surface 3b of the thermal sensing element 3 more uniform, and substantially the same as the temperature of the integrated circuit chip 2, thereby reducing the signal-to-noise ratio and improving the sensing accuracy of the thermal sensing package M1. In a preferred embodiment, the thermal conductivity of the thermally conductive and insulating adhesive 5 is greater than or equal to 1 W / m*K. The material of the thermally conductive and insulating adhesive 5 is, for example, epoxy or silicone, which can contain oxide particles such as zinc oxide, but the present application is not limited to the above examples.

[0036] Through actual tests, when the thermally conductive and insulating adhesive 5 has a thermal conductivity greater than or equal to 1 W / m*K, the temperature measurement error range of the thermal sensing package M1 can be from -0.5°C to 0.5°C. If other adhesive materials with a thermal conductivity less than 1 W / m*K or no thermally conductive and insulating adhesive 5 is used, the temperature measurement error range of the thermal sensing package M1 can be from -1°C to 1°C. Accordingly, in the present embodiment, the use of the thermally conductive and insulating adhesive 5 with a thermal conductivity greater than or equal to 1 W / m*K can further improve the measurement accuracy of the thermal sensing package M1.

[0037] In addition, since the heat absorbing surface 3a of the thermal sensing element 3 is used to receive the heat radiation of the object to be measured, the thermally conductive and insulating adhesive 5 does not cover the heat absorbing surface 3a of the thermal sensing element 3, so as not to affect the operation of the thermal sensing element 3 and thus affect the measurement accuracy of the thermal sensing element 3. Accordingly, the top surface 5s of the thermally conductive and insulating adhesive 5 is lower than or flush with the heat absorbing surface 3a of the thermal sensing element 3. Further, the thermally conductive and insulating adhesive 5 completely covers the integrated circuit chip 2 and partially covers the side surface 3c of the thermal sensing element 3.

[0038] In addition, please refer to Figure 2 and Figure 3 In the present embodiment, the thermally conductive and insulating adhesive 5 also covers the plurality of internal contacts 12 of the package frame 1, the plurality of wires 6, and the plurality of second bonding pads 22 of the integrated circuit chip 2. Accordingly, please refer to Figure 2 In the top view, the distribution range of the thermally conductive and insulating adhesive 5 of the present embodiment extends beyond the edge of the thermal sensing element 3 and the edge of the integrated circuit chip 2, but the present application is not limited thereto. In an embodiment, as long as the thermally conductive and insulating adhesive 5 fills the gap between the thermal sensing element 3 and the integrated circuit chip 2, and the distribution range of the thermally conductive and insulating adhesive 5 is greater than and overlaps the sensing range 3R of the thermal sensing element 3, the measurement accuracy of the thermal sensing package M1 can be improved.

[0039] Please refer to Figure 2 and Figure 3The cover plate 4 is combined with the package frame 1 and is arranged to close the accommodation space Hl in correspondence with the position of the opening. As shown in Figure 3 the present embodiment, the cover plate 4 is arranged on the top surface 110 of the surrounding side frame 11 of the package frame 1 to hermetically seal the thermal sensing element 3 and the integrated circuit chip 2 together in the accommodation space Hl. The cover plate 4 can be fixed on the top surface 110 of the surrounding side frame 11 by means of the bonding layer G1. In one embodiment, the accommodation space Hl can also be filled with nitrogen or other inert gas.

[0040] The material constituting the cover plate 4 can be an IR band-pass filter, such as a material allowing the passage of infrared light with a wavelength ranging from 1 to 15 μm but filtering visible light. By way of example, the material constituting the cover plate 4 can be silicon or germanium, a silicon / germanium substrate with an infrared optical coating, sapphire or quartz glass, etc. The present application is not limited thereto. In this way, the thermal radiation (infrared light) generated by the object to be measured can be received by the thermal sensing element 3 through the cover plate 4.

[0041] Referring to Figures 5 to 8 , cross-sectional views of the thermal sensing package according to the first embodiment of the present application at various steps of the manufacturing process are shown.

[0042] As shown in Figure 5 , after the integrated circuit chip 2 is arranged on the base 10 of the package frame 1, the thermal sensing element 3 is arranged on the upper surface 2s of the integrated circuit chip 2. The upper surface 2s of the integrated circuit chip 2 has a plurality of first connection pads 21 and a plurality of second connection pads 22. In one embodiment, the plurality of first connection pads 21 and the plurality of second connection pads 22 can be formed by means of a screen printing process, but the present application is not limited thereto. Subsequently, a plurality of connection pads 31 of the thermal sensing element 3 are electrically connected to a plurality of corresponding first connection pads 21 of the integrated circuit chip 2 by means of a plurality of conductive pastes P1. A gap g1 is defined between the thermal sensing element 3 and the integrated circuit chip 2.

[0043] Referring to Figure 6 , the integrated circuit chip 2 is electrically connected to the package frame 1 by means of wire bonding. In detail, the second connection pads 22 of the integrated circuit chip 2 are connected to corresponding internal contacts 12 by means of wires 6. Referring to Figure 7The thermally conductive and insulating adhesive 5 is formed in the accommodation space Hl so that a portion of the thermally conductive and insulating adhesive 5 fills the gap gl between the thermal sensing element 3 and the integrated circuit chip 2. In detail, the thermally conductive and insulating adhesive 5 in an uncured state is filled in the accommodation space Hl, and then the thermally conductive and insulating adhesive 5 is cured by heating. In this embodiment, the thermally conductive and insulating adhesive 5 covers the plurality of second connection pads 22, the plurality of conductive wires 6, and the plurality of internal connection points 12. However, the thermally conductive and insulating adhesive 5 does not cover the heat absorbing surface 3a of the thermal sensing element 3, and thus the thermally conductive and insulating adhesive 5 does not fill the entire accommodation space Hl.

[0044] Referring to Figure 8 The cover plate 4 is fixed to the packaging frame 1 to close the accommodation space Hl. In detail, the cover plate 4 can be fixed to the top surface 110 of the surrounding side frame 11 of the packaging frame 1 by the bonding layer G1. The above manufacturing process is only one possible embodiment, and is not intended to limit the present application.

[0045] [Second Embodiment]

[0046] Referring to Figure 9A and Figure 9B , the three-dimensional schematic view and the cross-sectional schematic view of the thermal sensing package of the second embodiment of the present application are shown, respectively. The elements of the thermal sensing package M2 of the second embodiment that are the same as or similar to those of the thermal sensing package Ml of the first embodiment have the same or similar reference numerals, and the same parts will not be described again.

[0047] As shown in Figure 9A and Figure 9B , in the packaging frame 1 of the thermal sensing package M2 of the second embodiment, the base 10 and the surrounding side frame 11 are not integrally formed, but are formed of different materials, respectively. For example, the material forming the base 10 can be ceramic or a circuit board, and the material forming the surrounding side frame 11 can be epoxy resin or plastic encapsulation adhesive or the like that can be used for plastic encapsulation. In this embodiment, the base 10 is a flat plate, and the plurality of internal connection points 12 are disposed on the surface of the flat plate.

[0048] In addition, in this embodiment, the surrounding side frame 11 covers the base 10 and partially covers the integrated circuit chip 2. As shown in Figure 9B , a portion (peripheral region) of the upper surface 2s and the side surface of the integrated circuit chip 2 are covered by the surrounding side frame 11. In addition, the surrounding side frame 11 of this embodiment further covers the plurality of conductive wires 6, the plurality of second connection pads 22 of the integrated circuit chip 2, and the plurality of internal connection points 12 of the packaging frame 1. In other words, the plurality of conductive wires 6, the plurality of second connection pads 22 of the integrated circuit chip 2, and the plurality of internal connection points 12 of the packaging frame 1 are embedded in the surrounding side frame 11. The surrounding side frame 11 is disposed around the thermal sensing element 3 to define the accommodation space Hl and the opening.

[0049] As shown in Figure 9A and Figure 9B , the surrounding side frame 11 also has a fitting structure E1, and the fitting structure E1 is located on the side of the surrounding side frame 11 away from the base 10. In this embodiment, the fitting structure E1 is formed on the top surface 110 of the surrounding side frame 11, that is, on the opening end. In this way, the cover plate 4 can be arranged above the thermal sensing element 3 through the fitting structure E1. Further, the cover plate 4 can be fitted into the surrounding side frame 11 through the fitting structure E1 to hermetically seal the thermal sensing element 3 and the integrated circuit chip 2 together in the accommodation space H1. In this embodiment, the fitting structure E11 of the surrounding side frame 11 is a stepped structure, and the cover plate 4 can be combined with the fitting structure E11 through the bonding layer G1.

[0050] In this embodiment, the top surface 4s of the cover plate 4 is flush with the top surface 110 of the surrounding side frame 11, but the present application is not limited thereto. In another embodiment, the top surface 4s of the cover plate 4 can also protrude or be lower than the top surface 110 of the surrounding side frame 11.

[0051] In addition, the thermally conductive insulating adhesive 5 is filled into the gap between the thermal sensing element 3 and the integrated circuit chip 2. However, in this embodiment, the thermally conductive insulating adhesive 5 only covers a part of the upper surface 2s of the integrated circuit chip 2, but does not cover the side surface of the integrated circuit chip 2.

[0052] Accordingly, when manufacturing the thermal sensing package M2 of this embodiment, the integrated circuit chip 2 and the thermal sensing element 3 are sequentially arranged on the base 10, and then the surrounding side frame 11 is formed by the injection molding process. In an embodiment, the surrounding side frame 11 can be formed by a film assisted molding process, but the present application is not limited thereto.

[0053] [Third Embodiment]

[0054] Please refer to Figure 10 , which shows a cross-sectional schematic view of the thermal sensing package of the third embodiment of the present application. The thermal sensing package M3 of this embodiment is the same as or similar to the thermal sensing package M2 of the second embodiment, and the same parts will not be described again.

[0055] As shown in Figure 10 , in the package frame 1 of the thermal sensing package M3 of this embodiment, the base 10 and the surrounding side frame 11 are not integrally formed, but are respectively formed by different materials. In this embodiment, the material of the base 10 is ceramic, and the material of the surrounding side frame 11 is metal. Further, the surrounding side frame 11 can be a pre-formed metal frame.

[0056] In this embodiment, the surrounding side frame 11 has a top plate 11A and a side wall 11B extending from the top plate 11A to the base 10. The top plate 11A has an opening 11h on the top surface 110, and the opening 11h corresponds to the thermal sensor element 3. The cover plate 4 is combined to the package frame 1, and is arranged at the position corresponding to the opening 11h. Further, the cover plate 4 is fixed to the inner side of the top plate 11A, and closes the opening 11h, so as to enclose the thermal sensor element 3 and the integrated circuit chip 2 in the accommodation space Hl.

[0057] In manufacturing the thermal sensor package M3 of this embodiment, the integrated circuit chip 2 and the thermal sensor element 3 are arranged on the base 10 in sequence, and then the thermally conductive insulating adhesive 5 is formed. After that, the surrounding side frame 11 is assembled to the base 10 together with the cover plate 4 which has been fixed to the surrounding side frame 11.

[0058] [Fourth Embodiment]

[0059] Please refer to Figures 11 to 13 . Figure 11 is a top view of the thermal sensor package of the fourth embodiment of the present application, and Figure 12 is a sectional view of the XII-XII section of Figure 11 . The thermal sensor package M4 of this embodiment has the same or similar elements as those of the first to third embodiments, and the same parts will not be described again.

[0060] As shown in Figure 11 , unlike the thermal sensor element 3 in the first to third embodiments, the thermal sensor element 3' of this embodiment has a plurality of contact pads 32, and the contact pads 32 are located on the side (top side) of the thermal sensor element 3' away from the integrated circuit chip 2. In addition, in this embodiment, the plurality of first connection pads 21 of the integrated circuit chip 2 are not arranged below the thermal sensor element 3', but are arranged around the thermal sensor element 3'. Accordingly, the thermal sensor package M4 further comprises a plurality of bonding wires 7, so that the plurality of contact pads 32 can be electrically connected to the plurality of first connection pads 21 respectively through the plurality of bonding wires 7.

[0061] In addition, the structure of the thermal sensor element 3' of this embodiment is also different from that of the thermal sensor element 3 of the first to third embodiments. For example, the thermal sensor element 3' of this embodiment is a membrane thermal sensor.

[0062] Please refer to Figure 12 , the thermal sensor element 3' comprises a frame 33 and a thermal sensor membrane 34. The material constituting the frame 33 is, for example, silicon, and the frame 33 can define a cavity 3H. In addition, the thermal sensor membrane 34 is arranged to be suspended above the integrated circuit chip 2 through the frame 33. Please refer to Figure 11 and Figure 12The thermal sensing film 34 covers the cavity 3H defined by the frame 33.

[0063] Please refer to Figure 13 , a partial schematic view of a thermal sensing element according to an embodiment of the present application. It should be noted that Figure 13 The structure of the thermal sensing film 34 shown is only an example and is not intended to limit the present application. In an embodiment, the thermal sensing film 34 includes a suspended support film 340, an infrared absorber 341, and a plurality of thermocouples 342. The suspended support film 340 is connected to the top surface 33s of the frame 33 and has a very high thermal resistance to avoid rapid heat dissipation. The suspended support film 340 has a sensing region 340A and a plurality of bridge regions 340B connecting the sensing region 340A to the frame 33. The plurality of bridge regions 340B extend radially from the sensing region 340A to the top surface 33s of the frame 33.

[0064] The infrared absorber 341 is configured to absorb thermal radiation (infrared rays) emitted by the object to be measured and is formed in the sensing region 340A of the support film 340. The plurality of thermocouples 342 are respectively disposed in the plurality of bridge regions 340B to measure the temperature difference between the frame 33 and the infrared absorber 341. In this embodiment, the hot junction 342a of each thermocouple 342 is connected to the infrared absorber 341, and the cold junction 342b is located on the frame 33. Accordingly, when the infrared absorber 341 absorbs the thermal radiation (infrared rays) of the object to be measured, the temperature of the infrared absorber 341 rises, causing a temperature difference between the sensing region 340A of the suspended support film 340 and the frame 33, thereby causing a voltage difference between the hot junction 342a and the cold junction 342b of the thermocouple 342. In an embodiment, the plurality of thermocouples 342 can be connected in parallel to form a thermopile to improve sensing sensitivity.

[0065] Accordingly, unlike the first to third embodiments described above, the thermal sensing package M4 of this embodiment does not necessarily need to be provided with the thermally conductive insulating adhesive 5. However, in another embodiment, the frame 33 can be fixed to the integrated circuit chip 2 by a thermally conductive adhesive to make the temperature of the frame 33 close to the temperature of the integrated circuit chip 2. The thermally conductive adhesive described above can be an insulating thermally conductive adhesive or a conductive thermally conductive adhesive. When the thermally conductive adhesive is an insulating thermally conductive adhesive, the surface of the integrated circuit chip 2 can be better protected.

[0066] [Advantages of the Embodiments]

[0067] One of the benefits of the present application is that the thermal sensing package M1-M4 can be set in the accommodation space H1 by the technical solutions of "the integrated circuit chip 2 is set in the accommodation space H1, and includes a plurality of first connection pads 21" and "the thermal sensing element 3 is stacked on the integrated circuit chip 2, and has a plurality of connection pads 31 (or connection pads 32), and the plurality of connection pads 31 (or connection pads 32) are electrically connected to the plurality of first connection pads 21", so that the size of the thermal sensing package M1-M4 is reduced, and the integration of the package is improved.

[0068] Further, the thermal sensing package M1-M3 of the first to third embodiments of the present application also has the heat-conducting insulating glue 5 with good heat conductivity, which is filled in the gap g1 between the thermal sensing element 3 and the integrated circuit chip 2, so as to improve the measurement accuracy of the thermal sensing package M1-M3.

[0069] The above disclosed content is only the preferred feasible embodiments of the present application, and does not limit the protection scope of the claims of the present application, so that any equivalent technical changes made by referring to the content of the present application and the drawings are included in the protection scope of the claims of the present application.

Claims

1. A thermal sensing package, comprising: The thermal sensing package comprises: a package frame defining an opening and a receiving space; an integrated circuit chip disposed in the receiving space and comprising a plurality of first connection pads; a thermal sensing element stacked on the integrated circuit chip and located in the receiving space, wherein the thermal sensing element has a plurality of contact pads, and the plurality of contact pads are electrically connected to the plurality of first connection pads respectively, so that the thermal sensing element is electrically connected to the integrated circuit chip; a thermally conductive and insulating adhesive disposed in the receiving space, wherein at least a portion of the thermally conductive and insulating adhesive fills a gap between the thermal sensing element and the integrated circuit chip, and the thermally conductive and insulating adhesive does not cover a heat absorption surface of the thermal sensing element; and a cover plate coupled to the package frame and closing the receiving space corresponding to the position of the opening; wherein the thermally conductive and insulating adhesive completely covers the integrated circuit chip and partially covers the side surface of the thermal sensing element, and the top surface of the thermally conductive and insulating adhesive is lower than or flush with the heat absorption surface of the thermal sensing element.

2. The thermal sensing package of claim 1, wherein, The thermal conductivity of the thermally conductive and insulating adhesive is greater than or equal to 1 W / m*K.

3. A thermal sensing package, characterized by, The thermal sensing package comprises: a package frame defining an opening and a receiving space; an integrated circuit chip disposed in the receiving space and comprising a plurality of first connection pads; a thermal sensing element stacked on the integrated circuit chip and located in the receiving space, receiving thermal radiation entering from the opening, wherein the thermal sensing element has a plurality of contact pads, and at least two of the contact pads are electrically connected to corresponding first connection pads, so that the thermal sensing element is electrically connected to the integrated circuit chip; and a cover plate coupled to the package frame and closing the receiving space corresponding to the position of the opening; wherein the thermal sensing element comprises a plurality of series-connected thermocouples for measuring the temperature difference between the thermal sensing element and the surface of the integrated circuit chip; wherein the thermal sensing element comprises an infrared radiation absorption layer, a thermoelectric stack layer, and a protective layer, the thermoelectric stack layer being located between the infrared radiation absorption layer and the protective layer, and the contact pads and the protective layer being located on the bottom side of the thermal sensing element, wherein the thermoelectric stack layer comprises a plurality of thermocouples, each thermocouple comprising a hot junction, a cold junction, a first pin group, and a second pin group; wherein the hot junction of each thermocouple is connected in series with the cold junction of an adjacent thermocouple through at least the first pin group or the second pin group, and the first pin group and the second pin group each comprise a plurality of nanowire clusters.

4. The heat sensing package of claim 3, wherein, The heat sensing package further comprises a thermally conductive insulating glue for making the temperature of the bottom surface of the heat sensing element close to the temperature of the integrated circuit chip, wherein the thermally conductive insulating glue is arranged only in the gap between the heat sensing element and the integrated circuit chip, or the thermally conductive insulating glue fills the gap between the integrated circuit chips and covers the side surface of the heat sensing element, and the top surface of the thermally conductive insulating glue is lower than or flush with the heat absorbing surface of the heat sensing element.

5. The heat sensing package of claim 3, wherein, The material constituting the cover plate allows infrared light with a wavelength ranging from 1 to 15 μm to pass through, while filtering visible light.

6. The heat sensing package of claim 3, wherein, The heat sensing element comprises a frame and a heat sensing film, the frame defines a cavity, the heat sensing film is arranged above the integrated circuit chip by the frame and covers the cavity, and the bonding pad is arranged on the top of the frame and surrounds the heat sensing film.

7. The thermal sensing package of any one of claims 1 to 6, wherein, The package frame comprises: a base; and a surrounding side frame which is arranged on the base in a surrounding manner, defines the opening and defines the accommodation space together with the base, wherein the cover plate is arranged at the opening position of the surrounding side frame.

8. The thermal sensing package of claim 7, wherein, The surrounding side frame has a fitting structure which is located on the side of the surrounding side frame away from the base, and the cover plate is arranged above the heat sensing element by the fitting structure.

9. The heat sensing package of claim 7, wherein, The surrounding side frame comprises a top plate and a side wall which extends from the top plate towards the base, the top plate has the opening corresponding to the heat sensing element, and the cover plate is fixed to the inner side of the top plate and closes the opening.

10. The heat sensing package of claim 7, wherein, The package frame has a plurality of internal contacts, the integrated circuit chip comprises a plurality of second connection pads, a plurality of the second connection pads are electrically connected to a plurality of the internal contacts by a plurality of wires, wherein when the base has a groove or a step structure, the internal contacts are located on the top surface of the groove or the step structure, and the height of the top surface of the groove or the step structure is close to the height of the integrated circuit chip; when the base is a flat plate, the internal contacts are arranged on the surface of the flat plate, a plurality of the internal contacts and a plurality of the second connection pads are covered by the surrounding side frame, and a plurality of the wires are embedded in the surrounding side frame.

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