Flow sensor chip convenient to package and capable of multidirectional detection

Abstract

The utility model relates to a flow sensor chip convenient to package and capable of multidirectional detection. The device comprises a central heat source structure, the first upstream thermopile temperature measuring element, the first downstream thermopile temperature measuring element, the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are arranged around the central heat source structure; a first upstream thermopile temperature measurement positive electrode, a first upstream thermopile temperature measurement negative electrode, a second upstream thermopile temperature measurement positive electrode, a second upstream thermopile temperature measurement negative electrode, a first downstream thermopile temperature measurement positive electrode and a first downstream thermopile temperature measurement negative electrode which are arranged in the same straight line are led out from the four groups of thermopile temperature measurement elements and the central heat source structure; a second downstream thermopile temperature measurement positive electrode, a second downstream thermopile temperature measurement negative electrode, a central heat source heating positive electrode and a central heat source heating negative electrode. By optimizing the electrode arrangement, the packaging process is simplified, and the convenience and reliability of packaging are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flow sensors, in particular to a flow sensor chip which is easy to package and capable of multi-directional detection. Background Art

[0002] Thermal flow sensors detect flow through temperature difference. The core principle is to use the heat conduction relationship between the heating resistor and the temperature measuring resistor. Thermistor sensors rely on their sensitivity to temperature. Temperature changes cause changes in resistance value. The temperature changes are reflected by resistance changes to measure flow. Thermopile sensors connect multiple thermocouples in series to superimpose the potential differences generated by each thermocouple, thereby amplifying the temperature difference signal and improving measurement accuracy.

[0003] However, existing flow sensor chips have certain limitations in packaging and multi-directional detection capabilities. The design of traditional flow sensor chips usually considers flow detection in a single direction, resulting in reduced accuracy when detecting flow in multiple directions. In addition, traditional designs also have inconveniences in packaging technology. The complex electrode arrangement increases the difficulty of packaging and reduces packaging reliability and production efficiency. Summary of the invention

[0004] To this end, the utility model provides a flow sensor chip that is easy to package and capable of multi-directional detection. By optimizing the electrode arrangement and simplifying the packaging process, the simplicity and reliability of packaging are improved; and high-sensitivity detection of flows from different directions is achieved and chip power consumption is reduced.

[0005] In order to solve the above technical problems, the utility model provides a flow sensor chip which is easy to package and capable of multi-directional detection, comprising:

[0006] Central heat source structure;

[0007] Four groups of thermopile temperature measuring elements, including a first upstream thermopile temperature measuring element, a first downstream thermopile temperature measuring element, a second upstream thermopile temperature measuring element, and a second downstream thermopile temperature measuring element arranged around the central heat source structure;

[0008] The first upstream thermopile temperature measuring element comprises a plurality of rows of first upstream temperature measuring element thermopiles arranged in parallel, and the plurality of rows of the first upstream temperature measuring element thermopiles are connected by wires to lead out a first upstream thermopile temperature measuring positive electrode and a first upstream thermopile temperature measuring negative electrode;

[0009] The second upstream thermopile temperature measuring element comprises a plurality of rows of second upstream temperature measuring element thermopiles arranged in parallel, and the plurality of rows of the second upstream temperature measuring element thermopiles are connected by wires to lead out a second upstream thermopile temperature measuring positive electrode and a second upstream thermopile temperature measuring negative electrode;

[0010] The first downstream thermopile temperature measuring element comprises a plurality of rows of first downstream temperature measuring element thermopiles arranged in parallel, and the plurality of rows of the first downstream temperature measuring element thermopiles are connected by wires to lead out a first downstream thermopile temperature measuring positive electrode and a first downstream thermopile temperature measuring negative electrode;

[0011] The second downstream thermopile temperature measuring element comprises a plurality of rows of second downstream temperature measuring element thermopiles arranged in parallel, and the plurality of rows of the second downstream temperature measuring element thermopiles are connected by wires to lead out a second downstream thermopile temperature measuring positive electrode and a second downstream thermopile temperature measuring negative electrode;

[0012] The central heat source structure leads to a central heat source to heat the positive electrode and a central heat source to heat the negative electrode;

[0013] The first upstream thermopile temperature measurement positive electrode, the first upstream thermopile temperature measurement negative electrode, the second upstream thermopile temperature measurement positive electrode, the second upstream thermopile temperature measurement negative electrode, the first downstream thermopile temperature measurement positive electrode, the first downstream thermopile temperature measurement negative electrode, the second downstream thermopile temperature measurement positive electrode, the second downstream thermopile temperature measurement negative electrode, the central heat source heating positive electrode and the central heat source heating negative electrode are arranged in the same straight line.

[0014] In one embodiment of the utility model, the central heat source structure is a cross structure, and the first upstream thermopile temperature measuring element and the first downstream thermopile temperature measuring element are respectively symmetrically arranged with the cross of the central heat source structure as the 45° axis of the XY axis coordinate system and the length direction is parallel to the 135° axis; the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are respectively symmetrically arranged with the 135° axis of the cross XY axis coordinate system of the central heat source structure and the length direction is parallel to the 45° axis; the first upstream thermopile temperature measuring element is respectively symmetrically arranged with the second upstream thermopile temperature measuring element along the X axis and symmetrically arranged with the second downstream thermopile temperature measuring element along the Y axis.

[0015] In one embodiment of the utility model, the first upstream thermopile temperature measuring element and the second upstream thermopile temperature measuring element both include multiple rows of upstream thermopile temperature measuring elements arranged in parallel; the first downstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element both include multiple rows of downstream thermopile temperature measuring elements arranged in parallel, and the upstream thermopile temperature measuring element and the downstream thermopile temperature measuring element both include cold junction area through holes and hot junction area through holes;

[0016] All the cold junction area through holes and all the corresponding hot junction area through holes of each of the first upstream thermopile temperature measuring element, the first downstream thermopile temperature measuring element, the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are arranged opposite to each other and respectively form a right angle structure, and two sides of the right angle structure are parallel to the X axis and the Y axis respectively.

[0017] In one embodiment of the utility model, the upstream temperature measuring element thermopile includes an upstream thermopile lower layer thermocouple and an upstream thermopile upper layer thermocouple, and the downstream temperature measuring element thermopile includes a downstream thermopile lower layer thermocouple and an upstream thermopile upper layer thermocouple.

[0018] In one embodiment of the utility model, the hot junction area through hole in the upstream temperature measuring element thermopile is provided with an upstream thermopile structure hot junction area, and the cold junction area through hole in the upstream temperature measuring element thermopile is provided with a first upstream thermopile structure cold junction area and a second upstream thermopile structure cold junction area;

[0019] A downstream thermopile structure hot junction region is arranged in the hot junction region through hole in the downstream temperature measuring element thermopile, and a first downstream thermopile structure cold junction region and a second downstream thermopile structure cold junction region are arranged in the cold junction region through hole in the downstream temperature measuring element thermopile;

[0020] The upstream thermopile structure hot junction area is connected between the upstream thermopile lower layer thermocouple and the upstream thermopile upper layer thermocouple;

[0021] The cold junction area of ​​the first upstream thermopile structure is connected to the lower thermocouple of the upstream thermopile;

[0022] The second upstream thermopile structure cold junction area is connected to the upper thermocouple of the upstream thermopile;

[0023] The downstream thermopile structure hot junction area is connected between the downstream thermopile lower layer thermocouple and the downstream thermopile upper layer thermocouple;

[0024] The cold junction area of ​​the first downstream thermopile structure is connected to the lower thermocouple of the downstream thermopile;

[0025] The second downstream thermopile structure cold junction area is connected to the upper thermocouple of the downstream thermopile.

[0026] In one embodiment of the utility model, it also includes a first insulating layer and a second insulating layer, the first insulating layer respectively covers the surfaces of the lower thermocouple of the upstream thermopile, the lower thermocouple of the downstream thermopile and the central heat source structure; the second insulating layer respectively covers the surfaces of the upper thermocouple of the upstream thermopile, the upper thermocouple of the downstream thermopile and a portion of the first insulating layer.

[0027] In one embodiment of the utility model, it also includes a substrate supported below the central heat source structure and the four groups of thermopile temperature measuring elements, and the substrate includes a silicon wafer and a silicon oxide support layer and a silicon nitride support layer respectively arranged along the surface of the silicon wafer.

[0028] In one embodiment of the present utility model, the central heat source structure has a cross hollow groove having the same shape as itself.

[0029] In one implementation of the present utility model, the central heat source structure adopts a platinum resistor.

[0030] In one embodiment of the present utility model, the outer contours of the first upstream thermopile temperature measuring element, the first downstream thermopile temperature measuring element, the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are rectangular; the outer contours of the wires of the first upstream thermopile temperature measuring element, the first downstream thermopile temperature measuring element, the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are respectively rectangular.

[0031] The above technical solution of the utility model has the following advantages compared with the prior art:

[0032] The utility model discloses a flow sensor chip that is easy to package and capable of multi-directional detection. The electrodes PAD are arranged in the same direction, which is convenient for subsequent packaging and wiring, and improves the simplicity and reliability of the packaging process. The central heat source structure adopts a cross-shaped hollow structure, which can not only reduce the power consumption of the chip, but also ensure that the four groups of temperature measuring thermopile elements around it feel sufficient and symmetrical heat generation. The diagonal design can make the thermocouple longer in a limited area, improving the sensitivity of chip temperature detection. At the same time, whether the flow is flowing in from the six directions of the X-axis, Y-axis, 45° axis, 135° axis or any direction, it can be stably detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0034] Figure 1 It is a schematic top view of the overall structure of the flow sensor chip capable of self-checking and multi-directional measurement of the utility model.

[0035] Figure 2 The utility model is a cross-sectional schematic diagram of a flow sensor chip capable of self-checking and multi-directional measurement.

[0036] Figure 3 It is a schematic diagram of the distribution of through holes in the hot junction area and the cold junction area of ​​the utility model.

[0037] Figure 4 It is a schematic diagram of the distribution of electrode pads and wires of the utility model.

[0038] Description of the Figures in the Specification:

[0039] 1. Substrate;

[0040] 2. Silicon oxide support layer;

[0041] 3. Silicon nitride support layer;

[0042] 4. Central heat source structure; 4a. Central heat source heats the positive electrode; 4b. Central heat source heats the negative electrode;

[0043] 5a, thermocouple of the lower layer of the upstream thermopile; 5b, thermocouple of the lower layer of the downstream thermopile;

[0044] 6a, a first insulating layer; 6b, a second insulating layer;

[0045] 7a, upper thermocouple of upstream thermopile; 7b, upper thermocouple of downstream thermopile;

[0046] 81. hot junction area of ​​upstream thermopile structure; 82. cold junction area of ​​first upstream thermopile structure; 83. cold junction area of ​​second upstream thermopile structure; 84. hot junction area of ​​downstream thermopile structure; 85. cold junction area of ​​first downstream thermopile structure; 86. cold junction area of ​​second downstream thermopile structure; 87. heat source wire structure;

[0047] 91, first upstream thermopile temperature measuring element; 911, first upstream thermopile temperature measuring element; 91a, first upstream thermopile temperature measuring positive electrode; 91b, first upstream thermopile temperature measuring negative electrode;

[0048] 92, first downstream thermopile temperature measuring element; 921, first downstream thermopile temperature measuring element; 92a, first downstream thermopile temperature measuring positive electrode; 92b, first downstream thermopile temperature measuring negative electrode;

[0049] 93, second upstream thermopile temperature measuring element; 931, second upstream thermopile temperature measuring element; 93a, second upstream thermopile temperature measuring positive electrode; 93b, second upstream thermopile temperature measuring negative electrode;

[0050] 94, second downstream thermopile temperature measuring element; 941, second downstream thermopile temperature measuring element; 94a, second downstream thermopile temperature measuring positive electrode; 94b, second downstream thermopile temperature measuring negative electrode;

[0051] 10a, through hole in cold junction area; 10b, through hole in hot junction area;

[0052] 11. Passivation layer;

[0053] 12. Back release cavity. DETAILED DESCRIPTION

[0054] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0055] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0056] In the present utility model, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present utility model, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0057] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0058] Reference Figures 1 to 3 As shown, the utility model is a flow sensor chip that is easy to package and capable of multi-directional detection, comprising:

[0059] Central heat source structure 4;

[0060] Four groups of thermopile temperature measuring elements, including a first upstream thermopile temperature measuring element 91, a first downstream thermopile temperature measuring element 92, a second upstream thermopile temperature measuring element 93 and a second downstream thermopile temperature measuring element 94 arranged around the central heat source structure 4;

[0061] The first upstream thermopile temperature measuring element 91 comprises a plurality of rows of first upstream temperature measuring element thermopiles 911 arranged in parallel, and the plurality of rows of the first upstream temperature measuring element thermopiles 911 are connected by wires to lead out a first upstream thermopile temperature measuring positive electrode 91a and a first upstream thermopile temperature measuring negative electrode 91b;

[0062] The second upstream thermopile temperature measuring element 93 comprises a plurality of rows of second upstream temperature measuring element thermopiles 931 arranged in parallel, and the plurality of rows of the second upstream temperature measuring element thermopiles 931 are connected by wires to lead out a second upstream thermopile temperature measuring positive electrode 93a and a second upstream thermopile temperature measuring negative electrode 93b;

[0063] The first downstream thermopile temperature measuring element 92 comprises a plurality of rows of first downstream temperature measuring element thermopiles 921 arranged in parallel, and the plurality of rows of the first downstream temperature measuring element thermopiles 921 are connected by wires to lead out a first downstream thermopile temperature measuring positive electrode 92a and a first downstream thermopile temperature measuring negative electrode 92b;

[0064] The second downstream thermopile temperature measuring element 94 comprises a plurality of rows of second downstream temperature measuring element thermopiles 941 arranged in parallel, and the plurality of rows of the second downstream temperature measuring element thermopiles 941 are connected by wires to lead out a second downstream thermopile temperature measuring positive electrode 94a and a second downstream thermopile temperature measuring negative electrode 94b;

[0065] The central heat source structure 4 leads to a central heat source heating positive electrode 4a and a central heat source heating negative electrode 4b;

[0066] The first upstream thermopile temperature measurement positive electrode 91a, the first upstream thermopile temperature measurement negative electrode 91b, the second upstream thermopile temperature measurement positive electrode 93a, the second upstream thermopile temperature measurement negative electrode 93b, the first downstream thermopile temperature measurement positive electrode 92a, the first downstream thermopile temperature measurement negative electrode 92b, the second downstream thermopile temperature measurement positive electrode 94a, the second downstream thermopile temperature measurement negative electrode 94b, the central heat source heating positive electrode 4a and the central heat source heating negative electrode 4b are arranged in the same straight line.

[0067] In one embodiment, the central heat source structure 4 is a cross structure, and the first upstream thermopile temperature measuring element 91 and the first downstream thermopile temperature measuring element 92 are respectively arranged symmetrically with the cross of the central heat source structure 4 as the 45° axis of the XY axis coordinate system, and the length direction is parallel to the 135° axis; the second upstream thermopile temperature measuring element 93 and the second downstream thermopile temperature measuring element 94 are respectively arranged symmetrically with the 135° axis of the cross XY axis coordinate system of the central heat source structure 4, and the length direction is parallel to the 45° axis; the first upstream thermopile temperature measuring element 91 is respectively arranged symmetrically with the second upstream thermopile temperature measuring element along the X axis and symmetrically with the second downstream thermopile temperature measuring element 94 along the Y axis.

[0068] In one embodiment, the first upstream thermopile temperature measuring element 91 and the second upstream thermopile temperature measuring element 93 both include multiple rows of upstream thermopile temperature measuring elements arranged in parallel; the first downstream thermopile temperature measuring element 92 and the second downstream thermopile temperature measuring element 94 both include multiple rows of downstream thermopile temperature measuring elements arranged in parallel, and the upstream thermopile temperature measuring element and the downstream thermopile temperature measuring element both include cold junction area through holes 10a and hot junction area through holes 10b;

[0069] All the cold junction area through holes 10a and the corresponding hot junction area through holes 10b of each of the first upstream thermopile temperature measuring element 91, the first downstream thermopile temperature measuring element 92, the second upstream thermopile temperature measuring element 93 and the second downstream thermopile temperature measuring element 94 are arranged opposite to each other and respectively form a right-angle structure, and the two sides of the right-angle structure are parallel to the X-axis and the Y-axis respectively.

[0070] In one embodiment, the upstream temperature measuring element thermopile includes an upstream thermopile lower thermocouple 5a and an upstream thermopile upper thermocouple 7a, and the downstream temperature measuring element thermopile includes a downstream thermopile lower thermocouple 5b and a downstream thermopile upper thermocouple 7b.

[0071] In one embodiment, the hot junction area through hole 10b in the upstream temperature measuring element thermopile is provided with an upstream thermopile structure hot junction area 81, and the cold junction area through hole 10a in the upstream temperature measuring element thermopile is provided with a first upstream thermopile structure cold junction area 82 and a second upstream thermopile structure cold junction area 83;

[0072] The hot junction area through hole 10b in the downstream temperature measuring element thermopile is provided with a downstream thermopile structure hot junction area 84, and the cold junction area through hole 10a in the downstream temperature measuring element thermopile is provided with a first downstream thermopile structure cold junction area 85 and a second downstream thermopile structure cold junction area 86;

[0073] The upstream thermopile structure hot junction area 81 is connected between the upstream thermopile lower layer thermocouple 5a and the upstream thermopile upper layer thermocouple 7a;

[0074] The first upstream thermopile structure cold junction area 82 is connected to the upstream thermopile lower layer thermocouple 5a;

[0075] The second upstream thermopile structure cold junction area 83 is connected to the upstream thermopile upper layer thermocouple 7a;

[0076] The downstream thermopile structure hot junction area 84 is connected between the downstream thermopile lower layer thermocouple 5b and the downstream thermopile upper layer thermocouple 7b;

[0077] The first downstream thermopile structure cold junction area 85 is connected to the downstream thermopile lower layer thermocouple 5b;

[0078] The second downstream thermopile structure cold junction area 86 is connected to the downstream thermopile upper layer thermocouple 7b.

[0079] In one embodiment, it also includes a first insulating layer 6a and a second insulating layer 6b, wherein the first insulating layer 6a covers the surfaces of the upstream thermopile lower thermocouple 5a, the downstream thermopile lower thermocouple 5b and the central heat source structure 4 respectively; and the second insulating layer 6b covers the surfaces of the upstream thermopile upper thermocouple 7a, the downstream thermopile upper thermocouple 7b and part of the first insulating layer 6a respectively.

[0080] In one embodiment, it also includes a substrate 1 supported below the central heat source structure 4 and the four groups of thermopile temperature measuring elements, wherein the substrate 1 includes a silicon wafer and a silicon oxide support layer 2 and a silicon nitride support layer 3 respectively arranged along the surface of the silicon wafer.

[0081] In one embodiment, the central heat source structure 4 has a cross hollow groove with the same shape as itself, and the central heat source structure 4 adopts a platinum resistor.

[0082] In one embodiment, the substrate 1 is provided with a back release cavity 12 to release the hot end positions of the central heat source structure 4 and the four groups of thermopile temperature measuring elements.

[0083] In one embodiment, referring to Figure 4 As shown, the outer contours of the first upstream thermopile temperature measuring element 91, the first downstream thermopile temperature measuring element 92, the second upstream thermopile temperature measuring element 93 and the second downstream thermopile temperature measuring element 94 are rectangular; the outer contours of the wires of each of the first upstream thermopile temperature measuring element 91, the first downstream thermopile temperature measuring element 92, the second upstream thermopile temperature measuring element 93 and the second downstream thermopile temperature measuring element 94 are rectangular.

[0084] Through the above settings, the central heat source structure 4 adopts a cross-shaped hollow structure, which can not only reduce the power consumption of the chip, but also ensure that the four groups of temperature-measuring thermopile elements around it feel sufficient and symmetrical heat. The electrode PADs are arranged in the same direction, which is convenient for subsequent packaging and wiring, and improves the simplicity and reliability of the packaging process.

[0085] In addition, the diagonal design allows the thermocouple to be designed longer in a limited area, improving the sensitivity of chip temperature detection. At the same time, whether the flow is from the six directions of the X-axis, Y-axis, 45° axis, 135° axis or any direction, stable detection can be achieved.

[0086] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to examples, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A flow sensor chip that is easy to package and capable of multi-directional detection, characterized in that: include: Central heat source structure (4); Four groups of thermopile temperature measuring elements, including a first upstream thermopile temperature measuring element (91), a first downstream thermopile temperature measuring element (92), a second upstream thermopile temperature measuring element (93) and a second downstream thermopile temperature measuring element (94) arranged around the central heat source structure (4); The first upstream thermopile temperature measuring element (91) comprises a plurality of rows of first upstream temperature measuring element thermopiles (911) arranged in parallel, the plurality of rows of the first upstream temperature measuring element thermopiles (911) being connected by wires to lead out first upstream thermopile temperature measuring positive electrodes (91a) and first upstream thermopile temperature measuring negative electrodes (91b); The second upstream thermopile temperature measuring element (93) comprises a plurality of rows of second upstream temperature measuring element thermopiles (931) arranged in parallel, the plurality of rows of the second upstream temperature measuring element thermopiles (931) being connected by wires to lead out a second upstream thermopile temperature measuring positive electrode (93a) and a second upstream thermopile temperature measuring negative electrode (93b); The first downstream thermopile temperature measuring element (92) comprises a plurality of rows of first downstream temperature measuring element thermopiles (921) arranged in parallel, the plurality of rows of the first downstream temperature measuring element thermopiles (921) being connected by wires to lead out first downstream thermopile temperature measuring positive electrodes (92a) and first downstream thermopile temperature measuring negative electrodes (92b); The second downstream thermopile temperature measuring element (94) comprises a plurality of rows of second downstream temperature measuring element thermopiles (941) arranged in parallel, the plurality of rows of the second downstream temperature measuring element thermopiles (941) being connected by wires to lead out a second downstream thermopile temperature measuring positive electrode (94a) and a second downstream thermopile temperature measuring negative electrode (94b); The central heat source structure (4) leads out a central heat source to heat the positive electrode (4a) and a central heat source to heat the negative electrode (4b); The first upstream thermopile temperature measurement positive electrode (91a), the first upstream thermopile temperature measurement negative electrode (91b), the second upstream thermopile temperature measurement positive electrode (93a), the second upstream thermopile temperature measurement negative electrode (93b), the first downstream thermopile temperature measurement positive electrode (92a), the first downstream thermopile temperature measurement negative electrode (92b), the second downstream thermopile temperature measurement positive electrode (94a), the second downstream thermopile temperature measurement negative electrode (94b), the central heat source heating positive electrode (4a) and the central heat source heating negative electrode (4b) are arranged in the same straight line.

2. A flow sensor chip that is easy to package and capable of multi-directional detection according to claim 1, characterized in that: The central heat source structure (4) is in a cross structure; the first upstream thermopile temperature measuring element (91) and the first downstream thermopile temperature measuring element (92) are respectively arranged symmetrically with the cross of the central heat source structure (4) as the 45° axis of the XY axis coordinate system, and their length directions are parallel to the 135° axis; the second upstream thermopile temperature measuring element (93) and the second downstream thermopile temperature measuring element (94) are respectively arranged symmetrically with the 135° axis of the cross XY axis coordinate system of the central heat source structure (4), and their length directions are parallel to the 45° axis; the first upstream thermopile temperature measuring element (91) is respectively arranged symmetrically with the second upstream thermopile temperature measuring element along the X axis and symmetrically with the second downstream thermopile temperature measuring element (94) along the Y axis.

3. A flow sensor chip that is easy to package and capable of multi-directional detection according to claim 1, characterized in that: The first upstream thermopile temperature measuring element (91) and the second upstream thermopile temperature measuring element (93) both comprise a plurality of rows of upstream temperature measuring element thermopiles arranged in parallel; the first downstream thermopile temperature measuring element (92) and the second downstream thermopile temperature measuring element (94) both comprise a plurality of rows of downstream temperature measuring element thermopiles arranged in parallel, and the upstream temperature measuring element thermopiles and the downstream temperature measuring element thermopiles both comprise cold junction area through holes (10a) and hot junction area through holes (10b); All the cold junction area through holes (10a) and all the corresponding hot junction area through holes (10b) of the first upstream thermopile temperature measuring element (91), the first downstream thermopile temperature measuring element (92), the second upstream thermopile temperature measuring element (93) and the second downstream thermopile temperature measuring element (94) are arranged opposite to each other and are respectively in a right-angle structure, and two sides of the right-angle structure are respectively parallel to the X-axis and the Y-axis.

4. A flow sensor chip that is easy to package and capable of multi-directional detection according to claim 3, characterized in that: The upstream temperature measuring element thermopile comprises an upstream thermopile lower layer thermocouple (5a) and an upstream thermopile upper layer thermocouple (7a), and the downstream temperature measuring element thermopile comprises a downstream thermopile lower layer thermocouple (5b) and a downstream thermopile upper layer thermocouple (7b).

5. The flow sensor chip that is easy to package and capable of multi-directional detection according to claim 4, characterized in that: An upstream thermopile structure hot junction region (81) is arranged in the hot junction region through hole (10b) in the upstream temperature measuring element thermopile, and a first upstream thermopile structure cold junction region (82) and a second upstream thermopile structure cold junction region (83) are arranged in the cold junction region through hole (10a) in the upstream temperature measuring element thermopile; A downstream thermopile structure hot junction region (84) is arranged in the hot junction region through hole (10b) in the downstream temperature measuring element thermopile, and a first downstream thermopile structure cold junction region (85) and a second downstream thermopile structure cold junction region (86) are arranged in the cold junction region through hole (10a) in the downstream temperature measuring element thermopile; The upstream thermopile structure hot junction area (81) is connected between the upstream thermopile lower layer thermocouple (5a) and the upstream thermopile upper layer thermocouple (7a); The first upstream thermopile structure cold junction area (82) is connected to the upstream thermopile lower layer thermocouple (5a); The second upstream thermopile structure cold junction area (83) is connected to the upper thermocouple (7a) of the upstream thermopile; The downstream thermopile structure hot junction area (84) is connected between the downstream thermopile lower layer thermocouple (5b) and the downstream thermopile upper layer thermocouple (7b); The first downstream thermopile structure cold junction area (85) is connected to the downstream thermopile lower layer thermocouple (5b); The second downstream thermopile structure cold junction area (86) is connected to the downstream thermopile upper layer thermocouple (7b).

6. A flow sensor chip that is easy to package and capable of multi-directional detection according to claim 5, characterized in that: It also includes a first insulating layer (6a) and a second insulating layer (6b), wherein the first insulating layer (6a) covers the surfaces of the lower thermocouple (5a) of the upstream thermopile, the lower thermocouple (5b) of the downstream thermopile and the central heat source structure (4); and the second insulating layer (6b) covers the surfaces of the upper thermocouple (7a) of the upstream thermopile, the upper thermocouple (7b) of the downstream thermopile and a portion of the first insulating layer (6a).

7. The flow sensor chip that is easy to package and capable of multi-directional detection according to claim 1, characterized in that: It also includes a substrate (1) supported below the central heat source structure (4) and the four groups of thermopile temperature measuring elements, the substrate (1) including a silicon wafer and a silicon oxide support layer (2) and a silicon nitride support layer (3) respectively arranged along the surface of the silicon wafer.

8. The flow sensor chip that is easy to package and capable of multi-directional detection according to claim 2, characterized in that: The central heat source structure (4) has a cross-shaped hollow groove having the same shape as itself.

9. A flow sensor chip that is easy to package and capable of multi-directional detection according to claim 8, characterized in that: The central heat source structure (4) adopts a platinum resistor.

10. The flow sensor chip that is easy to package and capable of multi-directional detection according to claim 1, characterized in that: The outer contours of the first upstream thermopile temperature measuring element (91), the first downstream thermopile temperature measuring element (92), the second upstream thermopile temperature measuring element (93) and the second downstream thermopile temperature measuring element (94) are rectangular; and the outer contours of the wires of each of the first upstream thermopile temperature measuring element (91), the first downstream thermopile temperature measuring element (92), the second upstream thermopile temperature measuring element (93) and the second downstream thermopile temperature measuring element (94) are rectangular.

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