Pressure sensor, substrate structure and manufacturing method thereof

Abstract

The present invention provides a pressure sensor, a substrate structure and a manufacturing method thereof. The substrate structure for the pressure sensor includes a substrate, and the substrate is provided with a pressure hole. The pressure hole includes a straight hole and a tapered hole arranged along a first direction. The tapered hole extends from the hole edge of the straight hole, and the aperture of the tapered hole is gradually widened along the first direction.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of pressure sensors, and in particular, to a pressure sensor, a substrate structure and a manufacturing method thereof. Background Art

[0002] The core body of a pressure sensor includes a substrate and a chip mounted on the substrate. The substrate is provided with a pressure hole through which the chip is bonded and covers. However, when detecting gas pressure in a humid environment, gas enters through the pressure hole and contacts the sensing element of the chip. At low temperatures, the vapor in the gas condenses into water and easily accumulates and freezes in the pressure hole. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide a pressure sensor, a substrate structure and a manufacturing method thereof, aiming to solve the problem that the pressure chip structure is prone to icing in a low-temperature environment.

[0004] To solve the above technical problems, an embodiment of the present invention provides a substrate structure for a pressure sensor, including a substrate. The substrate is provided with a pressure hole, and the pressure hole includes a straight hole and a tapered hole arranged along a first direction. The tapered hole extends from the hole edge of the straight hole, and the aperture of the tapered hole is gradually widened along the first direction.

[0005] In the present invention, by providing a pressure hole in the substrate, the pressure hole includes a straight hole and a tapered hole arranged along a first direction (in this embodiment, the first direction is the up-and-down direction). The tapered hole extends from the hole edge of the straight hole, and the aperture of the tapered hole is gradually widened along the first direction. In this way, a drainage slope can be formed. At low temperatures, the vapor in the gas condenses into water and can be discharged along the inner wall of the tapered hole, avoiding easy accumulation and icing in the pressure hole.

[0006] Preferably, in the substrate structure for a pressure sensor, the height of the tapered hole is H1, and 0.9 mm ≤ H1 ≤ 1.1 mm.

[0007] Preferably, in the substrate structure for a pressure sensor, H1 is 0.91 mm or 0.95 mm.

[0008] Preferably, in the substrate structure for a pressure sensor, the taper angle of the tapered hole is A, and 85° ≤ A ≤ 95°.

[0009] Preferably, in the substrate structure for a pressure sensor, the straight hole is filled with gel; or, the straight hole and the tapered hole are filled with gel.

[0010] Preferably, in the substrate structure for a pressure sensor, the substrate is provided with a mounting hole, and the mounting hole is filled with an insulating filler, and the insulating filler penetrates the pressure hole.

[0011] Preferably, in the substrate structure for a pressure sensor, a first metal layer is provided on the inner wall of the pressure hole; and / or,

[0012] A first metal layer is provided on the inner wall of the pressure hole; and / or,

[0013] The substrate has an upper surface close to the straight hole and a lower surface opposite to the upper surface. The insulating filler has an upper end surface adjacent to the upper surface and a lower end surface adjacent to the lower surface. The second metal layer covers the upper end surface and the lower end surface, and respectively extends beyond the upper end surface and the lower end surface and is correspondingly provided on the upper surface and the lower surface.

[0014] Preferably, in the substrate structure for a pressure sensor, the first metal layer includes a first copper layer and a first gold plating layer, and the first copper layer and the first gold plating layer are sequentially provided on the inner wall of the pressure hole.

[0015] Preferably, in the substrate structure for a pressure sensor, the insulating filler is resin;

[0016] The second metal layer includes a second copper layer and a second gold plating layer, and the second copper layer and the second gold plating layer are sequentially provided on the upper end surface and the lower end surface of the insulating filler, the upper surface and the lower surface of the substrate.

[0017] To achieve the above object, the present invention further provides a pressure sensor, including the above substrate structure for a pressure sensor.

[0018] To achieve the above object, the present invention further provides a manufacturing method of the above substrate structure for a pressure sensor, including:

[0019] Opening an installation hole in the substrate and pouring an insulating filler;

[0020] After the insulating filler solidifies, opening a pressure hole in the insulating filler;

[0021] Performing electroless copper plating on the inner wall of the pressure hole, the upper end surface and the lower end surface of the insulating filler to respectively form a first copper layer and a second copper layer, and the second copper layer covers the upper end surface and the lower end surface and extends beyond the upper end surface and the lower end surface respectively;

[0022] Plating gold on the first copper layer and the second copper layer to respectively form a first gold plating layer and a second gold plating layer. Description of the Drawings

[0023] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, unless otherwise stated. The drawings in the figures do not constitute a scale limitation.

[0024] Figure 1 FIG. 4 is a schematic structural diagram of an embodiment of a substrate structure for a pressure sensor provided by the present invention;

[0025] Figure 2 is Figure 1 a cross-sectional view taken along line I-I in FIG. 4;

[0026] Figure 3 is Figure 2 a partially enlarged schematic view at position G in FIG. 4;

[0027] Figure 4 is Figure 2 a partially enlarged schematic view at position F in FIG. 4;

[0028] Figure 5 FIG. 26 is a schematic flow diagram of an embodiment of a manufacturing method of a substrate structure for a pressure sensor provided by the present invention.

[0029] Description of the reference numerals in the drawings of the present invention:

[0030] Label Name Label Name 100 Substrate structure for pressure sensor 14 First metal layer 1 Substrate 141 First copper layer 11 Pressure hole 142 First gold plating layer 111 Straight hole 15 Second metal layer 112 Tapered hole 151 Second copper layer 12 Mounting hole 152 Second gold plating layer 13 Insulating filler

[0031] The realization of the objectives, functional features, and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the drawings. Detailed Embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0033] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0034] In addition, if the embodiments of the present invention involve descriptions such as "first" and "second", the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] The present invention provides a substrate structure for a pressure sensor. Please refer to Figure 1 and Figure 2 , the substrate structure 100 for the pressure sensor includes a substrate 1. The substrate 1 is provided with a pressure hole 11. The pressure hole 11 includes a straight hole 111 and a tapered hole 112 arranged in a first direction. The tapered hole 112 extends from the hole edge of the straight hole 111, and the aperture of the tapered hole 112 is gradually widened along the first direction.

[0036] In the present invention, by providing the pressure hole 11 in the substrate 1, the pressure hole 11 includes a straight hole 111 and a tapered hole 112 arranged in a first direction (in this embodiment, the first direction is the up-and-down direction). The tapered hole 112 extends from the hole edge of the straight hole 111, and the aperture of the tapered hole 112 is gradually widened along the first direction. In this way, on the one hand, a drainage slope can be formed, and when the steam in the gas condenses into water at low temperature, it can drain along the inner wall of the tapered hole 112, avoiding easy aggregation and icing in the pressure hole 11.

[0037] Furthermore, since the volume of the pressure sensor is getting smaller and smaller, correspondingly, the aperture of the pressure hole 11 (for example, the diameter of the pressure hole 11 is 0.4 mm to 0.6 mm, or even smaller) is also relatively small. Thus, it is very difficult to pour gel into the pressure hole 11. In the present invention, by including the straight hole 111 and the tapered hole 112 arranged in the first direction in the pressure hole 11, the opening size of the pressure hole 11 can be enlarged, facilitating glue pouring; on the other hand, since the pressure hole 11 includes the straight hole 111 and the tapered hole 112 extending from the hole edge of the straight hole 111 in the first direction, and the maximum aperture of the tapered hole 112 is larger than the aperture of the straight hole 111 (i.e., a large hole and a small hole are formed), when the gas first enters the tapered hole 112 and then enters the straight hole 111, it can play a certain buffering role and avoid directly impacting the chip.

[0038] Since in order to prevent the chip from directly contacting the detection medium, it is usually necessary to pour gel into the straight hole 111, and in order to reduce the bubbles in the gel, it is necessary to evacuate the pressure hole 11 to reduce the bubbles. Please refer to Figure 2, the height of the tapered hole 112 is H1. When the amount of glue is fixed, if H1 is too high, there will be too little gel in the straight hole 111; if H1 is too small, gel is likely to overflow from the pressure hole 11 after evacuating the pressure hole 11. In this embodiment, 0.9 mm ≤ H1 ≤ 1.1 mm. Preferably, H1 is 0.91 mm, 0.92 mm, 0.93 mm, 0.94 mm, 0.95 mm, 0.96 mm, 0.97 mm, 0.98 mm, 0.99 mm, or 1.0 mm.

[0039] The taper angle of the tapered hole 112 is A. In this embodiment, 85° ≤ A ≤ 95°. Preferably, A is 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, or 94°.

[0040] In addition, the straight hole 111 is filled with gel (the gel can be a conventional gel for pressure sensors); or the straight hole 111 and the tapered hole 112 are filled with gel. In this way, after installing the chip on the substrate 1, the chip can be prevented from directly contacting the detection medium, protecting the chip.

[0041] Since the pressure hole 11 penetrates through the substrate 1 (in this embodiment, the substrate 1 is an aluminum substrate), burrs are usually generated during drilling, affecting the overall performance. Therefore, in this embodiment, the substrate 1 is provided with a mounting hole 12, and the mounting hole 12 is filled with an insulating filler 13. The insulating filler 13 penetrates through the pressure hole 11, so that burrs can be reduced and the smoothness of the inner wall of the pressure hole 11 can be improved. In this embodiment, the insulating filler 13 is resin.

[0042] To improve the strength of the pressure hole 11, please refer to Figure 3 , a first metal layer 14 is provided on the inner wall of the pressure hole 11. The substrate 1 has an upper surface close to the straight hole 111 and a lower surface opposite to the upper surface. The insulating filler 13 has an upper end surface adjacent to the upper surface and a lower end surface adjacent to the lower surface. The second metal layer 15 covers the upper end surface and the lower end surface, and respectively extends beyond the upper end surface and the lower end surface and is correspondingly provided on the upper surface and the lower surface. In this way, the insulating filler 13 can be clamped between the second metal layers 15 located on the upper end surface and the lower end surface respectively, preventing the insulating filler 13 from overflowing and increasing the overall strength. In addition, the second metal layer 15 extends beyond the upper end surface and the lower end surface and is correspondingly provided on the upper surface and the lower surface, so that the second metal layer 15 not only covers the insulating filler 13, but also a part of it is connected to the substrate 1, increasing the connection stability.

[0043] Specifically, please refer to Figure 3The first metal layer 14 includes a first copper layer 141 and a first gold-plated layer 142, and the first copper layer 141 and the first gold-plated layer 142 are sequentially arranged on the inner wall of the pressure hole 11. During specific manufacturing, the first copper layer 141 can be formed by copper deposition on the inner wall of the pressure hole 11, and then gold is plated to form the first gold-plated layer 142, so that the strength of the inner wall of the pressure hole 11 can be enhanced.

[0044] In this embodiment, the insulating filler 13 is resin. In other embodiments, the insulating filler 13 may also be other insulating materials, which are not specifically limited here. Figure 3 The second metal layer 15 includes a second copper layer 151 and a second gold-plated layer 152, which are sequentially arranged on the upper end surface and the lower end surface of the insulating filler 13, and the upper surface and the lower surface of the substrate 1. During specific manufacturing, the second copper layer 151 can be formed by copper deposition on the upper end surface and the lower end surface of the insulating filler 13, and the upper surface and the lower surface of the substrate 1, and then gold is plated to form the second gold-plated layer 152.

[0045] In this example, see Figure 4 , the second metal layer 15 extends from the upper end surface and the lower end surface of the insulating filler 13 to the upper surface and the lower surface of the substrate 1 respectively, wherein the radius of the second metal layer 15 extending from the upper end surface of the insulating filler 13 to the upper surface of the substrate 1 and the radius of the upper end surface of the insulating filler 13 have a difference of R11, and the radius of the second metal layer 15 extending from the lower end surface of the insulating filler 13 to the lower surface of the substrate 1 and the radius of the lower end surface of the insulating filler 13 have a difference of R12, 0.05mm≤R12≤0.2mm. If R11 is too small, it will not have the effect of limiting the escape of the insulating filler 13. If R11 is too large, the cost will be too high. Therefore, in this embodiment, 0.05mm≤R11≤0.2mm. Similarly, if R12 is too small, it will not have the effect of limiting the escape of the insulating filler 13. If R12 is too large, the cost will be too high. Therefore, in this embodiment, 0.05mm≤R12≤0.2mm.

[0046] In this embodiment, the substrate 1 is an aluminum substrate. In other embodiments, the substrate 1 may also be made of other materials, such as ceramics, etc. The substrate structure 100 for a pressure sensor provided by the present invention includes a green oil, a circuit layer, an insulating layer, etc. laminated in sequence. Since it is a well-known structure in the art, it will not be described here.

[0047] In order to achieve the above object, the present invention also provides a pressure sensor, which includes the substrate structure 100 for a pressure sensor. Since the pressure sensor includes the substrate structure 100 for a pressure sensor, the embodiment of the pressure sensor includes the embodiment of the substrate structure 100 for a pressure sensor.

[0048] The present utility model also provides a manufacturing method for the substrate structure of the above-mentioned pressure sensor. Please refer to Figure 5 , and the manufacturing method for the substrate structure of the pressure sensor includes:

[0049] Step S210: Open mounting holes 12 in the substrate 1 and pour in insulating filler 13;

[0050] Specifically, the aperture of the mounting hole 12 is larger than the maximum aperture of the tapered hole 112. In this way, it is convenient to open the pressure hole 11 on the insulating filler 13. If the aperture of the mounting hole 12 is too large, it will affect the overall strength of the substrate structure of the pressure sensor; if it is too small, the pressure hole 11 cannot be formed by drilling. In this embodiment, the maximum aperture of the pressure hole 11 < the aperture of the mounting hole 12 ≤ the maximum aperture of the pressure hole 11 + 0.2 mm. The insulating filler 13 can be resin or other insulating materials, and no specific limitation is made here.

[0051] Step S220: After the insulating filler 13 solidifies, open the pressure hole 11 on the insulating filler 13;

[0052] Specifically, after the insulating filler 13 solidifies, the pressure hole 11 can be drilled on the insulating filler 13. In this embodiment, the tapered hole 112 can be drilled first, and then the straight hole 111 can be drilled. In other embodiments, the straight hole 111 can also be drilled first, and then the tapered hole 112 can be drilled. No specific limitation is made here.

[0053] The mounting hole 12 penetrates through the substrate 1, the insulating filler 13 is filled in the mounting hole 12, and the pressure hole 11 penetrates through the insulating filler 13. In this way, burrs can be reduced and the smoothness of the inner wall of the pressure hole 11 can be improved.

[0054] Step S230: Conduct copper deposition metallization on the inner wall of the pressure hole 11, the upper end face and the lower end face of the insulating filler 13 respectively to form a first copper layer 141 and a second copper layer 151 respectively, and the second copper layer 151 covers the upper end face and the lower end face and extends beyond the upper end face and the lower end face respectively;

[0055] Specifically, in step S230, when conducting copper deposition metallization on the inner wall of the pressure hole 11, the upper end face and the lower end face of the insulating filler 13, it can be done simultaneously, or the inner wall of the pressure hole 11 can be copper-deposited metallized first, or the upper end face and the lower end face of the insulating filler 13 can be copper-deposited metallized first. No specific limitation is made here.

[0056] The difference between the radius of the second metal layer 15 extending from the upper end surface of the insulating filler 13 to the upper surface of the substrate 1 and the radius of the upper end surface of the insulating filler 13 is R11, and the difference between the radius of the second metal layer 15 extending from the lower end surface of the insulating filler 13 to the lower surface of the substrate 1 and the radius of the lower end surface of the insulating filler 13 is R12, 0.05mm≤R12≤0.2mm. If R11 is too small, it will not have the effect of limiting the escape of the insulating filler 13. If R11 is too large, the cost will be too high. Therefore, in this embodiment, 0.05mm≤R11≤0.2mm. Similarly, if R12 is too small, it will not have the effect of limiting the escape of the insulating filler 13. If R12 is too large, the cost will be too high. Therefore, in this embodiment, 0.05mm≤R12≤0.2mm.

[0057] Step S240: gold is plated on the first copper layer 141 and the second copper layer 151 to form a first gold-plated layer 142 and a second gold-plated layer 152 respectively.

[0058] In other embodiments, the manufacturing method of the substrate structure of the pressure sensor further includes steps such as lamination (green oil, PP insulation layer, etc.), which are well-known techniques in the art and will not be described in detail herein.

[0059] It should be noted that the embodiment of the substrate structure of the pressure sensor provided by the present invention is an embodiment of the product corresponding to the manufacturing method of the substrate structure of the pressure sensor. Therefore, the embodiment of the product provided by the present invention can be implemented in conjunction with the embodiment of the manufacturing method of the substrate structure of the pressure sensor. The relevant technical details mentioned in the embodiment of the manufacturing method of the substrate structure of the pressure sensor are still valid in the substrate structure of the pressure sensor, and the technical effects that can be achieved in the embodiment of the manufacturing method of the substrate structure of the pressure sensor can also be achieved in the embodiment of the product provided by the present invention. In order to reduce repetition, they will not be repeated. Accordingly, the relevant technical details mentioned in the embodiment of the product provided by the present invention can also be applied in the embodiment of the manufacturing method of the substrate structure of the pressure sensor.

[0060] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A substrate structure for a pressure sensor, characterized in that, it includes a substrate. The substrate is provided with a pressure hole. The pressure hole includes a straight hole and a tapered hole arranged in a first direction. The tapered hole extends from the hole edge of the straight hole, and the aperture of the tapered hole is gradually widened along the first direction; a circuit layer is laminated on the substrate; the substrate is provided with a mounting hole, and the mounting hole is filled with an insulating filler, and the pressure hole penetrates through the insulating filler; wherein, the substrate has an upper surface close to the straight hole and a lower surface opposite to the upper surface. The insulating filler has an upper end surface adjacent to the upper surface and a lower end surface adjacent to the lower surface. A second metal layer covers the upper end surface and the lower end surface, and respectively extends beyond the upper end surface and the lower end surface and is correspondingly arranged on the upper surface and the lower surface.

2. The substrate structure for a pressure sensor according to claim 1, characterized in that, the height of the tapered hole is H1, and 0.9 mm ≤ H1 ≤ 1.1 mm.

3. The substrate structure for a pressure sensor according to claim 1, characterized in that, the taper angle of the tapered hole is A, and 85° ≤ A ≤ 95°.

4. The substrate structure for a pressure sensor according to claim 1, characterized in that, gel is filled in the straight hole; or, gel is filled in the straight hole and the tapered hole.

5. The substrate structure for a pressure sensor according to claim 1, characterized in that, a first metal layer is provided on the inner wall of the pressure hole. The first metal layer includes a first copper layer and a first gold plating layer, and the first copper layer and the first gold plating layer are sequentially arranged on the inner wall of the pressure hole.

6. The substrate structure for a pressure sensor according to claim 1, characterized in that, the insulating filler is resin; the second metal layer includes a second copper layer and a second gold plating layer, and the second copper layer and the second gold plating layer are sequentially arranged on the upper end surface and the lower end surface of the insulating filler, the upper surface and the lower surface of the substrate.

7. A pressure sensor, characterized in that, it includes the substrate structure for a pressure sensor according to any one of claims 1 to 6.

8. A manufacturing method of the substrate structure of a pressure sensor according to any one of claims 1 to 6, characterized in that, it includes: opening a mounting hole in the substrate and filling it with an insulating filler; after the insulating filler solidifies, opening a pressure hole in the insulating filler; performing electroless copper plating metallization on the inner wall of the pressure hole, the upper end surface and the lower end surface of the insulating filler to respectively form a first copper layer and a second copper layer, and the second copper layer covers the upper end surface and the lower end surface and respectively extends beyond the upper end surface and the lower end surface; performing gold plating on the first copper layer and the second copper layer to respectively form a first gold plating layer and a second gold plating layer.

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