SEMICONDUCTOR PRESSURE SENSOR DEVICE

Abstract

A semiconductor pressure sensor device in which the shape or the structure of a connector portion can be easily changed and which has high waterproof performance. A terminal housing and a second case are engaged with each other via an engagement structure. The terminal housing and a first case are fitted with each other via a fitting structure. Thus, the first case and the second case are fixed to each other via the terminal housing. The first case is fitted in the second case. Then, the terminal housing is fitted with the first case, and the terminal housing is engaged with the second case substantially at the same time. Through such simple process, an opening portion of the first case is covered and a connector portion configured to enable external terminals to be connected to ends, located on one side, of a plurality of lead terminals is formed.

Claims

1. A semiconductor pressure sensor device comprising: a first case made of an insulating resin and including an opening portion provided in one surface, a bottom wall portion opposing the opening portion, a peripheral wall portion integrally provided with the bottom wall portion, and a cylindrical body projecting in a direction away from the opening portion to form a pressure introduction port, wherein the first case houses a pressure sensor element made of a semiconductor such that a pressure introduced through the pressure introduction port acts on the pressure sensor element; a plurality of lead terminals each having a first end and a second end, wherein the first ends of the lead terminals are electrically connected to the pressure sensor element and the second ends of the lead terminals project in one direction from the peripheral wall portion of the first case; a second case made of a resin and configured to cover the opening portion of the first case, the second case including an opening portion through which the plurality of lead terminals extend when the second case slides to fit with the first case from a direction opposite to the one direction, and a groove portion with which the cylindrical body slides to fit; and a terminal housing made of a resin and attached to the first case via an engagement structure to surround the second ends of the plurality of lead terminals and to form a connector portion configured to enable external terminals to be connected to the second ends of the plurality of lead terminals, wherein: the terminal housing and the second case are engaged with each other via an engagement structure; the terminal housing and the first case are fitted with each other via a fitting structure; the engagement structure includes first to third engaged portions provided on one of the terminal housing and the second case, and first to third engaging portions provided on the other of the terminal housing and the second case to be respectively engaged with the first to third engaged portions; the first and second engaged portions are respectively provided on first and second sidewall portions of the second case that interpose the opening portion of the second case and in which the groove portion is not formed, and the third engaged portion is provided on a fourth sidewall portion opposing a third sidewall portion in which the groove portion is formed; the terminal housing includes first to fourth opposing sidewall portions fitted in the opening portion of the second case and respectively opposing the first to fourth sidewall portions; the first and second engaging portions are provided on the first and second opposing sidewall portions of the terminal housing, and the third engaging portion is provided on the fourth opposing sidewall portion; the first and second sidewall portions each have a flexible structure; the first and second engaged portions are each formed of a recess or a hole; the third engaged portion is formed of a recess, a hole, or a stepped portion; the first and second engaging portions are each formed of a protrusion to be fitted in the recesses or the holes that form the first and second engaged portions; and the third engaging portion is formed of a protrusion to be fitted in the recess or the hole that forms the third engaged portion or a protrusion that climbs over the stepped portion to be engaged with the stepped portion.

2. A semiconductor pressure sensor device comprising: a first case made of an insulating resin and including an opening portion provided in one surface, a bottom wall portion opposing the opening portion, a peripheral wall portion integrally provided with the bottom wall portion, and a cylindrical body projecting in a direction away from the opening portion to form a pressure introduction port, wherein the first case houses a pressure sensor element made of a semiconductor such that a pressure introduced through the pressure introduction port acts on the pressure sensor element; a plurality of lead terminals each having a first end and a second end, wherein the first ends of the lead terminals are electrically connected to the pressure sensor element and the second ends of the lead terminals project in one direction from the peripheral wall portion of the first case; a second case made of a resin and configured to cover the opening portion of the first case, the second case including an opening portion through which the plurality of lead terminals extend when the second case slides to fit with the first case from a direction opposite to the one direction, and a groove portion with which the cylindrical body slides to fit; and a terminal housing made of a resin and attached to the first case via an engagement structure to surround the second ends of the plurality of lead terminals and to form a connector portion configured to enable external terminals to be connected to the second ends of the plurality of lead terminals, wherein: the terminal housing and the second case are engaged with each other via an engagement structure; and the terminal housing and the first case are fitted with each other via a fitting structure.

3. The semiconductor pressure sensor device according to claim 2, wherein the engagement structure that engages the terminal housing and the second case includes first to n-th engaged portions provided on one of the terminal housing and the second case, n being a positive integer of 2 or more, and first to n-th engaging portions provided on the other of the terminal housing and the second case to be respectively engaged with the first to n-th engaged portions.

4. The semiconductor pressure sensor device according to claim 3, wherein: the first to n-th engaged portions include a first engaged portion to a third engaged portion; the first and second engaged portions are respectively provided on first and second sidewall portions of the second case that interpose the opening portion of the second case and in which the groove portion is not formed, and the third engaged portion is provided on a fourth sidewall portion opposing a third sidewall portion in which the groove portion is formed; the terminal housing includes first to fourth opposing sidewall portions fitted in the opening portion of the second case and respectively opposing the first to fourth sidewall portions; the first to n-th engaging portions include first to third engaging portions; and the first and second engaging portions are provided on the first and second opposing sidewall portions of the terminal housing, and the third engaging portion is provided on the fourth opposing sidewall portion.

5. The semiconductor pressure sensor device according to claim 4, wherein: the first and second sidewall portions each have a flexible structure; the first and second engaged portions are each formed of a recess or a hole; the third engaged portion is formed of a recess, a hole, or a stepped portion; the first and second engaging portions are each formed of a protrusion to be fitted in the recesses or the holes that form the first and second engaged portions; and the third engaging portion is formed of a protrusion to be fitted in the recess or the hole that forms the third engaged portion or a protrusion that climbs over the stepped portion to be engaged with the stepped portion.

6. The semiconductor pressure sensor device according to claim 4, wherein the fitting structure which fits the terminal housing and the first case with each other includes first to m-th fitted portions provided on one of the terminal housing and the first case, m being a positive integer of 2 or more, and first to m-th fitting portions provided on the other of the terminal housing and the first case to be respectively fitted with the first to m-th fitted portions.

7. The semiconductor pressure sensor device according to claim 6, wherein: the first to m-th fitted portions are provided on a sidewall portion of the peripheral wall portion of the first case from which the plurality of lead terminals extend; and the first to m-th fitting portions are provided at the terminal housing to be respectively fitted with the first to m-th fitted portions.

8. The semiconductor pressure sensor device according to claim 6, wherein: the first to m-th fitted portions include first to fourth fitted portions; the first to m-th fitting portions include a first fitting portion to a fourth fitting portion; the first and second fitting portions respectively include first and second projecting portions that project along a direction in which the first case and the terminal housing are brought closer to each other, and the third and fourth fitting portions respectively include first and second wall portions that form a part of the third opposing sidewall portion; and the first and second fitted portions respectively include recesses shaped to be opened in a direction toward the terminal housing and a direction away from each other and to be fitted with the first and second fitting portions, and the third and fourth fitted portions respectively include third and fourth projecting portions that project toward the terminal housing.

9. The semiconductor pressure sensor device according to claim 1, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

10. The semiconductor pressure sensor device according to claim 7, wherein: the first to m-th fitted portions include first to fourth fitted portions; the first to m-th fitting portions include a first fitting portion to a fourth fitting portion; the first and second fitting portions respectively include first and second projecting portions that project along a direction in which the first case and the terminal housing are brought closer to each other, and the third and fourth fitting portions respectively include first and second wall portions that form a part of the third opposing sidewall portion; and the first and second fitted portions respectively include recesses shaped to be opened in a direction toward the terminal housing and a direction away from each other and to be fitted with the first and second fitting portions, and the third and fourth fitted portions respectively include third and fourth projecting portions that project toward the terminal housing.

11. The semiconductor pressure sensor device according to claim 2, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

12. The semiconductor pressure sensor device according to claim 3, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

13. The semiconductor pressure sensor device according to claim 4, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

14. The semiconductor pressure sensor device according to claim 5, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

15. The semiconductor pressure sensor device according to claim 6, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

16. The semiconductor pressure sensor device according to claim 7, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

17. The semiconductor pressure sensor device according to claim 8, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

18. The semiconductor pressure sensor device according to claim 10, wherein the opening portion of the first case is blocked by a sheet that is air permeable but not water permeable.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a perspective view of a semiconductor pressure sensor device according to the present invention, illustrating that a first case, a second case, and a terminal housing are not assembled yet.

[0021] FIG. 2 is a perspective view of the semiconductor pressure sensor device of FIG. 1 before being assembled as viewed from the direction opposite to FIG. 1.

[0022] FIG. 3 is a front view illustrating the semiconductor pressure sensor device of FIG. 1 before being assembled.

[0023] FIG. 4 is a right side view illustrating the semiconductor pressure sensor device of FIG. 1 before being assembled.

[0024] FIG. 5 is a back view illustrating the semiconductor pressure sensor device of FIG. 1 before being assembled.

[0025] FIGS. 6A, 6B, and 6C are a plan view, a front view, and a bottom view, respectively, illustrating the semiconductor pressure sensor device of FIG. 1 after being assembled.

[0026] FIG. 7 is a right side view illustrating the semiconductor pressure sensor device of FIG. 6.

[0027] FIGS. 8A and 8B are a back view and a sectional view taken along line A-A of FIG. 6C, respectively, of the semiconductor pressure sensor device of FIG. 6.

[0028] FIG. 9 illustrates an additional waterproof structure.

[0029] FIG. 10 illustrates the configuration of a semiconductor pressure sensor device according to the related art.

DESCRIPTION OF EMBODIMENTS

[0030] A semiconductor pressure sensor device according to an embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 8 illustrate a semiconductor pressure sensor device according to an embodiment of the present invention. The semiconductor pressure sensor device according to the illustrated embodiment includes a first case 1, lead terminals 3, a second case 5, and a terminal housing 7.

[0031] The first case 1 has a generally rectangular parallelepiped shape, and includes an opening portion 13 formed in the upper surface, a bottom wall portion 15 opposing the opening portion 13, and a peripheral wall portion 17 with four surfaces integrally provided with the bottom wall portion 15. The first case 1 further includes a cylindrical body 21 projecting in a direction away from the bottom wall portion 15 to form a pressure introduction port 19.

[0032] As well illustrated in FIG. 8B, a pressure sensor element constituted of a semiconductor is mounted on a circuit substrate 25, and housed in the first case 1. The pressure sensor element 23 is housed in the first case 1 which is made of an insulating resin such that an external pressure introduced through the pressure introduction port 19 acts on the pressure sensor element 23. That is, when the external pressure acts on a diaphragm of the pressure sensor element 23 through the pressure introduction port 19, the diaphragm is deformed to vary the resistance value of a resistance element, and variations in resistance value are detected by a resistance bridge circuit to detect the pressure.

[0033] A fluid passed through the pressure introduction port 19, for example, water is subjected to pressure detection. Fluctuations in level of water in a tank can be monitored by disposing underwater the pressure introduction port 19 of the semiconductor pressure sensor device according to the embodiment and detecting the magnitude of the pressure.

[0034] An electrical signal that represents the pressure is output by the lead terminals 3. First ends of the lead terminals 3 are electrically connected to the pressure sensor element 23. Second ends of the lead terminal 3 project in one direction from one surface of the peripheral wall portions 17 of the first case 1.

[0035] The second case 5, which is made of an insulating resin, includes an opening portion 27 and a groove portion 29. Three lead terminals 3 extend through the opening portion 27 when the second case 5 slides to fit with the first case 1 from the direction opposite to one direction (the direction of projection of the lead terminals 3) . The cylindrical body 21 of the first case 1 slides to fit with the groove portion 29. The second case 5 covers the opening portion 13 of the first case 1. That is, the inner surface of the second case 5 is formed to be complementary to the outer shape of the first case 1 except for the cylindrical body 21. With the second case 5 configured in this way, the groove portion 29 with which the cylindrical body 21 slides to fit and the wall surface of the first case 1 completely oppose each other even if the semiconductor pressure sensor is installed with the cylindrical body 21 directed upward, thereby preventing water from directly entering the first case through the groove portion 29. Flanges 33, 33 project from side surfaces of the second case opposing each other. The flanges 33 and 33 allow the semiconductor pressure sensor device to be attached onto a flat surface using bolts or screws.

[0036] The terminal housing 7, which is made of a resin, is attached to the first case 1 to surround the second ends of the three lead terminals 3, and to form a connector portion 35 configured to enable external terminals to be connected to the second ends of the three lead terminals 3. To this end, the terminal housing 7 is formed to constitute a connector shape according to a predetermined standard together with the second ends of the lead terminals 3.

[0037] In the semiconductor pressure sensor device according to the embodiment, the terminal housing 7 and the second case 5 are engaged with each other via an engagement structure (9a.sub.1 to 9a.sub.3 and 9b.sub.1 to 9b.sub.3), and the terminal housing 7 and the first case 1 are fitted with each other via a fitting structure (11a.sub.1, 11a.sub.2, 11b.sub.1, 11b.sub.2, 18a.sub.1, 18a.sub.2, 18b.sub.1, and 18b.sub.2). As a result, most of the clearance formed between the first case 1 and the second case 5 which are fitted with each other is covered by the terminal housing 7, thereby preventing entry of water through the clearance.

[0038] As well illustrated in FIGS. 1 to 5, a plurality of engaged portions of the second case 5 of the semiconductor pressure sensor device according to the embodiment include a first engaged portion 9a.sub.1 to a third engaged portion 9a.sub.3. The first engaged portion 9a.sub.1 and the second engaged portion 9a.sub.2 are provided in the first sidewall portion 37 and the second sidewall portion 39 which interpose the opening portion 27 of the second case 5 and in which the groove portion 29 is not formed. The third engaged portion 9a.sub.3 is provided in the fourth sidewall portion 43 opposing the third sidewall portion 41 in which the groove portion 29 is formed. The terminal housing 7 has a first opposing sidewall portion 45 to a fourth opposing sidewall portion 51 to be fitted in the opening portion 27 of the second case 5 to oppose the first sidewall portion 37 to the fourth sidewall portion 43, respectively. The first engaging portion 9b.sub.1 to the third engaging portion 9b.sub.3 are provided on the first opposing sidewall portion 45 and the second opposing sidewall portion 47 of the terminal housing 7. The third engaging portion 9b.sub.3 is provided on the fourth opposing sidewall portion 51.

[0039] In the semiconductor pressure sensor device according to the embodiment, at least the first sidewall portion 37 and the second sidewall portion 39 have a flexible structure. In order to appropriately adjust the flexibility of the first sidewall portion 37 and the second sidewall portion 39 in the vicinity of the first engaged portion 9a.sub.1 and the second engaged portion 9a.sub.2, the first sidewall portion 37 and the second sidewall portion 39 are each provided with a slit 53 that extends from the opening portion 27 to pass near the first engaged portion 9a.sub.1 and the second engaged portion 9a.sub.2. The first engaged portion 9a.sub.1 and the second engaged portion 9a.sub.2 are each formed of a hole. The third engaged portion 9a.sub.3 is formed of a stepped portion. The first engaging portion 9b.sub.1 and the second engaging portion 9b.sub.2 are each formed of a protrusion to be fitted in a hole. The third engaging portion 9b.sub.3 is formed of a protrusion that climbs over a stepped portion to be engaged with the stepped portion.

[0040] With such an engagement structure, when the second case 5 and the terminal housing 7 are moved in the direction toward each other while retaining the attitude illustrated in the figures, the engaged portions (9a.sub.1 to 9a.sub.3) and the engaging portions (9b.sub.1 to 9b.sub.3) are engaged to be fixed to each other.

[0041] Further, in the semiconductor pressure sensor device according to the embodiment, the sidewall portion 17a, from which the three lead terminals 3 project, of the peripheral wall portion 17 of the first case 1 is provided with the first engaged portion 11a.sub.1, the second engaged portion 11a.sub.2, the third fitted portion 18a.sub.1, and the fourth fitted portion 18a.sub.2, and the terminal housing 7 is provided with the first fitting portion 11b.sub.1, the second fitting portion 11b.sub.2, the third fitting portion 18b.sub.1, and the fourth fitting portion 18b.sub.2 to be fitted with the first fitted portion 11a.sub.1, the second fitted portion 11a.sub.2, the third fitted portion 18a.sub.1, and the fourth fitted portion 18a.sub.2, respectively. The first fitting portion 11b.sub.1 and the second fitting portion 11a.sub.2 are each a projecting portion that projects along a direction in which the first case 1 and the terminal housing 7 are brought closer to each other. The third fitting portion 18b.sub.1 and the fourth fitting portion 18b.sub.2 each include a wall portion that forms apart of the third opposing wall portion 49. The first fitted portion 11a.sub.i and the second fitted portion 11a.sub.2 respectively include recesses shaped to be opened in a direction toward the terminal housing 7 and a direction away from each other and to be fitted with the first fitting portion 11b.sub.1 and the second fitting portion 11a.sub.2. The third fitted portion 18a.sub.1 and the fourth fitted portion 18a.sub.2 respectively include projecting portions that project toward the terminal housing 7.

[0042] With such a fitting structure, when the first case 1 and the terminal housing 7 are moved in a direction toward each other while retaining the attitude illustrated in the figures, the first fitting portion 11b.sub.1, the second fitting portion 11b.sub.2, the third fitting portion 18b.sub.1, and the fourth fitting portion 18b.sub.2 are fitted with the first fitted portion 11a.sub.1, the second fitted portion 11a.sub.2, the third fitted portion 18a.sub.1, and the fourth fitted portion 18a.sub.2, respectively, thereby allowing the first case 1 and the terminal housing 7 to be positioned with respect to each other even if dimensional accuracy of the components varies to some extent. The first case 1 and the second case 5 are fixed to each other with the terminal housing 7 interposed therebetween when the engaged portions (9a.sub.1 to 9a.sub.3) and the engaging portions (9b.sub.1 to 9b.sub.3) are engaged with each other.

[0043] According to the semiconductor pressure sensor device of the embodiment, by moving the second case 5 which houses the first case 1 in a direction toward the terminal housing 7 in the process of assembling the semiconductor pressure sensor device, the terminal housing 7 and the first case 1 are positioned with respect to each other by the fitting structure, the terminal housing 7 and the second case 5 are fixed to each other by the engagement structure at the same time, and then the first case 1 and the second case 5 are fixed to each other using the terminal housing 7.

[0044] Thus, an assembly is completed through a simple process. The opening portion of the first case 1 is covered and the connector portion 35 configured to enable external terminals to be connected to the second ends of the three lead terminals is formed as illustrated in FIGS. 6 to 8. In the assembling process, the housing of the first case 1 is slid to be fitted in the second case 5. Then, the terminal housing 7 is fitted with the first case 1 and at the same time the terminal housing 7 is engaged with the second case 5.

[0045] The embodiment described above is an example of preferred embodiments. When generally described, the engagement structure includes first to n-th engaged portions provided on one of the terminal housing 7 and the second case 5, n being a positive integer of 2 or more, and first to n-th engaging portions provided on the other of the terminal housing 7 and the second case 5 to be respectively engaged with the first to n-th engaged portions. The fitting structure includes first to m-th fitted portions provided on one of the terminal housing 7 and the first case 1, m being a positive integer of 2 or more, and first to m-th fitting portions provided on the other of the terminal housing 7 and the first case 1 to be respectively fitted with the first to m-th fitted portions.

[0046] In the semiconductor pressure sensor device according to the embodiment, the opening portion can be closed and the connector can be formed merely by sliding the first case 1, the second case 5, and the terminal housing 7 with respect to each other in the final assembling process. More complicated work such as welding and soldering is not required. Hence, it is possible to reduce the number of processes, and to simplify the processes.

[0047] As illustrated in FIG. 9, the opening portion 13 of the first case 1 may be covered by a sheet 14 that is air permeable but not water permeable. An air-permeable waterproof sheet formed of a porous resin material or the like can be used as such a sheet. Providing such a sheet can further enhance the waterproof property. In FIG. 9, internal components are not illustrated for simplification.

INDUSTRIAL APPLICABILITY

[0048] According to the present invention, the terminal housing 7 and the first case 1 are separately formed. Thus, the structure of the connector can be changed by changing one of the terminal housing 7 and the first case 1 in most cases. Thus, the shape or the structure of the connector portion can be changed easily.

DESCRIPTION OF REFERENCE NUMERALS

[0049] 1 first case [0050] 3 lead terminal [0051] 5 second case [0052] 7 terminal housing [0053] 9a.sub.1 to 9a.sub.3 first engaged portion to third engaged portion [0054] 9b.sub.1 to 9b.sub.3 first engaging portion to third engaging portion [0055] 11a.sub.1 first fitted portion [0056] 11a.sub.2 second fitted portion [0057] 11b.sub.1 first fitting portion [0058] 11b.sub.2 second fitting portion [0059] 18a.sub.1 third fitted portion [0060] 18a.sub.2 fourth fitted portion [0061] 18b.sub.1 third fitting portion [0062] 18b.sub.2 fourth fitting portion [0063] 13 opening portion [0064] 15 bottom wall portion [0065] 17 sidewall portion [0066] 19 pressure introduction port [0067] 21 cylindrical body [0068] 23 pressure sensor element [0069] 25 circuit substrate [0070] 27 opening portion [0071] 29 groove portion [0072] 33 flange [0073] 35 connector portion [0074] 37 first sidewall portion [0075] 39 second sidewall portion [0076] 41 third sidewall portion [0077] 43 fourth sidewall portion [0078] 45 first opposing sidewall portion [0079] 47 second opposing sidewall portion [0080] 49 third opposing sidewall portion [0081] 51 fourth opposing sidewall portion [0082] 53 slit