JP2009077211A - Chassis, and low-noise block-down converter having the chassis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chassis so designed as to prevent the intrusion of a sealer and to cut off radio waves, and to provide a low-noise block-down converter. <P>SOLUTION: In an LNB1, a circuit substrate 7 is disposed in the chassis 3. The chassis 3 comprises a chassis body 5 and a cover 13. The chassis body 5 is bottomed, and has a bottom 5a and a wall 5b at a chassis body side. The cover 13 has a cover body 13a for covering the inside of the chassis body 5 and a cover-side wall 13b. In the chassis body side wall 5b, a groove-shaped cover receiving portion 15 for receiving the lower end of the cover-side wall 13b is formed along the outer periphery. To each cover receiving portion 15, a sealer 6 is applied in a state of receiving the lower end of each cover-side wall 13b. On the inner wall surface of the chassis body side wall 5b, a sealer receiving portion 16 for receiving the intruded sealer 6 is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chassis and a low noise block down converter including the same, and more particularly to a chassis used in a satellite broadcast receiver and a low noise block down converter including such a chassis.

  A low-noise block down converter (hereinafter referred to as “LNB”) is generally widely used as one of the components of a satellite broadcasting receiver, together with a parabolic antenna, a receiver, and the like. The LNB includes an aluminum die-cast chassis main body (hereinafter simply referred to as “chassis main body”) mainly composed of aluminum, a circuit board, an aluminum die-cast frame, a cover, a horn cap, and a cabinet.

  The structure of the LNB will be specifically described. As shown in FIG. 6, a predetermined circuit component 109 for receiving and processing a satellite broadcast signal is mounted on one surface of the circuit board 107 of the LNB 101. Further, a ground line 108a is formed on one surface of the circuit board 107, and a ground pattern 108b is formed on the other surface. The chassis main body 105 has a bottom, and the circuit board 107 is disposed in the chassis main body 105 so that the ground pattern 108 b is in contact with the bottom surface of the chassis main body 105. Above the circuit board 107, an aluminum die-cast frame 111 is disposed so as to cover the circuit board 107 and to be in contact with the earth line 108a. The frame 111 and the circuit board 107 are fixed to the chassis main body 105 with screws (not shown) or the like.

A cover 113 is attached as a lid above the chassis body 105 so as to seal a space for accommodating the circuit board 107 and the like mounted on the chassis body 105. The cover 113 is made of a material mainly composed of aluminum or iron, for example. A groove-like cover receiving portion 115 that receives the lower end portion of the cover 113 is formed on the side surface of the chassis main body 105 along the outer periphery. In order to maintain airtightness in the chassis 103, the sealant 106 is applied to the cover receiving portion 115 in a state where the lower end portion of the cover 113 is received. As the sealant 106, for example, a material mainly composed of silicon is used. The conventional LNB 101 is configured as described above. Examples of documents disclosing LNB include, for example, Patent Document 1 and Patent Document 2.
Japanese Patent Laid-Open No. 11-289174 JP 2003-37510 A

  However, the conventional LNB 101 has the following problems. As described above, in the LNB 101, the sealing agent 106 is applied to the cover receiving portion 115 in order to keep the inside of the chassis 103 airtight. However, there is a possibility that the sealing agent 106 may enter the inside of the cover 113 through a gap between the lower end portion of the cover 113 and the cover receiving portion 115, for example, by a capillary phenomenon.

  Further, the surface of the chassis main body 105 or the like has irregularities having a size of 0.1 mm or less. For this reason, unnecessary radio waves may enter from the outside of the chassis 103 to the inside, or unnecessary radio waves may be output from the inside of the chassis 103 to the outside.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a chassis that can improve the above-mentioned supposed problems. Another object is to provide such a chassis. A low noise block downconverter is provided.

  The chassis according to the present invention includes a bottomed chassis main body, a cover portion, a sealant, and a pocket portion. A predetermined circuit board portion is disposed on the bottomed chassis body. The cover part is attached on the chassis body and covers the inside of the chassis body. The sealing agent is applied to the outer wall portion of the chassis main body so as to fill a gap between the chassis main body and the cover portion, and seals the inside of the chassis main body. The pocket portion is provided inside the chassis main body, captures the sealing agent flowing into the chassis main body, and prevents the sealing agent from flowing into the circuit board portion.

  According to this configuration, the pocket portion is provided inside the chassis main body. As a result, even if the sealing agent applied to the outer wall surface of the chassis body flows into the inside of the chassis body due to capillary action from the gap between the cover part and the chassis body, it is caught in the pocket part, The sealant can be prevented from flowing into the bottom of the chassis body. As a result, it is possible to prevent the sealing agent from flowing into the portion of the circuit board portion disposed in the chassis main body, and to prevent the electrical performance of the circuit board portion from being adversely affected.

  More specifically, the cover part includes a cover main body that covers the inside of the chassis main body, and a cover side wall that is erected along the outer periphery of the cover main body. The chassis main body is mounted with the circuit board part. A bottom portion, a chassis main body side wall portion erected along the outer periphery of the bottom portion, a cover receiving portion that is formed on the chassis main body side wall portion, receives the cover side wall portion from below, supports the cover portion, and is filled with a sealant Are preferably included.

  Further, specifically, the pocket portion is provided on the inner wall surface of the chassis main body side wall portion, and has a sealing agent receiving portion opened upward so as to catch the sealing agent flowing over the upper end of the chassis main body side wall portion. It is preferable to include.

  In addition, a frame portion that holds a circuit board portion placed on the bottom portion is provided, the frame portion is opposed to the inner wall surface of the chassis main body side wall portion with a space therebetween, includes a frame side wall portion that contacts the bottom portion, and a pocket portion. Preferably includes a gap between the chassis body side wall and the frame side wall.

  In this case, unnecessary radio waves enter the inside of the chassis body from the outside of the chassis main body and affect the circuit board portion due to the frame side wall, or unnecessary radio waves go out of the chassis main body from the circuit board portion. This can be suppressed.

  In order to more reliably prevent radio waves from entering and exiting, a chassis body partition wall portion is provided between the circuit board portion and the chassis body side wall portion and formed at the bottom so as to sandwich the frame side wall portion between the chassis body side wall portion. It may be. In addition, a recess that is dug down to a predetermined depth from the bottom surface to accommodate the circuit board portion may be formed in the bottom portion, and the frame side wall portion may be in contact with the bottom surface. Alternatively, a raised portion that is raised from the bottom surface to a predetermined height and on which the circuit board portion is placed may be formed on the bottom portion, and the frame side wall portion may be in contact with the bottom surface.

  In addition, a frame portion that holds the circuit board portion placed on the bottom portion is provided, and the frame portion is opposed to the inner wall surface of the chassis main body side wall portion with a space therebetween, and includes a frame side wall portion that is received by the sealant receiving portion. The pocket portion preferably includes a gap between the chassis main body side wall and the frame side wall.

  Also in this case, unnecessary radio waves enter the inside of the chassis body from the inside of the chassis main body and affect the circuit board section due to the frame side wall, or unnecessary radio waves go out of the chassis main body from the circuit board section. This can be suppressed.

  A low noise block down converter according to the present invention is a low noise block down converter including the chassis according to any one of claims 1 to 8, and a circuit for receiving and processing a satellite broadcast signal as a circuit board unit. A circuit board portion including the same is disposed on the chassis main body.

  According to this configuration, the sealing agent can be prevented from flowing into the chassis main body, and the electrical performance of the low noise block down converter can be prevented from being adversely affected. Further, it is possible to prevent unnecessary radio waves from entering the inside of the chassis body from the inside and affecting the circuit board section, or from emitting unnecessary radio waves from the circuit board section to the outside of the chassis body.

Embodiment 1
The LNB according to the first embodiment will be described. As shown in FIG. 1, in the LNB 1, a circuit board 7 that receives satellite broadcast signals is disposed inside the chassis 3. The chassis 3 includes a chassis body 5 and a cover 13. The chassis main body 5 has a bottom, and has a bottom portion 5a and a chassis main body side wall portion 5b. The chassis main body side wall 5b is erected along the edge of the bottom 5a. The cover 13 has a cover main body 13a that covers the inside of the chassis main body 5 and a cover side wall portion 13b, and is formed of, for example, a material mainly composed of aluminum or iron. The cover side wall part 13b is erected along the edge of the cover main body 13a.

  A predetermined circuit component 9 for receiving and processing a satellite broadcast signal is mounted on one surface of the circuit board 7. Further, a ground line 8a is formed on one surface of the circuit board 7, and a ground pattern 8b is formed on the other surface. The circuit board 7 is disposed in the chassis body 5 so that the ground pattern 8 b is in contact with the bottom 5 a of the chassis body 5. Above the circuit board 7, an aluminum die-cast frame 11 is disposed so as to hold the circuit board 7 and come into contact with the earth line 8a. The frame 11 and the circuit board 7 are fixed to the chassis body 5 with screws (not shown) or the like.

  The cover 13 is attached above the chassis main body 5 so as to seal a space for accommodating the circuit board 7 and the like mounted on the bottom 5a. A groove-shaped cover receiving portion 15 for receiving the lower end portion of the cover side wall portion 13b is formed along the outer periphery of the chassis main body side wall portion 5b. In order to maintain airtightness in the chassis 3, the sealant 6 is applied to the cover receiving portion 15 in a state where the lower end portion of the cover side wall portion 13 b is received. As the sealing agent 6, for example, a material mainly composed of silicon is applied. In the present LNB1, when the sealant 6 flows into the chassis main body 5, a sealant receiving portion 16 as a pocket portion for catching the inflowed sealant 6 is provided on the inner wall surface of the chassis main body side wall 5b. Yes.

  According to the LNB 1 described above, the sealing agent receiving portion 16 is formed on the inner wall surface of the chassis main body side wall portion 5b. Thus, when the sealing agent 6 is filled into the cover receiving portion 15, the chassis main body side wall portion 5b has a The sealing agent 6 applied to the outer wall surface flows into the inside of the chassis 3 by a capillary phenomenon from the gap between the cover 13 and the cover receiving portion 15, and the inflowing sealing agent 6 exceeds the upper end of the chassis body 5. Even if there exists, it can be caught by the sealing agent receiving part 16, and it can prevent that the sealing agent 6 flows into the bottom of a chassis main body. As a result, the sealing agent 6 is prevented from flowing between the bottom portion 5a of the chassis main body 5 and the ground pattern 8b of the circuit board 7, and it is possible to prevent the electrical performance of the LNB 1 from being adversely affected.

Embodiment 2
The LNB according to the second embodiment will be described. As shown in FIG. 2, the frame 11 is provided with a frame side wall portion 12 that faces the inner wall surface of the chassis main body side wall portion 5 b with a space in a state where the frame 11 is attached to the chassis main body 5. The lower end portion of the frame side wall portion 12 is in contact with the bottom portion 5 a of the chassis body 5. Further, the chassis body partition wall portion 4 is erected on the bottom portion 5a of the chassis body 5 so as to be positioned between the circuit board 7 and the chassis body sidewall portion 5b and sandwich the frame sidewall portion 12 between the chassis body sidewall portion 5b. Has been. In the LNB 1, a gap between the chassis main body side wall 5 b and the frame side wall 12 serves as a pocket 17 that captures the sealing agent 6. In addition, about the structure other than this, about the structure similar to LNB shown in FIG. 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  According to LNB1 mentioned above, the clearance gap between the chassis main body side wall part 5b and the frame side wall part 12 becomes the pocket part 17 which catches the sealing agent 6. FIG. Thereby, when the sealing agent 6 is filled into the cover receiving portion 15, the sealing agent 6 applied to the outer wall surface of the chassis main body side wall portion 5 b is caused by the capillary phenomenon from the gap between the cover 13 and the cover receiving portion 15. Even if the inflowing sealant 6 exceeds the upper end of the chassis body 5, it is caught by the pocket portion 17 and prevents the sealant 6 from flowing into the bottom of the chassis body 5. can do. As a result, the sealing agent 6 is prevented from flowing between the bottom portion 5a of the chassis main body 5 and the ground pattern 8b of the circuit board 7, and it is possible to prevent the electrical performance of the LNB 1 from being adversely affected.

  Further, the periphery of the circuit board 7 is surrounded by the frame side wall portion 12 and the chassis main body partition wall portion 4. As a result, it is possible to prevent unnecessary radio waves from entering the inside of the chassis 3 from inside and affecting the circuit board 7 or from emitting unnecessary radio waves from the circuit board 7 to the outside of the chassis 103. .

Embodiment 3
The LNB according to the third embodiment will be described. As shown in FIG. 3, the bottom 5a of the chassis body 5 is formed with a recess 5c dug down to a predetermined depth from the bottom. The circuit board 7 is accommodated in the recess 5c. The frame 11 is provided with a frame side wall portion 12 which is opposed to the inner wall surface of the chassis main body side wall portion 5b with a space in a state where the frame 11 is attached to the chassis main body 5. The lower end portion of the frame side wall portion 12 contacts the bottom surface of the bottom portion 5 a of the chassis body 5. A gap between the chassis main body side wall portion 5b and the frame side wall portion 12 serves as a pocket portion 17 for catching the sealing agent 6. In addition, about the structure other than this, about the structure similar to LNB shown in FIG. 2 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  According to LNB1 mentioned above, the clearance gap between the chassis main body side wall part 5b and the frame side wall part 12 becomes the pocket part 17 which catches the sealing agent 6. FIG. Thereby, when the sealing agent 6 is filled into the cover receiving portion 15, the sealing agent 6 applied to the outer wall surface of the chassis main body side wall portion 5 b is caused by the capillary phenomenon from the gap between the cover 13 and the cover receiving portion 15. Even if the inflowing sealant 6 exceeds the upper end of the chassis body 5, it is caught by the pocket portion 17 and prevents the sealant 6 from flowing into the bottom of the chassis body 5. can do. As a result, the sealing agent 6 is prevented from flowing between the bottom portion 5a of the chassis main body 5 and the ground pattern 8b of the circuit board 7, and it is possible to prevent the electrical performance of the LNB 1 from being adversely affected.

  In addition, the circuit board 7 is disposed so as to be embedded in the bottom portion 5 a of the chassis body 5, and the periphery of the circuit board 7 is surrounded by the frame side wall portion 12. As a result, it is possible to prevent unnecessary radio waves from entering the inside of the chassis 3 from inside and affecting the circuit board 7 or from emitting unnecessary radio waves from the circuit board 7 to the outside of the chassis 103. .

Embodiment 4
The LNB according to the fourth embodiment will be described. As shown in FIG. 4, a raised portion 5 d raised from the bottom surface to a predetermined height is formed on the bottom portion 5 a of the chassis body 5. The circuit board 7 is disposed on the raised portion 5d. The frame 11 is provided with a frame side wall portion 12 which is opposed to the inner wall surface of the chassis main body side wall portion 5b with a space in a state where the frame 11 is attached to the chassis main body 5. The frame side wall portion 12 is in contact with the bottom surface of the bottom portion 5a of the chassis main body 5 so as to isolate the circuit board 7 and the raised portion 8b from the chassis main body side wall portion 5b. In addition, about the structure other than this, about the structure similar to LNB shown in FIG. 2 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  According to LNB1 mentioned above, the clearance gap between the chassis main body side wall part 5b and the frame side wall part 12 becomes the pocket part 17 which catches the sealing agent 6. FIG. Thereby, when the sealing agent 6 is filled into the cover receiving portion 15, the sealing agent 6 applied to the outer wall surface of the chassis main body side wall portion 5 b is caused by the capillary phenomenon from the gap between the cover 13 and the cover receiving portion 15. Even if the inflowing sealant 6 exceeds the upper end of the chassis body 5, it is caught by the pocket portion 17 and prevents the sealant 6 from flowing into the bottom of the chassis body 5. can do. Moreover, the circuit board 7 is disposed on the raised portion 5d raised to a predetermined height from the bottom surface. As a result, the sealing agent 6 is surely prevented from flowing between the bottom portion 5a of the chassis body 5 and the ground pattern 8b of the circuit board 7, thereby preventing the electrical performance of the LNB 1 from being adversely affected. it can.

  Further, the periphery of the circuit board 7 is surrounded by the frame side wall portion 12. As a result, it is possible to prevent unnecessary radio waves from entering the inside of the chassis 3 from inside and affecting the circuit board 7 or from emitting unnecessary radio waves from the circuit board 7 to the outside of the chassis 103. .

Embodiment 5
The LNB according to the fifth embodiment will be described. As shown in FIG. 5, a sealing agent receiving portion 16 for catching the sealing agent 6 is provided on the inner wall surface of the chassis main body side wall portion 5b. The frame 11 is provided with a frame side wall portion 12 which is opposed to the inner wall surface of the chassis main body side wall portion 5b with a space and is received by the sealant receiving portion 16 in a state where the frame 11 is attached to the chassis main body 5. Yes. In addition, about the structure other than this, about the structure similar to LNB shown in FIG. 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  According to the above-described LNB 1, the gap between the frame side wall portion 12 received in the sealing agent receiving portion 16 and the chassis main body side wall portion 5 b becomes a substantial pocket portion 17 that captures the sealing agent 6. Thereby, when the sealing agent 6 is filled into the cover receiving portion 15, the sealing agent 6 applied to the outer wall surface of the chassis main body side wall portion 5 b is caused by the capillary phenomenon from the gap between the cover 13 and the cover receiving portion 15. Even if the inflowing sealant 6 exceeds the upper end of the chassis body 5, it is caught by the pocket portion 17 and prevents the sealant 6 from flowing into the bottom of the chassis body 5. can do. As a result, the sealing agent 6 is prevented from flowing between the bottom portion 5a of the chassis main body 5 and the ground pattern 8b of the circuit board 7, and it is possible to prevent the electrical performance of the LNB 1 from being adversely affected.

  In each of the above-described embodiments, the LNB has been described as an example. However, in addition to the LNB, the chassis is required to prevent unnecessary radio waves from entering the inside from the outside of the chassis, The present invention can be applied as a chassis of an electronic device that is required to suppress unnecessary radio waves from going outside.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of LNB which concerns on Embodiment 1 of this invention. It is a fragmentary sectional view of LNB concerning Embodiment 2 of the present invention. It is a fragmentary sectional view of LNB concerning Embodiment 3 of the present invention. It is a fragmentary sectional view of LNB concerning Embodiment 4 of the present invention. It is a fragmentary sectional view of LNB concerning Embodiment 5 of the present invention. It is sectional drawing of the conventional LNB.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 LNB, 3 Chassis, 4 Chassis main body side wall part, 5 Chassis main body, 5a Chassis main body bottom part, 5b Chassis main body side wall part, 5c Recessed part, 5d Raised part, 6 Sealant, 7 Circuit board, 8a Ground line, 8b Ground pattern, 9 Circuit board component, 11 frame, 12 frame side wall part, 13 cover, 13a cover body, 13b cover side wall part, 15 cover receiving part, 16 sealant receiving part, 17 pocket part.

Claims (9)

A bottomed chassis body on which a predetermined circuit board portion is disposed;
A cover part that is mounted on the chassis body and covers the interior of the chassis body;
A sealing agent that is applied to an outer wall portion of the chassis body so as to fill a gap between the chassis body and the cover portion, and seals the inside of the chassis body;
A chassis provided with a pocket portion provided inside the chassis main body and capturing the sealing agent flowing into the chassis main body and preventing the sealing agent from flowing into the circuit board portion. The cover part is
A cover body covering the inside of the chassis body;
A cover side wall portion erected along the outer periphery of the cover body,
The chassis body is
A bottom part on which the circuit board part is placed;
A chassis body side wall erected along the outer periphery of the bottom;
The chassis according to claim 1, further comprising: a cover receiving portion that is formed on the chassis main body side wall portion, receives the cover side wall portion from below, supports the cover portion, and is filled with the sealant.   The said pocket part is provided in the inner wall surface of the said chassis main body side wall part, and contains the sealing agent receiving part opened upwards so that the said sealing agent flowing over the upper end of the said chassis main body side wall part might be caught. 2. The chassis according to 2. A frame portion for holding the circuit board portion placed on the bottom portion;
The frame part includes a frame side wall part that is opposed to the inner wall surface of the chassis main body side wall part at a distance and contacts the bottom part,
The chassis according to claim 2 or 3, wherein the pocket portion includes a gap between the chassis main body side wall portion and the frame side wall portion.   The chassis main body partition part formed in the said bottom part so that it may be located between the said circuit board part and the said chassis main body side wall part, and may pinch | interpose the said frame side wall part with the said chassis main body side wall part. Chassis. The bottom portion is formed with a recess that is dug down to a predetermined depth from the bottom surface and accommodates the circuit board portion,
The chassis according to claim 4, wherein the frame side wall portion contacts the bottom surface. The bottom portion is formed with a raised portion on which the circuit board portion is placed by being raised to a predetermined height from the bottom surface,
The chassis according to claim 4, wherein the frame side wall portion contacts the bottom surface. A frame portion for holding the circuit board portion placed on the bottom portion;
The frame portion includes a frame side wall portion that faces the inner wall surface of the chassis main body side wall portion with a space therebetween and is received by the sealant receiving portion,
The chassis according to claim 3, wherein the pocket portion includes a gap between the chassis main body side wall portion and the frame side wall portion. A low noise block down converter comprising the chassis according to claim 1,
A low noise block down converter in which a circuit board part including a circuit for receiving and processing a satellite broadcast signal is disposed in the chassis body as the circuit board part.

Images