JP2014239089A - Electronic circuit and heat sink attachment detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit capable of easily detecting whether or not a heat sink is properly attached to a component or a housing, and a heat sink attachment detection method.SOLUTION: An electronic circuit includes: a conductive heat sink 20 capable of being connected to a component 11 and a grounding member 30; a substrate 10 having heat sink connection parts 15 arranged at positions where the heat sink connection parts 15 can be connected to the heat sink 20 when the heat sink 20 is attached to the component 11; a voltage application part 12 for applying a voltage to at least one of the heat sink connection parts 15; an electric potential detection part 17 for detecting electric potentials of the heat sink connection parts; and a connection determination part 18 for determining whether or not the heat sink 20 is connected to the heat sink connection parts 15 and the grounding member 30 on the basis of the result of electric potential detection by the electric potential detection part 17 and outputting the determination result.

Description

  The present invention relates to an electronic circuit that detects mounting of a heat sink, and a heat sink mounting detection method.

  Conventionally, a heat sink has been used in order to promote heat dissipation of a component that generates heat. The heat sink is attached to a component that generates heat, and the heat sink dissipates heat, thereby lowering the temperature of the component. For this heat sink, a metal such as aluminum or copper having a high thermal conductivity is generally used. A metal heat sink not only lowers the temperature of components, but also grounds the heat sink to a housing or the like, thereby eliminating the effects of static electricity and magnetism.

  For example, the heat dissipating structure of Patent Document 1 dissipates heat by conducting heat to a wall surface of a shield case via a coil spring-shaped heat sink when a heating element such as an integrated circuit is mounted on a printed wiring board and mounted on the shield case. The effect is improved.

  The cooling device for an LSI package disclosed in Patent Document 2 is generated from an LSI package by installing a heat-conductive heat sink surrounded by a ferrite core on a top surface of the LSI package via a rubber sheet having excellent heat conductivity. Suppresses both heat and radiation noise.

  The heat sink disclosed in Patent Document 3 smoothly connects the first contact portion in contact with the electric element, the second contact portion in contact with the bottom of the housing, and the first and second contact portions in a blowing direction by the exhaust fan. By making the bent portion convex along, the entire heat source is cooled efficiently while the heat source is focused on cooling.

JP-A-8-18263 JP-A-10-173113 JP 2010-203786 A

  However, even if the above-described conventional technology is used, there is a problem that the heat dissipation function and the static electricity and magnetism removal function cannot be sufficiently exhibited unless the heat sink and the components, the case, and the like are properly mounted. For example, if the heat sink is not properly attached to an IC (Integrated Circuit), heat dissipation by the heat sink becomes insufficient, and the IC may run out of heat, causing a risk of breakage or ignition. Further, if the heat sink and the housing are not in proper contact, there arises a problem that noise generated from the components cannot be shielded completely.

  An object of the present invention is to provide an electronic circuit capable of easily detecting whether or not a heat sink is properly mounted on a component or a casing, and a heat sink mounting detection method.

  An electronic circuit according to the present invention includes a conductive heat sink that can be connected to a component and a ground member, a substrate having a heat sink connection portion disposed at a position where the heat sink can be connected to the heat sink when the heat sink is attached to the component, and a heat sink. A voltage application unit that applies a predetermined voltage to at least one of the connection units, a potential detection unit that detects a potential of the heat sink connection unit, and a heat sink connected to the heat sink connection unit and ground based on the potential detection result in the potential detection unit A connection determination unit that determines whether or not the member is connected and outputs a determination result.

  In the electronic circuit according to the present invention, the heat sink connection portion includes a first heat sink connection portion to which a predetermined voltage is applied and a second heat sink connection portion to which the predetermined voltage is not applied.

  The heat sink attachment detection method of the present invention is a heat sink attachment detection method in an electronic circuit, comprising: a heat sink attachment step of attaching a heat sink to a component; and connecting the heat sink to a heat sink connection portion and a ground member; The heat sink is connected to the heat sink connection portion and the grounding member based on a voltage application step for applying a predetermined voltage to one, a potential detection step for detecting the potential of the heat sink connection portion, and a potential detection result in the potential detection step. A connection determination step for determining whether or not the connection determination step, and an output step for outputting a determination result in the connection determination step.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic circuit which can detect easily whether the heat sink is suitably mounted | worn with components and a housing | casing, and a heat sink mounting detection method can be provided.

1 is a plan view showing an electronic circuit 1 according to a first embodiment of the present invention. 2 is a side view showing a heat sink connection structure in the electronic circuit 1. FIG. It is a top view which shows the electronic circuit 2 which concerns on the 2nd Embodiment of this invention. 3 is a determination table for determining a connection state of a heat sink in the electronic circuit 2;

(First embodiment)
Hereinafter, an electronic circuit according to an embodiment of the present invention will be described. Hereinafter, as an example, a case where the component to which the heat sink is attached is an IC (Integrated Circuit) will be described. The IC includes a central processing unit (CPU), a system-on-a-chip (SOC), a digital signal processor (DSP), a microcomputer, and the like. The electronic circuit of the present invention can also be applied when a heat sink is attached to a component other than an IC.

  FIG. 1 is a plan view showing an electronic circuit 1 according to a first embodiment of the present invention. As shown in FIG. 1, the electronic circuit 1 of the present invention includes a substrate 10, a component 11 such as an IC mounted on the substrate 10, and a heat sink 20 mounted on the component 11. The heat sink 20 is mounted on the component 11 for the purpose of radiating heat from the component 11, and is also connected to a ground member 30 such as a casing or a shield case maintained at a ground potential for the purpose of removing static electricity or magnetism.

  The substrate 10 is provided with mounting holes 14 for fixing the heat sink 20 to the component 11 in a state where the heat sink 20 is mounted. At least one of the mounting holes 14 is provided with a heat sink connection portion 15 that is electrically connected to the heat sink 20 by being connected to the heat sink 20. In addition, a predetermined voltage is applied to at least one of the heat sink connection portions 15 from the power source that is the voltage application portion 12 via the resistor 13.

  The substrate 10 further includes a potential detection unit 17 that detects the voltage level of the heat sink connection unit 15 and a connection determination unit 18 that determines the connection state of the heat sink 20 based on the detection result of the potential detection unit 17. The voltage application unit 12, the potential detection unit 17, and the connection determination unit 18 included in the substrate 10 may be provided on a substrate different from the substrate 10.

  FIG. 2 is a side view showing a connection state between the heat sink 20, the component 11, and the grounding member 30.

  The heat sink 20 connects the base portion 21 disposed opposite to the substrate 10 and the component 11, the radiation fins 22 provided in parallel to each other on the base portion 21, and the heat sink 20 to a grounding member 30 such as a housing. For this purpose, a grounding member connecting portion 23 is provided. In addition, the base portion 21 is provided with a mounting hole 24 corresponding to the mounting hole 14 of the substrate 10, and by inserting a non-conductive mounting pin 25 into the mounting hole 14 and the mounting hole 24, the heat sink 20 is attached. It can be fixed to the substrate 10 while being mounted on the component 11.

  At this time, a metal gasket 26 is disposed in the heat sink connection portion 15 provided in a part of the mounting hole 14 of the substrate 10, and the heat sink connection portion 15 and the base portion 21 are connected via the metal gasket 26. On the other hand, a metal gasket 27 is disposed on the ground member connecting portion 23 of the heat sink 20, and the ground member connecting portion 23 is connected via the metal gasket 27 to a ground member 30 maintained at a ground potential such as a housing.

  The base part 21, the radiation fins 22, and the grounding member connection part 23 constituting the heat sink 20 are formed of a metal material having excellent thermal conductivity and conductivity such as aluminum and copper, for example. Further, the metal gasket 26 and the metal gasket 27 are connection members having conductivity and elasticity, and are made of a metal material.

  For this reason, when the heat sink 20 is appropriately attached to the component 11, the heat sink connection portion 15 is electrically connected to the base portion 21 via the metal gasket 26. Further, when the heat sink 20 and the ground member 30 are properly connected, the ground member connecting portion 23 is electrically connected to the ground member 30 through the metal gasket 27.

  Returning to FIG. 1, a method for determining the connection state of the heat sink 20 will be described. In the state where the heat sink 20 is not connected to the heat sink connection portion 15 on the substrate 10, for example, a voltage of 3.3 V is applied from the voltage application unit 12, and the potential is at the “High” level.

  In this state, when the base portion 21 of the heat sink 20 is connected to the heat sink connection portion 15 and further the ground member connection portion 23 of the heat sink 20 is connected to the ground member 30 maintained at the ground potential, the heat sink connection portion 15 passes through the heat sink 20. Thus, the grounding member 30 is in a conductive state, the potential of the heat sink connection portion 15 becomes the same as the grounding potential of the grounding member 30, and becomes “Low” level.

  As described above, when both the heat sink 20 and the heat sink connecting portion 15 and the heat sink 20 and the grounding member 30 are properly connected, the potential of the heat sink connecting portion 15 becomes “Low” and any of the above connections is defective. As a result, the potential of the heat sink connection 15 becomes “High”. Therefore, the connection determination unit 18 can determine whether the heat sink 20 is connected to the heat sink connection unit 15 and the ground member 30 based on the potential of the heat sink connection unit 15 detected by the potential detection unit 17. .

  The connection determination unit 18 may output a signal indicating a determination result to the component 11 when the component 11 is an integrated circuit that performs control or calculation of another device. For example, when the heat sink 20 is not properly connected to the heat sink connection portion 15 and the grounding member 30, a signal indicating the determination result is output to the component 11, and a warning is displayed by controlling a display device (not shown) from the component 11. Alternatively, by controlling a speaker device (not shown) and outputting a warning sound, it is possible to warn an assembly worker to reconnect the heat sink 20 appropriately.

  Further, when the heat sink 20 is not properly connected, there is a problem with the heat dissipation function and the shield function. However, by driving the component 11 in the safe mode of low-speed driving, the generation of heat and noise can be suppressed to reduce the influence. You can also.

  As described above, according to the electronic circuit of the present invention, it is possible to easily detect whether or not the heat sink 20 is properly attached to the heat sink connecting portion 15 and the grounding member 30, so that the connection of the heat sink 20 is properly performed. It is possible to correct it to a proper state.

(Second Embodiment)
FIG. 3 is a plan view showing the electronic circuit 2 according to the second embodiment. In the first embodiment, the case where there is one heat sink connection portion 15 has been described, but there may be two or more heat sink connection portions 15. In the present embodiment, the connection state of the heat sink 20 can be determined in more detail by providing the substrate 10 of the electronic circuit 2 with the first heat sink connection portion 15a and the second heat sink connection portion 15b. . In addition, description of the same part as 1st Embodiment is abbreviate | omitted, and only a different part from 1st Embodiment is demonstrated.

  As shown in FIG. 3, the substrate 10 of the electronic circuit 2 is connected to the first heat sink connection portion 15 a to which a predetermined voltage is applied from the voltage application portion 12 via the resistor 13 and the heat sink 20 is connected. A second heat sink connection portion 15b whose potential is indefinite until a predetermined time is provided.

  The connection determination unit 18 detects the potential of the first heat sink connection unit 15a and the second heat sink connection unit 15b by the potential detection unit 17, thereby connecting the heat sink 20 and the substrate 10 or the heat sink 20 The connection state with the ground member 30 is determined.

  FIG. 4 is a determination table for determining the connection state of the heat sink 20 in the connection determination unit 18. As shown in this determination table, the potentials of the first heat sink connection portion 15a and the second heat sink connection portion 15b are detected, and the connection state between the heat sink 20 and the substrate 10 is determined by combining these detection results. It is possible to distinguish and determine the connection state with the ground member 30.

  For example, when both the potential of the first heat sink connecting portion 15a and the potential of the second heat sink connecting portion 15b are at the “Low” level, the heat sink 20, the first heat sink connecting portion 15a, and the second heat sink connecting portion 15b It can be determined that the heat sink 20 and the grounding member 30 are also properly connected.

  On the other hand, when both the potential of the first heat sink connection portion 15a and the potential of the second heat sink connection portion 15b are at the “High” level, the heat sink 20, the first heat sink connection portion 15a, and the second heat sink connection portion 15b Although properly connected, it can be determined that the heat sink 20 and the ground member 30 are not properly connected.

  Further, when the potential of the first heat sink connection portion 15a is “Low” level and the potential of the second heat sink connection portion 15b is “indefinite”, the heat sink 20 and the first heat sink connection portion 15a are appropriately connected. Although the heat sink 20 and the grounding member 30 are also appropriately connected, it can be determined that the heat sink 20 and the second heat sink connecting portion 15b are not properly connected.

  Further, when the potential of the first heat sink connection 15a is “High” level and the potential of the second heat sink connection 15b is “Low”, the heat sink 20 and the second heat sink connection 15b are appropriately connected. Although the heat sink 20 and the grounding member 30 are also properly connected, it can be determined that the heat sink 20 and the first heat sink connection portion 15a are not properly connected.

  Further, when the potential of the first heat sink connection portion 15a is “High” level and the potential of the second heat sink connection portion 15b is “undefined”, the heat sink 20 and the second heat sink connection portion 15b are appropriately connected. It can be determined that the heat sink 20 and the ground member 30 are not properly connected.

  As described above, in the present embodiment, the connection determination unit 18 determines the combination of the detection results of the two potentials of the first heat sink connection unit 15a and the second heat sink connection unit 15b, so that It is possible to distinguish and determine the state of each connection portion in the first heat sink connection portion 15a, the heat sink 20 and the second heat sink connection portion 15b, and the heat sink 20 and the grounding member 30. For this reason, since it is possible to designate reconnection by specifying the location where the connection is defective, the heat sink 20, the first heat sink connection portion 15a, the second heat sink connection portion 15b, and all the connection portions of the grounding member 30 are all connected. It can be securely connected.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to them. Various changes and modifications can be made without departing from the scope of the present invention.

  In the above-described embodiment, the heat sink 20 and the heat sink connecting portion 15 are electrically connected by providing the metal gasket 26 on the mounting pin 25 made of a non-conductive material. The heat sink connection 15 may be electrically connected.

  For example, the mounting pin 25 may be formed of a conductive metal material. In this case, when the heat sink 20 is mounted on the component 11, the mounting pin 25 comes into contact with the base portion 21 and the heat sink connecting portion 15, and instead of the metal gasket 26, an electrical connection is made between the base portion 21 and the heat sink connecting portion 15. Can be connected.

  Further, when mounting and fixing the heat sink 20 on the component 11, it is not always necessary to use the mounting pin 25, and the heat sink 20 and the heat sink connection portion 15 have a structure in which the heat sink 20 and the heat sink connection portion 15 are electrically connected. It only has to be.

  In the above embodiment, the grounding member connecting portion 23 and the metal gasket 27 are provided so that the heat sink 20 and the grounding member 30 such as a housing are electrically connected. A spring-like material or a screw member may be used.

  In the above embodiment, the heat sink 20 is electrically connected to the ground member 30 by providing the ground member connecting portion 23 and the metal gasket 27 on the heat sink 20 side. It is good also as providing the same component for connecting with.

DESCRIPTION OF SYMBOLS 1 Electronic circuit 2 Electronic circuit 10 Board | substrate 11 Component 12 Voltage application part 13 Resistance 14 Mounting hole 15 Heat sink connection part 15a 1st heat sink connection part 15b 2nd heat sink connection part 17 Potential detection part 18 Connection determination part 20 Heat sink 21 Base part 22 Radiation fins 23 Grounding member connection 24 Mounting hole 25 Mounting pin 26 Metal gasket 27 Metal gasket 30 Grounding member

Claims (3)

A conductive heat sink connectable to the component and the ground member;
When the heat sink is attached to the component, a substrate having a heat sink connection portion disposed at a position connectable to the heat sink;
A voltage application unit for applying a predetermined voltage to at least one of the heat sink connection units;
A potential detector for detecting the potential of the heat sink connection;
A connection determination unit that determines whether the heat sink is connected to the heat sink connection unit and the ground member based on the detection result of the potential in the potential detection unit, and outputs a determination result;
An electronic circuit comprising:   2. The electronic circuit according to claim 1, wherein the heat sink connection portion includes a first heat sink connection portion to which a predetermined voltage is applied and a second heat sink connection portion to which a predetermined voltage is not applied. A heat sink mounting detection method in an electronic circuit according to claim 1 or 2,
A heat sink mounting step of mounting the heat sink to the component, and connecting the heat sink to the heat sink connection portion and the ground member;
A voltage applying step of applying a predetermined voltage to at least one of the heat sink connections;
A potential detection step of detecting a potential of the heat sink connection;
A connection determination step of determining whether or not the heat sink is connected to the heat sink connection portion and the ground member based on the detection result of the potential in the potential detection step;
An output step of outputting a determination result in the connection determination step;
Including a heat sink.