Thermal Load

Abstract

Thermal load (10) for simulating the thermal behavior of an electronic component on a substrate, in particular on a printed circuit board, with a housing (1), a heat source (2) with an adjustable heat output power, at least one first and / or one second heat transfer medium arrangement (3, 4), each comprising at least one heat transfer medium (5), in particular at least two heat transfer mediums (5, 6), wherein the first heat transfer arrangement (3) is configured to transfer heat from the heat source (2) to the housing (1), and the second heat transfer arrangement (4) is configured to transfer heat from the heat source to the support, wherein the thermal resistance of the first and / or the second heat transfer medium arrangement (3, 4) is adjustable, wherein the first and / or the second heat transfer medium arrangement (3; 4) has at least two heat transfer media (5, 6), and the thermal resistance of the heat transfer medium arrangement is adjustable by positioning the heat transfer media relative to each other, wherein the heat transfer medium arrangement and / or the heat transfer mediums (5, 6) include positioning means to position the heat transfer mediums relative to each other, characterized by the fact that The positioning device has a spring (7) and an adjustable stop (8) for the spring (7).

Description

AREA OF INVENTION

[0001] The present invention relates to a thermal load for simulating the thermal behavior of an electronic component on a substrate, in particular on a printed circuit board. SUMMARY OF THE INVENTION

[0002] Thermal tests are necessary during the development of electronic devices, such as control units or radio modules. However, these tests can currently only be carried out once all components of the electronic devices are fully developed and exist at least as prototypes.

[0003] A long period of time usually elapses until the production and software integration of the complete electronic device.

[0004] It is therefore desirable to conduct thermal tests during the development phase of an electronic device. A device for the thermal simulation of an electrical assembly is known from DE 10 2022 212 631 A1.

[0005] The object of the invention is to provide a thermal load improved compared to the prior art for simulating the thermal behavior of an electronic component on a substrate.

[0006] Accordingly, the following is planned: - A thermal load for simulating the thermal behavior of an electronic component on a substrate, in particular on a printed circuit board, comprising a housing, a heat source with adjustable heat output, at least one first and / or one second heat transfer arrangement, each comprising at least one heat transfer means, in particular at least two heat transfer means, wherein the first heat transfer arrangement is configured to transfer heat from the heat source to the housing, and the second heat transfer arrangement is configured to transfer heat from the heat source to the substrate, wherein the thermal resistance of the first and / or second heat transfer arrangement is adjustable, wherein the first and / or second heat transfer arrangement has at least two heat transfer means, and the thermal resistance of the heat transfer arrangement is adjustable.by positioning the heat transfer means relative to each other, wherein the heat transfer means arrangement and / or the heat transfer means have positioning means to position the heat transfer means relative to each other.

[0007] According to the invention, the positioning means has a spring and an adjustable stop for the spring.

[0008] A sensor, also known as a detector, transducer, or probe, is a technical component that can qualitatively or quantitatively detect certain physical or chemical properties or conditions, such as temperature, humidity, pressure, speed, brightness, acceleration, pH value, ionic strength, electrochemical potential, and / or the material composition of its environment. These quantities are detected using physical or chemical effects and converted into a processable electrical signal as sensor data.

[0009] The basic idea of ​​the invention is to provide a thermal load with a heat source whose heat output power is adjustable and whose thermal resistances between a semiconductor chip, a so-called junction, and the substrate, as well as between the semiconductor chip and the housing, are adjustable.

[0010] If the heating power and the thermal resistances between the semiconductor chip and the housing or between the semiconductor chip and the substrate are adjusted so that the aforementioned parameters correspond to those of the electronic device under development, the thermal load can be mounted on a substrate, such as a printed circuit board, to simulate its operation.

[0011] The thermal load is intended not to provide any core functionality of the electronic component under development, but merely to simulate the heat dissipation during the operation of the electronic device.

[0012] The heat output of the heat source can be adjusted directly via the heat output.

[0013] Accordingly, the thermal load is provided with a housing, or at least a frame, with a heat source located inside the housing or frame. The heat source can be connected to electrical conductors or otherwise supplied with electrical energy.

[0014] A heat transfer medium arrangement is positioned above and below the heat source. A first heat transfer medium arrangement, which is often located above the heat source, conducts heat from the heat source to the housing. A second heat transfer medium arrangement, which is often located below the heat source, conducts heat from the heat source to the substrate, in particular the printed circuit board.

[0015] The heat transfer medium arrangements are designed such that they have adjustable thermal resistances between the heat source and the support, as well as between the heat source and the housing.

[0016] The relationship between thermal resistance and properties of a heat transfer medium arrangement is: Rth=LX⋅A where: R_th is the thermal resistance. L is the thickness of a material (in meters), λ the thermal conductivity of the material (in watts per meter-kelvin, W / (m·K)), A is the cross-sectional area of ​​the heat transfer (in square meters).

[0017] Advantageous designs and further developments result from the further sub-claims as well as from the description with reference to the figures in the drawing.

[0018] For example, it is conceivable that a heat transfer medium arrangement could each include a heat transfer medium with an adjustable thermal conductivity. Materials can change their thermal conductivity in response to external stimuli such as temperature, mechanical pressure, electric fields, or magnetic fields.

[0019] Alternative concepts for a heat transfer medium arrangement are the subject of the dependent claims.

[0020] The heating element can have ball grids or chip feet so that it can be mounted on a circuit board.

[0021] It is advantageous if the spatial dimensions of the thermal load correspond as closely as possible to the spatial dimensions of the electronic component to be simulated.

[0022] Thus, for example, the thermal behavior of a printed circuit board populated with various electronic components can be simulated by populating a printed circuit board with thermal loads whose thermal behavior corresponds to a respective electronic component to be mounted on the printed circuit board.

[0023] According to the invention, the first and / or the second heat transfer medium arrangement comprises two heat transfer media, wherein the thermal resistance of the heat transfer medium arrangement is adjustable by positioning the heat transfer media of the heat transfer medium arrangement relative to each other.

[0024] Thus, the thermal resistance can be adjusted using a mechanism. This mechanism can be designed to be robust and easy to adjust.

[0025] According to the invention, the heat transfer medium arrangement and / or the heat transfer medium have positioning means to position the heat transfer medium relative to each other.

[0026] It is advantageous if the heat transfer media touch at a heat transfer surface and the thermal resistance of the heat transfer media arrangement is adjustable by setting an area dimension of the heat transfer surface, i.e., the surface at which the heat transfer media touch.

[0027] The dimensioning of the heat transfer surface using positioning devices is a simple, robust and cost-effective solution to flexibly and reversibly adjust thermal resistance.

[0028] It is conceivable that the position of the heat transfer means relative to each other can be read from the outside based on the position of the positioning means.

[0029] According to the invention, the positioning means has a spring and a stop, in particular an adjustable one.

[0030] In engineering, a stop is a device that limits or stops the movement of another part. A stop and the part it limits do not necessarily have to be in physical contact to fulfill their function.

[0031] For example, a spring and a stop can be arranged to work together, positioning the heat transfer medium from the housing to the inside of the housing. For instance, the spring could press the heat transfer medium against the stop, with the spring and stop located on opposite sides of the housing. If the stop is adjustable, the position of the heat transfer medium can be adjusted without replacing the spring, as the adjustable stop compresses the spring to varying degrees depending on its position.

[0032] The spring can be designed as a coil spring and the stop as an adjusting screw.

[0033] Alternatively, the positioning device could consist of a piston moving within a fluid, with the heat transfer medium being positioned by the piston. The fluid can be gaseous or liquid; accordingly, the positioning device can be operated hydraulically or pneumatically.

[0034] Hydraulics and pneumatics are two technologies used for power transmission and motion control. Both systems use a fluid as a transmission medium.

[0035] Hydraulic systems use a fluid, usually oil, to transmit power. In a hydraulic system, pressure is generated by a pump that forces the fluid into a cylinder. This pressure moves a piston inside the cylinder, which then performs a mechanical movement.

[0036] Pneumatic systems use compressed air or other gases to transmit force. Similar to hydraulics, pneumatics is based on the principle that pressure applied to a gas generates a force that can cause movement. In pneumatic systems, a compressor compresses the air and stores it in a compressed air reservoir. Pistons and cylinders are used in pneumatic systems to convert the energy of the compressed air into mechanical motion. These pneumatic cylinders consist of a cylinder housing and a piston that moves within it. The compressed air is directed to one side of the piston, causing it to move and thus perform a linear or rotary motion.

[0037] According to a preferred embodiment of the invention, the heat transfer means can be positioned relative to each other by sliding or rotating them. It is conceivable that sliding heat transfer means have a rectangular cross-section and rotatable heat transfer means have a circular segment-shaped cross-section.

[0038] Accordingly, the heat transfer surface can be adjusted by sliding stacked heat transfer media towards each other, if necessary until they overlap almost completely in a first end position or are held so close to the respective edge of the housing by the positioning means in a second end position that the heat transfer media overlap minimally or not at all, i.e. the heat transfer surface is minimal.

[0039] As an alternative to rectangular heat transfer devices that are pushed towards or away from each other, circular segment-shaped, especially semicircular, heat transfer devices are also conceivable, whose heat transfer surface can be adjusted by rotating the circular segment-shaped heat transfer devices.

[0040] The heat transfer medium can, for example, be disc-shaped and / or plate-shaped, meaning that its surface area in an X and a Y direction is significantly larger than its thickness in the Z direction, with the Z direction being perpendicular to the plane spanned by X and Y.

[0041] A disc has a round or circular segment-shaped base. A plate has a rectangular base.

[0042] The heat transfer medium can, for example, be made of copper or have a high copper content. It goes without saying that other materials with a suitable thermal conductivity coefficient are also conceivable.

[0043] According to a preferred embodiment of the invention, the thermal load includes a thermal sensor to monitor the heat output power of the heat source.

[0044] Therefore, it is also conceivable to regulate the heat output in response to thermal sensor data. It goes without saying that it is also conceivable to precisely adjust, i.e., control, the heat output of the heat source using other means.

[0045] In this patent application, the cross-section is oriented parallel to a support bearing the thermal load, or the cross-section is perpendicular to the Z-axis. CONTENT OF THE DRAWINGS

[0046] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawings. These show: Fig. 1 a thermal load according to an embodiment of the invention in a first end position; Fig. 2 a thermal load according to an embodiment of the invention in a second end position.

[0047] The accompanying drawings are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain the principles and concepts of the invention. Other embodiments and many of the advantages mentioned will become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale.

[0048] In the figures of the drawings, identical, functionally equivalent and equally effective elements, features and components - unless otherwise stated - are each provided with the same reference symbols. DESCRIPTION OF EXAMPLES OF EXECUTION

[0049] Fig. Figure 1 shows a thermal load 10 according to an embodiment of the invention in a first end position in which the heat transfer surface is set to its maximum.

[0050] The thermal load comprises a housing 1, comprising a frame and plates inserted into the frame, a heat source 2 located inside the thermal load, a first heat transfer medium arrangement 3 located above the heat source 2, and a second heat transfer medium arrangement 4 located below the heat source 2.

[0051] The housing comprises a frame 11 that extends over the edges of the thermal load and that supports several copper plates 12, 13 forming the outer walls of the thermal load. Fig. 1 The frame 11 comprises three components: an upper frame 11.1, a lower frame 11.2, and a middle piece 11.3 which connects the upper frame 11.1 and the lower frame 11.2.

[0052] The heat transfer element arrangements 3, 4 each comprise two heat transfer elements 5, 6, which are designed as copper-containing plates. Each heat transfer element 5, 6 is associated with a positioning element, comprising a spring 7, which is designed as a coil spring, and a stop 8, which is designed as an adjusting screw.

[0053] A copper-containing plate 14 or 15 is inserted between the heat source 2 and the heat transfer medium arrangements 3, 4.

[0054] In Fig. 1. The adjusting screws 8 extend maximally into the thermal load 10 and thus push their associated heat transfer elements 5 and 6 as far as possible towards the opposite side of the housing. Accordingly, the spring on the opposite side of the housing is also in a maximally compressed position. The heat transfer elements 5 and 6 are dimensioned such that this position of the positioning elements, consisting of a spring 7 and an adjusting screw, results in a maximum heat transfer surface area.

[0055] Fig. Figure 2 shows a thermal load of 10 according to Fig.1 in a second end position, in which the heat transfer surface is set to its minimum. Accordingly, the adjusting screws 8 protrude minimally into the interior of the thermal load 10, causing the spring 7 on the opposite side of the housing to be in a minimally compressed position. Consequently, the heat transfer elements 5 and 6 are held close to the housing 1, resulting in minimal overlap between them.

[0056] To change the position of the positioning means, the adjusting screw 8 must be actuated, i.e., screwed in or out into the interior of the thermal load 10. This compresses or decompresses the spring 7, thereby moving the respective heat transfer medium 5 or 6. By moving the heat transfer medium 5 or 6 away from or towards the housing 1, their heat transfer surface is adjusted. Reference sign 1 case 2 Heat source 3 Heat transfer device arrangement 4 Heat transfer medium arrangement 5 Heat transfer media 6 Heat transfer media 7 spring 8 stops 10 Thermal load 11 frames 11.1 upper frame 11.2 lower frame 11.3 Middle section 12 copper plates 13 copper plates 14 plates 15 plates

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