阅读说明：本技术 一种逐层推移测量多层材料热阻的方法 (A kind of method of layer-by-layer passage measurement multilayer material thermal resistance ) 是由 冯士维 何鑫 白昆 郑翔 胡朝旭 李轩 张亚民 于 2019-07-26 设计创作，主要内容包括：一种逐层推移测量多层材料热阻的方法属于电子器件电学和热学测量技术领域。装置包括被测材料,热源,温度采集设备和计算机。所述方法测量了热源温度随时间变化的曲线,即瞬态热响应曲线；然后,根据传统结构函数方法得到的热阻信息,进一步构造薄层材料前各层材料的热响应曲线,并将其从总的曲线中剔除,从而提取出薄层的热阻信息。本发明区分出了两个热时间常数相近的材料,提高了特殊情况下薄层热阻测量精度。(It is a kind of it is layer-by-layer passage measurement multilayer material thermal resistance method belong to electronic device electricity and heat field of measuring technique.Device includes measured material, heat source, temperature acquisition equipment and computer.The method measures the curve that heat source temperature changes over time, i.e. transient thermal response curve；Then, the thermal resistance information obtained according to traditional structure functional based method, further constructs the thermal response curve of layers of material before layer material, and it is rejected from total curve, to extract the thermal resistance information of thin layer.The present invention has distinguished material similar in two thermal time constants, improves thin layer thermal resistance measurement precision in special circumstances.)

1. a kind of method of precise measurement thin layer thermal resistance, device includes measured material, heat source, temperature acquisition equipment and computer； Measured material is multilayered structure, and the condition of one layer of low-heat capacity materials is wherein mingled between certain two layers of high fever capacity materials of several layers of satisfactions； Heat source heats material upper surface；Temperature acquisition equipment changes with time for measuring temperature at material upper surface；Computer For data processing；

It is characterised in that it includes following testing procedure:

Heat source is affixed on the upper surface of measured material by step 1, utilizes the temperature of temperature acquisition device measuring heat source；

Step 2, heat source are begun to warm up, meanwhile, temperature acquisition equipment is by all data in linear coordinate acquisition time of measuring Point, sample frequency are not less than 1Mhz；

Step 3,；The transient thermal response of material before the thermal resistance information structuring thin layer obtained by traditional structure functional based method Curve, and it is rejected from total curve, its interference to thin layer thermal resistance information is eliminated, it is accurate to extract thin layer thermal resistance；

It is specific as follows:

(1) preliminary treatment is carried out to transient response curve a (t) using structure function method, obtains multiple groups thermal resistance and thermal capacitance: R₁、C₁, R₂、 C₂…R_i、C_i..., when there is C_i>C_i+1When, then judge that i-th layer may includes first layer high fever capacity materials i₁With second layer low-heat Capacity materials i₂；

(2) thermal time constant τ is set_i=R_i*C_i, τ_iCorresponding thermal resistance is R on transient response curve a (t)_τi, △ τ is that the time is normal Number offset, initial to set △ τ=0, i indicates number of layers, R_nThe thermal resistance of each layer, τ before indicating i-th layer_iIndicate i-th layer Time constant, t indicate the time；As i=1, then R_n、τ_nIt is not present；Constructed fuction:

(3) transient response curve a (t) is subtracted into constructed fuction y (t), obtains new transient response curve b (t), which eliminates I₁Layer and its influence of each layer to transient response curve a (t) before；Then by time shaft to right translation τ_i/ 100, again to b (t) time shaft takes logarithm；

(4) b (t) is handled with structure function method, obtains i-th₂Layer thermal resistance and thermal capacitance: R_i2And C_i2, and combine in (1) The R known_i、C_i, by R_i、C_iSplit into two groups of results: R_i1、C_i1And R_i2And C_i2, respectively corresponded i-th₁Layer and i-th₂The heat of layer material Resistance and thermal capacitance；

(5) τ is set₁₁=R_i1*C_i1, τ₁₂=R_i2*C_i2, construct transient response curve z (t), wherein R_m、τ_mEach layer after indicating i-th layer Thermal resistance and time constant:

(6) goodness of fit of transient response curve a (t) He z (t) are asked:

Wherein, tmax indicates total time span, and t indicates time, i.e. abscissa in transient response curve, Y_tIt indicates in a (t) The thermal resistance value of corresponding time, y_tIndicate the thermal resistance value that the time is corresponded in z (t),Indicate Y_tAverage value；

(7) R is set²Minimum value, judge R²Whether meet the requirements, if meeting, it is determined that i-th layer of thermal resistance value is split as R_i1With R_i2；If not meeting, adjustment time constant offset △ τ repeats (3)-(6) until reaching the R that meets the requirements²Value.

Technical field:

The invention discloses a kind of methods for measuring multilayer material thermal resistance, belong to electronic device electricity and heat measuring technique Field.

Background technique:

Structure function method based on de-convolution operation is the important method of generally acknowledged electronic device and system thermal characteristic measurement. It is the transient temperature response curve obtained based on measurement, carries out series of values transformation to extract each structure sheaf of device inside The method of thermal resistance thermal capacitance.But during actual measurement, for complicated multilayer material, especially when a high thermal resistance is (low Thermal capacitance) when being located between two high fever capacity materials, layer material thermal resistance information can be submerged in closes in material layer layer material, nothing Method directly obtains the component heat resistance of the thin layer with structure function method.

The case where present invention can not be handled for traditional structure function method proposes a kind of new method, by acquisition comprising complete The original transient response curve of portion's data point carries out successive ignition, passage processing to it, successively extracts the thermal resistance of layers of material Information.

Summary of the invention:

For limitation of the existing technology, primary object of the invention is: proposing a kind of successively passage measurement multilayer The method of material thermal resistance has apparent advance than existing methods.

This method the technical solution adopted is as follows:

First measure measured device transient response curve, using traditional structure function method to the curve at Reason, obtains rough every layer material thermal resistance and thermal capacitance.The case where being submerged for thin layer thermal resistance that may be present, according to known The transient response curve of thermal resistance thermal capacitance information structuring high fever capacity materials.Then by the influence of high fever capacity materials from overall transient response It is eliminated in curve, to realize the layer-by-layer measurement to multilayer material thermal resistance.

The method is characterized by include measured material 1, heat source 2, temperature acquisition equipment 3 and computer 4.It is measured and monitored the growth of standing timber Material 1 is multilayered structure；Heat source 2 is used to heat material；Temperature acquisition equipment 3 is for measuring the change of hot source temperature at any time Change；Computer is used for data processing.

The method is characterized by, the specific steps are as follows:

1. acquiring temperature at heat source 2 by temperature acquisition equipment 1 to change with time, sample rate is not less than 1Mhz, processing Obtain transient response curve a (t).

2. take logarithm to its time shaft since the data volume for directly handling transient response curve a (t) is excessive, using being based on The structure function method of de-convolution operation carries out preliminary treatment to transient response curve a (t), obtains multiple groups thermal resistance and thermal capacitance: R₁、C₁, R₂、C₂…R_n、C_n, when there is C_i>C_i+1When, then judge that i-th layer may includes first layer high fever capacity materials i₁With second layer low-heat Capacity materials i₂。

3. setting thermal time constant τ_i=R_i*C_i, τ_iCorresponding thermal resistance is R on transient response curve a (t)_τi, Δ τ is the time Constant offset, initial to set Δ τ=0, i indicates number of layers, R_n, τ i indicate i-th layer of time constant, t indicates the time, when When i=1, then R_n、τ_nIt is not present.Constructed fuction:

4. transient response curve a (t) is subtracted constructed fuction y (t), new transient response curve b (t) is obtained, the curve Eliminate i₁Layer and its influence of each layer to transient response curve a (t) before, then by time shaft to right translation τ_i/ 100, again Logarithm is taken to the time shaft of b (t).

5. being handled with structure function method b (t), and known Ri, Ci in step 2 are combined, by R_i、C_iIt splits into Two groups of results: R_i1、C_i1And R_i2And C_i2, respectively corresponded i-th₁Layer material (high heat capacity) and i-th₂The heat of layer material (low heat capacity) Resistance.

6. setting τ₁₁=R_i1*C_i1, τ₁₂=R_i2*C_i2, construct transient response curve (wherein R_m、τ_mEach layer after being i-th layer Thermal resistance and time constant):

6. asking the goodness of fit of transient response curve a (t) He z (t):

Wherein, tmax indicates total time span, and t indicates time, i.e. abscissa in transient response curve, Y_tIndicate a (t) thermal resistance value of time, y are corresponded in_tIndicate the thermal resistance value that the time is corresponded in z (t),Indicate Y_tAverage value.

7. setting the minimum value of R2, R is judged²Whether meet the requirements, if meeting, it is determined that be split as i-th layer of thermal resistance value R_i1And R_i2；If not meeting, adjustment time constant offset Δ τ repeats step 3-6 until reaching the R that meets the requirements²Value.

For complicated multilayer material, take steps the judgment method in 2 for each layer, to realize, successively passage is surveyed The purpose of amount.

Detailed description of the invention:

Fig. 1 is the schematic diagram of test device of the present invention, and in figure, 1- measured material, 2- heat source, 3- temperature acquisition set It is standby, 4- computer；

Fig. 2 is the schematic diagram of measured material in this method；

Fig. 3 is transient response curve a (t)；

Fig. 4 is that processing obtains the schematic diagram of transient response curve b (t)；

Fig. 5 is to split time constant schematic diagram.

Specific embodiment:

More detailed explanation is carried out to the present invention with reference to the accompanying drawings and detailed description.

The test device of this method is as shown in Figure 1.It include measured material 1, heat source 2, temperature acquisition equipment 3 and computer 4.Measured material 1 is trilaminate material, meets and is mingled with one layer of low-heat capacity materials between two layers of high fever capacity materials；Heat source 2 is on material Surface heating；Temperature acquisition equipment 3 changes with time for measuring temperature at material upper surface；Computer is at data Reason.

The flow chart of this method is as shown in Figure 3, comprising the following steps:

1. acquiring temperature at heat source 2 by temperature acquisition equipment 1 to change with time, sample rate 1MHz, and save whole Data point, i.e. transient response curve a (t).

2. the time shaft of pair transient response curve takes logarithm, transient response curve a (t) is carried out just using structure function method Step processing, obtains two groups of thermal resistances and thermal capacitance: R₁、C₁, R₂、C₂, wherein R₁=2K/W, C₁=0.006J/ DEG C；R₂=1K/W, C₂= 0.907J/℃。

3. setting thermal time constant τ₁=R₁*C₁=12000 μ s, τ₁Ringing corresponding thermal resistance on curve a (t) in transient state is R_τ1, Δ τ is time constant offset, fixes tentatively Δ τ=0.Constructed fuction:

4. transient response curve a (t) is subtracted constructed fuction y (t), the transient state after the influence of the first layer material that is eliminated Then time shaft zero point is taken as 120 μ s, takes logarithm to the time shaft of b (t) again by response curve b (t).

5. being handled with structure function method b (t), and combine R in step 2₁=2K/W, C₁=0.006J/ DEG C, it will R₁、C₁Split into two groups of results: R₁₁=1.156K/W, C₁₁=0.010J/ DEG C and R₁₂=0.844K/W and C₁₂=0.030J/ DEG C, The thermal resistance and thermal capacitance of the i-th 1 layers and the i-th 2 layer materials are respectively corresponded.

5. setting τ₁₁=R₁₁*C₁₁=11560 μ s, τ₁₂=R₁₂*C₁₂=25320 μ s, τ₂=R₂*C₂=907000 μ s construct wink State response curve:

6. asking the goodness of fit of transient response curve a (t) He z (t):

Wherein, tmax indicates total time span, and t indicates time, i.e. abscissa in transient response curve, Y_tIndicate a (t) thermal resistance value of time, y are corresponded in_tIndicate the thermal resistance value that the time is corresponded in z (t),Indicate Y_tAverage value.

7. judging R²Whether meet the requirements, it is desirable that R²Not less than 0.9995, therefore, adjustment time constant offset Δ τ is repeated Step 3-6.After successive ignition calculates, as Δ τ=- 2000, R²=0.9998, reach the R of requirement²Value.At this point, being calculated 3 Layer thermal resistance is as follows: R1=1.031K/W；R2=0.969K/W；R3=1K/W；

With respect to preliminary treatment as a result, the result has distinguished material similar in two thermal time constants, it is special to improve In the case of thin layer thermal resistance measurement precision.