CN1303488C - Heat-pipe constant-temperature high-precision sampling resistor - Google Patents

Abstract

The present invention provides a heat pipe sampling resistor with constant temperature and high precision, which is composed of a temperature control winding, a thermally-sensitive element, a resistance wire, a basal body of the heat pipe and a supporting frame, wherein the basal body of the heat pipe is arranged on the supporting frame, the temperature control winding is arranged at one end of the basal body of the heat pipe, the thermally-sensitive element is arranged on the basal body of the heat pipe, the resistance wire is wound on the basal body of the heat pipe and is coated with heat conduction silicone grease, and the basal body of the heat pipe is provided with a heat radiator. The resistance wire is wound on the basal body of the heat pipe, and the basal body of the heat pipe is provided with the temperature control winding and the heat radiator. The heat pipe is used for radiating the heat, the stability is good, and the present invention can achieve the required index.

Description

Heat-pipe constant-temperature high-precision sampling resistor

(1) technical field

The present invention relates to a kind of sampling resistor.

(2) background technology

The height of electron beam exposure apparatus lens barrel light path system lens current supply degree of stability, stability and repeatability to electron beam light path system bundle point play an important role.The stability requirement of lens current supply itself is 1 * 10 ^-5More than, the precision of its sampling resistor just requires to reach 1 * 10 ^-6The order of magnitude, high-precision like this sampling resistor also can be used for other high stability power supply, as large-scale scanning electron microscope etc.Working current by this sampling resistor and can suitably be adjusted generally between 0.5-1A, and resistor required 24 hours or the continuous use of longer time, and the degree of stability of itself is not more than 3 * 10 ^-6The order of magnitude of V, it is very difficult reaching such index.

Disposal route for the lens current supply sampling resistor has following several now: dispel the heat with transformer oil (1), fuel tank constant temperature; (2) resistance base body adopts helix tube type, logical tap water cooling heat dissipation in the spiral pipe, and then invade constant temperature processing in the fuel tank; (3) adopt air-cooledly etc., the temperature control method that these adopt mediums heat radiation all has common weakness: complex structure, volume is big, uses inconvenient.From the effect that has reached, index level can only reach 1 * 10 ^-3～10 ^-4, not really desirable.

(3) summary of the invention

The present invention is directed to the deficiencies in the prior art, provide a kind of degree of stability good, the precision height can reach the heat-pipe constant-temperature high-precision sampling resistor of requirement index.

The present invention adopts following solution:

Heat-pipe constant-temperature high-precision sampling resistor is made up of temperature control winding, thermal sensing element, resistive conductor, heat pipe matrix and bearing support, the heat pipe matrix is installed on the bearing support, the temperature control winding is located at heat pipe matrix one end, thermal sensing element is installed on the heat pipe matrix, resistive conductor is wound on the heat pipe matrix and scribbles heat-conducting silicone grease, and the heat pipe matrix is provided with heating radiator.

Resistive conductor is a copper-manganese class alloy material.

The heat pipe matrix is processed into by aluminium alloy axial slot type pipe.

The present invention adopts heat pipe matrix wound resistance wire, and is provided with temperature control winding and heating radiator on the heat pipe matrix, utilizes heat pipe heat radiation, and degree of stability is good, and the precision height can reach the requirement index.

(4) description of drawings

Fig. 1 is the structural representation of high-precision sampling resistor of the present invention.

Fig. 2 is the thetagram of resistive conductor material.

Among the figure: 1, temperature control winding, 2, thermal sensing element, 3, heat-conducting silicone grease, 4, resistive conductor, 5, the heat pipe matrix, 6, bearing support, 7, heating radiator

(5) embodiment

Fig. 1 has provided the structural representation of high-precision sampling resistor of the present invention.The present invention is made up of temperature control winding 1, thermal sensing element 2, resistive conductor 4, heat pipe matrix 5 and bearing support 6, heat pipe matrix 5 is installed on the bearing support 6, temperature control winding 1 is located at heat pipe matrix 5 one ends, thermal sensing element 2 is installed on the heat pipe matrix 5, resistive conductor 4 is wound on the heat pipe matrix 5 and scribbles one deck heat-conducting silicone grease 3, and heat pipe matrix 5 is provided with heating radiator 7.

The resistive conductor material that the present invention adopts is a copper-manganese class alloy material, and the temperature curve of each resistive conductor material as shown in Figure 2.Under arbitrary temp, the calculating of resistance can be expressed as usually:

R _t＝R ₀〔1+α ₂₀(t-t ₀)+β ₂₀(t-t ₀) ²〕

Can analyze from the temperature curve of copper-manganese material, when the standard copper-manganese in 0～100 ℃ temperature range, can regard as is one section milder line segment, if can control its variation of temperature, move inward selection from 0 ℃ and 100 ℃ these 2, trend with temperature variation, be selected in a certain temperature range, the relative temperature curve in this a bit of interval can be regarded as and be a bit, be decided to be the optimal selection point of temperature, the numerical value change of Δ R/R (%) will be very little like this, also can regard roughly constant as, but the scope that changes at this its adaptive temperature of point is relatively with regard to broad, if can control the optimum of temperature, just reach the requirement of imagination, the resistance of resistance also just can be relative like this is stabilized in a certain numerical value, make it to change minimum, have advantages of higher stability and precision.

The present invention makes of following step:

(1) calculated resistance device resistance: resistor adopts the method for wire wound, the calculating of resistance:

$R=\mathrm{\&rho;}\frac{L}{S}=\mathrm{\&rho;}\frac{1}{\frac{\mathrm{\&pi;}}{4}{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="C20041007577600052.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}$

Wherein: ρ is a resistivity, and L is a resistive conductor length, and S is the resistive conductor sectional area.

Resistor is the form of Single-layer Windings, every circle resistive conductor

Length is $L_{\mathrm{\&Lambda;}}=\frac{\mathrm{\&pi;}(D+d)}{\cos \mathrm{\&alpha;}}$

The calculating of total resistance: Wherein: n is the resistive conductor number of turn, and D is the winding external diameter, and d is resistive conductor line footpath.

(2) coiling of resistive conductor 4: the matrix of resistor is a heat pipe, and heat pipe 5 is processed into by aluminium alloy axial slot type pipe, and external diameter is ф 20mm, and long is 360mm, and horizontal positioned is formed the radial heat pipe heat radiation.The winding structure of resistive conductor, having adopted two strands of diameters is ф 0.5mm, temperature coefficient is+2 * 10 ^-6/ ℃ the zero level manganese-copper filament, with four methods that bring out line, uniformly on heat pipe outer wall.In winding process, because resistance wire is generally thinner, pulling force is moderate, otherwise is elongated easily, produces nonuniform plastic deformation and elastic deformation, and keeping tension in resistive conductor.In the long-term from now on use of resistor, can influence the stability of resistance.In addition,, in winding process, also to take certain measure, as adopting the two-wire parallel wound, to reduce corresponding interference for time constant and distributed inductance and the distributed capacitance that reduces resistor.

(3) resistive conductor is handled: after resistive conductor winds, must carry out heat ageing and handle, eliminate its stress and other the factors of instability, make resistance reach stable.In order to increase the surface of contact of resistance wire and heat pipe matrix, reduce contact resistance, should in time be coated with last layer heat-conducting silicone grease 3 at the resistance wire winding process, as filler.Heat-conducting silicone grease 3 vacuum available silicone grease and Zinc oxide powder are formulated, every degree (℃) the conductible heat flux of temperature drop is 2000 kilocalorie/rice ²

The contact resistance of resistor itself, the stability of resistor, temperature coefficient, non-linear and current noise there is very big influence, in order to reduce the contact resistance of resistor self, extension line part to resistor, taked four to bring out the line connection, terminal directly is welded in through on the weld tabs of silver-plated processing, in order to reduce the contact resistance that failure welding brings, can adopt extraordinary solder flux welding.

The present invention is in low temperature range work, heat pipe matrix to resistor, temperature range applicable to 210-340 ° of K, according to the characteristic of heat pipe and the calculating of the heat of resistor own, can take the mode of electron temperature-control, can design the temperature automatically controlled heat pipe of electrical feedback, as the matrix of high stability resistor.

Claims (3)

1. heat-pipe constant-temperature high-precision sampling resistor, form by temperature control winding, thermal sensing element, resistive conductor, heat pipe matrix and bearing support, it is characterized in that: the heat pipe matrix is installed on the bearing support, the temperature control winding is located at heat pipe matrix one end, thermal sensing element is installed on the heat pipe matrix, resistive conductor is wound on the heat pipe matrix and scribbles heat-conducting silicone grease, and the heat pipe matrix is provided with heating radiator.

2. heat-pipe constant-temperature high-precision sampling resistor according to claim 1 is characterized in that: described resistive conductor is a copper-manganese class alloy material.

3. heat-pipe constant-temperature high-precision sampling resistor according to claim 1 is characterized in that: described heat pipe matrix is processed into by aluminium alloy axial slot type pipe.

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