JP3100231B2 - Adhesion test apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tackiness test apparatus and method capable of accurately measuring, for example, the tackiness of a solder paste.

[0002]

2. Description of the Related Art There is known an adhesion tester capable of automatically measuring the adhesion of various solder pastes, a so-called tacking tester. Knowing the adhesive properties of the solder paste, which depends on various conditions, is a matter of determining the mixing ratio of the paste,
This is important for properly setting the mechanical conditions when mounting components and setting the soldering time. The tacking tester measures the sample such as adhesive, cream solder, etc., and lowers the measurement probe attached to the stress sensor at a constant speed with respect to the sample placed at a certain thickness on the measurement stage, The probe is pressed for a predetermined time with a set predetermined stress, and then the tensile stress when the probe is pulled up (pulled away) at a constant speed is plotted with respect to the passage of time (pulling distance). Configuration.

[0003]

SUMMARY OF THE INVENTION The present invention aims to improve such a tacking tester and enables more accurate measurement. One of the problems with the conventional tacking tester is that the accuracy of setting the temperature conditions is insufficient. When measuring cream solder, actually 0.2 mm on a slide glass placed on a heating stage
It is printed in a thickness of. If only the temperature of the heating stage is controlled, the temperature condition fluctuates when the probe comes into contact with the cream solder, and the measurement accuracy deteriorates.

In addition, it is not possible to measure the actual temperature of a sample such as a cream solder unless an extremely fine thermocouple is embedded in the sample. As a next best measure, there is a method of keeping a thermocouple in contact with the surface of the slide glass near the sample.
However, when this method is realized, it is necessary to pay attention to the degree of contact between the glass surface and the thermocouple every time the slide glass is replaced, and there is a problem that handling is troublesome.

A second problem of the conventional tacking tester is the control accuracy in controlling the preload to a predetermined value during the probe pressurizing time. The accuracy of the preload holding is not very good in the conventional feedback control, which is about ± 10 to 20%.

A third problem is a problem of processing data obtained by measurement. That is, as the standing time of the sample increases, the adhesive strength tends to decrease. Conventionally, the state of the adhesive strength of a sample is determined based on the average value of about 10 measurements. However, the degree of the decrease in the adhesive strength after being left to stand varies from sample to sample. This is due to the fact that the surface of the sample dries, and whether or not the dried film is broken during the test has a large difference in adhesive strength.

It is, therefore, an object of the present invention to provide a tackiness test apparatus capable of performing highly accurate measurement by controlling the temperature of a probe and the temperature of a heating stage to predetermined ones.

Another object of the present invention is to provide an adhesion test apparatus capable of maintaining a preloaded pressure at a predetermined value with high accuracy and enabling highly accurate measurement.

It is still another object of the present invention to provide an adhesion test method which can judge the quality of a sample accurately based on the degree of decrease in adhesive force due to standing.

A still further object of the present invention is to provide a test method capable of measuring the viscosity of a sample using an adhesion tester.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an adhesion test apparatus which presses the tip of a probe against a sample, and then measures the adhesion of the sample from the stress applied to the probe when the sample is pulled up. A mechanism and a drive circuit for raising and lowering the probe, a control circuit for supplying a control signal to the mechanism and the drive circuit so that the probe moves up and down under preset conditions, and a stress applied to the probe. A sensor coupled to the probe, a data processing device for processing the detection signal from the sensor to obtain the adhesive force data, a sample stage for placing the sample, and a sample stage. A first temperature control device provided for controlling the temperature of the sample, and a second temperature control device provided in connection with the probe for controlling the temperature of the probe. That tacky test device.

According to a second aspect of the present invention, there is provided a heating device for heating a sample stage, a small piece provided on the sample stage near the glass plate and having substantially the same physical properties as the glass plate.
It has a temperature detecting element for detecting the temperature of the small piece, and a temperature control device that receives a detection signal from the temperature detecting element and generates a drive signal for the heating device.

According to a third aspect of the present invention, the control unit controls the mechanical unit and the drive circuit so that a constant pressurization is performed during the measurement period and the probe moves up and down under predetermined conditions. A control device for supplying a signal;
A mechanical pressurizing mechanism for applying a predetermined pressure to the sensor.

According to a fourth aspect of the present invention, there is provided a mechanism for raising and lowering a probe with respect to a sample and a drive circuit;
A control device for supplying a control signal to the mechanism and the drive circuit so that the probe moves up and down under preset conditions, and a sensor coupled to the probe to detect stress applied to the probe, In a measurement method using an adhesion tester including a data processing device for processing a detection signal from a sensor to obtain adhesive force data and a sample stage for placing a sample, a plurality of samples are obtained at each of different standing times. Steps of obtaining a plurality of pieces of adhesive force data at each of the standing times, calculating an average value of the adhesive force data at each of the leaving times, and determining a threshold value from the average value. At each of the step of leaving and the standing time, a plurality of pieces of adhesive force data that exceed the threshold value with respect to the threshold value. A measuring method characterized by comprising a step of obtaining a percentage.

According to a fifth aspect of the present invention, there is provided a mechanism for raising and lowering a probe with respect to a sample and a drive circuit;
A control circuit for supplying a control signal to the mechanism and the drive circuit, and a sensor coupled with the probe to detect a stress applied to the probe, such that the probe moves up and down under preset conditions, The probe is in contact with the sample in a measurement method using an adhesion tester consisting of a data processing device for processing the detection signal from the sensor to obtain adhesive force data and a sample stage for placing the sample. Push the probe at a constant speed from the end, stop once in the sample, then raise the probe so that it returns to the original position, and increase the area of the area enclosed by the going curve and the returning curve of the probe. This is a measuring method characterized by obtaining data of the viscosity of a sample from an area obtained by a data processing device.

[0016]

The temperature of not only the sample stage but also the probe itself is controlled, so that fluctuations in temperature conditions can be prevented. The temperature of the sample on the sample stage can be accurately controlled. Therefore, measurement accuracy can be improved. Since the preloaded pressure is controlled by both the electrical configuration and the mechanical configuration, control accuracy can be increased. The quality of the sample can be accurately determined from the data processing of the change in the adhesive strength of the sample when left unattended. The viscosity can be measured with the same device as well as the adhesive force.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. First, the appearance of the apparatus will be described with reference to FIG. 1 for easy understanding of the present invention. FIG.
Reference numeral 1 denotes a key panel. The key panel 1 includes a keyboard 2, a start switch 3, a lifting switch 4, and an LE switch.
A D (or LCD) display 5 and the like are provided. Further, a microcomputer for control and data processing and an electric circuit are provided inside the apparatus.

Reference numeral 11 denotes a mechanism, and a sensor arm 12 which can be moved up and down is projected. A stress sensor 13 is attached to the tip of the arm 12. A shaft-shaped probe 14 is attached to an operating portion of the sensor 13. The sensor 13 is
The stress applied to the tip of the probe 14 is detected. Sensor 1
The axes of 3 and probe 14 are aligned. The probe 14 can be easily removed from the sensor 13 by a screw, and the surface of the tip is parallel to the surface of the sample table 16 with good reproducibility. A plate-like member is fixed to the tip of a support shaft provided in parallel with these, and a sample holding ring 15 is attached to the center of the plate-like member.

The sample is placed on the sample stage 1 below the probe 14.
6 is put on. The sample stage 16 is a stage that can move in the X and Y directions. The holding ring 15 prevents the sample from floating when the sensor arm 12 moves up after the tip of the probe 14 presses the sample.
When the adhesive force of the sample is relatively small, for example, when the sample is cream solder, paste, or the like, the holding ring 15 is removable in consideration of the fact that the holding ring 15 is unnecessary.

FIG. 2 shows the mechanism section 11 in more detail. The press ring 15 is supported by support shafts 17a and 17b. These support shafts 17a, 17b (holding ring 15)
Is always biased downward, that is, in the direction of pressing the sample, by springs in the housings 18a and 18b. The holding ring 15 is made of a resin having a low thermal conductivity so that the temperature of the sample is not changed as much as possible when the sample is pressed.

In FIG. 2, reference numeral 21 denotes a stepping motor for moving the sensor arm up and down. The ball screw 22 to which the rotation is transmitted and the sensor arm 12 are connected via a screw member 23. When the motor 21 rotates,
The sensor arm 12 is moved up and down by the ball screw 22 and the screw member 23. Fixed support plates 24a and 24b are provided at predetermined intervals in the vertical direction, and a guide shaft 25
a and 25b are provided in parallel. Guide shaft 25a,
Bearings 26a and 26b that slide up and down 25b move up and down integrally with the sensor arm 12. A linear bush 27 provided between the bearings 26a, 26b and the guide shafts 25a, 25b allows the sensor arm 12
Is held horizontally.

The operation of the tacking tester shown in FIGS. 1 and 2 will be schematically described with reference to FIG.
FIG. 3 shows data in the case of a double-sided adhesive tape made of cloth. First, the user operates the keyboard 2 while looking at the display on the display 5 on the key panel 1 to input various measurement conditions.

Then, the sample 6 is set on the sample table 16. Sample 6 is a cream solder, an adhesive film, or the like. When the sample 6 is a cream solder, a paste, or the like, the holding ring 15 is unnecessary, so that the holding ring 15 is removed. The sample 6 is printed on a plate such as a slide glass or a metal plate and has a thickness of about 0.2 mm to 0.3 mm, and is placed on the sample table 16 for measurement. If the sample 6 is an adhesive film or the like, a holding ring 15 is attached, and the sample 6 is placed under the holding ring 15 with its measurement surface up. Since the holding ring 15 is biased by the springs in the housings 18a and 18b, the sample 6 is held on the sample stage 16 until the measurement is completed.
Press strongly on top. Further, a method of attaching to the lower surface of the holding ring 15 may be used.

When the sample 6 is a thin adhesive film or the like, a metal plate or a glass plate is placed on the sample stage 16 so that the sample 6 is pressed at a uniform pressure in a preloading (pre-pressing) stage prior to the measurement. Instead, an elastic plate or sheet of silicon rubber or the like is placed for measurement.

Next, the probe 1 is
The sensor arm 12 is lowered so that the tip of 4 comes to a position several mm above the sample 6. When the raising / lowering switch 4 is operated while the display on the LED display 5 is in the “READY TO START” state, the stepping motor 21 rotates, and the rotation causes the ball screw 22 and the screw member 23 to rotate.
The sensor arm 12 is moved up and down via.

When the probe 14 is stopped several mm above the sample 6, the start switch 3 is pressed. As shown in FIG. 3, the elevation of the probe 14 is automatically controlled by an operation controlled by the microcomputer according to the initially set conditions. As shown in FIG. 3, first, the probe 14 is pressed against the sample 6 and continues for a predetermined time, and then the probe 14 is pulled up, and the change in the output of the sensor 13 in this process, mainly when the probe 14 is pulled up Is measured by the sensor 13. Probe 1
The microcomputer 4 receives the stress signal from the sensor 13 and controls the pressing force so that the pressing force is set at a set value. When one measurement is completed, the probe 14 returns to the initial position.

The stress signal measured in this way is converted into a digital signal and processed by a microcomputer. After the measurement, the maximum value of the measured adhesive force is displayed on the display 5. At the same time, the distance (indentation) of the probe 14 into the sample 6 is also displayed as data. This distance is 10
It is obtained by counting the amount of movement of the probe 14 from a place where a stress exceeding [gf] is applied by a computer. Further, the time (= distance) change of the adhesive force from the start of the pulling up of the probe 14 as shown in FIG. 3 is plotted by the plotter.

The above is the process of one measurement. In this type of measurement, since a considerable variation in data is generally unavoidable, measurement under the same conditions is performed several times to several tens of times for one sample. Repeatedly, statistical processing is performed on the obtained data, and the data is adopted as data on the adhesive strength or the amount of indentation.

FIG. 4 shows a schematic configuration of the system of this embodiment. The stress signal from the sensor 13 is supplied to the microcomputer 32 via the amplifier 31. An A / D converter is provided in the microcomputer 32,
Convert stress signals to digital signals. As mentioned above,
In connection with the microcomputer 32, the key panel 1,
An LED display 5 and a printer / plotter 33 are provided.

The microcomputer 32 supplies a motor control signal to the motor driver 34, and a drive signal from the motor driver 34 is supplied to the stepping motor 21. The vertical mechanism 20 (the ball screw 22, the screw member 23, etc.) is operated by the stepping motor 21, and the sensor arm 12 moves up and down. Further, the microcomputer 32 performs setting of measurement conditions and processing of measurement data.

The sample 6 is printed on the slide glass 35 on the sample stage 16 with a thickness of, for example, 0.2 mm. The slide glass 35 is heated by a plate heater 36 provided on the sample stage 16. Slide glass 3
A temperature detection unit 37 is provided near the position where the device 5 is placed, for example, at a position of about 4 mm. This detection unit 37
Is composed of a glass piece of the same quality as the slide glass 35 and having the same thickness, and a detection thermocouple fixed thereon.

A detection signal from the detection unit 37 is supplied to the temperature controller 38, and a drive signal for the heater 36 is supplied from the temperature controller 38. By the feedback control, the temperature of the sample 6 can be controlled with an accuracy within about ± 2 degrees C with respect to the set temperature. This is sufficient temperature accuracy for actual measurement,
In addition, every time the sample 6, that is, the slide glass 35 is replaced, it is not necessary to consider the contact state between the thermocouple and the slide glass, and the reproducibility of the temperature is improved.

The temperature of the probe 14 is also controlled. The probe 14 is fixed via the sensor 13 and the ceramic member 39 for heat insulation. A probe heater 40 and a temperature detector 41 are attached to the probe 14,
By the feedback control by the temperature controller 42, the temperature of the probe 14 is controlled to a predetermined temperature. By controlling not only the temperature of the sample 6 but also the temperature of the probe 14, even if the probe 14 contacts the sample 6,
Can be prevented from changing, and the temperature conditions at the time of measurement can be strictly controlled.

FIG. 5A shows a solder paste as a sample.
It is an example of the adhesive force data actually obtained by the embodiment. Leaving time 0, 1 hour, 2 hours, 5 hours,
In each of the 22 hours, 12 measurements were taken,
Adhesion data is obtained. FIG. 5A also shows the average value of the adhesive force at each leaving time.

The decrease in the adhesive strength shown in FIG. 5A is an example, and the degree of change differs depending on the sample. The surface of the sample dries, and whether or not the dried film is broken during the test appears as a difference in adhesive strength. In consideration of this point, a threshold value is set, and data is processed based on the threshold value, rather than simply determining the quality of the sample from the average value.

In this example, the threshold value is 77.994, which is obtained by multiplying the average value (111.42) of the data when the leaving time is 0 (111.42) by 0.7. Then, the quality of the sample is determined based on the probability of exceeding the threshold. FIG. 5B shows a value obtained by subtracting the threshold value from the measured value. If this value is positive, it is above the threshold. The probability of occurrence is shown. The quality of the sample is determined from the data of the probability. Note that a coefficient (0.7) by which the average value is multiplied to set the threshold value
Is an example and is selected as appropriate. Further, not only the probability of exceeding but also the probability of falling may be obtained.

Further, not only adhesive force but also viscosity data can be obtained from the measured data. Probe 14
Is pushed into the probe 14 at a constant speed from the state in which the probe 14 is in contact with the surface of the sample 6, and then returned to the original position. The stress applied to the probe 14 during this time is graphed by the microcomputer 32, and the area of the portion surrounded by the going (down) curve and the returning (up) curve is calculated. This amount is proportional to the viscosity term of the sample. This amount is multiplied by a constant obtained from measurement of a sample having a known viscosity to obtain viscosity data.

Prior to the measurement, a preload for pressing the sample with a uniform pressure is performed. This preload can be performed by the microcomputer 32 controlling the position of the sensor arm 12 while watching the stress signal from the sensor 13. However, only such feedback control cannot control the preloaded pressure with high accuracy. Therefore, in this embodiment, not only the feedback control but also the mechanical preload is used in combination to improve the control accuracy.

FIG. 6 shows the structure of the mechanical preload.
A spring 51 is provided above the sensor 13, and the spring force of the spring 51 is applied to the linear bushing 52 and the stopper 5 above the spring 51.
3 to be received. The rotation of the adjusting screw 54 is adjusted so that the spring 51 is compressed by a force slightly smaller than the stress to be controlled. The mechanism of FIG. 6 and the above-described feedback control are used together.
As a result, the preload control accuracy can be improved.

[0040]

According to the present invention, the temperature of the sample on the sample stage can be controlled with high accuracy, and the temperature condition can be prevented from fluctuating even when the sample is replaced. Further, since the probe itself also controls the temperature, it is possible to prevent the temperature condition from fluctuating due to the probe coming into contact with the sample. As described above, by strictly controlling the temperature conditions, highly accurate measurement data can be obtained.

According to the present invention, since the preload is performed not only by the electric feedback control but also by a mechanical configuration for the sensor, the accuracy of the control of the preloaded pressure can be improved.

Further, the present invention introduces a threshold value when processing the data of the decrease in the adhesive strength due to the standing time, so that the quality of the sample is determined by using a simple average value. An accurate determination can be made according to the sample.

According to the present invention, the viscosity can be measured by applying an adhesion tester.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention.

FIG. 2 is a sectional view of a mechanism according to an embodiment of the present invention.

FIG. 3 is a schematic diagram used for describing a measurement operation of the present invention.

FIG. 4 is a block diagram showing a system configuration according to an embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating an example of measurement data.

FIG. 6 is a sectional view showing a mechanism for performing preloading.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Key panel 5 LED display 11 Mechanical part 12 Sensor arm 13 Stress sensor 14 Probe 16 Sample stand

Continuation of the front page (56) References JP-A-4-27841 (JP, A) JP-A-4-72546 (JP, A) JP-A-5-72153 (JP, A) JP-A-4-123864 (JP) JP-A-58-63835 (JP, A) JP-A-60-39531 (JP, A) JP-A-3-255935 (JP, A) JP-A-4-29855 (JP, U) Hybrid Circuits, No. 17, pp. 27-29, 1986, p. A. Ainsworth, "Measurement of Tackness of Solder Paste" (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 19/04 G01N 3/00-3/62 H05K 3/34 H01L 21/60 H01L 21 / 66 B23K 1/00 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. A probe tip is pressed against a sample,
Next, there is provided an adhesiveness test apparatus for measuring the adhesive force of the sample from the stress applied to the probe when the sample is pulled up, wherein a mechanism for raising and lowering the probe and a drive unit are set in advance. So that the probe moves up and down under the conditions
A control unit for supplying a control signal to the mechanism unit and the drive unit; a sensor coupled to the probe for detecting a stress applied to the probe; and a cohesive force by processing a detection signal from the sensor. A data processing unit for obtaining data, a sample stage for placing the sample, a first temperature control unit provided in association with the sample stage and controlling a temperature of the sample, An adhesiveness test apparatus provided in association therewith, and second temperature control means for controlling the temperature of the probe. 2. The probe tip is pressed against a sample,
Next, there is provided an adhesiveness test apparatus for measuring the adhesive force of the sample from the stress applied to the probe when the sample is pulled up, wherein a mechanism for raising and lowering the probe and a drive unit are set in advance. So that the probe moves up and down under the conditions
A control unit for supplying a control signal to the mechanism unit and the drive unit; a sensor coupled to the probe for detecting a stress applied to the probe; and a cohesive force by processing a detection signal from the sensor. Data processing means for obtaining data; a sample stage for placing a glass plate on which the sample is adhered; heating means for heating the sample stage; and the glass on the sample stage. A small piece provided near the plate and having substantially the same physical properties as the glass plate; a temperature detection element for detecting the temperature of the small piece; and a detection signal from the temperature detection element supplied to the heating means. An adhesiveness test apparatus comprising a temperature control means for generating a drive signal. 3. The probe tip is pressed against a sample,
Next, there is provided an adhesion test apparatus for measuring the adhesive force of the sample from the stress applied to the probe when the sample is pulled up, and a mechanism and a drive unit for raising and lowering the probe, and a measurement period. A control means for supplying a control signal to the mechanism unit and the drive means, so as to perform a constant pressurization while controlling, and so as to raise and lower the probe under a preset condition; A sensor coupled to the probe for detecting a stress applied to the probe; a mechanical pressurizing unit for applying a predetermined pressure to the sensor; a detection signal from the sensor; An adhesion test apparatus comprising: a data processing unit for obtaining force data; and a sample table on which the sample is placed. 4. A mechanism for driving a probe up and down with respect to a sample and a drive unit, and a control signal is supplied to the mechanism and the drive unit so that the probe moves up and down under preset conditions. Control means for detecting a stress applied to the probe, a sensor coupled to the probe, a data processing means for processing a detection signal from the sensor to obtain adhesive force data, and the sample A measuring method using an adhesion test device consisting of a sample table for placing a sample, wherein a plurality of measurements are repeated at each of the different leaving times, and a plurality of data of the adhesive strength are obtained at each of the above leaving times. Obtaining an average value of the data of the adhesive force in each of the leaving times, and determining a threshold value from the average value. And determining a ratio of a value exceeding the threshold value among the plurality of pieces of adhesive force data, based on the threshold value, in each of the leaving times. Measurement method to be performed. 5. A mechanism for driving a probe up and down with respect to a sample, and a drive unit, and a control signal is supplied to the mechanism and the drive unit so that the probe moves up and down under predetermined conditions. Control means for detecting a stress applied to the probe, a sensor coupled to the probe, a data processing means for processing a detection signal from the sensor to obtain adhesive force data, and the sample A measuring method using an adhesion test device comprising a sample stage for placing the probe, the probe is pushed in at a constant speed from a state in which the probe is in contact with the sample, and temporarily stopped in the sample, Next, the probe is raised so as to return to the original position, and the area of a portion surrounded by the curve going to the probe and the curve returning to the probe is subjected to the data processing. Determined by the step, the measurement method, characterized in that from the area obtain data viscosity of the sample.