JP2006300781A - Method for measuring adhesive force of holding assembly and its usage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for measuring an adhesive force of a holding assembly of a flexible circuit board, capable of obtaining exact measured values with little variations therein. <P>SOLUTION: In the method, a probe 5 in the form of a rectangle 10 mm long is attached to one surface of an adhesive material 2 which is attached to one surface of an aluminum plate 1, and a guide 7 is arranged next to the probe 5, and the aluminum plate 1 is fixed, and the probe 5 is fixed under a constant load, and then the probe 5 is pulled up in the approximately vertical direction at a constant speed, and the adhesive force is measured. In the case that the guide 7 is not used, a mechanism capable of detaching the probe 4 from the aluminum plate 1 in parallel is used. Moreover, this measuring method is applied to a manufacturing process and/or an implementation process, thereby realizing a stable production. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for measuring the adhesive force of an adhesive material on the upper surface of a holder.

  A flexible circuit board (flexible board) made of a polyimide sheet is used in various portable devices such as mobile phones. When mounting an electronic component on this flexible substrate, the flexible substrate is attached to an aluminum plate, a resin plate, or the like with a double-sided adhesive tape, and various mounting processes are performed (Patent Document 1). The mounting process includes a printing process, a mounting process, a heat treatment process, and the like, and this adhesive tape is required to have a uniform, strong adhesive force and heat resistance. However, there is no method for accurately measuring the adhesive force of the adhesive material on the holder.

  In designing and manufacturing an adhesive tape, it is important to evaluate the adhesive strength in accordance with practical characteristics, and a measurement method with as little measurement error (numerical value variation) as possible is known. Adhesive strength of adhesive tape is measured in accordance with JIS Z0237. Adhesive tape of a certain width is attached to the surface of the adherend, and the peel strength is measured after pressure bonding with a certain pressure. What is actually used as a body is used. The method will be described with reference to FIG.

  In FIG. 9, it consists of an aluminum plate 1, an adhesive tape 21, and presser plates 22 and 23. Adhesive tape 21 is attached to aluminum plate 1 with a roller or the like. Thereafter, the aluminum plate 1 is pressed by the presser plate 22, and the aluminum plate 1 and the adhesive tape 21 are pulled apart while the adhesive tape 21 is pressed by the presser plate 23. The force when pulling apart is measured, and the value is taken as the adhesive strength. The value is compared with the width of the adhesive tape 21 being constant.

  As another measurement method, when measuring the adhesive strength against a flexible material such as a synthetic resin foam, the adhesive tape 21 is previously attached to the aluminum plate 1 as shown in FIG. Affixing the synthetic resin foam 3 as an adherend to the pressure-sensitive adhesive surface to be measured, pressing the synthetic resin foam 3 at a constant pressure, and then measuring the peeling force when peeling the synthetic resin foam 3 ( For example, Patent Document 2).

As a method of pressing the synthetic resin foam 3 with a constant pressure, spacers 71 having a thickness of 25 to 50% of the thickness of the synthetic resin foam 3 are arranged on both sides of the foam 3, and the length over the upper surfaces of the spacers 71 on both sides is set. When the rubber roller 61 is rotated and moved in close contact with the spacer 71, the synthetic resin foam 3 is pressed against the adhesive surface of the adhesive tape 21 while being compressed by the thickness of the spacer 71.
JP 2003-142897 A JP 07-318479 A

  In the conventional method for measuring the adhesive strength with respect to the adhesive tape 21, it is possible to measure stably although the adhesive strength is strong, but when measuring a material having weak adhesive strength, it cannot be measured stably. The value changes with a slight change in the pulling direction, and stable measurement is not possible. In addition, when the non-measurement is not a tape, this method cannot be used directly.

  Further, in the above conventional method for measuring the adhesive strength against a foam, the adhesive tape 21 and the foam 3 are bonded while pressing a part with the roller 61. Therefore, the adhesive tape 21 is stretched in the plane direction and the plane direction is distorted. When this strain is restored due to elasticity, non-uniform stress is generated at the interface with the adhesive. If the adhesive strength is measured in this state, a large variation appears in the measured value, and the accurate adhesive strength cannot be evaluated.

  Further, since the roller 61 is used, the mechanism is complicated and large. Since it is the foaming body 3, the pressure to press is not constant. In addition, when this holder is used in a manufacturing process, it is necessary to accurately measure the adhesive strength, but the conventional method cannot obtain an accurate measurement value. Moreover, it was not possible to measure easily.

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide a method for measuring the adhesive strength of an adhesive material on a holder and a method for using the same, which can obtain accurate measurement values with little variation in measurement values. To do.

  In order to achieve the above object, the method for measuring the adhesive strength of the present invention is a method for measuring the adhesive strength of an adhesive material formed on a holder, and a measuring element is fixed on the adhesive material on the held fixture. A method for measuring the adhesive force of a holder is used, wherein the force is measured by pressing the load with a load and pulling the measuring element away from the adhesive material substantially perpendicularly. Further, as a method for measuring the adhesive force of the adhesive material formed on the holder, a guide and a measuring element are pressed against the adhesive material formed on the holder, and the force when the measuring element is peeled off from the adhesive material is measured. A method for measuring the adhesive strength of a holder is used.

  The measuring device may be made of a rigid material, and the surface of the measuring device in contact with the adhesive material may be a mirror surface. In addition, the adhesive force measuring method for a holder according to any one of the above, wherein the force for separating the measuring element from the adhesive material is measured while bringing the measuring element into contact with the guide. Any one of the above-described methods for measuring the adhesive strength of a holder using a plurality of guides can be used.

  Any one of the manufacturing process using the holder, the mounting process, and the assembly process may include a step of measuring the adhesive strength of the holder described in any of the above. The manufacturing method which the measurement location of the adhesive force of the holder in the above is the vicinity of the part corresponding to the alignment mark of the holding thing on the said holder can be used. A measurement value obtained by the above-described method for measuring adhesive strength is measured, and when the value is less than a certain value, a manufacturing method characterized by exchanging or maintaining the holder is used.

  According to the present invention, the adhesive force of the adhesive material on the holder can be easily and accurately measured.

  Hereinafter, a method for measuring the adhesive strength of an adhesive material of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a holder as a measurement object of the present invention, in which a silicon-based resin layer is formed as an adhesive material 2 on an aluminum plate 1, a thickness of about 2 mm, and a size of 50 mm × 120 mm. As a forming method, a method of applying a liquid material of the pressure-sensitive adhesive material 2 by a printing method was used, but various methods such as a method of transferring the pressure-sensitive adhesive material using a mold, die coating, and spin coating may be used. it can.

  Moreover, you may affix a double-sided adhesive sheet. You may spray an adhesive liquid with a spray. The aluminum plate 1 is the same in the case of a resin material, a metal material, or the like other than aluminum. The adhesive material 2 may be a fluorine-based resin in addition to the silicon-based material. In the mounting factory, the flexible substrate 4 is fixed to the adhesive material 2, solder printing, component mounting, and heat treatment are performed, and the flexible substrate 4 is peeled off. This process is repeated several times and used until the adhesive material 2 deteriorates. In the printing and mounting processes, the positional accuracy of the flexible substrate 4 is important. If the position is shifted, a printed pattern and a mounting position are shifted, and the flexible substrate 4 becomes defective. For this reason, the flexible substrate 4 needs to be firmly fixed to the adhesive material 2.

  Next, a method for measuring the adhesive strength of the adhesive material 2 on the aluminum plate 1 in FIG. 1 will be described. The method for measuring the adhesive strength of the adhesive material 2 will be described using the method shown in FIGS. 2 is a cross-sectional view, and FIG. 3 is a top view. The measuring element 5 was a 1 cm square cubic metal block having a mirror surface in contact with the adhesive material 2. The measuring element 5 is connected to the load cell 6 and can detect a weight from a weight control mechanism (not shown) at the top. Two guides 7 are arranged adjacent to the measuring element 5, and the measuring elements 5 are pulled up along the guide 7.

  First, the measurement method will be described. The measuring element 5 was affixed to the pressure-sensitive adhesive material 2, and a guide 7 was placed next to the measuring element 5, and the peeling force (adhesive force) when the measuring element 5 was pulled up and peeled was measured.

  As the measurement conditions, when the probe 5 is pushed into the adhesive material 2, the probe 5 is adhered with a certain value and an indentation holding time of 15 seconds, with an indentation speed of 0.2 mm / second, an indentation load of 50 to 500 g / cm2. When separating from the material 2, the surface of the adhesive material 2 was washed with alcohol before the measurement at a separation speed of 0.2 mm / second. Since the adhesive strength is weak, it is important to keep the initial surface state clean.

  If dust, dust, etc. are present on the surface, the dust, dust, etc. will be peeled off, and the adhesive force cannot be measured accurately. The conditions are not limited to these values. The environmental temperature does not greatly affect the measurement, but it is better to measure it according to a predetermined temperature. Around room temperature is good. The same applies to humidity. However, when used in a mounting factory, since the heat treatment temperature is 200 ° C. to 250 ° C., the measurement may be performed at a temperature in the vicinity thereof.

  When pulling apart, the probe 5 is pulled up while being in contact with the guide 7. For this reason, the direction of separation is constant, and the surface in contact with the measuring element 5 is separated from the surface of the adhesive material 2 almost simultaneously. As a result, the adhesive force can be measured without variation. In the case of a strong adhesive force such as the adhesive tape shown in the conventional example, variation due to the peeling direction is allowed, but since the adhesive material this time is the adhesive material 2 for temporarily fixing the flexible substrate, The adhesive strength is low, and this measurement method is very effective, and the adhesive strength can be measured without variation in measured values.

  One guide 7 may be provided. In addition, the guide 7 is not essential, and any apparatus configuration may be used so that the surface of the measuring element 5 can be separated from the surface of the adhesive material 2 at substantially the same time. When the probe 5 is pulled up, it does not need to be in contact with the guide 7 all the time. The probe 7 may be regulated when the probe 5 is inclined. For example, a mechanism for pulling up the probe 5 may be devised so that it can be pulled substantially perpendicular to the adhesive material surface at the same time.

  For example, as shown in FIG. 4, it may be pulled up in a point contact state. The load cell connecting portion 61 has a spherical shape, and the connecting portion 61 is pulled up by the load cell tension line 62. In addition, the aluminum plate 1 is fixed by a plurality of fixtures 9, and the surface of the adhesive material 2 of the probe 5 and the surface of the adhesive material are separated so as to be parallel to each other. A stable value can be produced. If it can pull apart so that it may become parallel, it will not be limited to a point contact. What is necessary is just to set it as the connection part which can change angle freely, such as a ball joint. It may be a free line contact type connection part in only one direction.

  The surface of the probe 5 that contacts the adhesive material 2 is preferably a mirror surface. This is because, in order to control the adhesive force of the adhesive material 2 and to provide unevenness, the measuring element 5 needs to be a mirror surface in order to accurately measure the adhesive force at that time.

  Moreover, FIG. 5 and FIG. 6 are shown as another embodiment. A guide 7 surrounds the periphery, and the measuring element 5 can be guided from a plurality of directions. The adhesive force can be measured more stably than when the number of the guides 7 is two. The position of the guide 7 is preferably around the portion where the measuring element 5 contacts the adhesive material 2. The shape of the guide 7 is not limited to a quadrangular prism shape, and may be a cylindrical shape. Stable measurement is possible in all directions. Moreover, it is not three-dimensional and may be a rod-shaped one. However, it is necessary to hold the vicinity of the probe 5 with the guide 7. This is because when the measuring element 5 is separated from the adhesive material 2, the aluminum plate 1 is bent and the lower surface of the measuring element 5 is not uniformly separated from the surface of the adhesive material 2.

  FIG. 11 shows a table representing the variation in adhesive strength between the comparative example without the guide 7 and the example with the guide 7. In this comparative example, the connecting portion shown above is not devised, but the measuring element 5 is simply pulled upward from the adhesive material 2. As can be seen from the figure, the types of the guides 7 of Examples 1-1 to 1-5 having a small variation in adhesive force have little variation. On the other hand, the comparative example 1-1 without the guide 7 has a large range of variation in adhesive force. This is because, as described above, the direction in which the probe 5 is separated from the adhesive material 2 is constant, and at the same time, the bonding surface is separated. It is preferable that the load cell 6 and the probe 5 can be pulled up in a state of point contact or tilting. This is because the probe 5 can be pulled up in this state even if the probe 5 is inclined with respect to the adhesive surface.

  Moreover, in order not to vary the measured value, the contact area of the probe 5 with the adhesive material 2 is preferably 0.1 or more and less than 2 square centimeters. If it is large, there are a plurality of points where the measuring element 5 and the adhesive material 2 are separated from each other. Therefore, the measurement value varies, and if it is small, the adhesive force is weak and it is difficult to measure, and the value varies.

  The guide 7 may be of any shape. For example, the guide 7 may have a cylindrical shape, a hole is formed in the center, and the measuring element 5 having the same shape passes therethrough. In the case of a cylindrical shape, it is best because it can be measured in any direction.

  The values measured using the above measurement methods can be compared by standardizing the contact area per square centimeter. If the contact surface of the measuring element 5 is set to 1 square centimeter, correction is unnecessary and simple. When the value is advertised in catalogs, product descriptions, the Internet, magazines, advertisements, and compared with other products, the performance of each holder may be compared.

  In addition to transporting the flexible substrate 4, the holder is used for temporarily fixing and transporting a semiconductor wafer, an optical lens, and other components such as a semiconductor chip and a package product. Can do. It can be used to transport objects on the mounting line. When a semiconductor wafer is cut into chips and mounted on a substrate, after the wafer is cut, bumps for connecting to the substrate are formed, and used as a holder to transport between each process of mounting the chip on the substrate it can.

  Moreover, in the case of an optical lens, it can be used as a holder that is transported to each process from the preparation of the optical lens by polishing to the incorporation into a set product. In the case of a package component, the package component can be used as a holder for transporting the package component from the manufacturer to the assembly company. In order to regularly measure the adhesive strength of these holders, the method for measuring the adhesive strength described above can be used. If the measured value is below a certain standard, it can be produced stably by replacing and maintaining the parts.

  The case where this measuring method is used for the mounting process will be described with reference to FIG. In the mounting process of the flexible substrate 4, in the first process 41, the flexible substrate 4 is affixed to the holder on which the adhesive material is formed. In the second step 42, a solder paste is printed on the flexible substrate 4 by a screen printer. In a third step 43, an electronic component is mounted on the solder paste by an electronic component mounter. In the fourth step 44, the solder is hardened by heat treatment in a reflow furnace. In a fifth step 45, the flexible substrate is removed from the holder. In a sixth step 46, the adhesive strength of the holder is measured.

  When the holder is used and its adhesive strength is reduced, it can be exchanged for a new holder when measured by the above measurement method and below a certain standard. By repeating these steps, the holder is used repeatedly. In this case, the adhesive is gradually deteriorated due to repeated peeling of the flexible substrate 4 and heat of the reflow furnace. The temperature of the reflow furnace is approximately 250 ° C., and the holder is passed through the furnace for several minutes.

  There are various sizes of holders, but large ones can be used up to 30 cm square. At some point, when a part of the flexible substrate 4 is easily peeled off, the flexible substrate 4 is positioned and connected to a defective product. The required pattern accuracy of the flexible substrate 4 is about several microns. In particular, when the end portion of the flexible substrate 4 is peeled off, and there is a position reference mark at that portion, the position regulation is shifted, and the mounting process 43 is shifted in component mounting, and the printing process 42 is shifted in pattern, resulting in a defect. There is.

  In order to prevent these defects from occurring, it is necessary to simply and partially measure the adhesive force with the present method. In particular, the measurement of the adhesive strength at and around the reference mark position of the substrate is effective. It is efficient to measure the adhesive force in the vicinity of the portion corresponding to the alignment mark of the holding object on the holder.

  It is also effective to measure the adhesive strength of a portion of the flexible substrate 4 that is difficult to adhere, for example, a small portion of the flexible substrate that is thin, that is, a connection portion with another device. Since the corresponding part of the holder is determined for each flexible substrate 4, the adhesive strength of that part may be measured periodically. In addition, if the adhesive force is memorized, analyzed, analyzed, and statistically processed for each holder, it will be understood how much replacement and maintenance should be performed. For maintenance, the surface of the adhesive can be washed, or the surface can be blasted, cut and polished to give a new surface.

  Also, with this method of measuring adhesive strength, it can be measured easily and in a short time, so the adhesive strength of the holder is measured once every few times to manage the adhesive strength, and discarded or new. Can be replaced. You may install as a measuring apparatus in a part of mounting line.

  Moreover, you may provide in a part of each manufacturing process. For example, a description will be given with reference to FIG. In the first step 51, a semiconductor chip is attached to the holder. Usually, it is pasted at a semiconductor manufacturing company or another factory. The second step 52 is a transportation step, which is a step of transportation by a truck, a conveyor or the like. The third step 53 is a step of peeling the semiconductor chip from the holder. The fourth step 54 is a step of mounting a chip on a substrate or the like. The fifth step 55 is a step of measuring the adhesive strength of the holder.

  Semiconductor chips are easy to apply and need to be firmly fixed when transported. However, on the contrary, it is necessary to easily remove the semiconductor chip. Therefore, it is important to measure and manage the adhesive strength simply by using the present measurement method in the fifth step 55. In addition, this method may be used to transport a lens for use in an assembly process of a lens or the like.

  Since this measurement method can evaluate adhesive materials very easily, it can be incorporated as one device on various production lines, or it can be attached to other production devices and measured on the production line or inline. Also good. For example, by using the object suction fixing portion of the printing machine in the mounting process, the object is sucked and fixed, the guide 7 and the measuring element 5 are lowered from the upper part to the object, and only the measuring element 5 is pulled up and adhered. The force may be measured and then the guide 7 may be pulled apart. It is even better if the measured data is transferred to the mounting process management control device for analysis and analysis. Moreover, you may install in the clearance gap between the apparatuses of various manufacturing apparatuses as an independent measuring apparatus. You may install in the conveyor part between apparatuses.

  INDUSTRIAL APPLICATION This invention can be utilized for the method of measuring the adhesive force of the adhesive material formed on the holder, and the method of utilizing.

The figure which shows the measuring object of this invention Side view showing an embodiment of the present invention The top view which shows the Example of this invention Side view showing an embodiment of the present invention Side view showing an embodiment of the present invention The top view which shows the Example of this invention The figure which shows the mounting process of this invention The figure which shows the manufacturing process of this invention Diagram showing conventional measurement method Side view showing a conventional measurement method Table of variation in adhesive strength with and without guide

Explanation of symbols

1 Aluminum plate 2 Adhesive material 3 Foam 5 Measuring element 6 Load cell 7 Guide 21 Adhesive tape 22 Press plate 23 Press plate 61 Roller 71 Spacer

Claims (8)

  As a method for measuring the adhesive force of the adhesive material formed on the holder, a measuring element is pressed against the adhesive material on the held holder with a constant load, and the measuring element is pulled away from the adhesive material substantially vertically. A method for measuring the adhesive strength of a holder, characterized by measuring the force of time.   As a method of measuring the adhesive force of the adhesive material formed on the holder, a guide and a measuring element are pressed against the adhesive material formed on the holder, and the force when the measuring element is peeled from the adhesive material is measured. A method for measuring the adhesive strength of a holding tool.   3. The method for measuring adhesive force of a holder according to claim 1, wherein the measuring element is made of a rigid material, and the surface of the measuring element that comes into contact with the adhesive material is a mirror surface.   4. The method for measuring the adhesive force of a holder according to claim 2, wherein a force for pulling the measuring element away from the adhesive material is measured while bringing the measuring element into contact with the guide.   The method for measuring the adhesive strength of a holder according to any one of claims 2 to 4, wherein a plurality of guides are used.   The manufacturing method characterized by including the process of measuring the adhesive force of the holder in any one of Claim 1 to 5 in any of the manufacturing process using a holder, a mounting process, and an assembly process.   The manufacturing method according to claim 6, wherein the measurement point of the adhesive strength of the holding tool is in the vicinity of a portion corresponding to the alignment mark of the holding object on the holding tool. 7. A manufacturing method comprising measuring a measured value obtained by the method for measuring an adhesive strength according to claim 6 and replacing or maintaining the holder when the measured value is less than a certain value.

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