JP2006250590A - Whisker measurement sheet, measuring device using the same, and measurement method of whisker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a whisker measurement method for easily measuring a whisker by flexibly coping with an object to be measured even if the object is a curved surface or a large material. <P>SOLUTION: Since a whisker is a metal crystal and has conductivity, a gel continuity adhesive sheet 11 is applied onto the plating surface (upper surfaces of 3A, 3B) of an object 4 to be measured. A needle whisker enters a sheet 1, and is grown inside the sheet 1 with a lapse of time. The sheet 1 is separated and the value of volume resistivity in the sheet 1 where the whisker remains inside is measured by a minute ohmmeter, and the measurement value is compared with the initial value of volume resistivity, thus quantitatively measuring the occurrence of whiskers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a whisker measuring sheet, a measuring apparatus using the whisker, and a measuring method therefor, and in particular, a whisker measuring sheet for measuring whiskers generated from plating or solder material used for electrical parts and the like, and a measuring apparatus using the whisker measuring sheet. And a measuring method thereof.

  Conventionally, acicular whiskers generated on zinc plating or tin plating on metal plating are very thin with a diameter of 10 μm or less, and the detection is visually confirmed with an optical microscope or SEM (scanning electron microscope). A long time is required for the confirmation, and confirmation of a large object is difficult.

  In addition, since the needle-like whisker is easily broken, there is a risk that the whisker will fall when the sample is moved during observation. Further, variations due to the light source, the angle of the object to be observed, the operator skill, etc. also occur. Observation with a microscope or SEM is limited to confirming a minute range, and it is difficult to confirm a wide range in a short time, and it cannot be measured quantitatively.

Therefore, referring to Patent Documents 1 to 3 and the like, techniques for measuring whiskers are disclosed.
JP-A-4-314345 JP 2001-074801 A JP 2001-228107 A JP 2001-146578 A

  The technique disclosed in each of the above publications has a problem that it is difficult to measure whiskers in a flexible manner when the object to be measured is a curved surface or a large material.

  An object of the present invention is to provide a whisker measurement sheet that can flexibly measure whisker easily when the object to be measured is a curved surface or a large material, a measuring apparatus using the whisker, and a measuring method therefor. That is.

  Another object of the present invention is to provide a whisker measurement sheet in which measurement is not limited to a minute range, and there is no difference due to the type of light source, the angle and direction of the object to be measured, the skill of the operator, and the like. It is to provide a measuring method of the measuring apparatus using the measuring method.

  The whisker measurement sheet according to the present invention is characterized in that it comprises a gel-like conductive adhesive sheet that can adhere to a measurement object.

  The whisker measuring apparatus according to the present invention includes a gel-like conductive adhesive sheet adhered to a measurement target object for a predetermined period of time, and a resistance meter that measures a resistance value of the gel-like conductive adhesive sheet.

  In the whisker measuring method according to the present invention, after the gel-like conductive adhesive sheet is adhered to the object to be measured for a predetermined period, the resistance value of this gel-like conductive adhesive sheet is measured, and whisker measurement is performed based on the measurement result. It is characterized by.

  The operation of the present invention will be described. Since the whisker is a metal crystal and has electrical conductivity, a gel-like conductive adhesive sheet is attached to the plating surface to be measured. Needle-like whiskers penetrate into the gel-like conductive adhesive sheet and grow inside the sheet as time elapses. Therefore, the gel-like conductive adhesive sheet is peeled off, and the volume resistance value of the gel-like conductive adhesive sheet in which the whisker remains is measured with a micro-resistance meter, and the whisker generation is quantified by comparing with the initial volume resistance value. Can be measured automatically.

  According to the present invention, the following effects can be obtained. The first effect is that the amount of whisker generated can be quantitatively measured by incorporating the whisker into the gel-like conductive adhesive sheet and changing the conductive resistance value. The second effect is that whiskers can be measured over a wide range. The third effect is that since the gel-like conductive adhesive sheet has an adhesive, it can be measured if it can be attached to a curved surface or a large material.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of the present invention. In FIG. 1, the gel-like conductive adhesive sheet 1 has a thickness of 50 μm to 200 μm and is conductive, and has an adhesive layer 11 on its lower surface. The metal 4 which is the object to be plated is provided with plating films 3a and 3b which should detect whisker generation.

  Here, since the whisker is a metal crystal and has conductivity and normally grows up to about 200 μm, the thickness of the gel-like conductive adhesive sheet 1 should be 50 μm to 200 μm in accordance with this whisker length. .

  Whisker, which is a metal crystal, is needle-shaped and can easily penetrate into soft gels due to its shape and hardness. Therefore, in the present invention, the gel-like conductive adhesive sheet 1 is stuck on the upper surface of the plating film of the object to be plated, which is a laminated structure of the metal film 4 to be measured and the plating films 3a and 3b.

  As shown in FIG. 2, the needle-like whisker 5 grows inside the gel-like conductive adhesive sheet 1 with the passage of time. Therefore, the gel-like conductive adhesive sheet 1 is peeled off from the object to be plated after an arbitrary time has elapsed. Since the acicular whisker 5 is thin and easy to fold, it peels off from the plating at the time of peeling, and remains inside the gel-like conductive adhesive sheet 1. The volume resistance value of the sheet 1 changes due to the metal needle-like whiskers 5 remaining inside the gel-like conductive adhesive sheet 1.

  Therefore, as shown in FIG. 3, the volume resistance value of the sheet 1 is measured by the micro-resistance meter 6 through the wiring 7. In this case, the occurrence of whiskers can be measured by comparing the initial volume resistance value with the measured volume resistance value.

  Further, since the gel-like conductive pressure-sensitive adhesive sheet 1 has flexibility, it has an advantage that it can be easily applied even if the object to be measured has various shapes regardless of the plane. For example, although it is difficult to detect whiskers by optical observation at the curved portion, whisker generation can be easily quantitatively measured by applying the gel-like conductive adhesive sheet 1. Similarly, it is effective in measuring the occurrence of whiskers for bent portions, wiring portions, large materials, and the like.

  In addition, as this gel-like conduction adhesive sheet 1, although what is disclosed by patent document 4 can be used, of course, it is not limited to it.

It is a whole perspective view for demonstrating embodiment of this invention. It is a figure which shows the example of whisker generation | occurrence | production in the state of FIG. It is a perspective view for demonstrating whisker measurement.

Explanation of symbols

1 Gel-like conductive adhesive sheet 3a, 3b Plating film
4 Metal
5 Whisker
6 Micro resistance meter
7 Wiring 11 Adhesive layer

Claims (7)

  A whisker measurement sheet for whisker measurement, comprising a gel-like conductive adhesive sheet that can be adhered to an object to be measured. A whisker measuring apparatus for whisker measurement, including a gel-like conductive adhesive sheet adhered to a measurement target object for a predetermined period, and a resistance meter for measuring a resistance value of the gel-like conductive adhesive sheet Characteristic whisker measuring device.   The whisker measurement apparatus according to claim 2, wherein an initial resistance value of the gel-like conductive pressure-sensitive adhesive sheet measured by the resistance meter is compared with a resistance value after elapse of a predetermined time, and whisker measurement is performed based on the comparison result.   The whisker measuring device according to claim 2 or 3, wherein the resistance meter measures a volume resistance value of the gel-like conductive adhesive sheet.   A whisker measuring method comprising: adhering a gel-like conductive adhesive sheet to a measurement object for a predetermined period, measuring a resistance value of the gel-like conductive adhesive sheet, and performing whisker measurement based on the measurement result.   6. The whisker measurement method according to claim 5, wherein an initial resistance value of the gel-like conductive adhesive sheet is compared with the measurement result, and the whisker measurement is performed based on the comparison result.   The whisker measurement method according to claim 5, wherein the resistance value is a volume resistance value.

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