Copper Plating Method Research Articles

無電解銅めっきにおけるフェナントロリン添加剤の作用機構

An electroless copper plating method using EDTA (ethylenediaminetetraacetic acid) as a complexing agent and HCHO as a reducing agent has been studied. Additives used were 2, 9-dimethyl-1, 10-phenanthroline (2, 9-dmph) and 5, 6-dimethyl-1, 10-phenanthroline (5, 6-dmph).The working mechanism of 2, 9-dmph, which had a cuproine functional group, was the reiteration of the following three steps:1. adsorption of 2, 9-dmph on the copper working electrode;2. production of Cu (I) (2, 9-dmph)2 complex on the electrode; and3. transference of the Cu(I)-complex to the plating solution.As a result, 2, 9-dmph prevented the active alcoholate ion from being adsorbed on the working electrode. Since the characteristic wave disappeared, polarization characteristics were explicable by the mixed potential theory, and copper complex ion Cu (II)Y2- was directly reduced to metallic copper. The surface of the deposit was uniform and the grains were linked. The cross section of the deposit was virtually identical to that of metallic copper.In the case of 5, 6-dmph, which had a ferroine functional group, copper complex Cu (I) (5, 6-dmph)2 formed on the electrode failed to transfer to the plating solution, and the mixed potential theory did not hold. The deposit was amorphous. The surface of the deposit was rough and the cross section was spongy.

Adhesion between copper-plated acrylic tray resin and a polysulfide rubber impression material

The method of copper plating on acrylic resin was developed, and the bond strength to polysulfide rubber was measured in comparison with that of the adhesive coating. The bond strength with copper plating was greater than with adhesive coating. The specimens with adhesive coating failed due to a rupture occurring at the elastomer-adhesive interface, while those with copper plating had cohesive-adhesive failure. The method of copper plating on acrylic resin improved the adhesion between the polysulfide rubber and the custom-built acrylic resin tray.

A modified electroless method for the fabrication of microstrip lines on alumina substrates

Experimental results on tho loss of microstrip transmission lines and various other component. have been measured on alumina substrates, which are fabricated, using a now method of electroless copper plating. A. 3 dB microstrip line branch guide directional coupler has been fabricated and its performance studied. In both cases experimental results are compared with theoretical values.

Measurement of Repeated Stress by Copper Plating Method

Measurement of Repeated Stress by Copper Plating Method

Method for visualizing the distribution of current in alloyed germanium p +-n junctions

In order to study the origins of inferior reverse characteristics of alloyed junctions, a method for visualizing the distribution of current in the junctions has been developed. In principle, this method consists of the following processes: the sample is immersed in an electrolytic solution and a voltage is applied between the sample and a counter electrode; an electrochemical change occurs on the surface of the sample corresponding to the value of current which flows through the junction; the patterns resulting from the electrochemical change are observed under the microscope. In the case of p +-n-junctions prepared by alloying indium into n-type germanium wafer, a copper plating method is most satisfactory, in which copper is deposited in correspondence with the current distribution of the junction. In order to get definite correspondence of the copper deposition pattern with the distribution of junction current, it is important to remove the potential barriers existing between plating solution and the surface of the sample. For this purpose, care must be taken with respect to the components of plating solution and to the method of application of plating voltage. Application of d.c. plating voltage is only effective for the samples having special voltage-current characteristics, whereas the pulse method, in which a short pulse voltage is applied to remove the potential barrier, and subsequently a small current is given to provide copper deposition, gives good results. This method can be utilized not only to detect defective structure in the junction which brings about inferior characteristics, but also to observe the distribution of junction current as a function of applied plating voltage, by the repetition of plating under several values of voltage, which leads to bringing out of non-uniform localized breakdown spots.

A SIMPLE APPARATUS FOR ACCURATELY FIXING BLOOD-SLIDES BY HEAT

In fixing blood-slides by heat, one finds that the results of the copperplate method are so inconstant that it is difficult to get a good specimen unless one keeps in constant practice. There is no way of determining the exact amount of heat used or of keeping the heat regular. I have devised the following simple apparatus for office and laboratory use: As shown in the illustration, an ordinary laboratory standard supports an iron dish, C, resting on an asbestos plate, under which is a gas burner. This iron dish is easily made by screwing a two-inch nipple into a pipe cap. This dish is filled with petrolatum, into which is sunk a small, thin copper cup so that the end sticks out as shown at B. This cup is just large enough to admit with ease the glass slide. In the petrolatum is sunk the bulb of a thermometer, A.