CN1462663A

CN1462663A - Method for mamufacturing oxidation resisting welding spots for surface adhesion components (SMD)

Info

Publication number: CN1462663A
Application number: CN 02121006
Authority: CN
Inventors: 薛维进; 林立昌; 黄玉洳; 李鸿国
Original assignee: NIANCHENG SCIENCE & TECHNOLOGY Co Ltd
Current assignee: NIANCHENG SCIENCE & TECHNOLOGY Co Ltd
Priority date: 2002-05-29
Filing date: 2002-05-29
Publication date: 2003-12-24

Abstract

A process for preparing the antioxidizing weld pads of surface mounted device (SMD) includes such steps as electroplating tin layer on the surface of pad, immersing the pad in hot oil at 250 deg.C for 3-5 seconds for smelting its surface structure, and cooling for making the molten tin flow into the surface gaps to compact it.

Description

Surface adhesion components (SMD) oxidation resisting welding spots manufacture method

Technical field

The present invention relates to a kind of surface adhesion components (SMD) oxidation resisting welding spots manufacture method, especially finger a kind of surface adhesion components (SMD) solder joint imposes after the tin layer is electroplated and soaks the processing of melting welding point tin layer, to make the regeneration of solder joint surface texture reach densified manufacture method, and then make solder joint have anti-oxidant, help weld job, and can increase wearability etc. and improve the surface mount technology effect.

Background technology

At present, the solder joint of general surface adhesion components (SMD) is for the ease of the surface mount of element at upper substrate, and this solder joint layer is silver layer from inside to outside in regular turn, nickel dam and tin layer (or tin lead layer) pile up and form, this kind solder joint layer is to utilize silver to have preferable electric conductivity, and with silver layer as connecting the chip internal wiring to outside interface, and utilize tin to have the reflow temperature of reduction very easily in combining with the adhesive agent tin cream, and with the tin layer as the outside weldings interface, again because silver layer sticks together more difficult the combination with the tin laminar surface, so utilize a nickel dam as the combine interface of silver layer therebetween, and this nickel dam can provide anti-welding heat and non-oxidizability with the tin interlayer.

The outside tin layer of above-mentioned solder joint layer is to adopt to be coated on the nickel dam with plating mode, adopt with the barrel plating principle because of surface adhesion components (SMD) volume is less again, (SMD) constantly rolls in electrolytic cell by surface adhesion components, and make the surface-coated metallic tin layer of solder joint, but with present electroplating technology, outermost tin layer can't reach the surface texture high compactionization, make between adjacent metal tin and can leave clearance space, loose tin laminar surface tissue like this, can form oxidative phenomena by the clearance space place, therefore on the upper plate weld job, all can influence the weldability and the reliability of element solder joint, so present stage surface adhesion components (SMD) can form a bottleneck on electroplating technology, the present invention that Here it is will study the problem that overcomes.

The inventor is based on the weldability demand of surface adhesion components (SMD) solder joint, concentrate on studies, be engaged in the experience and the knowledge of this industry for many years with accumulation, finally develop a kind of surface adhesion components (SMD) oxidation resisting welding spots manufacture method, improve the surface mount technology effect so that solder joint has is anti-oxidant, help weld job and can increase wearability etc., for demand utilization on this industry.

Summary of the invention

The object of the present invention is to provide a kind of surface adhesion components (SMD) oxidation resisting welding spots manufacture method, its main method is: the surface adhesion components behind the zinc-plated layer of solder joint surface electrical is implemented to soak melting welding point tin layer handle, this soaks the processing of melting welding point tin layer is that surface adhesion components solder joint tin stratification is gone into to be heated in the deep fat groove 250 ℃ with its surface texture of fusion, and through 3～5 seconds soak times, proposing the deep fat groove cools off, allow tin layer structure fusing fill up clearance space and reach the densified surface tissue, and then finish surface adhesion components smoothly and have oxidation resistant solder joint manufactured goods.

Another object of the present invention is to provide a kind of surface adhesion components (SMD) oxidation resisting welding spots manufacture method, main surface adhesion components (SMD) solder joint imposes after the tin layer is electroplated and soaks the processing of melting welding point tin layer, making solder joint surface texture regeneration reach densified, so make solder joint have anti-oxidant, help weld job and can increase wearability etc. to improve the surface mount technology effect.

Description of drawings

Fig. 1: be the implementing procedure figure of surface adhesion components oxidation resisting welding spots manufacture method of the present invention.

Fig. 2: be the sectional schematic diagram of surface adhesion components solder joint layer of the present invention.

Fig. 3: be the surface texture schematic diagram behind the surface adhesion components plating solder joint tin layer of the present invention.

Fig. 4: for surface adhesion components of the present invention is electroplated the surface texture schematic diagram of solder joint tin layer after soaking molten tin layer.

The specific embodiment

Now according to the above-mentioned announcement surface adhesion components that purpose adopts of the present invention (SMD) oxidation resisting welding spots manufacture method, now be described with reference to the accompanying drawings as follows:

As shown in Figure 1, be the implementing procedure figure of surface adhesion components of the present invention (SMD) oxidation resisting welding spots manufacture method.

Step 1, the solder joint layer that the ceramic body of coating wafer has been implemented silver layer sintering and nickel dam plating in both end sides adopts with the plating of rolling, make the surface adhesion components (SMD) of small size in electrolytic cell, constantly roll electroplating and make the solder joint outer surface metallic tin layer that is covered, be provided with finishing silver layer 10 as shown in Figure 2, nickel dam 20 and tin layer 30 are covered from inside to outside in regular turn and pile up the solder joint layer that forms, and the tin layer 30 surface texture figure that this plating of rolling forms as shown in Figure 3,301 in its adjacent metal tin can leave many spacings clearance space not of uniform size 302, so, soak the processing of melting welding point tin layer and carry out next step in order to make the loose tin layer 30 of surface texture can be more densified.

Step 2, surface adhesion components (SMD) behind the zinc-plated layer of solder joint surface electrical is implemented to soak melting welding point tin layer to be handled, it is inserted surface adhesion components (SMD) to impose in the deep fat groove and adds hot melt tin, this deep fat groove adds thermosol Xi Wendu for being set in 250 ℃, and the time that surface adhesion components (SMD) is soaked in the deep fat groove is about 3～5 seconds, heating-up temperature can be higher than the about 230 ℃ fusing point of tin, the about 1000 ℃ of nickel fusing points and the about 963 ℃ silver point that are not higher than the solder joint layer again, so allow tin layer 30 structure melt, cause the metallic tin 301 of tin layer 30 to be filled up in the clearance space 302.

Step 3, the surface adhesion components (SMD) that will soak melting welding point tin layer is cooled off, and makes solder joint tin layer 30 surface texture reach densified (as shown in Figure 4), and then finishes surface adhesion components (SMD) smoothly and have oxidation resistant solder joint manufactured goods.

Learn by above-mentioned explanation, the surface adhesion components that the present invention made (SMD), because of solder joint tin laminar surface tissue reaches densified, so the tin laminar surface is organized and is not had the hole phenomenon, and then have preferable non-oxidizability, when upper substrate welds, help weld job, and also can increase its wearability for the reliability-test of tin laminar surface tissue density, so surface adhesion components (SMD) product that the inventive method is made helps to improve the effect of surface mount technology, has industry applications.

In addition, surface adhesion components (SMD) solder joint outermost layer also can adopt tin lead layer, its also applicable above-mentioned manufacture method step and make surface adhesion components (SMD) and have oxidation resistant solder joint manufactured goods.

In sum, surface adhesion components proposed by the invention (SMD) oxidation resisting welding spots manufacture method, it is anti-oxidant and help the intended purposes of weldability to reach solder joint really, has high industry applications.

Claims

1. a surface adhesion components (SMD) oxidation resisting welding spots manufacture method, it is characterized in that, its main method is: the surface adhesion components behind the zinc-plated layer of solder joint surface electrical is implemented to soak melting welding point tin layer handle, this soaks the processing of melting welding point tin layer is that surface adhesion components solder joint tin stratification is gone into to be heated in the deep fat groove 250 ℃ with its surface texture of fusion, and through 3～5 seconds soak times, proposing the deep fat groove cools off, allow tin layer structure fusing fill up clearance space and reach the densified surface tissue, and then finish surface adhesion components smoothly and have oxidation resistant solder joint manufactured goods.