阅读说明：本技术 引线框架材料残余应力检测方法 (Method for detecting residual stress of lead frame material ) 是由 董振兴 张武 赵健 蒋强 任杰克 潘菲 于 2021-09-10 设计创作，主要内容包括：本发明涉及一种引线框架材料残余应力检测方法,包括下列步骤：在标准铜带材分条处理前进行取样,得到铜带样片；将铜带样片通过胶带固定到耐蚀板上,在胶带上设置至少一个位于铜带样片上的观测孔；将带有铜带样片的耐蚀板放入腐蚀液中腐蚀,直至观测孔中的铜带溶解；清洗铜带样片,晾干后测量铜带样片的翘曲高度。本发明提供的引线框架材料残余应力检测方法通过胶带将选取铜带样片贴合到耐蚀板上,再将其投入腐蚀液进行腐蚀,通过测量腐蚀后的铜带样片的翘曲高度,确定引线框架材料的残余应力大小,判断其是否满足生产使用要求,可以提前对引线框架材料的残余应力进行评价,并且检测方法简单,检测效率大幅度提升。(The invention relates to a method for detecting residual stress of a lead frame material, which comprises the following steps: sampling before the standard copper strip slitting treatment to obtain a copper strip sample wafer; fixing a copper strip sample on the corrosion-resistant plate through an adhesive tape, wherein the adhesive tape is provided with at least one observation hole positioned on the copper strip sample; putting the corrosion-resistant plate with the copper strip sample wafer into a corrosion solution for corrosion until the copper strip in the observation hole is dissolved; and cleaning the copper strip sample wafer, and measuring the warping height of the copper strip sample wafer after drying. According to the method for detecting the residual stress of the lead frame material, the selected copper strip sample is attached to the corrosion-resistant plate through the adhesive tape, then the copper strip sample is put into the corrosion-resistant plate for corrosion, the residual stress of the lead frame material is determined by measuring the warping height of the corroded copper strip sample, whether the residual stress meets the production and use requirements is judged, the residual stress of the lead frame material can be evaluated in advance, the detection method is simple, and the detection efficiency is greatly improved.)

1. A method for detecting residual stress of a lead frame material is characterized by comprising the following steps:

sampling before the standard copper strip slitting treatment to obtain a copper strip sample wafer;

fixing the copper strip sample on a corrosion-resistant plate through an adhesive tape, and arranging at least one observation hole on the copper strip sample on the adhesive tape;

putting the corrosion-resistant plate with the copper strip sample into a corrosion solution for corrosion until the copper strip in the observation hole is dissolved;

and cleaning the copper strip sample wafer, and measuring the warping height of the copper strip sample wafer after drying.

2. The method for detecting the residual stress of the lead frame material according to claim 1, wherein the length of the copper strip sample is 300-500 mm, and the width of the copper strip sample is 60-100 mm.

3. The method for detecting the residual stress of the lead frame material according to claim 1, wherein a transparent adhesive tape is adopted as the adhesive tape, and the corrosion-resistant plate is a plastic plate; in the width direction of the transparent adhesive tape, one part of the transparent adhesive tape is adhered to the corrosion-resistant plate, and the other part of the transparent adhesive tape is adhered to the edge of the copper strip sample.

4. The method for detecting the residual stress of the lead frame material according to claim 1, wherein the corrosive liquid comprises ferric trichloride and hydrochloric acid, and the concentration of the hydrochloric acid is 1-5%.

5. The method for detecting the residual stress of the lead frame material according to claim 1, wherein the temperature of the corrosive liquid is 25-35 ℃.

6. The method for detecting residual stress of lead frame material according to claim 1, wherein the step of cleaning the copper strip sample comprises:

and taking the corroded copper strip sample off the corrosion-resistant plate, washing the copper strip sample by using clear water and airing.

7. The method for detecting the residual stress of the lead frame material according to claim 1, wherein the step of measuring the warping height of the copper strip sample wafer after air drying comprises the following steps:

vertically suspending the dried copper strip sample, and loosening the lower edge of the copper strip sample;

and measuring the distance between the lower edge of the copper strip sample and the vertical surface, and determining the warping height of the copper strip sample.

Technical Field

The invention relates to the field of material detection methods, in particular to a method for detecting residual stress of a lead frame material.

Background

In the conventional C19400 (American standard iron bronze) lead frame master tape, residual stress can be generated in the material in the processing process, and with the trend of development of electronic industry towards lightness, thinness and precision, more and more selective etching processes in downstream procedures are used for processing the lead frame material, and the smaller the residual stress of the master tape material is, the better the residual stress is. Therefore, the residual stress detection work of the master tape material is especially necessary before the master tape material leaves the factory.

The traditional residual stress detection method is tedious and cannot ensure the accuracy of a detection result, and in order to meet the requirement of fast-paced production, the detection method needs to be continuously simplified and maintain more accurate measurement accuracy.

Disclosure of Invention

In view of the above, it is necessary to provide a method for detecting residual stress of lead frame material in view of at least one of the above-mentioned problems.

The invention provides a method for detecting residual stress of a lead frame material, which comprises the following steps:

sampling before the standard copper strip slitting treatment to obtain a copper strip sample wafer;

fixing the copper strip sample on a corrosion-resistant plate through an adhesive tape, and arranging at least one observation hole on the copper strip sample on the adhesive tape;

putting the corrosion-resistant plate with the copper strip sample into a corrosion solution for corrosion until the copper strip in the observation hole is dissolved;

and cleaning the copper strip sample wafer, and measuring the warping height of the copper strip sample wafer after drying.

In one embodiment, the length of the copper strip sample is 300-500 mm, and the width of the copper strip sample is 60-100 mm.

In one embodiment, the adhesive tape is transparent adhesive tape, and the corrosion-resistant plate is a plastic plate; in the width direction of the transparent adhesive tape, one part of the transparent adhesive tape is adhered to the corrosion-resistant plate, and the other part of the transparent adhesive tape is adhered to the edge of the copper strip sample.

In one embodiment, the corrosive liquid comprises ferric trichloride and hydrochloric acid, and the concentration of the hydrochloric acid is 1-5%.

In one embodiment, the temperature of the corrosive liquid is 25-35 ℃.

In one embodiment, the step of cleaning the copper strip sample includes:

and taking the corroded copper strip sample off the corrosion-resistant plate, washing the copper strip sample by using clear water and airing.

In one embodiment, the step of measuring the warp height of the copper strip sample after drying includes:

vertically suspending the dried copper strip sample, and loosening the lower edge of the copper strip sample;

and measuring the distance between the lower edge of the copper strip sample and the vertical surface, and determining the warping height of the copper strip sample.

The technical scheme provided by the embodiment of the invention has the following beneficial technical effects:

according to the method for detecting the residual stress of the lead frame material, the selected copper strip sample is attached to the corrosion-resistant plate through the adhesive tape, then the copper strip sample is put into the corrosive liquid for corrosion, the size of the residual stress of the lead frame material is determined by measuring the warping degree of the corroded copper strip sample, whether the residual stress meets the production and use requirements is judged, a sample can be selected before a large-size standard copper strip is cut into strips, the residual stress of the lead frame material can be evaluated in advance, the detection method is simple, and the detection efficiency is greatly improved.

Additional aspects and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a flowchart illustrating a method for detecting residual stress of a lead frame material according to an embodiment of the present invention;

FIG. 2 is a schematic view illustrating the attachment of a copper strip sample to a corrosion resistant plate according to an embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Possible embodiments of the invention are given in the figures. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein by the accompanying drawings. The embodiments described by way of reference to the drawings are illustrative for the purpose of providing a more thorough understanding of the present disclosure and are not to be construed as limiting the present invention. Furthermore, if a detailed description of known technologies is not necessary for illustrating the features of the present invention, such technical details may be omitted.

It will be understood by those skilled in the relevant art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is to be understood that the term "and/or" as used herein is intended to include all or any and all combinations of one or more of the associated listed items.

The technical solution of the present invention and how to solve the above technical problems will be described in detail with specific examples.

The method for detecting the residual stress of the lead frame material, disclosed by the invention, comprises the following steps as shown in figure 1:

s100: sampling is carried out before the standard copper strip is subjected to strip processing, and a copper strip sample is obtained. Optionally, in a specific implementation manner of an embodiment provided in the application of the present invention, the length of the copper strip sample is 300 to 500mm, the width of the copper strip sample is 60 to 100mm, for example, the length is 400mm, and the width of the copper strip sample is 80 mm.

S200: and fixing the copper strip sample on the corrosion-resistant plate through an adhesive tape, wherein at least one observation hole positioned on the copper strip sample is arranged on the adhesive tape. Optionally, as shown in fig. 2, the adhesive tape is transparent adhesive tape, and the corrosion-resistant plate is a plastic plate; in the width direction of the transparent adhesive tape, one part of the transparent adhesive tape is adhered to the corrosion-resistant plate, and the other part of the transparent adhesive tape is adhered to the edge of the copper strip sample.

S300: and putting the corrosion-resistant plate with the copper strip sample into the corrosive liquid to corrode until the copper strip in the observation hole is dissolved. Optionally, the corrosive liquid comprises ferric trichloride and hydrochloric acid, the concentration of the hydrochloric acid is 1-5%, and the concentration of the hydrochloric acid is specifically 2%. Optionally, the temperature of the corrosive liquid is 25-35 ℃.

S400: and cleaning the copper strip sample wafer, and measuring the warping height of the copper strip sample wafer after drying. Optionally, the step of cleaning the copper strip sample wafer comprises: and taking the corroded copper strip sample off the corrosion-resistant plate, washing the copper strip sample by using clear water and airing.

According to the method for detecting the residual stress of the lead frame material, the selected copper strip sample is attached to the corrosion-resistant plate through the adhesive tape, then the copper strip sample is put into the corrosive liquid for corrosion, the size of the residual stress of the lead frame material is determined by measuring the warping degree of the corroded copper strip sample, whether the residual stress meets the production and use requirements is judged, a sample can be selected before a large-size standard copper strip is cut into strips, the residual stress of the lead frame material can be evaluated in advance, the detection method is simple, and the detection efficiency is greatly improved.

Optionally, in a specific embodiment, the step of measuring the warp height of the copper strip sample after drying in the air includes: and (4) vertically suspending the dried copper strip sample, and loosening the lower edge of the copper strip sample. And measuring the distance between the lower edge of the copper strip sample and the vertical surface, and determining the warping height of the copper strip sample.

In a practical case, the whole set of methods can be refined as: sampling before stripping, preprocessing a sample (the length and the width of the sample are 400 multiplied by 80 and unit mm), adhering an adhesive tape (common transparent adhesive tape can be adopted) on one side of a copper strip sample and fixing the copper strip sample to a corrosion-resistant plate (all non-metal plastic materials), digging a hole on the single-side adhesive tape and stripping the adhesive tape at the dug hole, preparing etching solution (ferric chloride, hydrochloric acid and concentration are 2%), preheating the etching solution (setting 30 ℃), corroding the sample (2 samples can be corroded at one time, walking in the etching machine for 30 minutes in one direction, and main control parameters of the etching machine comprise walking speed and etching solution temperature), completing corrosion (observing that the copper strip at the dug hole is completely dissolved), taking out the sample and cleaning with clear water (flushing), airing, placing the sample vertically, and measuring the warping height (the distance between the strip and a vertical surface).

Specifically, compared with the traditional lead frame material residual stress detection method, the method provided by the application has the following beneficial technical effects:

1. the sample selection is advanced compared with the traditional method, and the sample can be selected before striping, and the residual stress of the lead frame material can be evaluated in advance.

2. The sample size is increased, and the finished product specification and detection requirements of customers are met. The detection time efficiency is improved, the detection time consumption of a single sample is reduced from the original 40 minutes to 20 minutes, and the main effects are that the number of corrosion sample pieces is increased for 1 time, 1 surface is reduced by tape pasting, and hole digging is changed from scribing.

3. The detection indexes are more suitable for the working conditions of customers, and the accuracy is improved.

4. The change of the corrosive liquid can be recycled, and the requirements of energy conservation, consumption reduction and environmental protection are met.

Those of skill in the art will appreciate that the various operations, methods, steps in the processes, acts, or solutions discussed in this application can be interchanged, modified, combined, or eliminated. Further, other steps, measures, or schemes in various operations, methods, or flows that have been discussed in this application can be alternated, altered, rearranged, broken down, combined, or deleted. Further, steps, measures, schemes in the prior art having various operations, methods, procedures disclosed in the present application may also be alternated, modified, rearranged, decomposed, combined, or deleted.

The foregoing is only a partial embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations should also be regarded as the protection scope of the present application.