A method for designing the dimensions of a pressure welding fixture

Abstract

This invention discloses a method for designing the dimensions of a pressure welding fixture. The pressure welding fixture includes a pressure plate and a heating block, and is used to weld metal wire onto a frame. The design method includes the following steps: measuring the dimensions of the frame and setting the reference dimensions of the pressure plate and the heating block; calculating the dimensional offset k1 of the frame, the reference dimensional offset k2 of the pressure plate, and the reference dimensional offset k3 of the heating block according to the formula k=L0×T×α; then calculating the dimensions of the pressure plate and the heating block according to the formula L=L0+Δk, and finally obtaining the dimensions of the pressure welding fixture. This method for designing the dimensions of a pressure welding fixture incorporates the dimensional changes caused by the thermal expansion of the frame into the design of the fixture dimensions. This avoids misalignment between the fixture and the frame due to thermal expansion, ensuring normal welding operations and improving product yield.

Description

Technical Field

[0001] This invention belongs to the field of pressure welding fixture packaging technology, and specifically relates to a design method for the dimensions of pressure welding fixtures. Background Technology

[0002] In the existing technology, the operating temperature of wire bonding machines is generally 200℃. Under such high temperature conditions, the frame, pressure plate and heating block will expand thermally, which will increase the distance between the windows on the frame, pressure plate and heating block. As a result, the components will be misaligned during pressure welding and cannot be aligned. The windows between the pressure plate and heating block and the frame will not coincide, which will lead to the inability to perform pressure welding or a low product qualification rate. Summary of the Invention

[0003] In view of this, in order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a design method for the size of a pressure welding fixture, which solves the problem that the windows between the pressure welding fixture and the frame do not coincide and cannot be aligned due to thermal expansion caused by heating.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] One object of the present invention is to provide a design method for the dimensions of a pressure welding fixture, the pressure welding fixture including a pressure plate and a heating block, the pressure welding fixture being used to weld metal wires to a frame, the design method comprising the following steps:

[0006] The dimensions of the frame are measured and the reference dimensions of the pressure plate and the heating block are preset; according to the formula k=L0×T×α, the dimensional offset k1 of the frame, the reference dimensional offset k2 of the pressure plate and the reference dimensional offset k3 of the heating block are calculated respectively; then according to the formula L=L0+Δk, the dimensions of the pressure plate and the heating block are calculated respectively, and finally the dimensions of the pressure welding fixture are obtained.

[0007] In the formula, k is the offset, L and L0 are both side lengths, T is the welding temperature, α is the coefficient of thermal expansion, and Δk is the difference between k1 and k2 or between k1 and k3. The welding temperature is 180℃-220℃. During welding, the pressure plate and the heating block are located on the upper and lower sides of the frame, respectively.

[0008] Because both the welding fixture and the frame undergo thermal expansion under the high temperatures of welding, the company can take into account the dimensional changes caused by thermal expansion of the frame under high temperatures when designing the welding fixture, based on the frame material provided by the customer. Since the frame is usually made of copper and the welding fixture is made of steel, the coefficient of thermal expansion of the frame is greater than that of the welding fixture. Under high temperatures, the welding fixture will also undergo thermal expansion, causing a change in size. However, the change in size of the welding fixture is less than that of the frame. Therefore, it is only necessary to calculate the difference in dimensional changes between the welding fixture and the frame, and take this difference into account when designing the length and width of the welding fixture to obtain the actual dimensions after considering the thermal expansion of the welding fixture and the frame. Since the size of the frame remains unchanged while the size of the welding fixture increases, the windows between the frame and the welding fixture can still be aligned and overlapped after the frame undergoes thermal expansion during high-temperature welding, thus allowing for normal operation.

[0009] According to some preferred embodiments of the invention, the dimensions of the frame include the length and width of the frame, the reference dimensions of the pressure plate include the reference length and reference width of the pressure plate, and the reference dimensions of the heating block include the reference length and reference width of the heating block.

[0010] According to some preferred embodiments of the present invention, in the step of presetting the reference dimensions of the pressure plate and the heating block, the reference dimensions of the pressure plate and the heating block are equal to the dimensions of the frame.

[0011] According to some preferred embodiments of the present invention, when calculating the length of the pressure plate, Δk is the difference between the offset of the frame length and the offset of the reference length of the pressure plate; when calculating the width of the pressure plate, Δk is the difference between the offset of the frame width and the offset of the reference width of the pressure plate.

[0012] According to some preferred embodiments of the present invention, when calculating the length of the heating block, Δk is the difference between the offset of the frame length and the offset of the reference length of the heating block; when calculating the width of the heating block, Δk is the difference between the offset of the frame width and the offset of the reference width of the heating block.

[0013] Specifically, the design method for the dimensions of a pressure welding fixture according to the present invention includes the following steps:

[0014] Measure the length and width of the frame, and set the reference length and width of the pressure plate and the reference length and width of the heating block;

[0015] According to the formula k=L0×T×α, the length offset and width offset of the frame, the reference length offset and reference width offset of the pressure plate, and the reference length offset and reference width offset of the heating block are calculated respectively.

[0016] Then, calculate the difference between the offset of the frame length and the offset of the pressure plate reference length, the difference between the offset of the frame width and the offset of the pressure plate reference width, the difference between the offset of the frame length and the offset of the heating block reference length, and the difference between the offset of the frame width and the offset of the heating block reference width.

[0017] Finally, the length and width of the pressure plate and the length and width of the heating block are calculated according to the formula L=L0+Δk, and the dimensions of the pressure welding fixture are finally obtained.

[0018] According to some preferred embodiments of the invention, the welding temperature T is in the range of 180°C-220°C.

[0019] According to some preferred embodiments of the invention, Δk is greater than 0.

[0020] According to some preferred embodiments of the invention, the coefficient of thermal expansion of the frame is greater than that of the pressure plate and the heating block.

[0021] According to some preferred embodiments of the present invention, both the pressure plate and the heating block are made of steel, and the frame is made of copper. In some embodiments of the present invention, the coefficient of thermal expansion of the frame is 17.5 × 10⁻⁶. -6 / ℃, the pressure plate and heating block have the same coefficient of thermal expansion, both being 13×10. -6 / ℃.

[0022] According to some preferred embodiments of the present invention, the pressure plate includes multiple rows of uniformly spaced first window units, each row of first window units including multiple spaced first windows; the heating block includes multiple rows of uniformly spaced second window units, each row of second window units including multiple spaced second windows; the frame includes multiple rows of uniformly spaced third window units, each row of third window units including multiple spaced third windows; during welding, the first, second, and third windows are aligned. Since the first windows in the pressure plate, the second windows in the heating block, and the third windows in the frame are all uniformly spaced in their respective components, once the actual length and width of the pressure plate and the heating block are designed, the distance between adjacent first windows on the pressure plate and the distance between adjacent second windows on the heating block are also designed accordingly. Compared to the reference dimensions of the pressure welding fixture, in the actual size of the pressure welding fixture, the distance between adjacent first windows on the pressure plate increases, and the distance between adjacent second windows on the heating block also increases.

[0023] Due to the adoption of the above technical solutions, the advantages of the present invention compared with the prior art are as follows: The design method of the pressure welding fixture of the present invention incorporates the dimensional changes caused by the thermal expansion of the frame into the dimensional design of the pressure welding fixture, which can avoid the situation where the windows between the pressure welding fixture and the frame do not coincide due to the thermal expansion of the frame, thus ensuring the normal progress of welding operations and improving the product qualification rate. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] The design method for the dimensions of a pressure welding fixture in this embodiment specifically includes the following steps:

[0026] Measure the length and width of the frame, and preset the reference length and width of the pressure plate and the reference length and width of the heating block according to the length and width of the frame; wherein the reference length of the pressure plate and the reference length of the heating block are equal to the length of the frame, and the reference width of the pressure plate and the reference width of the heating block are equal to the width of the frame.

[0027] Based on the formula k=L0×T×α, the length offset and width offset of the frame, the reference length offset and reference width offset of the pressure plate, and the reference length offset and reference width offset of the heating block are calculated respectively.

[0028] Then calculate the difference between the offset of the frame length and the offset of the pressure plate reference length, the difference between the offset of the frame width and the offset of the pressure plate reference width, the difference between the offset of the frame length and the offset of the heating block reference length, and the difference between the offset of the frame width and the offset of the heating block reference width.

[0029] Finally, the length and width of the pressure plate and the length and width of the heating block are calculated according to the formula L=L0+Δk, and the dimensions of the pressure welding fixture are finally obtained.

[0030] Example 1

[0031] This embodiment provides a method for designing the dimensions of a pressure welding fixture, including the following steps:

[0032] The measured length of the frame is 100mm and the width is 78mm. The reference length of the preset pressure plate is 100mm and the reference width is 78mm, as is the reference length of the heating block.

[0033] According to the formula k = L0 × T × α, where the welding temperature T is 200℃ and the coefficient of thermal expansion of the frame is 17.5 × 10⁻⁶. -6 / ℃, the coefficient of thermal expansion of both the pressure plate and the heating block is 13×10. -6 / ℃, the length offset of the frame is calculated to be 100mm × 200℃ × 17.5 × 10. -6 / ℃=0.35mm, width offset is 78mm×200℃×17.5×10 -6 / ℃=0.273mm; the reference length offset of the pressure plate is 100mm×200℃×13×10 -6 / ℃=0.26mm, the reference width offset is 78mm×200℃×13×10 -6 / ℃=0.2028mm, the reference length offset of the heating block is 100mm×200℃×13×10 -6 / ℃=0.26mm, reference width offset is 78mm×200℃×13×10 -6 / ℃=0.2028mm.

[0034] Then, the differences between the offset of the frame length and the offset of the pressure plate reference length are calculated as follows: 0.35mm-0.26mm=0.09mm; the differences between the offset of the frame width and the offset of the pressure plate reference width are 0.273mm-0.2028mm=0.0702mm; the differences between the offset of the frame length and the offset of the heating block reference length are 0.35mm-0.26mm=0.09mm; and the differences between the offset of the frame width and the offset of the heating block reference width are 0.273mm-0.2028mm=0.0702mm.

[0035] Finally, according to the formula L=L0+Δk, the length of the pressure plate is calculated to be 100mm+0.09mm=100.09mm and the width is 78mm+0.0702mm=78.0702mm, and the length of the heating block is calculated to be 100mm+0.09mm=100.09mm and the width is 78mm+0.0702mm=78.0702mm, thus obtaining the actual dimensions of the pressure welding fixture.

[0036] In this embodiment, the pressure plate is provided with multiple rows of uniformly spaced first window units, each row of first window units including multiple spaced first windows; the heating block is provided with multiple rows of uniformly spaced second window units, each row of second window units including multiple spaced second windows. Since the double-base island frame located between the pressure plate and the heating block is also provided with multiple rows of uniformly spaced third window units, each row of third window units including multiple spaced third windows, during welding, the first, second, and third windows located in the same vertical direction are aligned and overlapped, which can ensure a good welding effect and improve the product qualification rate.

[0037] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method of designing a size of a press-bonding jig including a press plate and a heating block, the press-bonding jig being used to weld a metal wire on a frame, characterized by, The design method comprises the following steps: measuring the size of the frame and presetting the reference size of the pressing plate and the heating block; calculating the size offset k1 of the frame, the reference size offset k2 of the pressing plate and the reference size offset k3 of the heating block according to the formula k=L0×T×α, wherein k is the offset, L0 is the side length, T is the welding temperature, and α is the thermal expansion coefficient; then calculating the size of the pressing plate and the size of the heating block according to the formula L=L0+Δk, and finally obtaining the size of the press welding fixture; wherein L is the side length, and Δk is the difference between k1 and k2 or the difference between k1 and k3.

2. The design method of claim 1, wherein, The size of the frame includes the length and width of the frame, the reference size of the pressing plate includes the reference length and reference width of the pressing plate, and the reference size of the heating block includes the reference length and reference width of the heating block.

3. The method of designing according to claim 2, wherein, In the step of presetting the reference size of the pressing plate and the heating block, the reference size of the pressing plate and the heating block is equal to the size of the frame.

4. The method of designing according to claim 3, wherein, When calculating the length of the pressing plate, the Δk is the difference between the offset of the frame length and the offset of the reference length of the pressing plate; when calculating the width of the pressing plate, the Δk is the difference between the offset of the frame width and the offset of the reference width of the pressing plate.

5. The method of claim 3, wherein, When calculating the length of the heating block, the Δk is the difference between the offset of the frame length and the offset of the reference length of the heating block; when calculating the width of the heating block, the Δk is the difference between the offset of the frame width and the offset of the reference width of the heating block.

6. The method of claim 1, wherein, The welding temperature T ranges from 180℃ to 220℃.

7. The method of claim 1, wherein, The Δk is greater than 0.

8. The design method of claim 1, wherein, The thermal expansion coefficient of the frame is greater than the thermal expansion coefficient of the pressing plate and the heating block.

9. The design method of claim 8, wherein, The materials of the pressing plate and the heating block are both steel, and the material of the frame is copper.

10. The method of claim 1, wherein, The pressing plate comprises a plurality of first window units arranged in uniform intervals, each column of the first window units comprises a plurality of first windows arranged at intervals; the heating block comprises a plurality of second window units arranged in uniform intervals, each column of the second window units comprises a plurality of second windows arranged at intervals; the frame comprises a plurality of third window units arranged in uniform intervals, each column of the third window units comprises a plurality of third windows arranged at intervals; during welding, the first windows, the second windows and the third windows are aligned.