Calculation method for lead frame stepping parameters

Abstract

The invention relates to the technical field of semiconductor integrated circuit package testing, and discloses a method for calculating lead frame stepping parameters, which comprises the following steps of: 1, inputting parameters; 2, calculating the number of stepping columns of each unit; 3, calculating lndex and the total length of each unit; 4, the number of Index numbers / the number of stepping times is calculated; step 5, calculating a light index center (Right index center); step 6, calculating a Left index center (Left index center); step 7, calculating the Y (Front Center offset), and calculating the Y (Front Center offset); step 8, calculating # imgabs0 #; and step 9, outputting: # imgabs 1 #. According to the method, the calculation deviation caused by human factors is avoided through automatic calculation, so that the calculation of the stepping parameters is more reliable, the universality and flexibility of the method are improved, an existing manual calculation method is improved into the mode that the needed stepping parameters are obtained through automatic calculation by inputting part of parameters of the lead frame, and the calculation efficiency is improved. And the operation is simple.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor integrated circuit packaging and testing, and in particular to a method for calculating stepping parameters of a lead frame. Background Art

[0002] As the main structural material in integrated circuits, lead frames can play the basic role of heat dissipation, supporting and fixing chips, as well as the key role of connecting external circuits and transmitting electrical signals. With the development of science and technology, the scale of the integrated circuit market continues to expand, and based on this, the demand for lead frames with different advancements is also gradually increasing.

[0003] The stepping parameters of the lead frame refer to the variables that the lead frame needs to move when the welding head moves to the next set of circuits to be bonded. Setting appropriate stepping parameters is crucial to ensure the quality of bonding and production efficiency. Before wire bonding, in order to ensure smooth stepping of the frame, the stepping parameters need to be set on the pressure welding machine, which changes with the inherent parameters of the frame. Every time a new product is introduced, if the lead frame used by the new product is different from the frame size or number of rows and columns of the existing lead frame, the stepping parameters of the two are different, and the lead frame stepping parameters need to be calculated and set for the frame. If there are a large number of new product frames, manual calculation is more cumbersome. Summary of the invention

[0004] Technical issues solved: In view of the deficiencies in the prior art, the present invention provides a method for calculating the stepping parameters of a lead frame, which improves the existing manual calculation method into a method for calculating the required stepping parameters by inputting some parameters of the lead frame. The method has the advantages of simple operation, effective reduction of labor costs, and improvement of the efficiency of introducing new products, thus solving the problems of the above-mentioned technologies.

[0005] Technical solution: To achieve the above object, the present invention provides the following technical solution: a method for calculating stepping parameters of a lead frame, comprising the following steps: Step 1. Input parameters: frame length A, frame width B, total number of frame columns C, distance from the center of the leftmost column to the 0 point D, distance from the leftmost frame edge to the 0 point in the frame drawing E, spacing between each column F, and hot seat adsorption length G; Step 2: Calculate the number of step columns per unit: ; Step 3: Calculate Lndex, the total length of each unit: ; Step 4: Calculate the Index number / number of steps: ; Step 5. Calculate the right index center: subtract the length from the rightmost half unit to the right edge from the total length. ; Step 6. Calculate the Left index center: that is, the length from the leftmost half unit to the left edge position, and conduct classification discussion: When a is an even number, ; When is an odd number, ; ; Step 7: Calculate Y Front center offset; Step 8. Calculation ; Step 9. Output: ; ; ; ; .

[0006] By inputting key parameters such as frame length, width, and total number of columns, the system can perform subsequent calculation steps without manual intervention, greatly reducing the errors that may occur during manual calculations and improving the calculation speed. The calculation formulas involved in this method are all accurately derived and verified, which can ensure the accuracy of the calculation results. Compared with manual calculations, automated calculations avoid calculation deviations caused by human factors, making the calculation of step parameters more reliable. Users only need to enter the necessary parameters according to the prompts without having to understand the complex calculation process. This simple operation method reduces the requirements for user expertise, allowing more people to easily master and use this method. This method is suitable for the calculation of step parameters of lead frames of different specifications and sizes. By adjusting the input parameters, users can easily cope with the calculation requirements in various scenarios, improving the versatility and flexibility of the method, and achieving the improvement of the existing manual calculation method to calculate the required step parameters by inputting some parameters of the lead frame.

[0007] Preferably, in step 2, a is rounded up and the decimal part is discarded.

[0008] Original manual calculation method: During the manual calculation process, there will be non-integer step column numbers, which will increase the complexity and error rate of subsequent calculation steps. If the step column number a is not an integer unit, the subsequent step times and step distance calculations will be affected.

[0009] Improved calculation method: By rounding a and discarding the decimal part, it is ensured that the step column number a is an integer. This processing method paves the way for the subsequent calculation of the last step and improves the accuracy of the last step calculation.

[0010] Original manual calculation method: The length needs to be measured through a measuring microscope, the value is not accurate, and it is easy to pull off or step poorly during the lead frame stepping process.

[0011] Improved calculation method: The calculated stepping parameters can be used to coordinate with the machine to step the lead frame to the optimal position.

[0012] In actual production, the size of the frame usually has a certain batch deviation. If measured manually, multiple measurements are required to obtain the average value to obtain the drawing calculation value, and the measuring equipment has a systematic error. Therefore, according to the error propagation formula, the total error value will be larger. The present invention calculates the stepping parameters through the drawing, and the error value is small. It is also more in line with actual production needs through verification.

[0013] This processing method makes the calculation results more in line with actual production needs and avoids operational difficulties and errors caused by measurement errors. In actual production, there are errors between the size measurement values ​​of the lead frame and the drawing values, and the actual values ​​fluctuate above and below the drawing values. If calculated based on the drawing values, the propagation of errors can be avoided as much as possible, ensuring the practicality and feasibility of the calculation results.

[0014] Rounding and discarding the decimal part provides a unified calculation standard for all related calculation steps. The unified calculation standard ensures the consistency and reliability of the calculation results and reduces the errors and deviations caused by different calculation standards. When calculating the number of steps c and the last step distance M, the unified integer step column number a ensures the consistency of the calculation results.

[0015] Preferably, in step 4 Round up to the nearest digit.

[0016] Original manual calculation method: If a is not rounded up, the number of steps c may not be enough to cover all the columns. If the result is close to an integer but less than an integer, the number of steps may be insufficient, resulting in some columns not being covered.

[0017] Improved calculation method: By rounding a to an integer and adding one digit, it is ensured that the number of steps c is sufficient to cover all the columns. This processing method avoids the problem of insufficient number of steps and ensures that all columns can be correctly covered.

[0018] Rounding up to the nearest integer ensures that the number of steps c can accurately cover all columns, avoiding omissions or insufficient coverage. The accurate number of steps covers all columns, improves the accuracy and completeness of the calculation results, and avoids calculation errors and omissions caused by insufficient number of steps.

[0019] Original manual calculation method: If the number of steps is not rounded up, the subsequent step number calculation may require complex adjustments or judgments, increasing the complexity of the calculation and the risk of human error.

[0020] Improved calculation method: By rounding up to the nearest integer, the calculation of the number of steps c is simplified, making the subsequent calculation steps more direct and simple. When calculating the last step distance M, the number of steps c after rounding up can be directly used without complicated adjustments and judgments.

[0021] In actual production, the number of steps usually needs to cover all the columns to ensure that all products can be processed correctly. Rounding up to the nearest integer ensures that the calculation results meet the actual operation requirements. This processing method makes the calculation results more in line with the actual production requirements and avoids the operational difficulties and errors caused by insufficient stepping times. In actual production, it is necessary to ensure that all products can be processed correctly. Rounding up to the nearest integer ensures the practicality and feasibility of the calculation results.

[0022] Rounding up to the nearest integer provides a unified calculation standard for all related calculation steps, ensuring the consistency of the number of steps. The unified calculation standard ensures the consistency and reliability of the calculation results and reduces the errors and deviations caused by different calculation standards. When calculating the last step distance M, the unified number of steps c ensures the consistency of the calculation results.

[0023] Preferably, in step five .

[0024] Preferably, in step five .

[0025] Preferably, in step five .

[0026] Preferably, when a is an even number in step 6, the Left index center calculation formula is: .

[0027] Preferably, in step six When it is an odd number, the Left index center calculation formula is: .

[0028] Preferably, the calculation formula of step seven is: .

[0029] Preferably, the calculation formula of step eight is: .

[0030] Compared with the prior art, the present invention provides a method for calculating stepping parameters of a lead frame, which has the following beneficial effects: 1. The present invention provides a method for calculating the stepping parameters of a lead frame. By inputting the key parameters of frame length, width, and total number of columns, the subsequent calculation steps can be automatically performed without manual intervention, which greatly reduces the errors that may occur in the manual calculation process and improves the calculation speed. The calculation formulas involved in the method are all accurately derived and verified, which can ensure the accuracy of the calculation results and greatly reduce the calculation errors. Compared with manual calculation, automated calculation avoids the calculation deviation caused by human factors, making the calculation of stepping parameters more reliable. Users only need to enter the necessary parameters according to the prompts without understanding the complex calculation process. This simple operation method reduces the requirements for user professional knowledge, allowing more people to easily master and use the method. The method is suitable for the calculation of stepping parameters of lead frames of different specifications and sizes. By adjusting the input parameters, users can easily cope with the calculation requirements in various scenarios, improve the versatility and flexibility of the method, and achieve the beneficial effect of improving the existing manual calculation method to automatically calculate the required stepping parameters by inputting some parameters of the lead frame, which is simple to operate.

[0031] 2. The present invention inputs key parameters: frame length, width, total number of columns, etc., and the system automatically completes all calculation steps, greatly reducing the need for manpower. For example, when calculating the number of stepping columns a and the number of stepping times c per unit, the system automatically rounds and classifies and discusses without manual intervention. When calculating the left center position Y, the system automatically selects the corresponding calculation formula according to the parity of a, reducing errors in human judgment. The system can complete the calculation of the number of stepping times c and the last stepping distance M in a few seconds, greatly improving the speed of new product introduction. By adjusting the input parameters: frame length, width, total number of columns, the system can automatically adapt to the calculation of stepping parameters of lead frames of different specifications and sizes. Users only need to input the parameters of different frames, and the system can automatically calculate the required stepping parameters, greatly improving the flexibility and efficiency of new product introduction, and achieving the beneficial effect of effectively reducing labor costs and improving the efficiency of new product introduction.

[0032] This processing method makes the calculation results more in line with actual production needs and avoids operational difficulties and errors caused by measurement errors. In actual production, there are errors between the size measurement values ​​of the lead frame and the drawing values, and the actual values ​​fluctuate above and below the drawing values. If calculated based on the drawing values, the propagation of errors can be avoided as much as possible, ensuring the practicality and feasibility of the calculation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a method for calculating stepping parameters of a lead frame in an embodiment of the present invention.

[0034] Figure 2 Schematic diagram of the K&S machine frame structure in an embodiment of the present invention.

[0035] Figure 3 A coordinate system diagram is established when a new product framework is introduced into a K&S machine in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] like Figure 1 As shown, the present invention provides a method for calculating stepping parameters of a lead frame, comprising the following steps: Step 1. Input parameters: frame length A, frame width B, total number of frame columns C, distance from the center of the leftmost column to the 0 point D, distance from the leftmost frame edge to the 0 point in the frame drawing E, spacing between each column F, and hot seat adsorption length G; Step 2: Calculate the number of step columns per unit: ; Step 3: Calculate Lndex, the total length of each unit: ; Step 4: Calculate the Index number / number of steps: ; Step 5. Calculate the right index center: subtract the length from the rightmost half unit to the right edge from the total length. ; Step 6. Calculate the Left index center: that is, the length from the leftmost half unit to the left edge position, and conduct classification discussion: When a is an even number, ; When is an odd number, ; ; Step 7: Calculate Y Front center offset; Step 8. Calculation ; Step 9. Output: ; ; ; ; .

[0038] By inputting key parameters: frame length, width, and total number of columns, the system automatically completes all calculation steps, greatly reducing the need for manpower. For example, when calculating the number of stepping columns a and the number of stepping times c per unit, the system automatically rounds and classifies the discussion without manual intervention. When calculating the left center position Y, the system automatically selects the corresponding calculation formula based on the parity of a, reducing human judgment errors. The system can calculate the number of stepping times c and the last stepping distance M in a few seconds, greatly improving the speed of new product introduction. By adjusting the input parameters: frame length, width, and total number of columns, the system can automatically adapt to the calculation of stepping parameters of lead frames of different specifications and sizes. Users only need to input the parameters of different frames, and the system can automatically calculate the required stepping parameters, greatly improving the flexibility and efficiency of new product introduction.

[0039] Preferably, in step 2, a is rounded up and the decimal part is discarded.

[0040] Original manual calculation method: During the manual calculation process, there will be non-integer step column numbers, which will increase the complexity and error rate of subsequent calculation steps. If the step column number a is not an integer unit, the subsequent step times and step distance calculations will be affected.

[0041] Improved calculation method: By rounding a and discarding the decimal part, it is ensured that the step column number a is an integer. This processing method paves the way for the subsequent calculation of the last step and improves the accuracy of the last step calculation.

[0042] Original manual calculation method: The length needs to be measured through a measuring microscope, the value is not accurate, and it is easy to pull off or step poorly during the lead frame stepping process.

[0043] Improved calculation method: The calculated stepping parameters can be used to coordinate with the machine to step the lead frame to the optimal position.

[0044] In actual production, the size of the frame usually has a certain batch deviation. If measured manually, multiple measurements are required to obtain the average value to obtain the drawing calculation value, and the measuring equipment has a systematic error. Therefore, according to the error propagation formula, the total error value will be larger. The present invention calculates the stepping parameters through the drawing, and the error value is smaller. It is also more in line with actual production needs through verification.

[0045] This processing method makes the calculation results more in line with actual production needs and avoids operational difficulties and errors caused by non-integer stepping column numbers. In actual production, the stepping operation cannot step decimal column numbers, and the rounding process ensures the practicality and feasibility of the calculation results.

[0046] Rounding and discarding the decimal part provides a unified calculation standard for all related calculation steps. The unified calculation standard ensures the consistency and reliability of the calculation results and reduces the errors and deviations caused by different calculation standards. When calculating the number of steps c and the last step distance M, the unified integer step column number a ensures the consistency of the calculation results.

[0047] Preferably, in step 4 Round up and add one; this ensures that all columns are correctly covered.

[0048] Original manual calculation method: If a is not rounded up, the number of steps c may not be enough to cover all the columns. If the result is close to an integer but less than an integer, the number of steps may be insufficient, resulting in some columns not being covered.

[0049] Improved calculation method: By rounding a to an integer and adding one digit, it is ensured that the number of steps c is sufficient to cover all the columns. This processing method avoids the problem of insufficient number of steps and ensures that all columns can be correctly covered.

[0050] Rounding up to the nearest integer ensures that the number of steps c can accurately cover all columns, avoiding omissions or insufficient coverage. The accurate number of steps covers all columns, improves the accuracy and completeness of the calculation results, and avoids calculation errors and omissions caused by insufficient number of steps.

[0051] Original manual calculation method: If the number is not rounded up, the subsequent step count calculation may require complex adjustments or judgments, increasing the complexity of the calculation and the risk of human error. Improved calculation method: By rounding up, the calculation of the number of steps c is simplified, making the subsequent calculation steps more direct and simple. When calculating the last step distance M, the number of steps c after rounding up can be used directly without complex adjustments and judgments.

[0052] In actual production, the number of steps usually needs to cover all the columns to ensure that all products can be processed correctly. Rounding up to the nearest integer ensures that the calculation results meet the actual operation requirements. This processing method makes the calculation results more in line with the actual production requirements and avoids the operational difficulties and errors caused by insufficient stepping times. In actual production, it is necessary to ensure that all products can be processed correctly. Rounding up to the nearest integer ensures the practicality and feasibility of the calculation results.

[0053] Rounding up to the nearest integer provides a unified calculation standard for all related calculation steps, ensuring the consistency of the number of steps. The unified calculation standard ensures the consistency and reliability of the calculation results and reduces the errors and deviations caused by different calculation standards. When calculating the last step distance M, the unified number of steps c ensures the consistency of the calculation results.

[0054] Preferably, in step five .

[0055] Preferably, in step five .

[0056] Preferably, in step five .

[0057] Preferably, when a is an even number in step 6, the Left index center calculation formula is: .

[0058] Preferably, in step six When it is an odd number, the Left index center calculation formula is: .

[0059] Preferably, the calculation formula of step seven is: .

[0060] Preferably, the calculation formula of step eight is: .

[0061] See also Figure 1 , Embodiment 1: For QFN64L (9×9), the frame length is 258.0mm and the width is 78mm: (the following length units are all millimeters) Step 1: Input frame length A=258.0; frame width B=78.0; total number of frames C=26; distance from the center of the leftmost column to the 0 point D=26.00; distance from the leftmost frame edge to the 0 point E=39.25; length of each column F=9.3; hot seat adsorption length G=43.8; Step 2: Calculation is performed by the present invention.

[0062] Step 3: Output Index number = number of steps = 7; Right index center = 26.20; Left index center = 27.20; Y Front center offset = 39.00; Last index = 18.60 Embodiment 2: For QFN24L (4×4), the frame length is 258.0mm and the width is 78mm: (the following length units are all millimeters) Step 1: Input frame length A=258.0; frame width B=78.0; total number of frames C=57; distance from the center of the leftmost frame to the 0 point D=30.15; distance from the leftmost frame edge to the 0 point E=39.25; length of each column F=4.3; hot seat adsorption area G=43.8; Step 2: Calculation is performed by the present invention.

[0063] Step 3: Output Index number = number of steps = 6; Right index center = 27.45; Left index center = 28.45; Y Front center offset = 39.00; Last index = 30.10.

[0064] Example 3 Take QFN48L (7 mm × 7 mm) as an example and perform manual calculation: The adsorption length of the hot seat is 43.8mm, and the length of each column is 7.3mm. 43.8 / 7.3=6, that is, each unit has 6 columns, and the frame has 33 columns in total. 33 / 6=5.5, that is, 6 steps are required; The distance from the center of the leftmost column of the frame to the 0 point = 26.55mm; the distance from the left edge of the frame to the 0 point = 39.25mm; the distance from the center of the leftmost column of the frame to the leftmost edge of the frame is 39.25-26.55=12.7mm; to calculate the distance on the right, that is, the rightmost half unit + the right edge of the frame = the total length 258-the distance from the center of the leftmost column of the frame to the leftmost edge of the frame-the length of the middle column (the number of middle columns is 33 columns-3 columns on the right-the distance from the center of the leftmost column of the frame to the leftmost edge of the frame, including 0.5 columns) = 258-12.7-29.5*7.3=29.95mm; That is, Right index center = 29.95mm Left index center = left edge length + left half unit length =The distance from the center of the leftmost column of the frame to the leftmost frame edge + 2.5 columns = 12.7 + 2.5 * 7.3 = 30.95 mm Y Front center offset = frame width / 2=39.00 mm Because the last unit only needs to step 3 columns, so Last lndex = 3*7.3=21.9mm Take QFN48L (7 mm×7 mm) as an example, and use this invention to calculate: Step 1: Input the frame length A=258.0 mm; frame width B=78.0 mm; total number of frame columns C=33 mm; distance from the center of the leftmost column to the 0 point D=26.55 mm; distance from the leftmost frame edge to the 0 point E=39.25 mm; length of each column F=7.3 mm; hot seat adsorption area G=43.8 mm; Step 2: Calculation by the present invention Step 3: Output Index number = number of steps = 6; Right index center=29.95 mm; Left index center=30.95 mm; Y Front center offset =39.00 mm; Last index M=21.90mm.

[0065] like Figure 2 , Figure 3 As shown, when the present invention imports a new product (QFN\DFN) frame on a K&S machine (Ultra, Elite, Connx, etc.), by inputting parameters such as the length, width, and total number of frames, the index number, right index center, left index center, Y front center offset, and last step distance (Last lndex) can be calculated. This greatly reduces the cost of human calculation and avoids possible calculation errors that may occur during manual calculation.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for calculating stepping parameters of a lead frame, characterized in that: The following steps are involved: Step 1. Input: frame length A, frame width B, total number of frame columns C, distance from the center of the leftmost column to the 0 point D, distance from the leftmost frame edge to the 0 point in the frame drawing E, spacing between each column F, and hot seat adsorption length G; Step 2: Calculate the number of step columns per unit: ; Step 3: Calculate Lndex, the total length of each unit: ; Step 4: Calculate the Index number / number of steps: ; Step 5. Calculate the right index center: subtract the length from the rightmost half unit to the right edge from the total length. ; Step 6. Calculate the Left index center: that is, the length from the leftmost half unit to the left edge position, and conduct classification discussion: When a is an even number, ; When is an odd number, ; ; Step 7: Calculate Y Front center offset; Step 8. Calculation ; Step 9. Output: ; ； ； ； 。 2. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In the step 2, a is rounded to an integer and the decimal part is discarded.

3. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In step 4 Round up to the nearest digit.

4. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In step five .

5. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In step five .

6. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In step five .

7. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: When a is an even number in step 6, the left index center calculation formula is: 。 8. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: In step six When it is an odd number, the left index center calculation formula is: 。 9. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: The calculation formula of step seven is: .

10. The method for calculating stepping parameters of a lead frame according to claim 1, characterized in that: The calculation formula of step eight is: .

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