A 100mm wide high-density lead frame and production method thereof

Abstract

The present invention relates to a 100mm wide high-density lead frame, with an overall width of 100mm, 36 rows of product units, a reinforcing rib arranged between every 12 rows of product units, 12 columns of product units, each product unit comprising a base island and a pin, a glue hook groove parallel to the line to be cut is arranged on the back of the pin located near the line to be cut, and a glue hook convex strip is formed on the front of the pin accordingly; a plurality of notches are arranged at intervals at the edge of the base island, the notches are punched through from the front of the base island to the back, and a plurality of stamping steps are arranged on the back of the edge of the base island. The present invention relates to a 100mm wide high-density lead frame, which can be mass-produced to meet market requirements, and at the same time, the horizontal bonding force and vertical bonding force between the lead frame and the package body are both high, and it is not easy to be damaged when cutting after the package is completed, thereby improving the yield rate.

Description

Technical Field

[0001] The invention relates to a 100mm wide high-density lead frame and a production method thereof. Background Art

[0002] In view of the growing market demand for lead frames, the existing SOT-23 product density design can no longer meet the market demand, and the production cost pressure is increasing, so it is necessary to break the routine and design a high-density frame to meet market demand; in addition, since the horizontal and vertical bonding forces between the lead frame and the package of the traditional SOT-23 product are low, it is easy to be damaged when cutting after the package is completed:

[0003] 1. For example, see Figure 1-Figure 2 When the chip is sheared after plastic encapsulation, when the pin is subjected to shear tension N, the chip will be directly subjected to the reaction force n of the plastic encapsulation body, and the chip and the bonding wire are prone to relative displacement, thus affecting the product reliability;

[0004] 2. The edge of the original base island is a smooth surface. When shearing is performed after plastic encapsulation, the bonding force between the base island and the plastic encapsulation body along the vertical direction of the lead frame is poor, which can easily cause abnormal stratification between the lead frame base island and the plastic encapsulation body, thus affecting product reliability.

[0005] Therefore, it is also urgent to find a solution to improve the horizontal and vertical bonding forces between the lead frame and the package body to improve product reliability. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a 100mm wide high-density lead frame that can be mass-produced to meet market requirements. At the same time, the horizontal and vertical bonding forces between the lead frame and the package body are relatively high. When cutting after packaging, it is not easy to be damaged, thereby improving the yield rate.

[0007] The object of the present invention is achieved in that:

[0008] A 100mm wide high-density lead frame has an overall width of 100mm, 36 rows of product units, a reinforcing rib is arranged between every 12 rows of product units, and the number of product unit columns is 12. Each product unit includes a base island and a pin. The pin located near the to-be-cut line is provided with a glue hooking groove parallel to the to-be-cut line from the back side, and a corresponding glue hooking convex strip is formed on the front side of the pin; a plurality of notches are arranged at intervals at the edge of the base island, and the notches are punched through from the front side of the base island to the back side, and a plurality of stamping steps are arranged on the back side of the edge of the base island.

[0009] As a preferred embodiment, the notch is a semicircular structure.

[0010] As a preferred embodiment, the radius of the notch is 0.07 mm

[0011] As a preferred embodiment, the notch and the straight edge of the base island are transitioned through an arc.

[0012] As a preferred embodiment, two notches are respectively arranged at each edge of the base island.

[0013] As a preference, the stamping step is stamped from the back side of the base island to half the height of the base island.

[0014] As a preferred embodiment, the stamping step is located between two adjacent notches and outside the outermost notch.

[0015] As a preferred embodiment, the edge of the base island at the stamping step forms a natural extension outward.

[0016] A production method for a 100mm wide high-density lead frame, characterized in that a lower die adjustable correction mechanism is used to adjust the lower die, the lower die adjustable correction mechanism comprises a lower die seat, a concave die fixing plate is arranged on the lower die seat, a pad is arranged at the bottom of the middle section of the concave die fixing plate, a correction insert embedding groove which passes through from top to bottom is arranged on the middle section of the concave die fixing plate and the pad, a correction insert, a pad and an inclined wedge are arranged in sequence from top to bottom in the correction insert embedding groove, the bottom surface of the inclined wedge is higher on the left and lower on the right, and a left-through correction insert is also arranged at the bottom of the pad. A strip drawing channel, the strip drawing channel extends out of the left end of the die fixing plate, a strip drawing channel is arranged in the strip drawing channel, the bottom surface of the strip drawing is in close contact with the top surface of the lower die seat, an inclined surface with a higher left end and a lower right end is downwardly opened on the top surface of the strip drawing, a hook is formed at the right end of the inclined surface, the inclination of the inclined surface matches the bottom surface of the inclined wedge, a plurality of step holes with smaller upper parts and larger lower parts are upwardly opened on the bottom surface of the lower die seat, an upward bolt is arranged in the step hole, the bolt passes through the strip drawing, the inclined wedge, the cushion block to the step hole in the correction insert, and a compression spring is arranged between the step and the bottom of the bolt;

[0017] The specific adjustment working methods are as follows:

[0018] Under normal conditions, due to the action of the compression spring, the correction insert is pulled down to a certain height. At this time, if the height of the correction insert does not meet the working height, it is necessary to rotate the adjusting nut to control the left and right movement of the draw bar.

[0019] When the height of the correction insert needs to be raised, the draw bar is controlled to move to the right, and the draw bar cooperates with the inclined surface of the inclined wedge to lift the correction insert;

[0020] When the height of the correction insert needs to be lowered, the draw bar is controlled to move to the left, and the draw bar cooperates with the inclined surface of the inclined wedge to lower the correction insert.

[0021] The overall width is 100mm, the number of product unit rows is 36, a reinforcing rib is arranged between every 12 rows of product units, the number of product unit columns is 12, each product unit includes a base island and a tube pin, and the tube pin located near the line to be cut is provided with a glue hooking groove parallel to the line to be cut from the back, and a glue hooking convex strip is formed on the front of the tube pin accordingly; a plurality of notches are arranged at intervals at the edge of the base island, the notches are punched from the front of the base island to the back, and a plurality of stamping steps are arranged on the back of the edge of the base island.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The invention provides a 100mm wide high-density lead frame, which can be mass-produced to meet market requirements. At the same time, the horizontal and vertical bonding forces between the lead frame and the package body are relatively high. When cutting after packaging, it is not easy to be damaged, thereby improving the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the stress state of a traditional lead frame when it is sheared after plastic encapsulation.

[0025] Figure 2 for Figure 1 sectional view of .

[0026] Figure 3 It is a schematic diagram of the structure of a 100mm wide high-density lead frame.

[0027] Figure 4 for Figure 3 Enlarged view of point B.

[0028] Figure 5 for Figure 4 AA section view.

[0029] Figure 6 This is a schematic diagram of the forces acting on a 100mm wide high-density lead frame when it is sheared after plastic encapsulation.

[0030] Figure 7 for Figure 6 A partial enlarged view of point A.

[0031] Figure 8 Schematic diagram of the adjustable correction mechanism of the lower mold.

[0032] Fig. 9 This is a top view of the adjustable correction mechanism of the lower mold.

[0033] Fig.10 for Figure 8 A partial enlarged view of point A.

[0034] in:

[0035] Base island 1, pin 2, glue hook groove 3, chip 4, welding wire 5, notch 6, stamping step 7, natural extension part 8, to-be-cut line 9, reinforcing rib 10, plastic sealing body 11, glue hook convex strip 12;

[0036] The shear tension N on the pins and the reaction force n on the chip from the plastic package;

[0037] The reaction force N1 of the plastic sealing body on the glue hooking groove and the reaction force N2 of the plastic sealing body on the glue hooking convex strip.

[0038] Lower die base 101, step hole 101.1, die fixing plate 102, avoidance groove 102.1, pad correction insert 103, pad 104, oblique wedge 105, pad 106, draw bar 107, waist round mounting hole 107.1, hollow 107.2, hook 107.3, fixing bolt 107.4, C-type adjustment block 108, adjusting screw 109, adjusting nut 110, bolt 111, compression spring 112, locking bolt 113. DETAILED DESCRIPTION

[0039] 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 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.

[0040] See also Figure 4-Figure 10 The present invention relates to a 100mm wide high-density lead frame, the overall width of which is 100mm, the number of rows of product units is 36, a reinforcing rib 4 is arranged between every 12 rows of product units, and the number of rows of product units shown in the figure is 12.

[0041] In order to realize rapid batch production, not only the number of product units on the lead frame is increased, but also when different lead frames are replaced for production, an adjustable correction mechanism for the lower mold is used to adjust the lower mold to improve the production efficiency of the lead frame.

[0042] A lower die adjustable correction mechanism, comprising a lower die base 101, a die fixing plate 102 is arranged on the lower die base 101, a backing plate 106 is arranged at the bottom of the middle section of the die fixing plate 102, a correction insert embedding groove which passes through from top to bottom is arranged on the middle section of the die fixing plate 102 and the backing plate 106, a correction insert 103, a backing block 104 and an inclined wedge 105 are arranged in the correction insert embedding groove from top to bottom, the bottom surface of the inclined wedge 105 is higher on the left and lower on the right, and a draw bar which passes through to the left is also arranged at the bottom of the backing plate 106 Channel, the strip-drawing channel extends out of the left end of the die fixing plate 102, and a strip-drawing channel 107 is arranged in the strip-drawing channel, and the bottom surface of the strip-drawing 107 is close to the top surface of the lower die base 101, and the top surface of the strip-drawing 107 is downwardly provided with a slope that is higher on the left end and lower on the right end, and the slope of the slope is preferably 5 degrees, and a hook 107.3 is formed at the right end of the slope, and the slope of the slope matches the bottom surface of the inclined wedge 105, and the slope is just located at the lateral position of the correction insert embedding groove and the distance between the left and right ends of the slope is greater than the lateral dimension of the correction insert embedding groove.

[0043] The left end face of the die fixing plate 102 is provided with an avoidance groove 102.1 recessed to the right, and each avoidance groove 102.1 corresponds to two draw bars 107. The draw bars 107 located outside the die fixing plate 102 are provided with a waist-shaped mounting hole 107.1 and a draw bar slot, wherein the waist-shaped mounting hole 107.1 is located on the left side of the draw bar slot, and a fixing bolt 107.4 passes through the waist-shaped mounting hole 107.1 to fix and lock the draw bar 107 to the top surface of the lower die base 101, and a C-shaped adjustment block 108 with an opening upward is clamped in the draw bar slot, and the C-shaped adjustment block 108 and the draw bar 107 are locked by a locking bolt 113, and an adjusting screw 109 is screwed into the die fixing plate 102 from the left end of the C-shaped adjustment block 108, and an adjusting nut 110 is screwed on the adjusting screw 109 in the middle opening part of the C-shaped adjustment block 108.

[0044] The bottom surface of the lower die base 101 is provided with a plurality of stepped holes 101.1 which are smaller at the top and larger at the bottom. An upward bolt 111 is arranged in the stepped hole. The bolt 111 passes through the draw bar 107, the inclined wedge 105, and the pad 104 to the correction insert 103. The draw bar 107 is provided with a hollow 107.2 to avoid the bolt 111 from passing through. The hollow 107.2 ensures that the draw bar 107 can move left and right smoothly without touching the bolt 111. A compression spring 112 is arranged between the step of the stepped hole 101.1 and the bottom of the bolt 111.

[0045] A working method of a lower die adjustable correction mechanism:

[0046] Under normal conditions, due to the action of the compression spring 112, the correction insert 103 is pulled down to a certain height. At this time, if the height of the correction insert 103 does not meet the working height, it is necessary to rotate the adjustment nut 110 to control the draw bar 107 to move left and right.

[0047] When it is necessary to raise the height of the correction insert 103, first loosen the fixing bolt 107.4, control the draw bar 107 to move to the right, and the draw bar 107 and the inclined surface of the inclined wedge 105 cooperate to lift the correction insert 103. The highest lifting height is when the left end of the inclined surface of the draw bar 107 contacts the right end of the bottom of the inclined wedge 105. This is the highest lifting height. Even if the draw bar continues to move to the right, it cannot continue to lift the height of the correction insert 103. After the correction is in place, tighten the fixing bolt 107.4;

[0048] When it is necessary to lower the height of the correction insert 103, first loosen the fixing bolt 107.4, control the draw bar 107 to move to the left, and the draw bar 107 and the inclined surface of the bevel 105 cooperate to lower the correction insert 103. The lowest lowering height is when the hook 107.3 of the draw bar 107 contacts the bottom right end of the bevel 105. This is the lowest lowering height and no subsequent action can be performed. After the correction is in place, tighten the fixing bolt 107.4.

[0049] The draw bar 107 is generally provided with an inclined surface with a height difference of 0.16 mm as required, that is, the height of the correction insert 103 can be adjusted by plus or minus 0.08 mm within the normal adjustment range.

[0050] The mold only needs to be assembled once, and the height adjustment does not require the lower mold to be disassembled. The correction insert can be flexibly adjusted in height by adjusting the draw bar to move left and right on the punch press.

[0051] A 100mm wide high-density lead frame, each product unit includes a base island 1 and a pin 2, and it is assumed that there is a virtual cutting line to be cut in the horizontal and vertical directions between two adjacent product units. The pin 2 located near the cutting line is provided with a glue hooking groove 3 parallel to the cutting line. The glue hooking groove 3 is pressed from the back side to the front side of the lead frame by a mold, so that the glue hooking groove 3 is formed on the back side of the pin, and correspondingly, a glue hooking convex strip 12 is formed on the front side of the pin, and the glue hooking convex strip is on the outside of the chip 4.

[0052] When shearing, the pin 2 is subjected to shear tension, and the reaction force is transferred from the force n exerted on the original chip 4 and the welding wire 5 to the force N1 exerted on the glue hook groove 3 and the force N2 exerted on the glue hook convex strip 12, preventing the relative position change of the chip 4 and the welding point, thereby improving the reliability of the product under horizontal force.

[0053] A plurality of notches 6 are arranged at intervals at the edge of the base island 1, and the notches 6 are punched from the front side of the base island 1 to the back side, and the notches 6 are of a semicircular structure with a radius of 0.07 mm. The notches 6 and the straight sides of the base island 1 are transitioned by arcs. Preferably, two notches 6 are arranged at each edge of the base island 1, and a plurality of stamping steps 7 are arranged on the back side of the edge of the base island 1, and the stamping steps 7 are punched from the back side of the base island 1 to half the height of the base island 1. The stamping steps 7 are located between two adjacent notches 6 and on the outside of the notch 6 at the edge, and a natural extension portion 8 is formed outward at the edge of the base island 1 at the stamping steps 7. The combination of a plurality of notches 6 and the natural extension portion 8 can improve the vertical bonding force between the base island 1 and the plastic encapsulation body, and the stamping steps 7 can not only improve the vertical bonding force between the base island 1 and the plastic encapsulation body, but also improve the horizontal bonding force.

[0054] During production, the notch is processed first, and then the stamping step is processed.

[0055] The above are only specific application examples of the present invention and do not constitute any limitation on the protection scope of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the present invention.

Claims

1. A 100mm wide high-density lead frame, characterized in that The overall width is 100mm, the number of rows of product units is 36, a reinforcing rib is arranged between every 12 rows of product units, the number of product unit columns is 12, each product unit includes a base island and a tube pin, a glue hooking groove parallel to the to-be-cut line is arranged on the back of the tube pin located near the to-be-cut line, and a glue hooking convex strip is formed on the front of the tube pin accordingly; a plurality of notches are arranged at intervals at the edge of the base island, the notches are punched and cut from the front of the base island to the back, and a plurality of stamping steps are arranged on the back of the edge of the base island; The notch is a semicircular structure; The radius of the notch is 0.07mm; The gap and the straight edge of the base island are transitioned by an arc; Two notches are respectively arranged at each edge of the base island; The stamping step is stamped from the back of the base island to half the height of the base island; The stamping step is located between two adjacent notches and outside the outermost notch; The edge of the base island at the stamping step forms a natural extension outward; The lower die is adjusted by using a lower die adjustable correction mechanism, the lower die adjustable correction mechanism comprising a lower die base (101), a die fixing plate (102) being arranged on the lower die base (101), a pad (106) being arranged at the bottom of the middle section of the die fixing plate (102), a correction insert embedding groove penetrating from top to bottom being arranged at the middle sections of the die fixing plate (102) and the pad (106), a correction insert embedding groove being arranged from top to bottom in sequence with a correction insert (103), a pad (104) and an oblique wedge (105), the bottom surface of the oblique wedge (105) being higher on the left and lower on the right, a strip drawing channel penetrating to the left being arranged at the bottom of the pad (106), the strip drawing channel extending beyond the left end of the die fixing plate (102), the strip drawing channel extending to the left and the strip drawing channel extending to the left and the strip drawing channel extending to the left end of the die fixing plate (102), ... A draw bar (107) is arranged in the channel, the bottom surface of the draw bar (107) is in close contact with the top surface of the lower die seat (101), the top surface of the draw bar (107) is provided with an inclined surface with a higher left end and a lower right end downwardly, the right end of the inclined surface forms a hook (107.3), the inclination of the inclined surface matches the bottom surface of the inclined wedge (105), the bottom surface of the lower die seat (101) is provided with a plurality of stepped holes (101.1) with smaller upper parts and larger lower parts upwardly, an upward bolt (111) is arranged in the stepped hole, the bolt (111) passes through the draw bar (107), the inclined wedge (105), the cushion block (104) to the step of the stepped hole (101.1) in the correction insert (103), and a compression spring (112) is arranged between the step and the bottom of the bolt (111); The specific adjustment working methods are as follows: Under normal conditions, due to the action of the compression spring, the correction insert is pulled down to a certain height. At this time, if the height of the correction insert does not meet the working height, it is necessary to rotate the adjusting nut to control the left and right movement of the draw bar. When the height of the correction insert needs to be raised, the draw bar is controlled to move to the right, and the draw bar cooperates with the inclined surface of the inclined wedge to lift the correction insert; When the height of the correction insert needs to be lowered, the draw bar is controlled to move to the left, and the draw bar cooperates with the inclined surface of the inclined wedge to lower the correction insert.

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