A heating block unit and a heating device

Abstract

The present invention relates to a heating block unit and a heating device. In various embodiments, a heating block unit is provided, comprising a recess, the recess comprising a bottom and sidewalls, the recess comprising: a pad placement area; and two pull rod placement areas disposed on either side of the pad placement area; characterized in that the heating block unit further comprises one or more fuse lead placement areas disposed across the bottom and the sidewalls.

Description

[0001] Information related to divisional application

[0002] This invention is a divisional application of the invention patent application filed on November 19, 2019, with application number 201911136223.X and invention title "A heating block unit and heating device". Technical Field

[0003] This invention relates generally to integrated circuit packaging technology, and more particularly to the design of heater blocks with series fuse leads. Background Technology

[0004] In the semiconductor industry, it is usually necessary to package the manufactured integrated circuit chips (dies) (or bare dies) to form the final integrated circuit chip product, which also plays an important role in protecting the chip, enhancing its electrothermal performance, and facilitating the assembly of the whole machine.

[0005] Existing SO packaging technology uses series-connected fuse leads to connect the pins to the die pads to ground the chip, and the die pads are recessed below the pin plane to improve the stability of subsequent processes. Typically, this packaging process requires slotting on the heating block.

[0006] However, since there is an inevitable degree of offset in the material pressing of the machine, it will cause the fuse lead to come into contact with the heating block and warp, which will negatively affect the workability of the first and second solder joints of the product and thus damage the product quality.

[0007] Therefore, there is an urgent need in this field to provide improvement solutions to address the above problems. Summary of the Invention

[0008] In view of this, the present invention provides a heating block unit comprising a groove, the groove comprising a bottom and a sidewall, the groove comprising: a pad placement area; and two pull rod placement areas disposed on both sides of the pad placement area; characterized in that the heating block unit further comprises one or more fuse lead placement areas disposed across the bottom and the sidewall.

[0009] One embodiment of the present invention provides a heating block that further includes a vacuum hole located within the pad placement area.

[0010] One embodiment of the present invention provides a heating block, wherein the two rod mounting areas are arranged opposite to each other.

[0011] One embodiment of the present invention provides a heating block, wherein the plurality of fuse lead placement areas are located on opposite sides of the fuse lead placement areas.

[0012] One embodiment of the present invention provides a heating block, wherein the plurality of fuse lead placement areas are located on the same side of the fuse lead placement areas.

[0013] One embodiment of the present invention provides a heating block, wherein the plurality of fuse lead placement areas are adjacent to or not adjacent to each other.

[0014] An embodiment of the present invention provides a heating device comprising a groove, the groove including a bottom and sidewalls, the groove including: a pad placement area; and two pull rod placement areas disposed on both sides of the pad placement area; characterized in that the heating device further includes one or more fuse lead placement areas, the one or more fuse lead placement areas having a dimension in a first direction greater than the maximum permissible object offset distance in the first direction, and a dimension in a second direction greater than the maximum permissible object offset distance in the second direction.

[0015] An embodiment of the present invention provides a heating device, wherein the plurality of fuse lead placement areas are located on opposite sides of the fuse lead placement areas.

[0016] An embodiment of the present invention provides a heating device, wherein the plurality of fuse lead placement areas are located on the same side of the fuse lead placement areas.

[0017] One embodiment of the present invention provides a heating device in which the plurality of fuse lead placement areas are adjacent to or not adjacent to each other. Attached Figure Description

[0018] Figure 1 A top view of the material bar unit.

[0019] Figure 2 show Figure 1 A partially enlarged side view of the fuse lead 10 connecting the pin lead 2 to the chip pad 9.

[0020] Figure 3 This is a cross-sectional view showing the normal operating state when there is no machine pressure offset.

[0021] Figure 4 This displays a cross-sectional view of the operation when there is an abnormal operating status due to machine pressure offset.

[0022] Figure 5 Showing a top view of the heating block unit used in the prior art.

[0023] Figure 6 This shows a top view of the heating block unit proposed in this invention.

[0024] Figure 7 Shows a top view of the strip unit implemented according to the design rules.

[0025] Figure 8A A schematic diagram showing that there are two or more fuse leads on the display bar unit, and the fuse leads are adjacent to each other and located on the same side.

[0026] Figure 8B Display and Figure 8A Design a schematic diagram of the corresponding heater.

[0027] Figure 9A This diagram shows a material bar unit with two or more fuse leads that are not adjacent to each other or located on different sides.

[0028] Figure 9B Display and Figure 9A Design a schematic diagram of the corresponding heater.

[0029] Figure 10 A side view showing a strip unit placed above a heating block with a fuse lead housing area, where no machine pressure offset has occurred.

[0030] Figure 11 A side view showing a strip unit that causes machine pressure deviation, positioned above a heating block with a fuse lead placement area. Detailed Implementation

[0031] To better understand the spirit of the present invention, the following description, in conjunction with some preferred embodiments of the present invention, will provide further details.

[0032] The directional terms used in this invention, such as above, below, left, right, front, back, side, horizontal, transverse, and vertical, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrating and understanding this invention, and not for limiting it.

[0033] Various embodiments of the invention are discussed in detail below. Although specific embodiments are discussed, it should be understood that these embodiments are for illustrative purposes only. Those skilled in the art will recognize that other components and configurations can be used without departing from the spirit and scope of the invention.

[0034] Figure 1 This shows a top view of a common spool unit in the prior art. The spool unit has a chip pad 9 in the center, with lead wires 1-8 and tie bars 12 and 13 arranged around the outer perimeter of the chip pad 9. The pad placement area 11 represents the area in the corresponding heating block unit used to place the pads; this area can be formed by a slotting process. A fuse lead 10 connects the chip pad 9 to the lead wires 2 of the lead wires 1-8 to achieve chip grounding. Preferably, the tie bars 12 and 13 are arranged opposite each other.

[0035] Figure 2 show Figure 1 A partially enlarged side view of the fuse lead 10 that connects chip pad 9 to pin lead 2. Figure 2 In this configuration, fuse lead 10' connects chip pad 9' to pin lead 2' to ground the chip. As one embodiment, the upper surface of fuse lead 10' forms approximately a 45° angle with the upper surface of chip pad 9'. However, this angle can be any acute angle.

[0036] Figure 3 The side view shows the normal operating state without machine pressure deviation, including: a heating block unit 301, a pressure plate 302, and a strip unit that is normally pressed together without deviation. The heating block unit 301 has a pad placement area 309. From the side view, the strip unit consists of leads 303 located above and on both sides of the heating block unit 301, chip pads 305 located below and within the pad placement area 309, and fuse leads 304 connecting the chip pads 305 and part of the leads 303; a chip 306 located above the chip pads 305, a welding line 307 connecting the chip 306 and the leads 303, and a first solder joint 308 and a second solder joint 308'. In the normal operating state, i.e., when there is no machine pressure deviation, the fuse lead 304 does not warp or deform, the solder needle ball pressing trajectory is complete, and the second solder joint 308' is in the normal operating position.

[0037] During the production process, when wire bonding is performed on the pre-bonded die-attached strip units, the strip units are placed above the heating block, and then pressed down with a pressure plate to ensure a tight fit between the strip units and the heating block for easy operation. The heating block may contain one or more heating block units. However, in actual operation, the following situations usually occur: First, because the strip units are thin and the track width is greater than the strip unit width (the machine track width is fixed and not adjustable), the feed of the feed claws prevents the strip units from always remaining parallel to the track, and even with machine parameter settings and regular maintenance, slight offsets will still exist; second, there are errors in the black-and-white ratio of the lights around the welding pins, and the black-and-white ratio is also affected by burrs on the pin edges; third, due to a large number of simultaneous production tasks, frequent cutting also causes pressure offset.

[0038] Furthermore, even though the machine performs secondary pressing based on feedback from various parts, the material strip unit will still shift during the second pressing of the pressure plate. The maximum shift distance in the X direction is the shortest distance from the edge of the lead inside the pad to the edge of the pad in the X direction, and the maximum shift distance in the Y direction is the shortest distance from the edge of the lead inside the pad to the edge of the pad in the Y direction. This shift can cause the fuse lead to make unfavorable contact with the edge of the heating block unit and be deformed or heat-induced due to pressure. Moreover, in the depth direction, the groove depth of the pad placement area is shallower than the chip pad recess depth. When the material strip unit shifts, the lead will lift up, which will affect the workability of the solder joints (especially the two solder joints connected to the lead).

[0039] Figure 4 This is a side view showing an abnormal operating state during actual production when machine pressure misalignment occurs. It includes: a heating block unit 401, a pressure plate 402, and a strip unit where abnormal pressure misalignment occurs between them. The heating block unit 401 has a pad placement area 409. From a side view, the strip unit consists of a lead wire 403 located above and to the sides of the heating block unit 401, a chip pad 405 located below and within the pad placement area 409, and a fuse lead wire 404 connecting the chip pad 405 and the lead wire 403. Above the chip pad 405 is a chip 406, a welding line 407 connecting the chip 406 and the lead wire 403, and a first solder joint 408 and a second solder joint 408'. In this abnormal operating state, i.e., when machine pressure misalignment occurs, the fuse lead wire 404 warps or deforms, the solder needle ball trajectory is incomplete, and the second solder joint 408' is warped at its operating position.

[0040] Figure 5 This diagram shows a top view of a heating block unit commonly used in the prior art, comprising a pad placement area 501 for accommodating chip pads; and a pair of lever placement areas 502 and 503, respectively positioned on either side of the pad placement area 501 to accommodate levers in the strip unit. Preferably, Figure 5 The heating block unit shown may also include a vacuum hole 504 located within the pad placement area 501 for vacuum adsorption of the strip unit. As one embodiment, the vacuum hole 504 may be located at the center of the pad placement area 501. Preferably, the pull rod placement areas 502 and 503 are positioned opposite each other. Figure 5 In practice, insufficient design margin at the fuse lead will lead to contact between the fuse lead and the heating block unit due to the offset of the material strip unit during actual operation. This can cause deformation problems such as warping or heat deformation, thus affecting product performance.

[0041] Figure 6The diagram shows a top view of the heating block unit proposed in this invention, which includes a pad placement area 601 for accommodating chip pads; a pair of lever placement areas 602 and 603, respectively located on both sides of the pad placement area 601, for placing levers in the strip unit; and a fuse lead placement area 604 specifically designed to overcome the aforementioned strip unit misalignment problem, for placing one or more fuse leads, and designed to provide sufficient design margin for the fuse leads to prevent deformation due to contact with the heating block unit. Preferably, Figure 6 The heating block unit shown may also include a vacuum hole 605 located within the pad placement area 601 for vacuum adsorption of the strip unit. Although Figure 6 The fuse lead placement area 604 extends across the edge of the pad placement area, but it can also be placed anywhere within or near the pad placement area. Preferably, the fuse lead placement area 604 is a reinforced groove specifically designed for the corresponding fuse lead, with sufficient design margin in both the horizontal and vertical directions to effectively prevent the fuse lead from contacting the heating block and deforming due to heat. With the fuse lead placement area 604, the present invention provides omnidirectional redundancy to avoid deformation caused by contact between the fuse lead and the heating block unit due to machine tool offset, thereby effectively reducing the negative impact on the workability of the first and second solder joints and comprehensively improving product quality.

[0042] The specific design principle for the fuse lead placement area 604 is to design a heating block containing one or more heating block units based on the material strip unit and the fuse lead, wherein one or more heating block units correspond one-to-one with each material strip unit. Specifically, each heating block unit may be equipped with:

[0043] 1) Heating block base, which has a heating function and is provided with vacuum holes in the pad placement area to perform vacuum adsorption operation on the product;

[0044] 2) The pad placement area is located on the heating block base and accommodates the chip pads. The groove depth is the vertical distance between the bottom surface of the pin and the bottom surface of the chip pad. The pad size ≤ the pad placement area size ≤ the area formed by the periphery of the pin inside the lead.

[0045] 3) Tie bar placement area, located on the heating block base, is used to place the tie bar.

[0046] 4) Fuse lead placement area, located on the heating block base, is used to place fuse leads. The fuse lead placement area is determined according to the material bar unit and fuse lead design. This can effectively solve the problem of material bar unit offset when the pressure plate is pressed down, and provide sufficient design margin so that the heating block unit will not come into contact with the fuse lead and heat it, thereby avoiding the fuse lead from being heated, deformed and abnormal operation.

[0047] Figure 7 This displays a top view of the strip unit implemented according to the design rules. The top view of the implemented strip unit is shown in... Figure 7 On the left side, a fuse lead 16 is connected between lead 13 and chip pad 15. This fuse lead 16 is partially enlarged and shown in the image. Figure 7 Upper right side. By Figure 7 As can be seen, although the fuse lead 16 is displayed as an irregular shape, after being constrained by the redundancy design rules, the fuse lead 16 can be completely contained within the area defined by the fuse lead placement area 17 in both the X and Y directions, thereby avoiding contact with the heating block unit and thermal deformation. A schematic diagram of the design rules upon which the material strip unit is based is shown in... Figure 7On the lower right side, the fuse lead placement area 701 is designed to cover the fuse lead 702 with an irregular shape, thereby providing sufficient design redundancy. To achieve this design redundancy, it must be ensured that the dimensions of the fuse lead placement area 701 in both the X and Y directions are greater than or equal to the corresponding dimensions of the fuse lead 702 in both the X and Y directions. As an embodiment, if the maximum lateral span of the left and right edges of the fuse lead placement area 701 is denoted as X and the maximum lateral span from the leftmost end to the rightmost end of the fuse lead 702 is denoted as A, then the fuse lead placement area 701 can provide additional redundancy dimensions a1 and a2 compared to the lateral sides of the fuse lead 702, where a1 represents the minimum allowable distance from the left edge of the fuse lead placement area 701 to the leftmost end of the fuse lead 702, and a2 represents the minimum allowable distance from the right edge of the fuse lead placement area 701 to the rightmost end of the fuse lead 702. Similarly, if the maximum longitudinal span of the upper and lower edges of the fuse lead placement area 701 is represented by Y and the maximum longitudinal span from the uppermost to the lowermost end of the fuse lead 702 is represented by B, then the fuse lead placement area 701 can provide additional redundant dimensions b1 and b2 compared to the longitudinal sides of the fuse lead 702, where b1 represents the minimum allowable distance from the upper edge of the fuse lead placement area 701 to the uppermost end of the fuse lead 702, and b2 represents the minimum allowable distance from the lower edge of the fuse lead placement area 701 to the lowermost end of the fuse lead 702. As another embodiment, the vertical depth of the fuse lead placement area 701 can be greater than or equal to the slot depth of the heating block unit pad placement area. In some embodiments, the vertical depth of the fuse lead placement area 701 can be 10 μm greater than the slot depth of the heating block unit pad placement area, thereby reserving space at the fuse lead connection to prevent the fuse lead from warping.

[0048] Figure 8A This diagram illustrates a material bar unit with two or more fuse leads that are adjacent to each other and located on the same side. The fuse lead placement area 801 is located at one edge of the pad placement area 802 and covers two adjacent fuse leads 803 on the same side. (See diagram for details.) Figure 8A As shown, the fuse lead placement area 801 should spatially cover at least the fuse lead 803, that is, it can extend a1, a2, b1, b2 from the outermost endpoints in the X and Y directions along the X and Y horizontal directions to their corresponding sides. Preferably, the vertical depth of the fuse lead placement area 801 can be greater than or equal to the slot depth of the heating block unit pad placement area 802. In some embodiments, the vertical depth of the fuse lead placement area 801 can be 10 μm greater than the slot depth of the heating block unit pad placement area 802, thereby reserving space at the fuse lead connection to prevent the fuse lead from warping.

[0049] Figure 8B Display and Figure 8A Design a schematic diagram of the corresponding heater. For example... Figure 8B As shown, the fuse lead placement area 804 can accommodate two or more fuse leads that are adjacent to each other and located on the same side. In this case, the fuse leads accommodated in the fuse lead placement area 804 can be regarded as a whole, and the fuse lead placement area can be designed accordingly.

[0050] Figure 9A This diagram illustrates a material bar unit with two or more fuse leads that are not adjacent to each other or located on different sides. (Example:) Figure 9A As shown, within the pad placement area 902, the first fuse lead placement area 901 spatially covers at least the corresponding first fuse lead 903, and the second fuse lead placement area 904 spatially covers at least the corresponding second fuse lead 905. For example, to achieve the above-mentioned coverage effect, the lateral dimension X of the first fuse lead placement area 901 can extend a1 and a2 from each side at most relative to the lateral dimension A of the first fuse lead 903, and the longitudinal dimension Y of the first fuse lead placement area 901 can extend b1 and b2 from each side at most relative to the longitudinal dimension B of the first fuse lead 903. Similarly, the lateral dimension X' of the second fuse lead placement area 904 can extend a1' and a2' from each side at most compared to the lateral dimension A' of the first fuse lead 903, and the longitudinal dimension Y' of the second fuse lead placement area 904 can extend b1' and b2' from each side at most compared to the longitudinal dimension B' of the first fuse lead 903. Preferably, the vertical depth of the fuse lead placement areas 901 and 904 can be greater than or equal to the slot depth of the heating block unit pad placement area 902. In some embodiments, the vertical depth of the fuse lead placement areas 901 and 904 can be 10 μm greater than the slot depth of the heating block unit pad placement area 902, thereby reserving space at the fuse lead connection to prevent the fuse lead from warping.

[0051] Figure 9B Display and Figure 9A Design a schematic diagram of the corresponding heater. For example... Figure 9B As shown, the fuse lead placement area 906 accommodates two non-adjacent fuse leads on the same side. However, two or more fuse leads can also be located on different sides. When a material bar unit has two or more fuse leads that are not adjacent or located on different sides, a fuse lead placement area can be designed independently for each fuse lead.

[0052] Figure 10A side view showing a strip unit placed above a heating block with a fuse lead placement area, where no machine pressure deviation has occurred, specifically including the fuse lead placement area 1007. (See image below.) Figure 10 As shown, under ideal conditions, the center of the material strip unit coincides with the center of the heating block (i.e., section B-B'), so there is no relative offset of the machine pressing material. Therefore, the fuse lead 1004 does not come into contact with the heating block unit 1001 and is deformed by heat.

[0053] In comparison, Figure 11 A side view showing a strip unit that causes machine pressure deviation, positioned above a heating block with a fuse lead placement area, specifically including the fuse lead placement area 1107. (See image below.) Figure 11 As shown, in this actual situation, the center of the material strip unit (i.e., section C-C') is offset from the center of the heating block (i.e., section B-B'), resulting in relative machine pressing offset. However, even so, since the heating block has a fuse lead placement area 1107, it can provide sufficient accommodation space in the horizontal and / or vertical directions, thereby preventing the fuse lead 1104 from contacting the heating block unit 1101 and being deformed by heat, thus significantly improving product quality.

[0054] The technical content and features of this invention have been described in the above-described embodiments; however, these embodiments are merely examples for implementing this invention. Those skilled in the art may still make various substitutions and modifications based on the teachings and disclosures of this invention without departing from its spirit. Therefore, the disclosed embodiments of this invention do not limit the scope of this invention. Conversely, modifications and equivalent settings included in the spirit and scope of the claims are all included within the scope of this invention.

Claims

1. A heating block unit comprising a groove, the groove including a bottom and sidewalls, the groove comprising: The pad placement area; and Two tie rod placement areas are located on either side of the pad placement area; Its features are, The heating block unit further includes one or more fuse lead placement areas, the one or more fuse lead placement areas having slots spanning the bottom and the sidewalls, the slots being configured to provide sufficient design margin for the fuse leads such that the vertical depth of the one or more fuse lead placement areas is greater than the slot depth of the pad placement areas.

2. The heating block unit according to claim 1, further comprising a vacuum hole located within the pad placement area.

3. The heating block unit according to claim 1, wherein the two tie rod mounting areas are positioned opposite each other.

4. The heating block unit according to claim 1, wherein the plurality of fuse lead placement areas are located on opposite sides of the fuse lead placement areas.

5. The heating block unit according to claim 1, wherein the plurality of fuse lead placement areas are located on the same side of the fuse lead placement areas.

6. The heating block unit according to claim 5, wherein the plurality of fuse lead placement areas are adjacent to each other or not adjacent to each other.

7. The heating block unit according to claim 1, wherein the vertical depth of the one or more fuse lead placement areas is 10 μm greater than the groove depth of the pad placement area.

8. A heating device comprising a recess, the recess including a bottom and sidewalls, the recess comprising: The pad placement area; and Two tie rod placement areas are located on either side of the pad placement area; Its features are, The heating device further includes one or more fuse lead placement areas, each having a slot spanning the bottom and the sidewall. The slot's lateral dimension is greater than the maximum permissible lateral fuse lead offset distance in the lateral direction, which extends a certain distance from both sides relative to the maximum lateral dimension of the first fuse lead. The slot's lateral dimension in the longitudinal direction perpendicular to the lateral direction is also greater than the maximum permissible longitudinal fuse lead offset distance in the longitudinal direction, which extends a certain distance from both sides relative to the maximum longitudinal dimension of the first fuse lead. The vertical depth of the one or more fuse lead placement areas is greater than the slot depth of the pad placement area.

9. The heating device according to claim 8, wherein the plurality of fuse lead placement areas are located on opposite sides of the fuse lead placement areas.

10. The heating device according to claim 8, wherein the plurality of fuse lead placement areas are located on the same side of the fuse lead placement areas.

11. The heating device according to claim 10, wherein the plurality of fuse lead placement areas are adjacent to each other or not adjacent to each other.

12. The heating device according to claim 8, wherein the vertical depth of the one or more fuse lead placement areas is 10 μm greater than the groove depth of the pad placement area.

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