Lead frame base island and base island processing device
By setting resist bumps on the outer edge of the lead frame base island, the problem of silver paste overflow was solved, enabling the accommodation of larger chip sizes and improving processing efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-04-07
AI Technical Summary
In the prior art, in order to prevent silver paste overflow, a safe distance needs to be maintained between the lead frame base island and the chip, which limits the size of the chip that the base island can accommodate.
An adhesive-blocking boss is provided on the outer edge of the lead frame base island. The height of the adhesive-blocking boss is greater than the maximum height of the silver paste. It is formed by stamping to prevent the silver paste from overflowing, thus eliminating the need for a safety distance.
This increases the chip size that the leadframe base island can accommodate, simplifies the manufacturing process, and reduces equipment modification costs.
Smart Images
Figure CN224098156U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chip manufacturing technology, and more specifically, to a leadframe base island. Furthermore, this invention also provides a base island processing apparatus for the aforementioned chip leadframe base island. Background Technology
[0002] For products that use silver paste to bond chips, in order to prevent the silver paste from flowing along the edge of the base island to the back of the lead frame during the coating process, the distance d from the outer edge of the chip to the outer edge of the base island needs to be controlled to be ≥75μm to prevent silver paste overflow. The above-mentioned safe distance limits the chip size that the lead frame base island can accommodate.
[0003] In summary, how to increase the chip size that the leadframe base island can accommodate is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide a lead frame base island, which has a resistive protrusion on the outer edge of the base island body to prevent silver paste overflow, thus eliminating the need for a safety distance reserved for overflow space and thereby increasing the chip size that the lead frame base island can accommodate.
[0005] In addition, this utility model also provides a base island processing device for the above-mentioned lead frame base island, which can use stamping to process the adhesive resist boss and the base island body in one step, with high processing efficiency.
[0006] To achieve the above objectives, this utility model provides the following technical solution:
[0007] A lead frame base island for bonding with a chip includes a base island body. The upper part of the base island body for bonding with the chip is provided with a resist bump. The resist bump is located on the outer edge of the base island body, and the height of the resist bump is greater than the maximum height of the silver paste.
[0008] Preferably, the thickness t of the adhesive resisting boss is greater than 25 μm, and the thickness of the adhesive resisting boss is the same from bottom to top.
[0009] Preferably, the height h of the upper end face of the adhesive-resistant boss from the upper end face of the base island body is 50-75 μm.
[0010] Preferably, the adhesive-resistant protrusion is disposed on the upper end face of the base island body, and the adhesive-resistant protrusion and the base island body are an integral structure.
[0011] Preferably, the adhesive-blocking boss is a bent L-shaped structure. The adhesive-blocking boss includes an adhesive-blocking part for preventing silver paste from overflowing and a connecting part for connecting with the base island body. The connecting part is horizontally arranged and protrudes from the outer side of the base island body.
[0012] Preferably, the adhesive-resistant protrusion is inclined relative to the base island body, and the distance between the adhesive-resistant protrusion and the axis of the base island body gradually increases from bottom to top.
[0013] A base island processing apparatus for a lead frame base island as described in any of the above claims, comprising a lower punching die, an upper punching die for punching in cooperation with the lower punching die, and a punching power mechanism, wherein at least one of the upper punching die and the lower punching die is connected to the punching power mechanism.
[0014] Preferably, the lower die is provided with a punch for stamping the lower step of the base island body, and the size of the upper die is smaller than that of the lower die, so that the upper die can stamp the adhesive-resistant boss on the upper part of the base island body.
[0015] Preferably, the size of the punching die gradually increases from top to bottom so as to punch out the adhesive-resistant boss that is inclined outward.
[0016] Preferably, the lower punching die is fixedly mounted on the punching machine tool, and the upper punching die is connected to the punching machine tool through a punching power mechanism.
[0017] The lead frame base island provided by this utility model has a resist protrusion on the outside of the base island body. The resist protrusion can prevent silver paste from overflowing, so there is no need to maintain a safe distance between the outer edge of the control chip and the outer edge of the base island, which allows the lead frame base island to accommodate a larger chip size.
[0018] In addition, this utility model also provides a base island processing device for the aforementioned lead frame base island. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0020] Figure 1 A schematic diagram of a specific embodiment of the lead frame base island provided by this utility model;
[0021] Figure 2 This is a schematic diagram of the stamping principle of the base island processing device provided by this utility model.
[0022] Figures 1-2 middle:
[0023] 10-Lead frame base island; 11-Base island body; 12-Resistant boss; 20-Chip; 30-Silver paste; 200-Upper punching die; 300-Lower punching die; 310-Punch. Detailed Implementation
[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0025] The core of this utility model is to provide a lead frame base island, which has a resistive protrusion on the outer edge of the base island body to prevent silver paste overflow, eliminating the need for a safety distance reserved for overflow space, thereby increasing the chip size that the lead frame base island can accommodate.
[0026] In addition, this utility model also provides a base island processing device for the above-mentioned lead frame base island, which can use stamping to process the adhesive resist boss and the base island body in one step, with high processing efficiency.
[0027] The lead frame base island provided by this utility model is used to bond and connect with the chip 20. It includes a base island body 11. The upper part of the base island body 11 for bonding with the chip 20 is provided with a resist protrusion 12. The resist protrusion 12 is located on the outer edge of the base island body 11. The height of the resist protrusion 12 is greater than the maximum height of the silver paste 30.
[0028] Please refer to Figure 1 The resist bump 12 is located on the outer edge of the base island body 11 to prevent the silver paste 30 from overflowing to the back of the lead frame base island 10. Since the chip 20 is coated with silver paste 30 on all sides, in order to prevent the silver paste 30 from overflowing, the resist bump 12 is arranged around the outer edge of the base island body 11 to ensure that the silver paste 30 cannot overflow in any direction.
[0029] The adhesive-resistant boss 12 can be connected to the upper end face of the base island body 11 or to the outer side of the base island body 11. The connection method between the adhesive-resistant boss 12 and the base island body 11 can be determined according to the processing method of the base island body 11 and the size of the adhesive-resistant boss 12 in actual production.
[0030] For example, when the size of the adhesive resisting boss 12 is large, the adhesive resisting boss 12 can be connected to the upper end face or outer side of the base island body 11 by means of bonding; while for the smaller size of the adhesive resisting boss 12, the adhesive resisting boss 12 and the base island body 11 are usually integrated into one structure and processed by stamping or laser cutting.
[0031] The smaller the thickness of the resist bump 12 is while meeting the limit size requirements allowed by the processing method used in actual production, the larger the chip 20 can be accommodated under the condition that the size of the base island body 11 remains unchanged. The thickness of the resist bump 12 can be the same from bottom to top, or it can gradually decrease from bottom to top. However, considering the strength and stability of the connection between the resist bump 12 and the base island body 11, it is not advisable to set the thickness of the resist bump 12 to gradually increase from bottom to top.
[0032] To facilitate the machining of the adhesive resist boss 12, the thickness t of the adhesive resist boss 12 is usually set to be greater than 25μm, and the thickness of the adhesive resist boss 12 is the same from top to bottom. Figure 1 As shown, the cross-section of the adhesive-resistant boss 1 is rectangular, with a regular shape, which facilitates processing.
[0033] The height of the adhesive blocking boss 12 should be greater than the maximum height of the silver paste 30. The height of the silver paste 30 is usually in the range of 10-20μm. Considering factors such as actual processing difficulty, the height h of the upper end face of the adhesive blocking boss 12 from the upper end face of the base island body 11 is usually set to be 50-75μm to ensure the blocking effect of the adhesive blocking boss 12 on the silver paste 30.
[0034] In this embodiment, a resist protrusion 12 is provided on the outside of the base island body 11. The resist protrusion 12 can prevent the silver paste 30 from overflowing. Therefore, there is no need to maintain a safe distance between the outer edge of the control chip 20 and the outer edge of the base island, so that the lead frame base island 10 can accommodate a larger chip size.
[0035] Considering that the lead frame base island 10 is mostly formed by stamping in actual production, preferably, an adhesive resisting boss 12 can be set on the upper end face of the base island body 11. The adhesive resisting boss 12 and the base island body 11 are an integral structure, so that the adhesive resisting boss 12 and the base island body 11 can be formed together by stamping. This not only saves the connection steps after separately processing the adhesive resisting boss 12 and the base island body 11, but also effectively reduces the cost of modifying existing processing equipment for structural adjustment of the lead frame base island 10.
[0036] In addition, if the processing technology allows, the adhesive blocking boss 12 can be configured as a bent L-shaped structure. The adhesive blocking boss 12 includes an adhesive blocking part for blocking the silver paste 30 from overflowing and a connecting part for connecting with the base island body 11. The connecting part is horizontally arranged and protrudes from the outer side of the base island body 11.
[0037] Since the connecting part protrudes from the outer side of the base island body 11, the horizontal part of the resist boss 12 extends outward to increase the size of the base island body 11, thereby increasing the distance between the resist part of the resist boss 12 and the axis of the base island body 11, making it easier for the base island body 11 to accommodate a larger chip 20.
[0038] Based on the above embodiments, in order to further increase the size of the chip 20 that the lead frame base island 10 can accommodate, the resist bump 12 can be set at an angle relative to the base island body 11, and the distance between the resist bump 12 and the axis of the base island body 11 gradually increases from bottom to top.
[0039] The angle between the resist bump 12 and the axis of the base island body 11 is the outward tilt angle α of the resist bump 12. With the size of the base island body 11 remaining unchanged, the larger the outward tilt angle α of the resist bump 12, the longer the resist bump 12 protrudes beyond the outer edge of the base island body 11, and the larger the size of the chip 20 that the lead frame base island 10 can accommodate.
[0040] Considering the actual processing difficulty, the outward tilt angle α of the adhesive resisting boss 12 should not be too large. Usually, the outward tilt angle α of the adhesive resisting boss 12 is set to ≤30°.
[0041] In this embodiment, the resist protrusion 12 is inclined outward relative to the base island body 11, which expands the space on the upper part of the base island body 11 for accommodating the chip 20, so that the base island body 11 can accommodate a larger chip 20 under the same size.
[0042] In addition to the lead frame base island 10 described above, this utility model also provides a base island processing device for the lead frame base island disclosed in the above embodiments. The base island processing device includes a lower punching die 300, an upper punching die 200 for cooperating with the lower punching die 300, and a punching power mechanism. At least one of the upper punching die 200 and the lower punching die 300 is connected to the punching power mechanism.
[0043] The shape and size of the upper punching die 200 are determined by the shape and size of the upper part of the lead frame base island 10 to be processed, while the shape and size of the lower punching die 300 need to be determined according to the shape and size of the lower part of the lead frame base island 10 to be processed.
[0044] The punching power mechanism is connected to at least one of the upper punching die 200 and the lower punching die 300 to drive the upper punching die 200 and the lower punching die 300 to move closer to each other so as to perform punching processing on the profile to be processed;
[0045] The punching power mechanism can be specifically configured as a hydraulic cylinder, pneumatic cylinder, etc. The punching pressure and stroke of the punching power mechanism will affect the height of the adhesive resist boss 12 on the upper part of the lead frame base island 10.
[0046] Considering that the profile to be processed is supported by the lower punching die 300 during punching, it is preferable to set the lower punching die 300 fixed on the punching machine tool, while the upper punching die 200 is connected to the punching machine tool through the punching power mechanism;
[0047] During the punching process, the height of the punching die 300 and the height of the profile to be processed remain unchanged. The punching power mechanism does not need to overcome the gravity of the two, which helps to reduce the power of the punching power mechanism and the power consumption of the base island processing device, thereby reducing the processing cost and equipment cost of the lead frame base island 10.
[0048] Please refer to Figure 2 The size of the upper punching die 200 is smaller than that of the lower punching die 300 so that the upper part of the lead frame base island 10 is punched to form the adhesive resist boss 12. The size difference between the upper punching die 200 and the lower punching die 300 determines the width of the adhesive resist boss 12.
[0049] The lower die 300 is provided with a punch 310 for stamping the bottom step of the base island body 11. The punch 310 is usually located in the center of the lower die 300. The structure, shape and size of the punch 310 are determined according to the structure, shape and size of the lower step of the lead frame base island 10 in actual production, and will not be described in detail here.
[0050] During stamping, the punching power mechanism drives the upper punching die 200 to move closer to the lower punching die 300, and punches the profile to be processed placed between the upper punching die 200 and the lower punching die 300. The upper punching die 200 flattens the profile to be processed to form the upper surface of the base island body 11, and at the same time extrudes the edge profile to form... Figure 1 The lead frame base island 10 is shown.
[0051] In this embodiment, the base island processing device uses the relative proximity and extrusion of the upper punching die 200 and the lower punching die 300 to extrude the profile of the outer edge of the base island body 11 to form the adhesive-resistant boss 12, so that the lead frame base island 10 is integrally formed, which is convenient to process and has a low cost.
[0052] Preferably, the size of the upper punching die 200 can be set to gradually increase from top to bottom so as to punch outwardly inclined resist bosses 12, thereby increasing the size of the chip 20 that the lead frame base island 10 can accommodate.
[0053] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0054] The lead frame base island and base island processing device provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.
Claims
1. A lead frame base island for bonding and connecting with a chip (20), characterized in that, The base island body (11) is provided with an adhesive resist boss (12) on its upper part for bonding with the chip (20). The adhesive resist boss (12) is located on the outer edge of the base island body (11), and the height of the adhesive resist boss (12) is greater than the maximum height of the silver paste (30). The adhesive-blocking boss (12) is a bent L-shaped structure. The adhesive-blocking boss (12) includes an adhesive-blocking part for blocking the overflow of silver paste (30) and a connecting part for connecting with the base island body (11). The connecting part is horizontally arranged and protrudes from the outer side of the base island body (11) to increase the distance between the adhesive-blocking part of the adhesive-blocking boss (12) and the axis of the base island body (11).
2. The lead frame base island according to claim 1, characterized in that, The thickness t of the adhesive resisting boss (12) is greater than 25 μm, and the thickness of the adhesive resisting boss (12) is the same from bottom to top.
3. The lead frame base island according to claim 1, characterized in that, The height h of the upper end face of the adhesive-resistant boss (12) from the upper end face of the base island body (11) is 50-75μm.
4. The lead frame base island according to any one of claims 1-3, characterized in that, The adhesive-resistant boss (12) is located on the upper surface of the base island body (11), and the adhesive-resistant boss (12) and the base island body (11) are an integral structure.
5. The lead frame base island according to any one of claims 1-3, characterized in that, The adhesive-resistant protrusion (12) is inclined relative to the base island body (11), and the distance between the adhesive-resistant protrusion (12) and the axis of the base island body (11) gradually increases from bottom to top.
6. A base island processing apparatus for the lead frame base island (10) according to any one of claims 1-5, characterized in that, It includes a lower punching die (300), an upper punching die (200) for punching in cooperation with the lower punching die (300), and a punching power mechanism, wherein at least one of the upper punching die (200) and the lower punching die (300) is connected to the punching power mechanism.
7. The base island processing apparatus according to claim 6, characterized in that, The lower die (300) is provided with a punch (310) for stamping the lower step of the base island body (11). The size of the upper die (200) is smaller than that of the lower die (300) so that the upper die (200) can stamp the adhesive-resistant boss (12) on the upper part of the base island body (11).
8. The base island processing apparatus according to claim 7, characterized in that, The size of the upper punching die (200) gradually increases from top to bottom so as to punch out the adhesive-resistant boss (12) that is inclined outward.
9. The base island processing apparatus according to claim 7, characterized in that, The lower punching die (300) is fixedly mounted on the punching machine tool, and the upper punching die (200) is connected to the punching machine tool through the punching power mechanism.