TW480695B - Method of bonding lead fingers of a lead frame and a substrate - Google Patents

Abstract

A method of bonding lead fingers of a lead frame and a substrate, it includes: (a) providing at least a substrate, its electrically bonding surface has a plurality of connection pads; (b) providing a lead frame, which possesses a plurality of lead fingers and some lead fingers attach a tape; (c) thermally compressing the lead fingers of the lead frame, wherein a solder material between the inner lead of a lead finger and the corresponding connection pad is limited by the tape while thermal compression. As a result, a plurality of lead fingers are bonded to a substrate strongly mechanically and electrically by one thermal compression.

Description

480695

[Field of the Invention] The present invention relates to an inner lead bonding method of a lead frame and a substrate, and particularly to a method of bonding a lead and a frame to a substrate, wherein the lead frame is adhered with an adhesive tape, It is used to fix the lead of the lead frame and block the improper flow of solder. [Prior art] It is known that a semiconductor chip is packaged with a package body to protect the chip from the external environment, and a lead frame is used as the semiconductor package chip and the printed circuit board. For electrical connection, such as outer quadratic package [I Quad Flat Package, QFP] on the four perimeters of the package or external pins on both sides of the package] [Small Outline Package, S0P]. 2. The lead fingers of the lead frame are electrically connected to the internal chip. The conventional method is to wire the leads to the chip electrically by wire-bonding, but the disadvantage is that they must be wired one by one to form each wire. , The efficiency is poor. In order to shorten the manufacturing time, especially during the internal electrical connection process between the index finger and the wafer, US Patent No. 6,008,604, "Semiconductor Device with TAB Index and Manufacturing Method" discloses an internal index finger combination Method [丨 nner lead bonding] 'This is to achieve the purpose of electrically connecting a plurality of internal lead fingers to the chip at a time by thermal compression. As shown in Figures 1 and 2, a semiconductor package 100 It includes a wafer 1 1 0 'wafer 11 0 has an electrical bonding surface 1 1 1, a plurality of bumps 11 2 are formed on the electrical bonding surface jj 1, and a first Sub-heat pressing method is used to attach a TAB tape 150 (TAB is automatically reeled by tape

480695 V. Description of Invention (2)

The abbreviation of Tape Automated Bonding], TAB tape 150 is a soft polyimide tape and is formed with an opening 1 51. The opening 1 5 1 must be smaller than the electrical bonding surface 1 1 1 of the wafer 1 1 1 and exposed. The bumps 112 on the electrical bonding surface 1 1 1 of the wafer are ejected, and a plurality of tab fingers 140 are carried and fixed on the TAB tape 150, and the inner ends of the plurality of TAB fingers 140 are bonded by a second heat compression. To the corresponding bumps 11 2 ′, a plurality of τ AB fingers 1 4 0 · are bonded to the corresponding lead frame fingers 1 3 0 by the third thermal compression, and are subjected to molding [molding], potting [ [injecti〇n] and cutting [cutting] to get the semiconductor package 100 as shown in Figures 1 and 2, but because of the TAB tape 150 with Ding ^ leading 140 is tough, for winding up in one Reel φ [reel], TAB index finger 140 does not provide sufficient mechanical strength / degree when pouring glue, resulting in [encapSulant jecti 〇n] when pouring glue, wafer chip 1 10 is within package 1 20 Offset and tilt, in addition, each semiconductor package 100 in the manufacturing process must be made by three thermal compression bonding, package over ': It seems complicated. [Objective and Summary of the Invention] The main object of the present invention is to provide a method for combining a lead frame finger and a substrate, and the lead frame finger is directly bonded to the substrate by thermocompression bonding.

5th and 31th, a sufficient amount of tape is formed between the index finger and the substrate connection pad. There is an adhesive tape attached to the index finger around the second board to block the solder. 1.2 ^: The material can be between the index finger and the substrate. The connection pads provide a solid mechanical strength to achieve a fast and stable bond. The second objective of the present invention is to provide a semiconductor package. The solder is directly combined with the lead of the lead frame and the substrate.

According to the invention, there is provided: at least an electrical bonding surface frame having a plurality of the plurality of finger fingers close to the inner finger finger tape with a tape connection between the substrate connection should be formed with a welding finger Electrical properties of the substrate [Detailed description of the invention is an adhesive tape adhered to a lead, and a lead frame electrically connected to lead a substrate, which is formed into a plurality of frames, L, and an inner surface of each finger is affixed with an adhesive surface. The base pad, which leads the solder, when the inner finger is in contact with the pair of bonding surfaces. Ming] The method of combining the finger and the substrate by blocking the solder overflow, achieving bonding and correcting the mold flow. The substrate has an electrical bonding surface connection pad; a lead frame frame hole is provided with a plurality of leads corresponding to the substrate. Connection pads; and the direction of the plate of the thermocompression lead frame, the inner finger of the inner finger and the corresponding base solder are melted by the substrate connection pad to which the tape should be applied, and it is stable once. The steps are “in” the “wire guide” and “in the guide”, and the pressure is limited to the board connection pad by partial pressure. The tape is adjacent to the “drawings”. The present invention will enumerate the following examples: ^ As shown in FIGS. 3 to 5 is a first embodiment of the present invention, a method for combining a lead frame finger and a substrate, as shown in FIG. 4, firstly providing two lead frames 250 [1 ead frame], The lead frame 25 is made by a conventional stamping or etching method from a metal plate such as copper, iron, or gold [alloy 42, which contains 42% nickel and 58% iron]. In the present embodiment, it is better to use a copper plate with better thermal conductivity. The lead frame 250 has a plurality of frame holes 251, and each frame hole 251 has a plurality of lead fingers 230. finger], wherein the inner end of the plurality of lead fingers 230 corresponds to a connection pad 213 of a substrate 21 and extends to form 480695 V. Description of the invention (4) An inner finger 231 [inner lead] 230 near the inner finger 231 with a window tape 240 [window tape] Several index fingers 230 are not easy to shift and are coplanar. The window tape 24 is preferably a polyimide tape with single-sided adhesiveness. The window tape 2 4 0 has an opening 2 41 and an opening 2 4 1 is slightly larger than the substrate 21 0 to accommodate the substrate 210 [as shown in FIG. 3]. In this embodiment, the substrate 210 is a silicon substrate, such as a semiconductor wafer. The substrate 210 has a plurality of connection pads 21 3 [connection pads], such as aluminum pads, which are formed on the substrate 21. Around the electrical bonding surface 211, and an integrated circuit element is formed at the electrical bonding surface 211, and constitutes an appropriate micro-processing Is, 5 memory or logic chip. In this embodiment, solder 2 1 2 ′ [solder material, ie, so-called bump] is formed on the connection 塾 2 1 3 in advance by electrical, steam bonding, wire bonding, or printing methods, such as gold or lead-tin bump 0

As shown in FIG. 5, when the lead frame 250 is moved and positioned, at this time, the window film strip 240 is located on the lower surface of the index finger 2 30, and the substrate 2 10 is transported and raised by a carrier 4 ^ j to make the index finger 230 The surface on which the window tape 24 is attached (that is, the lower surface of the table) faces the electrical bonding surface 2 11 of the substrate 210, and the finger portion 23 within the lead 23 is a connection pad 213 corresponding to the substrate 210, and a pressure 々Iq [compression head] presses the finger from the top to the bottom within 23 ° and refers to 2 3 1 'The compression head 4 1 0 has a temperature of several hundred degrees Celsius, so that the finger 231 and the corresponding part within the flutter 230 Solder between the substrate 210 and the connection pad 213

480695 V. Description of the invention (5) 212 The heat and pressure of 212 will be dazzled and melted, and then one person can refer to the inner part of the finger 230 and connect to the corresponding substrate 21G i. Since the window tape 24 0 is adjacent to the electrical bonding surface 2 11 of the substrate 21 0, the material 2 1 2 is restricted or hindered by the window tape 2 4 0. The solder 2 1 2 refers to the metal within 23 0 The finger 231 and the connection pad 213 have a good combination. At the same time, under the surface tension of the solder 2 1 2, the solder 2 丨 2 can be evenly formed between the inner finger 231 and the corresponding connection pad 213. Finally, in the After the sealant is cured and cut, the semiconductor package 200 shown in FIG. 3 can be obtained. Therefore, the method of combining the lead frame finger and the substrate of the present invention has the following effects: First, the combination of the lead frame finger 2 3 0 and the substrate 2 0 can be completed quickly with a single thermal compression; second, solder 212 Under the restriction of the window tape 240, a sufficient amount of solder 212 can provide a stable mechanical bonding strength between the index finger and the substrate without overflowing;

Second, the index finger 230 has the advantage that the index finger is coplanar and is not easy to shift during the process under the limitation of the window tape 240. After sealing, there is no need to trim the support rib (dam bar). It is located near the periphery of the substrate 210, and has the effect of correcting the mold flow in a proper shape. According to the above-mentioned method of combining the lead frame finger and the substrate, as shown in FIG. 3, a semiconductor package 200 includes a substrate 210, and the substrate 210 has an electrical bonding surface 21 1 on the electrical bonding surface. 2 11 is formed with a plurality of connection pads 213; a plurality of fingers 2 2 30, wherein the plurality of fingers 23 have

Page 9 V. Description of the invention (6) Within the inner part 4 is the part 231 and the pin 232 is outside the package 220, wherein the inner part 2 3 1 is the connection pad 2 1 corresponding to the substrate 2 1 0 3; A plurality of solders 212 'are formed between the inner finger portion 231 and the connection pad 213, and are electrically connected and mechanically combined with the finger 23 0 and the substrate 21 0;-the window tape 24o, point on the finger 230 toward the substrate 2 10 One surface of the electrical bonding surface 211, which is adjacent to the electrical bonding surface 211 of the substrate 210, is used to fix the finger 23o and the limiting solder 212, and a package 220 to protect the substrate 21o. Therefore, this The semiconductor package 200 has the advantages of fast packaging, stable mechanical bonding strength, and correction of upper and lower mold flow. The method of combining with the substrate… etc., in order to understand that in the lead frame index of the present invention, the type of the substrate and the shape of the tape are not limited. A printed substrate is first provided-a substrate 310, which is a two-printed circuit board or a ceramic circuit board, which has an electrical bonding surface and a mating surface 311, and a plurality of connection pads 313. For example, as a finger [gold finger], the report # & ε is a circuit board 31〇 ^ 承承公 古 $ 奴 7 and $ becomes a long finger, the substrate 3 10 can be pre-loaded with a plurality of wafers 35G [ As shown in Figure 9]. The wire Π7 is provided after the second copy of the picture—the lead frame [not shown in the figure]. If the part corresponds to the connection of the substrate 31 塾 = number: ^ Purpose 33 内 内 之 之-the surface is formed with solder ": Inner core 1 and other conductive welding materials, 1 such as nickel, palladium, lead-tin, gold, and silver are affixed-strip tape 34 °. The index finger 330 on the side is close to the inner finger 331 480695 5. Description of the invention ( 7) As shown in FIG. 8, the plurality of fingers 3 3 〇 are hot-pressed, and the finger 310 within the finger 33 is pressed in correspondence with the surface of the finger 3 3 〇 with the tape 340 toward the substrate 31 〇 For the substrate connection pad 313, the solder 3 1 2 between the inner finger portion 331 of the lead 330 and the corresponding substrate connection pad 3 1 3 is melted and restricted by the tape 340 adjacent to the substrate 310, effectively retaining a sufficient amount of solder 312 The inner finger 3 3 1 of the soldering lead 3 3 0 and the corresponding substrate connection pad 3 3 and 3 are finally cured and cut after molding, to obtain a multi-chip semiconductor package 300. Similarly, according to According to the method for combining the lead frame finger and the substrate of the present invention, the second: J3: 0 also has a stable mechanical junction which can be obtained by rapid packaging: Degree and the effect of correcting the upper and lower mold flow. ^ Therefore, the scope of protection of the present invention shall be subject to the patent applicant attached hereto. Those who do not depart from the scope of the present ~ are all within the spirit and scope of the second. ♦ Qiming's protection range 480695 Schematic description of the diagram [Schematic diagram No. 1: Picture 2: No. Figure 3: Figure 4: Figure 5: Figure 6: Figure 7: Figure 8: Figure 9: [Figure says 100 semiconducting II 0 chip III electrical properties] US patent device and US patent device And a view thereof; a conductor package according to the present invention; a conductor provided according to the present invention; a conductor provided according to the present invention; a base provided according to the present invention; a guide provided according to the present invention; a semiconductor seal according to the present invention; No. 6, 0 8 0, 6 04 "Semiconductor package with TAB manufacturing method" No. 6, 0 80, 604 "Semiconductor package with TAB manufacturing method" Reference semi-structured top conductor Figure, conductor knot through the conductor The lead frame shown in the cut-off lead frame and the base lead plate are viewed from the bottom. The lead frame is supported by the lead frame of the lead frame. The illustration of the combination of the frame index and the substrate shows the intention of the frame index and the base, the method of combining the frame index and the substrate, another schematic view; the cross section of the frame index and the base and the substrate; . Board bonding method, the proposed intention; board bonding method, another board bonding diagram, board bonding method diagram; and bonding method another 112

Page 12 480695 Brief description of the diagram 120 Package 130 Lead 140 TAB Lead 150 TAB Tape 151 Open σ 200 Semiconductor package 210 Substrate 211 Electrical bonding surface 212 Solder 213 Connection 塾 220 Package 230 Lead 231 Inner finger 232 External pin 240 window σ tape 241 open V 250 lead frame 251 frame L 300 semiconductor package 310 substrate 311 electrical bonding surface 312 solder 313 connection pad 320 package 330 lead 331 inner finger 340 tape 350 chip 410 compression head 420 load station

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Claims (1)

480695 VI. Application Patent Scope 1. A method for combining a lead frame finger and a substrate, comprising the steps of: providing at least one substrate, the substrate having an electrical bonding surface, and a plurality of electrical bonding surfaces being formed on the electrical bonding surface Connection pad; providing a lead frame, the lead frame has a plurality of frame holes, a plurality of lead fingers are formed in each frame hole, wherein the inner fingers of the plurality of lead fingers correspond to the connection pads of the substrate, and A tape is affixed near the inner finger of the lead; and the lead of the thermocompression lead frame is pressed against the corresponding substrate connection pad with the surface of the lead with the leading tape facing the substrate, where the lead is A solder is formed between the inner finger and the corresponding substrate connection pad. When the solder is melted, it is restricted by the tape. The inner finger of the index finger is soldered to the corresponding substrate connection pad, and the tape is adjacent to the substrate. Electrical bonding surface. The method for combining a lead frame lead and a substrate as described in item 1 of the scope of patent application, wherein the substrate is a wafer. The method of connecting a lead frame finger to a substrate as described in item 1 of the scope of patent application, wherein the substrate is a circuit substrate. 4. The method of combining the lead frame finger and the substrate as described in item 1 of the scope of the patent application, wherein the connection pads of the substrate are long fingers. 5. The method for joining the lead frame finger and the substrate as described in item 1 of the scope of the patent application, wherein the tape is a window tape having an opening slightly larger than the electrical bonding surface of the substrate. 6. The lead frame lead as described in item 1 of the scope of the patent application, and the substrate 480695 VI. Method for applying patent scope, wherein the adhesive tape is strip-shaped 7. A semiconductor package includes: a substrate having an electrical bonding surface, and a plurality of connection pads formed on the surface; Fingers, in which the inner fingers of the plurality of fingers are the connection pads of the substrate; μ a plurality of solders are formed between the inner fingers and the connection pads; at least one tape is affixed to the electrical bonding surface of the fingers toward the substrate 'And adjacent to the electrical bonding surface of the substrate; and a package. 8. According to the semiconductor package mentioned in item 7 of the scope of patent application, the board is a wafer. 9. As in the semiconductor package described in item 7 of the Shenjing patent scope, the board is a circuit substrate. 10. The semiconductor substrate described in item 9 of the scope of patent application carries at least one wafer. Package 11. The connection of the semi-substrate as described in item 7 of the scope of patent application is a long finger. Package 12 The semiconductor tape as described in item 7 of the patent scope of Shenyan is a window tape, which has an opening, which is the electrical bonding surface of the substrate. The opening 13 π is a semiconductor sealing tape as described in item 7 of Shen Qing's patent scope. The package is electrically connected to a surface corresponding to one of the surfaces, wherein the base, the base, where the, where the, where the mouth is slightly larger, where the Page 15