TW561563B - Flip-chip packaging process and its fixture - Google Patents

Abstract

A kind of flip-chip process suitable for use in an underfilling method includes the following steps: providing a chip having an active surface with plural metal bumps arranged at intervals; providing a substrate, in which one surface of the substrate has a chip bonding area that has plural bonding pads arranged at intervals and having the pre-placed soldering paste; using a printing screen to conduct a screen printing method, so as to form the filling material between the bonding pads inside the chip bonding area; attaching the metal bumps to the bonding pads to adhere the chip to the substrate; using a flip-chip packaging fixture in a flip-chip packaging process; and using screen printing to form underfilling material on a substrate through the printing area, in which the utilized printing screen contains a printing area and the other areas. The printing area contains plural opening regions, plural masking portions, and plural connecting lines for connecting the masking portions to the other regions of the printing screen, and the connection between the masking portions.

Description

561563

[Field of the Invention] A flip-chip packaging process and a fixture thereof, particularly a process in which a filler material is formed on a substrate, and the present invention relate to a fixture by screen printing. [Background of the Invention] With the urgent demand for high-density, high-power electronic packaging, flip chip technology is becoming the focus of attention from all walks of life. The so-called cover is to install the bare dle with the substrate in a surface-down manner.

Techniques for joining. When using an organic substrate (〇rganic :; the case of the magic 'due to the coefficient of thermal expansion of the organic substrate (CTE; c〇ef 1 Cient of thermal expansi) is about AH Qing / t and the CTE of Shi Xi wafer (about 4 ppm / it) Lamb ^, ΓΤί7 ^, PPm / 〇 The gap is too large, the CTE does not match during thermal expansion and contraction: the stress caused by the stress can easily cause the contact to be damaged. Inside the door gap: L2 Considerations' Usually, an underfill is required to be filled in the gap between the substrate and the wafer to reduce the stress on the contacts, such as knife-to-moon to colloidal fines. 10. The wide cracks of the 1 system can be extended to extend the contact. The fatigue life of the point. In addition, the above-mentioned bottom knee is an insulating material, which can also prevent the transmission #-0 + 1 T to prevent the leakage of current # caused by impurities between the contacts.

UeliabiHty) 5-10 times higher. Because of the bottom structure: the primer can be ^ reliable W / Yu Yue 4 Because the primer can effectively improve the bonding system :: Therefore, in the process of covering Yang Fengxiang, the primer is an indispensable ... [Previous skill] However, the most talked about sickness in the filling process lies in its filling and hardening.

561563 V. Description of the invention (2) (c u r i n g) The time is too long, leading to a strong filling process. Most of the bottlenecks in the production of clothing occur when = the front primer is mostly dispensed with liquid sealant material (μ =, into the process, the low viscosity liquid colloid = the shape of the pores, the wafer and the seal The fine capillary pressure (caPiUary pressure) between the substrates is used as the number and the gap between the full contacts. The disadvantage of this process is that the next two = the square of the distance is proportional, such as the filling time required for a 7_ square m 2 temperature Several minutes to ten minutes; ⑴ due to the two ^ finite two filling is easy to remain voids in the sealing body, boundary ， m: insufficient, the bubbles are likely to cause popcorn of the package in the subsequent thermal process The effect (popcorn) makes the package fail, or the seal is destroyed due to stress concentration and accelerated failure when it is under stress, which affects the yield of the flip-chip package or the reliability and service life of the product;) Filling can only be used to dispense a single package at a time. If you want to dispense two or more packages at the same time, it is necessary to prepare multiple sets of equipment to increase the cost burden; (4) Fill the primer Before the package substrate must be Shaped, separated into single packaging unit or package substrate, the subsequent processes, e.g. bumping ·· Flip Chip BGA package (ball, 'placement) process output (throughput) adversely affected. [Summary of the invention] The purpose of the present invention is to provide a flip-chip packaging process and its fixture, which can complete the process of filling the primer in a short time to improve the conventional process charge 0702-8683TWF; 91P46; Dwwang. ptd page 6 561563 V. Description of the invention (4) During the assembly process, a screen is used to fill a substrate on the substrate. The printing screen used is formed by "brush blocks" and other areas, where the above printing Area 3 blessing :: brushing the block; using several masks, and a plurality of connecting lines as the hole area; complex [example] the connection between x and the above masks. The diagrams A ~ 1E show the process used to explain this kind of flip-chip packaging process. This month, the process of filling the primer in this package is added to increase the flip-chip sealing. 2: Complete the flip-chip sealing and test the following steps: "Day Reliability and service life; please refer to r sound 1: 2: test 1 ^ picture 'the surface of the flip-chip package substrate 100-has a-guard layer 102 (sodium mask), also known as "green paint", middle, The above-mentioned internal circuit is contaminated by solder. 7 There are a plurality of openings 106 (openings) arranged in a specific manner. 4 (bump pad) is exposed, and its arrangement is the same as that of the crystal bumps 31o (shown at ^) on the active surface 31o of the 1C wafer 300 to be accessed; 1 () 4 is connected to the internal circuit of the above-mentioned cover substrate 100, and after the post-process is connected to the IC chip: ^ 1st circle), the 'make-up chip package substrate' (㈣ 0702 ~ 8683TWF; 91P46; Dwwang.ptd Page 8 561563 V. Description of the invention (5) The chip 300 is turned on, and the distance between the pads 104 (bump pad ρΗ (^) is preferably not less than 180, and the pad ⑻ The above has been completed—the process of pre-applying a solder paste (Uolder * paste), a solder paste 11 is formed thereon, = solder paste HG = the main ingredients are-metal powder and a flux (not shown in the figure), It is used to assist the bonding of the flip-chip bump 3110 (shown in FIG. 1D) and soldering. Please refer to FIG. 1B to align the flip-chip package substrate 100 with a printing screen and align (or print one The screen plate 200 is aligned with the flip-chip package base plate), the solder paste 110 on the pad 104 is aligned with the mask portion 23 of the printed screen plate 200, and the dry bonding area is in the range of 150 The areas outside the pad openings in the inside are aligned with the opening area 220 of the printing screen 〇〇; a knee filling material 120 is placed on the printing screen ^, and then screen printing is performed with a scraper 21 〇 ( S (lueegee) forms the filler material 120 in one direction through the opening area 22 of the printing screen 200 in a region other than the openings 106 of each solder pad within the range 150 of the wafer access area. Please refer to section The ic diagram shows that the filler material 12 has been formed in the area other than the openings of the solder joints within the range of crystal = 150. Next, referring to the figure, the plurality of crystalline wafer bumps 31 of the -1C wafer 3 00 and The corresponding solder pads 104 on the flip-chip package f board 1 and 〇 are aligned, where the flip-chip bumps 31 〇 =: gold, copper, Cu based alloy, tin-lead alloy, Or tin-containing alloys. Please refer to FIG. 1E, and join the aligned IC chip 3〇 () with, 0 to become a letter 00. After that, a metal powder with a melting point of not higher than two 110 or a temperature higher than the melting point of the flip-chip bump 3, and the package 400 can be used to harden the filling material 120, and then one can not lower the tin. mouth

I Page 9 〇7〇2.8683W; 91P46; Dwwang.ptd 561563 V. Description of the invention (7) Privately, you can also use 1 or an array with a total of g seal nightmare to fill the bottom of the board. Depending on process requirements. The design of the package base ==== version of the design: the formula can be based on the ability of the Fengxiang substrate, the dream course · I,:, the clothing of the printing press (not shown in the drawing), or other conditions To make changes,-or a plurality of packaging units or packages-or a process with a primer, is not limited to the substrate shown in Figure 2A-rLRef Λ Figure 2B 'shows ^ In the figure,-in a printed block 51 is an enlarged view of a domain A. It can be known from the 2A and the print block 51 that the print block 51 is composed of a plurality of opening regions 512, a mask portion 514, and a connection line 516. The opening area 512 is used to form a filler material (not shown in the drawing) on a flip-chip packaging substrate (not shown in the drawing) during screen printing; the mask and the part 514 are It is used to mask the areas on the flip-chip package substrate that do not need to form the filler material (such as solder pads or other areas) during screen printing to prevent the filler material from forming on the substrate without forming the filler material. Area of adhesive material; the connecting line 5 1 6 is used to connect the individual mask portions 5 1 4 or to connect the individual mask portions 5 1 4 to other areas of the printing screen 5 0 0. Please note that the opening area 5 1 2, the mask portion 5 1 4, and the arrangement and size of the connection line 5 1 6 are different according to the design method of the corresponding flip-chip package substrate (not shown in the figure). Some adjustments are not limited to the example shown in Figure 2B; and the distance between the mask portions 514 is preferably not less than 18〇β m 〇 The material of the printing screen 5 0 0 can be metal Or organic polymer-coated metal composites; in addition to prevent surface dots on screen printing 500

0702-8683TWF; 91Ρ46; Dwwang.p td

561563

V. Description of the invention (8) It is attached with other materials such as rubber packing materials, to prevent corrosion, or to prevent the surface of the printing screen 500 printing screen 500 from being affected by the life of the printing screen printing 500 or The filling of 3 sides of the bottom cover is so bad that it affects the method of using the glue on the surface of the above-mentioned printing screen 5,000. The surface coating or a surface plating is as described above, but it is not intended to be used without departing from the spirit of the invention. Therefore, the protection of the invention shall prevail. Although the present invention has been limited to the present invention by a preferred embodiment: Any person skilled in the art, and within the scope, can make a few changes and modifications. The scope is subject to the scope of the attached patent application.

561563 Brief description of the drawings [The invention is detailed for easy understanding, and the detailed description is as follows: [The first embodiment of the drawing overlaps the second embodiment of the 2A] [Symbols say 100 ~ 104 ~ 110 ~ 150 ~ 210 ~ 230 ~ 310 ~ 50 0 ~ 512 ~ 516 ~ Detailed description] The above and other objects, features, and advantages of the present invention can be made clearer. The preferred embodiments will be listed below, and will be described in detail with the accompanying drawings: Brief description]-~ 1 Figure E is a series of cross-sectional views for explaining the flow of the first solid-crystal packaging process method of the present invention. ~ 2B is a schematic diagram for explaining the composition of the second flip chip packaging jig of the present invention. Ming】 Flip-chip package substrate, solder pad, solder paste, wafer bonding area, scraper cover, flip-chip bump printing screen, opener, L-zone connection line 1 0 2 ～ solder mask 1 0 6 ～ pad opening 120 ～ filler 2 0 0 to printed screen 2 2 0 to open area 3 0 0 to IC chip 400 to package 5 1 0 to printed block 5 1 4 to mask

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Claims (1)

561563 6. Scope of Patent Application 1 · A flip-chip packaging process, suitable for a method of filling a primer, the following steps: i # Provide a wafer with an active surface, which has metal bumps arranged at intervals; Provide a substrate, the substrate One surface has a wafer bonding area, and the wafer bonding area has a plurality of spaced-apart and pre-soldered Xue Xue ^ using the solder pads on the substrate. 2 · If the printing screen, a plurality of wafer holes are connected to the wafer on the crystal pad area; Area connection 3 · As the printing screen 4. As the printing screen 5 · As an area other than a printing screen, some metals The connection between the bump and the application special edition has a mask part to fill the bonding material in the bonding area, and the application for the special edition applies for the special application. The scope of patent application is a printing and the wiring system formed with the material in the compound area. The covered areas are formed of a gold-filled area and formed of a filling material; and the fresh-bonded joints make the chip adhere to the flip-chip packaging process described in the first item, in which blocks The printing area has a plurality of openings and a plurality of connecting lines, wherein the opening areas i are the areas between the fresh pimples and the ones on the substrate; the mask portions are similar ^ 鲜 ς 'Avoid the formation of the gadolinium material between the mask portions which are the mask portions and the other mask portions of the printing base plate. The flip-chip packaging process described in item 1 is straightforward. The chip-on-chip packaging system described in Item 1 belongs to the composite raw material of organic materials with organic polymers. 561563 2. Patent application Fan Yuan Contains a baking process to harden the rubber filling material. Renyi 6 · = Flip-chip packaging process described in item 丨 of the scope of patent application, and a 5 reflow soldering process is used to weld the metal bumps to the pads. Renyi 7 · = The chip-on-sealing process described in item 丨 of the scope of application for patent, still includes: the reflow process makes the metal bumps and the pads weld to make the filler material harden. ^ 8 · The flip-chip packaging process as described in item 1 of the scope of the patent application, wherein among the spaced-apart metal bumps, the distance between the individual metal bumps is not less than 180 °. ^ 9 · The flip-chip sealing process as described in item 1 of the scope of the patent application, wherein among some of the pads arranged at intervals, the distance between the individual pads is not less than 1 8 0 # π]. ^ 1 0 · The flip-chip packaging process as described in item 2 of the scope of patent application, wherein the space between the individual mask portions among the mask portions is not less than 180 / zm 〇11 · A crystal packaging jig, which is suitable for a flip-chip packaging process, in which a filling material is formed on a substrate by screen printing. A printing screen used includes at least a printing block, wherein the printing block includes : A plurality of opening areas; a plurality of masking portions; and a plurality of connecting lines as the connection between the masking portions and other areas of the printing screen and the speed knot between the army covering portions. 1 2. The flip-chip package jig as described in item 11 of the scope of patent application, wherein the connecting wires are far away and the opening areas are separated at the same time. 561563 6. Scope of patent application 1 3. The flip-chip packaging jig described in item 11 of the scope of patent application, wherein the material of the printing screen is metal. 1 4. The flip-chip packaging jig as described in item 11 of the scope of patent application, wherein the material of the printing screen is an organic polymer-coated metal composite material. 1 5. The flip-chip packaging jig according to item 11 of the scope of application for a patent, wherein the printing screen plate further comprises a surface coating layer or a surface mineral layer. 1 6. The flip-chip packaging jig as described in item 11 of the scope of patent application, wherein the space between the individual mask portions among the mask portions is not less than 1 80 // m 〇 0702-8683TWF; 91P46; Dwwang.p t d p. 16