TW511258B - Substrate-on-chip packaging process - Google Patents

Abstract

A SOC (substrate-on-chip) packaging process is disclosed. A layer of two stage thermosetting mixture with solvent is coating on an upside of a substrate. Thereafter, the substrate is heated for removing solvent so that the two stage thermosetting mixture becomes a dry adhesive film without solvent. Thus, the bonding pads of the chip are not covered by the dry adhesive film and a better operating flexibility is obtained in the SOC packaging process. Preferably, the dry adhesive film is cured during molding.

Description

511258

[Field of the Invention] The present invention relates to a packaging process of a substrate on a wafer (sUbStrate-0n-chiP, soc), and particularly relates to a die bonding step in the packaging process of a substrate on a wafer. [Previous technology] The so-called "SOC package" is Substrate-0n ~ Chii) package [US board on the chip] t for short, belongs to a commonly used semiconductor packaging structure; it is a circuit substrate with a window attached to a chip And a plurality of metal bonding wires are passed through the window to connect the circuit substrate and the wafer, and the circuit substrate is formed with a plurality of matrix-arranged solder balls. In the US Patent No. 6, 1 90, 943 "wafer size packaging method" A SOC packaging structure and a packaging method are disclosed therein. As shown in FIG. 1, the SOC packaging structure 20 includes a substrate 22, a wafer 24, and a plurality of solder balls 44. The substrate 22 has a It is used to fix the upper surface 30 of the wafer 24, a lower surface 38 for solder balls 44 and a through hole 34 penetrating the upper surface 30 and the lower surface 38. The wafer 24 is adhered to the substrate with a thermoplastic adhesive layer 28 The upper surface 30 of 22, because the through hole 34 of the substrate 22 is the pad 36 exposed in the middle of the active surface 26 (active surf ace) of the wafer 24, so that the metal bonding wire 32 can pass through the through hole 34 'to be electrically connected The bonding pad 36 of the wafer 24 and the guide of the substrate 22 The contact pad 41 is composed of a conductive layer 40 on the lower surface 38 of the substrate 22, and a sealing material 42 is formed at the through hole 34 and the periphery of the wafer 24, which is an insulation and thermosetting property. Epoxy epoxy silicone filling material. In U.S. Patent No. 6, 1 90, 943 "Chip Size Packaging Method": The packaging method for the above-mentioned SOC package structure 20 is shown in Fig. 2, & f α T step: a) Provide a substrate 22 ， 上 30 30 on the substrate 22

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Has at least one sticky crystal region 3 02, which includes the above-mentioned through holes 3 4; b) a liquid thermoplastic adhesive layer 28 is screen-printed [st enc i 1 i ng] on the sticky crystal region 302; c) the wafer 24 is stuck To the die attach area 302, so that the active surface 26 of the wafer 24 contacts the thermoplastic adhesive layer 28, and the position of the pad 36 on the active surface 26 corresponds to the through hole 34; d) at a predetermined temperature, pressure and time, apply Press and heat the substrate 22 and the wafer 24; e) Wi-bonding the metal bonding wire 32 through the through hole 34 to connect the lead pad 41 of the substrate 22 and the pad 36 of the wafer 24; f) provide an adhesive material 42 around the through hole 34 and the wafer 24; g) a plurality of solder balls 44 arranged in a matrix are planted on the lower surface 38 of the substrate 22. Through the above steps to prepare the SOC package structure 20, the 9 thermoplastic adhesive layer 28 in the step b) is a solvent-free, elastic and translucent silicone rubber. Because the thermoplastic adhesive layer is not bonded before, μ is in a liquid state, and the pressure heating in step d) can easily cause the liquid thermoplastic adhesive layer 28 to overflow and cover the pads 36 of the wafer 24, resulting in packaging failure. Therefore, this substrate packaging method on a wafer (S0C) The yield is low. In addition, another inconvenience is that after the liquid thermoplastic adhesive layer 28 is printed on step b), multiple substrates 2 cannot be stacked for transportation or storage. The upper wafer 24 must be adhered as soon as possible. Otherwise, the substrates 22 will be contaminated and the substrates 22 will be improperly adhered to each other, causing processing difficulties. [Objective and Summary of the Invention] The main object of the present invention is to provide a packaging process of a substrate on a wafer, which utilizes a two-stage characteristic [tw stage] thermosetting mixture with a solvent to adhere the wafer, and is printed on the substrate and dried. A non-adhesive thermosetting adhesive dry film is formed on the surface of the substrate, which makes it difficult for the thermosetting adhesive dry film to cover the pads of the wafer when heating and pressure is applied, so as to increase the S0C package MM 9012 ^ 00 5. Description of the invention (3) Yield. The process of amending the hair, forming a dry film on the solid mixing surface. In this process, the yield of the compression package of the solid mixed two fluidity stamper is the assembly process. The lower surface of the screen printing mixture and the upper surface are pressed to heat the wafer and the substrate; If there is a second order, use a two-stage object to stick the crystals with non-sticky substrates. You can stack it again. Use a two-stage object to 'dry' in the mold to eliminate the original one. The steps to achieve the above are: One layer and two stages; then, removing the film; then, the solder substrate and the wafer substrate of the wafer on the active side; and finally, in order to meet the demand, the connection is to provide a package stage characteristic of the substrate on the wafer. Solvent hot sheet 'is printed on the substrate and dried on the surface of the substrate-thermosetting adhesive dry film, so that it has thermosetting adhesive handling or storage, which is beneficial to the subsequent S0C packaging is to provide a package segment characteristics of the substrate on the wafer (two stage] After the heat of the solvent is formed, an adhesive dry film is formed to fix the wafer and avoid the process of curing the thermosetting mixture at the same time. Use the gap that may be hidden in the dry film to improve the performance of the S pad and remove the pad. The solvent is supplied to the pad. The mounting method is to seal the substrate on the wafer according to the method of the present invention. 'The substrate has an upper surface and a through hole; then, two stages on the upper surface of the substrate] have a thermosetting solvent, so that the thermosetting mixture forms a solvent-free wafer, and the wafer has an active surface, wherein the active surface of the wafer contacts the substrate The through hole corresponding to the substrate is set; thereafter, the solvent-free adhesive dry film is cured and the through-holes are wired to electrically connect the solder pads of the wafer to form an adhesive material in the through holes of the substrate. A solder ball is formed on the substrate. Quality

Into SOC package structure. [Detailed description of the invention] = f. As shown in the attached drawings, the present invention will enumerate the following embodiment descriptions: On-chip (snr, one of the specific embodiments of the invention i 'as shown in Figure 3, the substrate in the crystal, ^) The step of loading / packing mainly includes: "providing the base" i ^, forming a two-stage characteristic thermosetting mixture with a solvent ",

"Yu," Mixture "," Providing wafers to substrates "," Electrically connecting wafers I = ^ "Forming sealing compound" and "Curing the sealing compound and the solvent-free sales solid mixture", the details are as follows:

As shown in FIG. 3, a substrate no is first provided, and the substrate 110 has an upper surface 111, a lower surface 112, and a through hole 113 'that communicates with the upper and lower surfaces m and 112. In this embodiment, the substrate is A printed circuit board (such as glass fiber-reinforced resin such as FR-4, FR-5, or BT). A circuit pattern layer [circuU pattern] is formed on the lower surface 112 of the substrate 1 ().

[Drawing], such as lead pads, solder ball pads, and metal circuits connecting the lead pads and the solder ball pads; after that, a two-stage characteristic is printed on the top surface of the substrate 1 1 1 1 screen printing. Solvent [thermosetting mixture] 130 [thermosetting mixture], the two-stage adhesive thermosetting mixture 130 contains a thermosetting resin, such as polyimide, polyquinolin or phenylcyclobutene [ benzocyc 1 obutene], and solvents capable of dissolving the above thermosetting resins, such as a mixed solvent of butyrolactone (butyro lactone) and cyclopentanone (cyclopentanone) or 1,3,5-trimethylbenzyl [mesity 1 ene] The two-stage thermosetting mixture 130 has the characteristics of A-stage [A-stage] at the time of application, which is liquid, which makes it easy

Page 8 511258 Amendment No. 90123399 V. Description of the invention (5) In addition to the screen printing method, it can be printed · [painting], spraying [spinning], or spinning [dipping] ] And other methods are formed on the top surface of the substrate 11! ^; Then 'heat the substrate 110 to an appropriate temperature [approximately 90 ° C ~ 5 ° C] to remove the solvent' to make the thermosetting mixture 1 30 form a solvent-free adhesion The dry film 131 is preferably subjected to another vacuum drying heating to completely remove the solvent 'at this time'. The adhesive dry film 1 31 on the substrate 1 1 1 has the characteristics of β-stage [B-stage]. At temperature, it becomes a non-sticky film [Tg ^ 40 ° C]. Tg is the glass transition temperature. When the adhesive dry film 131 is higher than its glass transition temperature, it will change from rigid to Soft and adhesive, so the substrate 11 with the adhesive dry film 131 can be stacked and stored at room temperature, which is beneficial to the subsequent processing of the SOC package;

120, the wafer 120 has an active surface 121 [active surface] and a plurality of pads 122 on the active surface 121, wherein the active surface 121 of the wafer 120 is in contact with the upper surface U1 of the substrate 11 and the pad 122 of the wafer 120 The position corresponds to the through hole 113 of the substrate 110. In this embodiment, the bonding pad 122 is located in the middle of the active surface 121 of the wafer 120; thereafter, the substrate 11 and the wafer 120 are heated under pressure, at about 180 ° C and at It is maintained under appropriate pressure for several seconds, so that the solvent-free adhesive dry film 131 can mechanically bond the wafer 120 and the substrate 110, but it does not need to be completely cured. 131 does not have high fluidity, and does not have the phenomenon of being squeezed to the pads 122 of the wafer 120; The dagger 113 is electrically connected to the solder pad U0 of the wafer 12 with a metal bonding wire 140; finally, a thermosetting sealing material 150 is formed on the substrate 11 () \ 511258

U 3 places' In this embodiment, it is formed in the form of a stamper [_ 丨 d 丨 ，], and the sealant 150 is sealed. The sealant 150 is sealed and the wafer 120 is sealed. The same sealant 丨 50 ° C is cured by heating (about 200 degrees Celsius and maintained for several hours) to cure the adhesive dry film 1 3 1, due to the pressure of the die, it may be excluded that the dry film may be latently adhered before being cured 丨 3 The gap of 1 is entered into the package with a yield of 1. If necessary, a plurality of solder balls are implanted on the lower surface 112 of the substrate, and after cutting and separation, a plurality of soc packaging structures 100 are formed. ~ Because =, the present invention uses a two-stage package (two stages) with a compound 130 on the substrate on the wafer.) The packaging process covers the lack of J1 "materials" on the wafer 120 and the soldering material 122 to avoid the liquid adhesive. Forming a thermosetting adhesive dry film i 3 i beauty (meaning, put together) is conducive to subsequent processing of the SOC package 110 substrate can be stacked for transportation or storage. Therefore, the scope of protection of the present invention is subject to the attached one, any familiar with this Any changes and modifications made within the scope defined by the "artist" range are the spirit and scope of the Ming. Θ belongs to the protection scope of the present invention 511258 ----90123399 Schematic description of the month, day and day '— " [Schematic description] The Figure 1: In the US Patent No. 6,19,943, a section of the SOC package structure is revised, Figure 2 and Figure 3 [Figure No. Description 20 SOC package structure substrate "chip size packaging aspects; In the US Pat. No. 6,190,943 "wafer size packaging method", the manufacturing flow chart of the SOC package structure; and according to a specific embodiment of the present invention, the process of packaging the substrate on the wafer (soc) Manufacturing flow chart. 2228 34 40 44 through-hole conductive layer solder ball 1 00 SOC package structure 110 substrate 111 upper surface 120 wafer 130 two-stage thermoset 1 4 0 metal bonding wire 3 0 2 die bonding area 24 chip 26 active surface 30 upper surface 32 metal bonding wire 36 Pad 38 lower surface 41 lead pad 42 sealing material. 1 I ', 1; 112 lower surface 113 through hole 121 active surface 122 pad mixture 131 adhesive dry film 150 sealing material 160 solder ball 1

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Claims (1)

? / Nianyi, double, MM 9012339a VI. Patent application scope [Patent application scope, process, the steps include a substrate on the wafer a) Provide a substrate with through holes through the upper and lower surfaces; The surface and the b) on the substrate-士 stage Ί JL ^ formation of the two-stage characteristics [two stage] thermosetting mixture with a bath agent; film c;) remove the agent 'to make the thermosetting mixture into a solvent-free Adhesive dry film, the chip has an active surface and a plurality of pads on the active surface, and ay々 + 仏 Q ut ^ /, the active surface of the film is in contact with the upper surface of the substrate and _ The position of the f pad is corresponding to the through hole of the substrate; e)》 e pressure heats the substrate and the wafer, so that the above solvent-free adhesive dry film is combined with the wafer and the substrate; f) the pad is electrically connected to the wafer through the through hole. To the substrate; g) forming a sealant at the through hole of the substrate by compression molding; and h) heating and curing the adhesive sealant and the solvent-free dry film. : The packaging process of the substrate [S0C] on the wafer as described in item 1 of the scope of patent application is to form a layer of thermosetting mixture by screen printing. 3. The packaging process of the substrate [S0C] on the wafer as described in item ί of the scope of the patent application, which is performed by printing [painting], spraying (spraying), spin coating (spinning) or dipping (dipping). A layer of thermosetting mixture is formed. On page 12, the packaging process of the substrate on the wafer [S〇t] as described in item 丨 of the scope of the patent application, which includes the following steps after the "h) step of" heat curing the sealing material " A plurality of solder balls are planted on the lower surface of the substrate. The substrate is encapsulated on the wafer as described in item 1 of the scope of patent application, wherein the sealing material is a sealed wafer. The packaging process of the substrate [SOC] on the wafer as described in item 1 of the scope of the patent application, wherein the solvent is removed by heating or vacuum. Jin Yun, the packaging process of the substrate on the wafer (SOC) as described in item 1 of the scope of patent application, where the temperature of the heat curing step in h) is higher than the temperature in the step of removing the solvent. Dish