JP2002118130A - Resin sealing method for matrix package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for resin sealing of a matrix package by which the productivity is improved and the separation of undesired resin from a molded product becomes easier when the package on which semiconductor chips are flip chip mounted in a matrix arrangement is molded with underfill. SOLUTION: Products to be molded which are formed on a substrate 2 and whose position of gate runner 11 of molded products is covered with adhesive tape 9 are carried into a mold 1 and are clamped. Sealing resin is fed by pressure into the gap between the semiconductor chips 5 and the substrate 2 through mold gate runner 10 formed on the adhesive tape 9 for performing molding with underfill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for clamping a molded product having semiconductor chips arranged in a matrix by flip-chip connection on a substrate by a mold, and sealing the molded product in a cavity including a gap between the semiconductor chip and the substrate. The present invention relates to a method of sealing a matrix package in which a sealing resin is pressure-fed to seal the resin.

[0002]

2. Description of the Related Art After a semiconductor chip is flip-chip connected to a substrate, a so-called underfill mold is used to protect the junction between the semiconductor chip and the substrate and to reduce the influence of thermal stress between the two. . In this underfill mold, a liquid resin is dropped by potting around a side corresponding to one side or two sides of a semiconductor chip to incline the substrate, thereby injecting the resin into a gap between the semiconductor chip and the substrate by a capillary phenomenon and heating and curing. And resin sealing.

In addition, the gap between the semiconductor chip and the substrate is narrowed, so that bubbles are easily generated in the liquid resin, and since the resin contains a filler or the like, the flowability is poor and the molding quality tends to be unstable. The present applicant has proposed a resin sealing method and a resin sealing device in which underfill molding is performed by transfer molding instead of the potting method because the production efficiency is low and the potting resin is expensive. (See JP-A-11-274197).

In this method, a substrate (molded product) on which a semiconductor chip is flip-chip mounted is set on a lower mold, and a release film covering the substrate and the resin path is adsorbed to upper and lower mold surfaces, respectively, and the resin is placed in a pot. Insert the tablet. Then, the mold is closed, the molded object is clamped, and the resin tablet is heated and melted, and is pressure-fed by a plunger to seal the resin. In this case, in order to reliably perform underfill molding in the gap between the semiconductor chip and the substrate, side blocks are provided on both side surfaces of the semiconductor chip (both sides in the resin filling direction of the underfill portion). The side block is projected into the cavity recess in advance, the release film is pressed onto the substrate, and underfill molding is performed. When the resin flows out from the downstream side of the semiconductor chip, the side block is retracted and the remaining side surfaces of the semiconductor chip are removed. It is designed to be sealed with resin.

[0005]

Problems to be Solved by the Invention
In the resin sealing method and the resin sealing apparatus disclosed in Japanese Patent Publication No. 97, a resin is supplied to one mold cavity or two mold cavities by one resin tablet to perform resin sealing, and thus the semiconductor is sealed. When the chips are arranged in a matrix, the productivity decreases. Further, there is an upper release film covering the whole including the semiconductor chip and a lower release film covering the resin path for preventing the resin from adhering to the substrate. For this reason, after setting the molded article in the mold, the lower release film is set in the mold, the resin tablet is set in the mold between the upper and lower release films, and the upper release film is set. A complete set must be made by the automation mechanism. Similarly, removal of a molded product after molding requires a complicated automatic mechanism. Also, when removing a molded product, since the molded product is at the bottom, how and when to break the gate, and because the molded product can only be removed after removing the upper and lower release films, It is very difficult to remove the unnecessary resin from the mold or when and how to remove the unnecessary resin because there is unnecessary resin between the upper and lower release films. If the release film and the molded product are taken out of the mold at the same time without gate break, the molded product may fall into the mold during transportation. Also, if you try to break the gate in the mold, you need a mechanism to break the gate after sandwiching the molded product up and down,
The gate break mechanism becomes complicated. Either method does not work well to remove the upper and lower release films, unnecessary resin and molded products.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to improve the productivity of underfill molding a package in which semiconductor chips are mounted in a flip-chip manner in a matrix arrangement, and to separate unnecessary resin from a molded product. It is an object of the present invention to provide a matrix package resin sealing method which is easy to perform.

[0007]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, a molded product in which a semiconductor chip is arranged in a matrix on a substrate by flip-chip connection is clamped by a mold, and the sealing resin is pressure-fed to a cavity including a gap between the semiconductor chip and the substrate to seal the resin. In the resin sealing method of the matrix package to be stopped, a molded product whose gate runner position formed on a substrate is covered with a mask material is carried into a mold die, clamped, and formed on the mask material. Underfill molding by pressure-feeding the sealing resin to a gap between the semiconductor chip and the substrate via the mold gate runner. Further, the upper mold surface including the cavity recess accommodating the semiconductor chip and the resin path communicating with the cavity recess is covered with a release film, and the molded article is clamped by the upper mold and the lower mold to form a gap between the mask material and the release film. The underfill mold is performed via a mold runner formed in the mold. In addition, the gap between the semiconductor chip and the substrate in each cavity and the periphery of the semiconductor chip are sealed with a resin by a mold runner. Also, the movable block provided in the upper mold on both sides with respect to the gate side of the semiconductor chip is projected in advance into the cavity recess, the release film is pressed against the substrate, and underfill molding is performed, and the movable block is retracted. The semiconductor device is characterized in that both side surfaces of the semiconductor chip are sealed with resin. In addition, the gap between the semiconductor chip and the substrate in each cavity and the periphery of the semiconductor chip are sealed with a resin by a mold runner. Further, the mask material is characterized in that it is sealed with a resin by adhering an adhesive tape to the substrate surface in the width direction, or is resin-sealed by forming metal plating in the width direction on the substrate surface.

[0008] As another means, a molded product in which a semiconductor chip is flip-chip connected in a matrix on a substrate is clamped by a mold and sealed in a cavity including a gap between the semiconductor chip and the substrate. In a resin sealing method for a matrix package in which resin is fed by resin feeding and sealing, a molded article is carried into a mold die and clamped, and the semiconductor chip and the substrate are passed through a die gate runner formed on the substrate. Underfill molding by pressure-feeding a sealing resin to a gap between the substrate and the resin sealing while leaving a molded product gate runner crossing the substrate on the substrate. In addition, the upper mold surface including the cavity recess accommodating the semiconductor chip and the resin path communicating with the cavity recess is covered with a release film, and the molded article is clamped by the upper mold and the lower mold to form a gap between the substrate and the release film. Underfill molding is performed via a mold gate runner to be formed. In addition, the gap between the semiconductor chip and the substrate in each cavity and the periphery of the semiconductor chip are resin-sealed by the mold gate runner. Also, the movable block provided in the upper mold on both sides with respect to the gate side of the semiconductor chip is projected in advance into the cavity recess, the release film is pressed against the substrate, and underfill molding is performed, and the movable block is retracted. The semiconductor device is characterized in that both side surfaces of the semiconductor chip are sealed with resin.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a matrix package resin sealing method according to the present invention will be described below in detail with reference to the accompanying drawings. [First Embodiment] FIGS. 1A, 1B, and 1C are top views of a molded product clamped in a mold using a release film, sectional views in the directions of arrows XX and YY, FIG. 2 (a)
(B) is a top view and a sectional view of a molded product after resin sealing, FIG.
4A and 4B are a top view and a cross-sectional view of a molded product after resin sealing without a release film, and FIGS. 4A and 4B are a top view and a cross-sectional view of a molded product after a gate break. FIG. 5 (a)
(B) and (c) are explanatory views showing a cutting line and a cutting method when a molded product is separated into individual pieces.

First, a schematic configuration of a resin sealing apparatus for performing resin sealing using the method of sealing a matrix package according to the present invention will be described. In FIG. 1B, reference numeral 1 denotes a molding die, which includes a lower die 3 on which a substrate 2 is placed and an upper die 4 in which a resin path is formed. The upper mold 4 is provided with a cavity 6 for accommodating the semiconductor chip 5 flip-chip connected to the substrate 2, and a resin path such as a mold gate runner 7 communicating with the cavity 6. The substrate 2 to which the semiconductor chip 5 is flip-chip connected via connection terminals 5a such as bumps or solder balls is used as a molded article. As the substrate 2, an epoxy resin substrate, a polyimide resin substrate, BT (Bismaleimide
In addition to the zine) substrate, a ceramic substrate or the like is also used.
Further, the substrate 2 may be a single-layer substrate or a multilayer substrate. The lower die 3 is provided with a pot containing a plunger (not shown).

Reference numeral 8 denotes a release film which covers the cavity recess 7 of the upper mold 4 and a resin path (mold gate runner 7, mold cull, etc.) communicating with the cavity recess 6, and upper surfaces of the semiconductor chip 5 and the substrate 2. Is exposed and resin sealing is performed. The release film 8 has heat resistance enough to withstand the heating temperature of the mold 1, is easily peeled from the mold surface, and has flexibility and extensibility such as PTFE and ETFE. , PET, FEP,
Fluorine impregnated glass cloth, polypropylene, polyvinylidene chloride and the like are preferably used. Release film 8
Is sucked and held by sucking air from a suction hole (not shown) formed on the parting surface of the upper mold 4. The release film 8 may be continuously supplied to the mold 1 by a release film supply mechanism (not shown) in a long form wound between reels, or may be previously formed into a strip shape. Cut pieces may be used. still,
As shown in FIGS. 3A and 3B, the release film 8 can be omitted.

The lower die 3 is provided with a projecting pin (not shown), and the tip of the projecting pin projects above the substrate 2. The upper die 4 is provided with an insertion hole at a position facing the protruding pin. When the mold 1 is clamped, the projecting pins slightly push the release film 8 into the insertion holes to correct wrinkles and slack of the release film 8. Further, the resin sealing device is, for example, a known mold opening / closing mechanism for moving the lower mold 3 up and down by an electric motor using a toggle mechanism or the like to open and close the mold 1. It is equipped with a transfer mechanism for pressure-feeding.

Further, the position of a molded product gate runner formed in the width direction on the substrate 2 on which the semiconductor chips 5 are mounted in a matrix is covered with a mask material. As the mask material, as shown in FIGS. 1A and 1B and FIGS. 2A and 2B, a heat-resistant adhesive tape (for example, polyimide tape) 9 is suitably used. A mold gate runner 7 is provided on the adhesive tape 9, mold gates 12 are formed on both sides of the mold gate runner 7, and a sealing resin 10 is supplied to the cavities on both sides. For this reason, the adhesive tape 9 is formed on the substrate 2 every other row in the width direction.

FIG. 1 shows a resin sealing method.
(A) As shown in (b), the release film 8 is held by suction at the cavity concave portion 6 accommodating the semiconductor chip 5 of the upper mold 4 and the upper mold surface including the resin path communicating with the cavity concave portion 6. Then, the substrate 2 to which the semiconductor chip 5 is flip-chip connected and the adhesive tape 9 is adhered at the position of the molded product gate runner is carried into the lower mold 3 of the mold 1. Further, a resin tablet is put into the pot, and a mold opening / closing mechanism (not shown) is operated to clamp the mold 1. Then, the transfer mechanism (not shown) is operated to raise the plunger, and as shown in FIGS. 2A and 2B, the mold gate runner (formed between the adhesive tape 9 and the release film 8 of the substrate 2). The sealing resin 10 is pressure-fed to the cavity via the resin path) 7.

At this time, as shown in FIGS. 2A and 2B, the semiconductor chip 5 is removed from the gap between the semiconductor chip 5 and the substrate 2 in each cavity arranged in a matrix on both sides of the mold gate runner 7. The underfill mold is performed by feeding the sealing resin 10 to the surroundings. In addition, movable blocks 22 are provided in advance on both sides of the gate side of the semiconductor chip 5 of the upper die 4 (see FIGS. 1A and 1C), and the movable blocks 22 are projected into the cavity recesses 6. By setting the release film 8 in a state of being pressed against the substrate 2, the underfill molding may be performed by preferentially feeding the sealing resin 10 to the gap between the semiconductor chip 5 and the substrate 2. . In this case, when the sealing resin 10 reaches the downstream side from the gate side of the semiconductor chip 5, the movable block 22 is retracted upward to perform resin sealing. It is desirable that the movable block 22 be retracted from the substrate 2 at the same time as or after the sealing resin 10 is filled in at least the underfill portion.

As shown in FIGS. 2 (a) and 2 (b), the molded product is molded with the resin while the molded product gate runner 11 connected to the underfill portion is left on the adhesive tape 9 of the substrate 2.
Since the molded product gate runner 11 is formed by narrowing the cross section of the resin path at the position of each mold gate 12, the gate break can be easily performed at a fixed position. Also, the mold gate 12
Is set to match the size of the width of both sides of the adhesive tape 9. This is because the molded product gate runner 11 is removed by gate breaking simultaneously with the peeling of the adhesive tape 9.

Next, referring to FIGS. 4A and 4B, the substrate 2
The adhesive tape 9 is peeled off from the end of the pot opposite to the width direction. At this time, the molded product gate runner 11 remaining on the adhesive tape 9 is subjected to a shear stress at the position of the mold gate 12 to cause a gate break, and is removed together with the adhesive tape 9. Further, the molded product gate runner 11 may be separated and removed from the molded product cull 13 by the peeling of the adhesive tape 9, or may be removed integrally.

Next, in FIGS. 5A and 5B, the substrate 2 having each package is cut into a matrix by a dicing saw 14 and separated into individual pieces. FIG. 5 (c)
As shown in FIG. 7, perforations 15a may be formed in a matrix at the cutting position of the substrate 2 in advance, or notches 15b may be formed at one or both sides of the cutting position of the substrate 2 in advance.

According to the resin encapsulation method, since the matrix package can be collectively transfer-molded, voids are less likely to occur than in potting, so that molding quality can be improved and productivity can be improved. The position of the molded product gate runner 11 formed on the substrate 2 is
And resin sealing, the gate break of the unnecessary resin can be performed by a simple mechanism, and can be removed together with the peeling of the adhesive tape 9, so that the gate break and the scrap can be easily removed.

[Second Embodiment] Next, another example of a method for sealing a matrix package with a resin will be described with reference to FIGS. The same members used in the description of the resin sealing method described above are given the same reference numerals, and the description is used. In FIGS. 6A and 6B, for example, gold plating 16 is formed in the width direction as a mask material at the position of the gate runner of the molded product formed on the substrate 2. A mold gate runner 7 is provided on the gold plating 16. Mold gates 12 are formed on both sides of the mold gate runner 7, and the sealing resin 10 is supplied to cavities on both sides. For this reason,
The gold plating 16 is formed on the substrate 2 every other row in the width direction.

Alternatively, as shown in FIGS. 7 (a) and 7 (b), the gap between the semiconductor chip 5 and the substrate 2 through the mold gate runner 7 formed on the substrate 2 without providing a mask material. The underfill molding may be performed by pressure-feeding the sealing resin 10 to the portion, and the resin sealing may be performed while the molded product gate runner 11 traversing the substrate 2 is left on the substrate 2. Also, the upper mold surface including the cavity concave portion 6 for accommodating the semiconductor chip 5 and the resin path communicating with the cavity concave portion 6 is covered with the release film 8 and the molded object is clamped by the upper mold 4 and the lower mold 3 so as to form a substrate. The underfill molding may be performed via a mold gate runner 7 formed between the mold and the release film. Also, a movable block 22 is provided on the upper die 4 on both sides with respect to the gate side of the semiconductor chip 5, the movable block 22 is protruded in advance into the cavity concave portion, and the release film 8 is pressed against the substrate 2 to underfill. The molding may be performed, and the movable block 22 may be retracted to seal both sides of the semiconductor chip with resin.

The resin encapsulation method is the same as the resin encapsulation method of the above-described embodiment, but as shown in FIGS.
After the resin sealing, the molded product gate runner 11 and the molded product gate runner 11 are separated from the end of the substrate, and then the substrate 2 or the substrate 2 and the molded product gate runner 11 are cut by the dancing saw 14 while the molded product gate runner 11 is left on the substrate 2. To separate into pieces. Further, perforations 15a may be formed in a matrix at the cutting position of the substrate 2 in advance, or notches 15b may be formed at one or both sides of the cutting position of the substrate 2 in advance. The first embodiment and the second embodiment may be used simultaneously. For example, metal plating may be performed immediately adjacent to the semiconductor chip, and an adhesive tape may be attached so as to slightly overlap the metal plated portion.

The semiconductor package 17 of this embodiment is
As shown in FIGS. 9A and 9B, the gap between the semiconductor chip 5 and the substrate 2 and the periphery of the semiconductor chip 5 are resin-sealed. A flange-shaped sealing portion 18 is formed around the semiconductor chip 5 at a height higher than the underfill portion and lower than the height of the chip. As another example of the semiconductor package, as shown in FIG. 10, a resin sealing portion 19 having a height substantially equal to the height of the semiconductor chip 5 may be formed around the semiconductor chip 5. The resin is molded so that the height of the peripheral portion of the resin sealing portion 19 is slightly higher than the height of the chip. That is, resin molding is performed so as to form the molded product concave portion 20 on the upper surface of the chip. Semiconductor chip 5
A heat radiating plate 21 is bonded to the upper surface after resin sealing. At this time, an adhesive is applied to the molded product concave portion 20 formed in the resin sealing portion 19 and the heat radiating plate is bonded. As described above, in order to bond the heat radiating plate 21 to the upper surface of the semiconductor chip 5, an adhesive for bonding the heat radiating plate is formed by forming the molded product concave portion 20 in the resin sealing portion 19 that seals the periphery of the semiconductor chip 5. Since the thickness of the layer can be absorbed by the resin sealing portion 19,
The height of the package can be kept low.

Although various preferred embodiments of the present invention have been described above, the resin sealing method is not limited to each of the above-described embodiments. For example, the material and layout of the mask material formed on the substrate are not limited. It is optional, and the layout of the gate position is also optional. Also, the case where the semiconductor chips on both sides of the adhesive tape are simultaneously sealed with resin has been described as an example. However, the semiconductor chip can be similarly sealed even with the semiconductor chip arrangement on only one side of the adhesive tape, and the spirit of the invention is not deviated. Of course, many modifications can be made within the scope.

[0025]

According to the resin sealing method of the matrix package according to the present invention, since the matrix package can be collectively transfer-molded, voids are hardly generated as compared with potting, and the molding quality is improved and the productivity is improved. Can be improved. When the position of the molded product gate runner formed on the substrate is covered with a mask material and sealed with resin, gate break of unnecessary resin can be easily performed, and scrap can be easily removed.

[Brief description of the drawings]

FIG. 1 is a top view of a molded product clamped in a mold using a release film according to a first embodiment, and an arrow X.
It is sectional drawing in the -X and YY direction.

FIG. 2 is a top view and a sectional view of a molded product after resin sealing.

FIG. 3 is a top view and a cross-sectional view of a molded product after resin sealing without a release film.

FIG. 4 is a top view and a cross-sectional view of a molded product after a gate break.

FIG. 5 is an explanatory diagram showing a cutting line and a cutting method when a molded product is separated into individual pieces.

6A and 6B are a top view and a cross-sectional view of a molded product clamped to a mold according to a second embodiment.

FIG. 7 is a top view and a sectional view of a molded product after resin sealing.

FIG. 8 is an explanatory view showing a cutting line and a cutting method when a molded product is separated into individual pieces.

FIG. 9 is a top view and a sectional view of a semiconductor package.

FIG. 10 is a top view and a cross-sectional view of a semiconductor package according to another example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold 2 Mold 3 Substrate 3 Lower mold 4 Upper mold 5 Semiconductor chip 6 Cavity recess 7 Mold gate runner 8 Release film 9 Adhesive tape 10 Sealing resin 11 Mold gate runner 12 Mold gate 13 Mold cal 14 Dicing saw 15a Perforated line 15b Notch 16 Gold plating 17 Semiconductor package 18 Flange-shaped sealing portion 19 Resin sealing portion 20 Mold recess 21 Heat sink 22 Movable block

Continued on the front page F term (reference) 4F202 AD02 AD05 AD08 AD35 AH37 CA11 CB01 CB17 CK06 CK25 CM72 CQ05 4F206 AD02 AD05 AD08 AD35 AH37 JA07 JB17 JF05 JL02 JM02 JN32 JQ06 JQ81 5F061 AA01 BA03 CA21 FA06

Claims (10)

[Claims] 1. A molded article having semiconductor chips arranged in a matrix on a substrate by flip-chip connection is clamped by a mold and a sealing resin is pressure-fed to a cavity including a gap between the semiconductor chip and the substrate. In the resin sealing method of a matrix package that performs resin sealing, the molded product gate runner position formed on the substrate is loaded into the mold and covered with the mask material and clamped, A resin sealing method for a matrix package, wherein underfill molding is performed by pressure-feeding a sealing resin to a gap between a semiconductor chip and a substrate via a mold gate runner formed on the mask material. 2. The mask material, wherein an upper mold surface including a cavity recess accommodating the semiconductor chip and a resin path communicating with the cavity recess is covered with a release film and the molded article is clamped by an upper mold and a lower mold. 2. An underfill mold is performed through a mold gate runner formed between the mold and a release film.
The resin sealing method of the matrix package described in the above. 3. The resin for a matrix package according to claim 1, wherein a gap between the semiconductor chip and the substrate in each cavity and a periphery of the semiconductor chip are resin-sealed by the mold gate runner. Sealing method. 4. An underfill mold is formed by projecting a movable block provided on the upper mold into a cavity recess in advance on both sides of a gate side of the semiconductor chip and pressing the release film against a substrate; 4. The method according to claim 1, wherein the movable block is retracted to seal both sides of the semiconductor chip with resin. 5. The resin sealing of a matrix package according to claim 1, wherein the mask material is sealed with a pressure-sensitive adhesive tape on the substrate surface in a width direction. Method. 6. The resin encapsulation of a matrix package according to claim 1, wherein said mask material is formed by applying a metal plating in a width direction on said substrate surface and encapsulating with a resin. Method. 7. A molded product having semiconductor chips arranged in a matrix on a substrate by flip-chip connection is clamped by a mold, and sealing resin is pressure-fed to a cavity including a gap between the semiconductor chip and the substrate. In the resin sealing method of a matrix package, the molded article is carried into a mold and clamped, and the semiconductor chip and the substrate are connected via a mold gate runner formed on the substrate. Resin sealing of a matrix package, wherein underfill molding is performed by pressure-feeding a sealing resin to a gap portion of the matrix package, and resin sealing is performed while a molded product gate runner crossing the substrate is left on the substrate. Method. 8. An upper mold surface including a cavity recess accommodating the semiconductor chip and a resin path communicating with the cavity recess is covered with a release film, and the molded article is clamped by an upper mold and a lower mold to form the substrate with the substrate. 8. The resin sealing method for a matrix package according to claim 7, wherein underfill molding is performed via a mold gate runner formed between the release film and the mold film. 9. The matrix package resin according to claim 7, wherein a gap between the semiconductor chip and the substrate in each cavity and a periphery of the semiconductor chip are resin-sealed by the mold gate runner. Sealing method. 10. A movable block provided on the upper mold at both side portions with respect to a gate side of the semiconductor chip is projected into a cavity recess in advance, and the release film is pressed against a substrate to perform underfill molding. 10. The resin sealing method for a matrix package according to claim 7, wherein the movable block is retracted to seal both sides of the semiconductor chip with resin.