JP2002299360A - Semiconductor device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for minimizing troubles, caused by damage on a cutting surface during dicing of each chip by forming an insulation resin layer and a re-wiring circuit at one time on a wafer before dividing a semiconductor wafer into chips and thereafter dicing them, for realizing low cost for a wafer-level package. SOLUTION: An insulation resin layer at a dicing blade passing part is made thin, damages to a resin wafer interface is reduced, and it is shaped so that the thickness thereof changes smoothly to hardly raise stress concentration. Thereby, troubles caused by damages on a cutting surface is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly, to a method of manufacturing a wafer-level package which contributes to miniaturization and cost reduction of a semiconductor device. .

[0002]

2. Description of the Related Art In recent years, with the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration and high-density mounting of electronic components have been progressing. Semiconductor packages used in these electronic devices have become smaller and have more pins, and mounting substrates for mounting electronic components including the semiconductor packages have also become smaller. Furthermore, in order to enhance the storage in electronic devices, a rigid-flex board, in which a rigid board and a flexible board are laminated and integrated to be bent, has been used as a mounting board.

[0003] With the miniaturization of semiconductor packages,
In a package using a conventional lead frame, the miniaturization has reached its limit. Recently, a BGA (Ball (Ball)) has been used in which a chip is mounted on a circuit board.
Grid Array), CSP (Chip Sc)
ALE Package) has been proposed. In these semiconductor packages, the electrical connection between the electrodes of the semiconductor chip and the terminals of the substrate, which are made of various materials such as plastics and ceramics, are called semiconductor package substrates and have the function of the lead frame of the conventional semiconductor package. As a typical connection method, a wire bonding method or TAB (Tape Automated Bon
ding) method, and furthermore, FC (Flip Chip)
Although there are known methods such as BGA and C
The structure of the SP has been actively proposed. However, these packages have to be individually packaged and tested after singulating the semiconductor chips, which is a factor that increases the cost.

[0004] For this reason, various packaging methods (wafer level packages) have been proposed by various companies before semiconductor chips are separated into individual pieces. Among them, in order to obtain sufficient reliability after mounting a semiconductor device on a motherboard without underfill, 50 to 50
It has been confirmed that a method of providing a stress relaxation layer having a thickness of 200 μm is effective.

[0005]

In a semiconductor device having the above structure, a rewiring and an insulating layer and a stress relaxation layer are formed on a wafer.
It is necessary to dice the semiconductor wafer, the insulating layer and the stress relieving layer into individual pieces.However, since the characteristics of the semiconductor wafer made of silicon and the insulating layer and the stress relieving layer made of a cured resin are significantly different, dicing is performed at once. Then, it is easy to receive damage near the silicon-resin interface on the cut surface,
This has been a factor in lowering the reliability of the semiconductor device.

According to the present invention, an insulating resin layer is formed on the entire surface of an active layer (wafer surface) of a semiconductor wafer, which is an aggregate of semiconductor chips, and a semiconductor chip formed between the insulating resin layer and the wafer is formed. It has a conductor circuit (re-wiring circuit) that connects the output terminal and the terminal for connection to the motherboard, and a conductor circuit (pillar) on a pillar that penetrates the insulating resin layer, and completes the entire process of manufacturing a semiconductor package on a wafer. Thereafter, with respect to a semiconductor device obtained by singulation with a dicing blade, a structure of a semiconductor device capable of improving the reliability of the semiconductor device and a method for manufacturing the same are provided.

[0007]

Means for Solving the Problems The present inventors have made the insulating resin layer formed on the semiconductor wafer and the stress relaxation layer thinner by making the thickness of the resin layer at the portion where the dicing blade passes through thinner than at other portions. It has been found that when dicing a resin layer (resin layer) for this purpose, it is possible to greatly reduce damage to the cut surface thereof, and have completed the present invention.

That is, according to the present invention, there is provided a semiconductor I / O terminal having an insulating resin layer formed on the entire surface of an active layer on a semiconductor wafer side and formed between the insulating resin layer surface or the insulating resin layer and the semiconductor wafer. And a conductor circuit (re-wiring circuit) connecting the terminal for connecting to the motherboard and a conductor circuit (pillar) on a pillar penetrating the insulating resin layer, and are singulated by a dicing blade. Accordingly, in the semiconductor device supplied as the semiconductor device, the thickness of the resin at a portion through which the dicing blade passes when the semiconductor device is singulated is thinner than other portions.

In the present invention, the thickness of the resin layer at the portion where the dicing blade passes is ideally 0, but is 10% or less, preferably 5% or less of the thickness of the resin layer at other portions.
% Is desirable.

Further, the present invention provides, as a first manufacturing method,
Forming a projection in a mirror image relationship with a dicing blade passage portion of a semiconductor package formed on a semiconductor wafer active layer side surface on a metal plate, forming an insulating resin layer on the metal plate having the projection, The resin layer surface is bonded to the semiconductor wafer active layer side surface, and the metal plate is removed by etching with a chemical solution.

As a second manufacturing method, an insulating resin layer is formed of a photosensitive resin on the surface of the semiconductor wafer on the active layer side,
Exposure and exposure of the insulating resin layer through the dicing blade
It is characterized in that the thickness of the resin is adjusted by development.

In the second manufacturing method, the photosensitive resin contains a thermosetting resin component, and by controlling the amount of exposure during exposure and development, the resin is allowed to flow during thermosetting,
It is characterized in that the resin thickness having a certain width from the dicing blade passage portion where the resin thickness becomes the smallest becomes a gentle shape.

As the resin for forming the insulating resin layer used in the present invention, any of a thermosetting resin, a thermoplastic resin and a photosensitive resin can be used. A metal projection that can be removed with an etching solution similar to a metal plate is provided on a metal plate that can be dissolved and removed with a solution by an electrolytic plating method so as to have a mirror image relationship with the dicing blade passage portion. After applying the resin layer on the wafer so that the resin layer and the wafer face each other, remove the metal plate and protrusions with an etchant to make the dicing blade passage part thinner than other places. Can be.

In this case, it is necessary to grasp the relationship between the thickness of the projection and the thickness of the resin layer in the dicing blade passage portion in advance according to the characteristics of the resin used. However, the thickness of the projection is at least smaller than the thickness of the resin layer. Not be. In addition, the area where the thickness of the resin layer is thin is limited by the arrangement of input / output terminals for making an electrical connection with the printed wiring board. It must be outside the area where it is located.

Further, the resin used for the insulating resin layer is:
When thermosetting resin and photosensitive resin are used, they are in a state before complete curing, and when formed into a layer on a copper plate with projections, they can withstand the handling of the wafer surface sufficiently in the post-process. It is necessary to have sufficient adhesiveness after curing by receiving appropriate energy in the post-process, and when using a thermoplastic resin, when it is formed in a layer on a copper plate with protrusions Need to have sufficient adhesion to the wafer itself.

The second method, which will be described below, can be applied only to a photosensitive resin. However, the photosensitive resin affixed on the wafer through the dicing blade is made soluble in the developing solution by an appropriate method. By exposing and developing as described above, the thickness of the resin layer at the portion where the dicing blade passes is made thinner than other portions. The thickness of the resin layer passing through the dicing blade thus obtained depends on the development time.

If the thickness of the insulating resin layer changes rapidly from a thin portion to a thick portion, stress tends to concentrate on the corner, and from the viewpoint of improving the reliability of the semiconductor device, the corner should be eliminated as much as possible. Is preferable.

When a photosensitive resin having a thermosetting component is used, by optimizing the exposure amount and the curing temperature gradient,
It is possible to obtain a structure in which the thickness of the insulating resin layer gradually changes from the thinnest portion of the insulating resin layer.

The above-mentioned region where the thickness of the insulating resin layer is gradually changed is also limited by the arrangement of input / output terminals for making an electrical connection with the printed wiring board. When this happens, it must be a region outside the region where the input / output terminals are arranged.
If the above conditions are satisfied, the effect is expected to increase as the area where the thickness of the insulating resin layer changes gradually is wide.
When using a photosensitive resin having a thermosetting component,
After resin development, it is difficult to completely stop the deformation of the resin during thermosetting, so if proper development processing is performed, the resin does not always rise vertically from a thin part to a thick part, In any case, it can be said that the thickness changes gradually. However, when the thickness is changed gradually positively, it is desirable that the width of the area where the thickness changes is 25% or more of the thickness of the resin.

The structure obtained by the above method, in which the insulating resin layer is formed on the wafer, is cut at a portion where the insulating resin layer is thinned by a dicing blade, and becomes an independent semiconductor device. In particular, it is possible to reduce damage to portions near the insulating resin layer, thereby suppressing a decrease in reliability due to damage to a cut surface of a semiconductor device and a decrease in connection reliability after a semiconductor is mounted on a printed wiring board. Will be able to

[0021]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto.

Example 1 A photosensitive plating resist layer was formed on a 70 μm thick 42 alloy molded to the same size and the same shape as a wafer, and exposed to light to develop a mirror image relationship with a dicing blade passage portion of the wafer. An opening is provided. The width of the opening was set to be 100 μm.
Next, a layer of copper is formed using the 42 alloy as a power supply layer and the opening is formed to a thickness of 100 μm by electrolytic plating. Thereafter, the plating resist layer was peeled off using a 3.0% sodium hydroxide solution to obtain a 42-alloy plate having protrusions.

In order to cover the entire metal plate with the projections,
A printable semiconductor encapsulation resin made of a flexible epoxy resin, a flexible hardener, and a filler is printed so as to have a thickness of 110 μm. The structure obtained in this way is aligned so that the above-mentioned protrusions coincide with the dicing blade passage portions, and an insulating resin layer for rewiring is formed in advance with a photosensitive polyimide resin, and the surface layer is formed by an additive method. Print encapsulation resin is applied to the surface of the wafer on which a copper post with a thickness of 100 μm and a thin tip is used to be used as an input / output terminal with a finer circuit for rewiring and a printed wiring board. After bonding by a becquerel type vacuum laminator, the printing sealing resin is cured by heating at 180 ° C. for 1 hour.

Thereafter, the protrusion formed of the 42 alloy and copper is removed by etching, the resin surface is polished until the tip of the copper post is completely exposed, and dicing is performed to form an insulating resin layer on one surface of the chip. To obtain a singulated semiconductor device having the structure described above. At this time, the thickness of the sealing resin in the dicing blade passage portion was 2 μm or less because the resin slightly flowed when the metal plate was attached. In the semiconductor device thus obtained, the input / output terminals were connected to the printed wiring board via the solder balls, and it was confirmed that the operation as the semiconductor device was not hindered.

Example 2 A photosensitive plating resist layer was formed on a 70 μm-thick 42 alloy formed into the same size and the same shape as the wafer, and exposed to light to develop a mirror image relationship with the dicing blade passage portion of the wafer. An opening is provided. The width of the opening was set to be 150 μm. Next, a layer of copper is formed using the 42 alloy as a power supply layer and the opening is formed to a thickness of 110 μm by electrolytic plating. Thereafter, the plating resist layer was peeled off using a 3.0% sodium hydroxide solution to obtain a 42-alloy plate having protrusions.

In order to cover the entire metal plate with projections,
An NMP solution of an adhesive composed of a silicon-modified polyimide-epoxy resin was applied by a spin coater and dried at 180 ° C. for 15 minutes with a hot air drier five times to form a resin layer having a thickness of 130 μm. The structure obtained in this way is aligned so that the above-mentioned protrusions coincide with the dicing blade passage portions, and an insulating resin layer for rewiring is formed in advance with a photosensitive polyimide resin, and the surface layer is formed by an additive method. 130μ height used as finer rewiring circuit and input / output terminal with printed wiring board
The printing encapsulation resin is adhered to the surface of the wafer on which the copper posts having the thickness of m with the thin end covered by gold plating are adhered by a vacuum press.

Thereafter, the protrusions formed of the 42 alloy and copper are removed by etching, and the resin surface is desmeared with a permanganate-based desmear liquid until the tip of the copper post is completely exposed, followed by dicing. An individualized semiconductor device having a structure in which an insulating resin layer was formed on one surface of a chip was obtained. At this time, the thickness of the sealing resin at the dicing blade passage portion was 10 μm because the resin slightly flowed when the metal plate was attached. In the semiconductor device thus obtained, the input / output terminals were connected to the printed wiring board via the solder balls, and it was confirmed that the operation as the semiconductor device was not hindered.

Example 3 On an electrolytic copper foil having a thickness of 18 μm,
A novolak positive photosensitive resin having a thickness of 100 μm and a copper foil were coated by applying a MEK solution of the novolak positive photosensitive resin by a bar coater, and drying at 60 ° C. for 10 minutes and at 80 ° C. for 10 minutes. Was obtained.
This RCC was attached to the surface of a semiconductor wafer by a roll laminator to obtain a structure. Next, a dry film plating resist is stuck on this structure by a roll laminator to form a plating resist layer, and a wire bond finger, a solder ball pad, and a portion to be a circuit for connecting them are photo-formed. After opening by lithography, a 10 μm thick copper layer, a 5 μm thick nickel layer, and a 1 μm thick gold layer were formed here by electrolytic plating. After this, 3 times of plating resist
After stripping and removing with an aqueous solution of sodium hydroxide, the copper foil of RCC was flash-etched using the gold plating layer as a resist to form a conductor circuit immediately below the gold plating layer.

Further, the resin surface from which the copper foil has been removed by etching is subjected to parallel light exposure using an exposure mask designed so that portions on the input / output terminals of the semiconductor element and the dicing blade passage portion can be developed and opened. 3 UV light on the machine
After irradiation with 00 mJ, the resin at a predetermined position was dissolved and removed with a 2.38% TMAH aqueous solution. The width of the resin opening in the dicing blade passage portion was set to 120 μm. Thereafter, ultraviolet rays are applied to the resin surface by 500 mJ using a mask designed so as to shield only a region having a width of 50 μm from the resin opening and the opening edge of the dicing blade passage portion.
After the irradiation, by heating at 150 ° C. for 1 hour, the surface of the wafer is coated with a resin opening for wire bonding, an opening of a dicing blade passage where the resin thickness of a single part is gradually changed, and gold plating. Fully cured thick layer thickness 97 with coated wire bond fingers, solder ball pads, and circuits connecting them
A μm insulating resin layer was obtained.

In the thus obtained chip with an insulating layer, a solder resist is provided on the insulating resin and the circuit provided thereon, and the chip and the circuit on the insulating resin are connected by a gold wire through the resin opening. After joining, the resin opening and the periphery of the wire bond finger were sealed with a printing sealing resin. Furthermore, it was confirmed that the solder ball was mounted at a predetermined position and did not hinder the operation as a semiconductor device.

[0031]

According to the present invention, an insulating resin layer is provided on a semiconductor wafer, which is an aggregate of semiconductor chips, and then singulated, and a rewiring circuit is formed on the insulating resin layer or between the wafer and the insulating resin layer. It is possible to improve the reliability of the semiconductor device having the above.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4M109 AA01 CA26 DA01 EA09 EA15 EC04 5F061 AA01 CA26

Claims (5)

[Claims] An insulating resin layer formed on the entire surface of the semiconductor wafer on an active layer side; a semiconductor input / output terminal formed on the insulating resin layer surface or between the insulating resin layer and the semiconductor wafer; A semiconductor device is formed by forming a structure having a conductor circuit (re-wiring circuit) connecting to a terminal for connection and a conductor circuit (pillar) on a pillar penetrating an insulating resin layer, and singulated by a dicing blade. A semiconductor device provided as a semiconductor device, wherein a thickness of a resin at a portion through which a dicing blade passes when individualized is smaller than that of other portions. 2. The semiconductor device according to claim 1, wherein the thickness of the resin at the portion where the dicing blade passes is 10% or less of the thickest portion of the other portions. 3. A projection having a mirror image relationship with a dicing blade passage portion of a semiconductor package formed on a semiconductor wafer active layer side surface on a metal plate, and an insulating resin layer is formed on the metal plate having the projection. A method of manufacturing a semiconductor device, comprising: forming an insulating resin layer surface on a semiconductor wafer active layer side surface; and etching and removing the metal plate with a chemical solution. 4. An insulating resin layer is formed on a semiconductor wafer active layer side surface by a photosensitive resin, and a thickness of the resin is adjusted by exposing and developing a portion of the insulating resin layer passing through a dicing blade. Semiconductor device manufacturing method. 5. A dicing blade passage portion where the photosensitive resin contains a thermosetting resin component and controls the amount of exposure during exposure and development to flow the resin during thermosetting and minimize the resin thickness. 5. The method of manufacturing a semiconductor device according to claim 4, wherein a change in the resin thickness having a certain width from the first step is a gentle shape.