JP2002141439A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device and a manufacturing method thereof which is easy to handle a thinned semiconductor element. SOLUTION: The semiconductor device 7 has a bumper 4' being a reinforcing member bonded with adhesives 5 to the backside of a semiconductor element 1' to its electrode forming surface. The element 1' is bonded to the bumper 4' deformably with the low-elastic modulus adhesives 5 easily expandable/ shrinkable after bonding. This facilitates handling the semiconductor device 7 and allows the element 1' to be deformed according to the deformation of a substrate 11 after mounting, thereby effectively relaxing thermal stresses in a heat cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which a reinforcing member is bonded to the back surface of an electrode forming surface of a semiconductor element with an adhesive, and a method of manufacturing the semiconductor device.

[0002]

2. Description of the Related Art A semiconductor device mounted on a substrate or the like of an electronic device is a package in which a semiconductor element having a circuit pattern formed in a wafer state is connected with a lead frame pin or a metal bump and sealed with a resin or the like. It is manufactured through a aging process. With the recent miniaturization of electronic devices, miniaturization of semiconductor devices has progressed, and in particular, efforts have been actively made to make semiconductor elements thinner.

Since a thinned semiconductor element has low strength against external force and is easily damaged during handling, a semiconductor device using a thinned semiconductor element in the related art has a resin layer for reinforcing the semiconductor element. A structure for sealing is common.

[0004]

However, in the process of forming a resin layer on the surface of a thin semiconductor element, defects such as warping and cracking of the semiconductor element due to curing shrinkage during the formation of the resin layer are likely to occur. Was. This problem becomes more conspicuous as the semiconductor element becomes thinner, and it becomes difficult to seal the semiconductor element even with a very thin semiconductor element having a thickness of 100 μm or less.

Accordingly, an object of the present invention is to provide a semiconductor device in which a thinned semiconductor element can be easily handled and a method of manufacturing the semiconductor device.

[0006]

According to a first aspect of the present invention, there is provided a semiconductor device having a semiconductor element having an electrode forming surface on which electrodes for external connection are formed, and a resin adhesive having a low elastic coefficient on a back surface of the electrode forming surface. And a reinforcing member joined through the reinforcing member.

According to a second aspect of the present invention, in the semiconductor device according to the first aspect, the bending rigidity of the reinforcing member is:
It is larger than the bending rigidity of the semiconductor element.

A semiconductor device according to a third aspect is the semiconductor device according to the first aspect, wherein the resin adhesive joins the semiconductor element to a reinforcing member in a state where the semiconductor element is allowed to deform.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor device.
A method of manufacturing a semiconductor device for manufacturing a semiconductor device in which a reinforcing member is joined to a back surface of an electrode forming surface on which an electrode for external connection of a semiconductor element is formed via a resin adhesive having a low elastic modulus, Thinning step of shaving the back surface of the electrode forming surface of the semiconductor wafer on which the semiconductor element is formed, and a joining step of joining a reinforcing member to the back surface of the semiconductor element after the thinning step via a resin adhesive having a low elastic modulus. And

According to a fifth aspect of the present invention, there is provided a method of manufacturing a semiconductor device.
5. The method of manufacturing a semiconductor device according to claim 4, wherein in the bonding step, a plurality of semiconductor elements in a semiconductor wafer state are bonded together to a reinforcing member.

According to the present invention, the semiconductor device has a structure in which a reinforcing member is bonded to the back surface of the electrode forming surface of the semiconductor element via a resin adhesive having a low elastic modulus, thereby handling the thinned semiconductor element. And a semiconductor device having high reliability after mounting can be realized.

[0012]

(Embodiment 1) FIGS. 1 and 2 are process explanatory views of a method for manufacturing a semiconductor device according to Embodiment 1 of the present invention, and FIG. 3 is a semiconductor device according to Embodiment 1 of the present invention. FIG. 4 is an explanatory view of a method of mounting the semiconductor device according to the first embodiment of the present invention. 1 and 2 show a method of manufacturing a semiconductor device in the order of steps.

In FIG. 1A, reference numeral 1 denotes a semiconductor wafer on which a plurality of semiconductor elements are formed. On the upper surface of the semiconductor wafer 1, bumps 2 as electrodes for external connection are formed. As shown in FIG. 1B, a sheet 3 is adhered to the bump forming surface (electrode forming surface) on the upper surface of the semiconductor wafer 1, and the back surface of the electrode forming surface is thinned while being reinforced by the sheet 3. Is performed. As the thinning means, there is a polishing apparatus using a grindstone, an etching using a dry etching apparatus, and an etching using a chemical reaction of a chemical solution. As a result, the semiconductor wafer 1 has about 5
It is thinned to a thickness of 0 μm.

Next, the bumper plate 4 is attached to the lower surface of the thinned semiconductor wafer 1. As shown in FIG. 1C, an adhesive 5 is applied to the upper surface of the bumper plate 4 formed of a material such as resin, ceramic, or metal in a plate shape.
Here, the adhesive 5 is a resin adhesive having a low elastic coefficient, and is made of a material such as an elastomer having a small elastic coefficient in a joined state and easily expanding and contracting with a small external force.

Next, the thinned semiconductor wafer 1 is attached to the surface to which the adhesive 5 is applied. This bumper plate 4
In a state where a semiconductor device is formed by being divided for each semiconductor element, the semiconductor device functions as a holding portion for handling the semiconductor device and also has a role as a reinforcing member for protecting the semiconductor element from external force and impact. For this reason, the bumper plate 4 has a sufficient thickness to have a bending rigidity larger than the bending rigidity of the semiconductor element. After this, FIG.
As shown in (d), the holding sheet 6 in the dicing step is adhered to the lower surface of the bumper plate 4 after the semiconductor wafer 1 is adhered, and the sheet 3 is separated from the electrode forming surface.

Next, the bumper plate 4 and the semiconductor wafer 1 held by the sheet 6 are sent to a dicing process. Here, as shown in FIG. 2A, two-stage dicing is performed in which the bumper plate 4 and the semiconductor wafer 1 are cut at different dicing widths. That is, the semiconductor wafer 1 is cut at a dicing width b1 and divided into individual semiconductor elements 1 ', and the bumper plate 4 has a dicing width b smaller than b1.
2, the individual bumper members 4 'are obtained.

Then, the semiconductor element 1 ′ is bonded by the adhesive 5.
By peeling the bumper member 4 ′ bonded to the sheet 6 from the sheet 6, as shown in FIG.
Is completed. The semiconductor device 7 includes a semiconductor element 1 ′ on which a bump 2 serving as an electrode for external connection is formed, and a bumper member as a reinforcing member bonded to the back surface of the electrode forming surface of the semiconductor element 1 ′ by an adhesive 5. 4 ', the size B2 of the bumper member 4' is larger than the size B1 of the semiconductor element 1 ', and the outer peripheral end of the bumper member 4' projects outward from the outer peripheral end of the semiconductor element 1 '. . The bumper member 4 ′ has a structure in which the semiconductor element 1 ′ and the adhesive 5 are joined. Since the adhesive 5 is a resin adhesive having a low modulus of elasticity, the semiconductor element 1 ′ is allowed to be deformed.
This semiconductor element 1 'is joined to a bumper member 4'.

As shown in FIG. 3, a component code 8 as identification information is printed on the upper surface of the bumper member 4 'similarly to the upper surface of the conventional resin-encapsulated electronic component. Is formed with a polarity mark 9 for specifying a mounting direction. That is, the back surface of the bonding surface of the bumper member 4 'with the semiconductor element 1' is a surface to which the identification information is applied. Thereafter, a taping process is performed in which the individual semiconductor devices 7 are turned upside down so that the bumper member 4 ′ is placed on the upper surface side and housed in a tape for supplying electronic components. As a result, the semiconductor device 7
The electronic component mounting apparatus is ready for mounting.

The present inventors manufactured a dummy of a semiconductor device using a silicon plate having a thickness of 50 μm in place of the semiconductor element 1 ′, and conducted a drop test from a height of 1 m. As a result, no damage such as cracks occurred in the silicon plate. As a result, it has been confirmed that the semiconductor device of the present invention has no problem even if it is handled in the same manner as a normal electronic component. Furthermore, since it has a simple structure in which the bumper member 4 'is simply attached to the semiconductor element 1' via the adhesive 5, an extremely thin semiconductor element which is difficult to handle with conventional resin sealing can be used.

The mounting of the semiconductor device 7 will be described with reference to FIG. As shown in FIG. 4A, the upper surface of the bumper member 4 'is sucked and held by the mounting head 10, and the semiconductor device 7 is located above the substrate 11 by moving the mounting head 10. Then, with the bumps 2 of the semiconductor device 7 aligned with the electrodes 12 of the substrate 11, the mounting head 10 is lowered to land the bumps 2 of the semiconductor element 1 ′ on the electrodes 12 of the substrate 11.

After that, the bumps 2 are soldered to the electrodes 12 by heating the substrate 11. That is, in handling when the semiconductor device 7 is mounted on the substrate 11,
The mounting head 10 allows the bumper member 4 ′ as a holding unit to be held.
Hold. Note that the bumps 2 may be bonded to the electrodes 12 by a bonding method using a conductive resin adhesive.

The mounting structure in which the semiconductor device 7 is mounted on the substrate 11 has a structure in which the semiconductor device 7 is fixed to the substrate 11 by bonding the bumps 2 serving as the electrodes of the semiconductor device 7 to the electrodes 12 of the substrate 11 serving as the work. It is a form to be done.
As shown in FIG. 4 (c), when the substrate 11 undergoes bending deformation due to some external force after mounting, the semiconductor element 1 'is thin and easily bent, and the adhesive 5 has a low elastic coefficient and is easily deformed. Is used, only the adhesive layer of the semiconductor element 1 ′ and the adhesive 5 follows the bending deformation of the substrate 11 and deforms.

Further, in the semiconductor device of the present invention, 100
By using an ultra-thin semiconductor element of μm or less, the stress generated in the bump 2 due to the difference in the coefficient of thermal expansion between the semiconductor element 1 ′ and the substrate 11 can be reduced. In a conventional electronic component with a bump (semiconductor device), since a thick semiconductor element is used, the stress generated in the bump 2 becomes excessive, and there is a possibility of disconnection. For this reason, reinforcement such as an underfill resin is required between the electronic component with bumps and the substrate. By making the semiconductor element 1 'extremely thin, the stress at the joint is reduced without the need for reinforcement processing such as filling an underfill resin after mounting, and the semiconductor element 1' and the bumper member 4 'are simply separated. With a simple package structure of joining with the adhesive 5, reliability after mounting is ensured.

(Embodiment 2) FIGS. 5 and 6 are process explanatory views of a method for manufacturing a semiconductor device according to Embodiment 2 of the present invention. 5 and 6 show a method of manufacturing a semiconductor device in the order of steps.

In FIG. 5A, reference numeral 1 denotes a semiconductor wafer on which a plurality of semiconductor elements are formed, similarly to the semiconductor wafer shown in the first embodiment, and bumps 2 for external connection are formed on the upper surface. I have. A sheet 6 is adhered to the lower surface of the semiconductor wafer 1, and the semiconductor wafer 1 is diced while being held by the sheet 6 as shown in FIG.
Dicing grooves 1a are formed at boundaries between the semiconductor elements 1 '. Next, in this state, a sheet 3 for reinforcement in the thinning step is adhered to the bump formation surface of each conductor element 1 '. Then, with the sheet 3 reinforced, the back surface of the bump forming surface of each semiconductor element 1 ′ is thinned at once.
As a result, the semiconductor elements 1 ′ are thinned to a thickness of about 50 μm and are individually separated by the dicing grooves 1a.

Next, as shown in FIG. 5D, the bonding of the semiconductor element 1 'and the bumper plate 4 is performed at one time. That is, the adhesive 5 is applied to the upper surface of the bumper plate 4 similar to that shown in the first embodiment. Here, the material of the adhesive 5 is the same as that shown in the first embodiment. Then, the thinned semiconductor element 1 ′ is adhered to the application surface of the adhesive 5.

Next, as shown in FIG. 6A, a sheet 6 for holding in the dicing step is stuck on the lower surface of the bumper plate 4 after the semiconductor element is stuck, and the bumper plate held by the sheet 6 is held. 4 is diced. Here, after removing the sheet 3 on the bump forming surface of the semiconductor element 1 ′, the bumper plate 4 is cut at a dicing width b 2 smaller than the dicing width b 1 of the semiconductor element 1 ′ as shown in FIG. Bumper member 4 ′. Then, the bumper members 4 ′ adhered to the semiconductor element 1 ′ by the adhesive 5 are peeled off from the sheet 6 one by one, whereby FIG.
As shown in (c), a semiconductor device 7 of the same size as that of the first embodiment is completed. This semiconductor device 7 is subjected to a taping process as in the first embodiment.

(Embodiment 3) FIGS. 7 and 8 are process explanatory views of a method of manufacturing a semiconductor device according to Embodiment 3 of the present invention, and FIGS.
FIG. 9 is an explanatory diagram of a method for mounting a semiconductor device according to a third embodiment of the present invention. 7 and 8 show a method of manufacturing a semiconductor device in the order of steps.

In FIG. 7A, reference numeral 1 denotes the first embodiment,
2 is a semiconductor wafer similar to that of FIG. 2, and has bumps 2 for external connection formed on the upper surface. Next, as shown in FIG. 7B, a sheet 3 is adhered to the electrode forming surface on the upper surface of the semiconductor wafer 1, and the lower surface of the semiconductor element is thinned while being reinforced by the sheet 3. Thereby, the semiconductor wafer 1 is thinned to a thickness of about 50 μm.

Thereafter, a sheet 6 for holding in the dicing step is adhered to the lower surface of the semiconductor wafer 1, and the sheet 3 for reinforcement at the time of thinning is removed. Then, sheet 6
The semiconductor wafer 1 held by the semiconductor wafer 1 is sent to the dicing step, where the dicing groove 1 is formed as shown in FIG.
a is processed, and the semiconductor wafer 1 is cut for each semiconductor element 1 ′. And the separated semiconductor element 1 '
Is peeled off from the sheet 6 and taken out individually as shown in FIG.

Next, the bumper case 14 of the semiconductor element 1 '
Is applied. As shown in FIG. 8B, the reinforcing member used in the third embodiment has a protrusion 14a around its periphery and a concave portion 14b at a portion where the semiconductor element 1 'is joined.
Are formed in the bumper case 14. Recess 14
In b, an adhesive 5 made of the same material as that shown in the embodiment is applied to a portion corresponding to the range of the semiconductor element 1 '. Then, as shown in FIG. 8C, the semiconductor element 1 ′ is mounted in the recess 14 b, and the bumper case 14 and the semiconductor element 1 ′ are joined by the adhesive 5. Thus, the semiconductor device 15 is completed. Here, in the bonded state with the semiconductor element 1 ′, the dimension of the end of the protrusion 14 a of the bumper case 14 is set so as not to protrude from the lower end of the bump 2 of the semiconductor element 1 ′.

The bumper case 14 is used in the first and second embodiments.
Similarly to 2, it functions as a holding portion for handling the semiconductor device 15 and also has a role as a reinforcing member for protecting the semiconductor element 1 ′ from external force and impact. In the third embodiment, the semiconductor device 1 ′ has a shape that also protects the lateral sides, so that the reliability of the semiconductor device 15 is further improved. Thereafter, the semiconductor device 15 is turned upside down as shown in FIG. As a result, the semiconductor device 15 can be mounted by the electronic component mounting apparatus.

The mounting of the semiconductor device 15 will be described with reference to FIG. As shown in FIG. 9A, the upper surface of the bumper case 14 is sucked and held by the mounting head 10, and the semiconductor device 15 is located above the substrate 11 by moving the mounting head 10. Embodiment 3
Then, the periphery of the electrode 12 on the upper surface of the substrate 11 (bumper case 1)
The adhesive 16 is applied in advance to the position corresponding to the protrusions 14a of No. 4). Then, with the bumps 2 of the semiconductor device 15 aligned with the electrodes 12 of the substrate 11, the mounting head 1
0 is lowered so that the bumps 2 of the semiconductor element 1 ′ land on the electrodes 12 of the substrate 11.

Thus, the projection 14 of the bumper case 14
a contacts the adhesive 16 on the upper surface of the substrate 11. Thereafter, by heating the substrate 11, the bumps 2 are soldered to the electrodes 12 as shown in FIG. 9B, and the bumper case 14 is fixed to the substrate 11 by the adhesive 16. That is, the mounting operation in the third embodiment is also
Bumper case 1 which is a holding part in the handling of 5
4 is held by the mounting head 10.

The mounting structure formed by mounting the semiconductor device 15 on the substrate 11 is the same as that of the bump 2 serving as an electrode of the semiconductor device 15.
Is bonded to the electrode 12 of the substrate 11 as a work, and the periphery of the bumper case 14 is bonded to the substrate 11, so that the semiconductor device 15 is fixed to the substrate 11. Also in this mounting structure, the semiconductor element 1 'is allowed to deform, and the same effects as those of the semiconductor element 1' shown in the first and second embodiments are obtained.

Further, as shown in FIG. 9B, in the third embodiment, the semiconductor element 1 'of the semiconductor device 15 has a structure in which the upper surface and the periphery are completely sealed after mounting. In addition, it is possible to prevent moisture and foreign substances from being mixed into the joint portion between the substrate 11 and the electrode 12, thereby improving the reliability after mounting.

[0037]

According to the present invention, a semiconductor device having a thinned semiconductor device is constructed by joining a reinforcing member to a back surface of an electrode forming surface of a semiconductor device via a resin adhesive having a low elastic modulus. And a semiconductor device with high reliability after mounting can be realized.

[Brief description of the drawings]

FIG. 1 is a process explanatory view of a method for manufacturing a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a process explanatory view of the method for manufacturing the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a perspective view of the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a diagram illustrating a method for mounting the semiconductor device according to the first embodiment of the present invention;

FIG. 5 is a process explanatory view of a method for manufacturing a semiconductor device according to a second embodiment of the present invention;

FIG. 6 is a process explanatory view of the method for manufacturing the semiconductor device according to the second embodiment of the present invention;

FIG. 7 is a process explanatory view of a method for manufacturing a semiconductor device according to a third embodiment of the present invention;

FIG. 8 is a process explanatory view of the method for manufacturing the semiconductor device according to the third embodiment of the present invention;

FIG. 9 is a diagram illustrating a method for mounting a semiconductor device according to a third embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 1 'Semiconductor element 2 Bump 3 sheet 4 Bumper plate 4' Bumper member 5 Adhesive material 6 Sheet 7, 15 Semiconductor device 14 Bumper case

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Maeda 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 5F044 QQ00

Claims (5)

[Claims] 1. A semiconductor device having an electrode forming surface on which an electrode for external connection is formed, and a reinforcing member joined to a back surface of the electrode forming surface via a resin adhesive having a low elastic coefficient. A semiconductor device characterized by the above-mentioned. 2. The semiconductor device according to claim 1, wherein the bending rigidity of the reinforcing member is larger than the bending rigidity of the semiconductor element. 3. The semiconductor device according to claim 1, wherein the resin adhesive bonds the semiconductor element to a reinforcing member in a state where the semiconductor element is allowed to deform. 4. A semiconductor device manufacturing method for manufacturing a semiconductor device in which a reinforcing member is joined to a back surface of an electrode forming surface on which an electrode for external connection of a semiconductor element is formed via a resin adhesive having a low elastic modulus. A thinning step of shaving the back surface of the electrode forming surface of the semiconductor wafer on which a plurality of semiconductor elements are formed, and a reinforcing member on the back surface of the semiconductor element after the thinning step via a resin adhesive having a low elastic modulus. And a bonding step of bonding the semiconductor devices. 5. The method according to claim 4, wherein in the bonding step, a plurality of semiconductor elements in a semiconductor wafer state are bonded together to a reinforcing member.