JP2001358258A - BGA type semiconductor device - Google Patents

Abstract

(57) Abstract: In a BGA type semiconductor device, it is possible to prevent a phenomenon that mold resin in a bonding portion flows into a via hole portion for a solder ball. A BGA type semiconductor device in which an insulating film (2) made of a photo solder resist (PSR) is provided on a surface of a tape base (5) on which a wiring pattern (3) is provided so as to leave a via hole (12) for a solder ball. In this case, a dam portion 14 for preventing the flow of the molding resin 11 is formed between the sealing portion of the bonding wire 9 and the via hole 12 for the solder ball by partially increasing the thickness of the insulating film 2. Mold resin 11 into via hole 12
To prevent inflow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BGA (Ball Grid Array) type semiconductor device using a TAB tape or the like as an interposer between an LSI chip and external terminals. The present invention relates to a so-called PSR via type BGA type semiconductor device in which an insulating film of a resist (PSR) is provided leaving a via hole (PSR via) for a solder ball.

[0002]

2. Description of the Related Art In recent years, various types of devices using semiconductor devices have been reduced in size and weight, especially for portable devices and mobile devices. Therefore, there is a demand for semiconductor devices used in these devices to be smaller and thinner. In response to this demand, recently, a package called a chip size package (hereinafter abbreviated as CSP) having a size substantially the same as a semiconductor element has been proposed, and a semiconductor device using the same has been proposed. Has been commercialized.

Conventionally, such CSP semiconductor devices are of a type using a ceramic wiring substrate (CCSP) as an interposer between an LSI chip and external terminals, a TAB (Tape Automated Bonding) or a TCP (TCP). A device using a flexible wiring board (TCSP) similar to that of the Tape Carrier Package) is known.

[0004] As a representative example of these, FIG. 6 and FIG.
BGA (Ba) using TAB tape as an interposer
ll Grid Array) type semiconductor device.

[0005] This is because an insulating film 2 made of a photo solder resist (PSR) is provided on the surface of the tape base 5 made of an insulating film on which the wiring pattern 3 is provided.
Are provided so as to leave via holes (PSR vias) 12 for solder balls, a so-called PSR via type BGA.
Semiconductor device.

FIGS. 6 and 7 show the structure of a conventional semiconductor device which is a particular object of the present invention. A TAB tape 1 used for a semiconductor device is a tape made of a polyimide resin insulating film. A wiring pattern 3 formed by photo-etching a copper foil bonded on one side of a base material 5 with an adhesive 4, and a bonding pad 10 for semiconductor connection is formed at one end of the wiring pattern 3; From a wiring pattern 3 having a solder ball mounting pad 30 formed at the other end or an intermediate part, and a photo solder resist resin printed on the wiring pattern 3 by a printing plate, a predetermined PSR pattern is formed through pattern exposure and development. A via hole for a solder ball is formed on the wiring pattern surface in the region of the solder ball mounting pad 30 in the formed insulating film 2. Formed so as to leave 2 and an insulating film 2.

This wiring tape TA for mounting a semiconductor element is TA.
In the B tape 1, a window hole 15 is usually formed by punching in a central portion due to wire bonding, and the insulating film 2 is formed in a region of the bonding pad 10 on the tape base material 5 and a region further inside than this. Is not formed.

Then, using this TAB tape 1, FIG.
When manufacturing the semiconductor device shown in FIG.
On the side (opposite side) where the wiring pattern 3 is not provided,
The semiconductor chip 7 is adhered via the adhesive 6, and the electrode 8 of the semiconductor chip 7 and the bonding pad 1 of the TAB tape are attached.
0 is electrically connected with a bonding wire 9 made of a gold wire.

Next, the connection part by the wire bonding, that is, the part of the bonding lead is connected to the molding resin 11.
Then, the solder balls 13 formed by the reflow process are attached to the solder ball attachment pads 30 in a form of being arranged in an array in the solder ball via holes 12.

According to this semiconductor device, the semiconductor chip 7
Since the wiring pattern 3, which is a wiring pattern, is provided on the surface opposite to the surface of the tape base on which the element forming surface is mounted, the bonding wire passing through the window hole 15 with the device electrode 8 of the semiconductor chip 7 and the wiring pattern 3 is provided. 9 can be joined. Therefore, the bonding wires 9 can be provided without turning the outer peripheral side of the semiconductor chip 7, so that it is not necessary to secure a wiring space for the bonding wires 9 on the outer peripheral side of the semiconductor chip 7.・ Thinning can be achieved.
In addition, since wire bonding can be performed, the difference in the coefficient of thermal expansion between the semiconductor element and the substrate can be absorbed by the bonding wires 9, thereby making it possible to use an inexpensive resin substrate instead of an expensive ceramic substrate. Advantages such as being possible are obtained.

[0011]

However, when the bonding leads are sealed with the molding resin, a phenomenon occurs in which the molding resin propagates on the PSR pattern and flows into the solder ball via hole (PSR via). It has been found that this causes a defect that the solder ball is missing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a BGA type semiconductor device which solves the above-mentioned problem and is configured to prevent a phenomenon that a molding resin flows into a via hole for a solder ball.

[0013]

In order to achieve the above object, a BGA type semiconductor device according to the present invention comprises forming a wiring pattern on one side of a tape base made of a resin insulating film with a metal foil, A bonding pad for semiconductor connection is formed at one end, and a solder ball mounting pad is formed at the other end or halfway, leaving a solder ball via hole on the wiring pattern surface in the area of the solder ball mounting pad. To form a BGA-type interposer by forming a window hole for performing wire bonding, wherein the interposer is configured to partially increase the thickness of the insulating film, A dam is provided to prevent the flow of the mold resin into the via hole, and the semiconductor element is mounted on the tape base of the interposer. And the electrodes of the semiconductor element and the bonding pads are wire-bonded through the window holes, sealed with a mold resin injected into the window holes, and the mold resin flows into the via holes for solder balls. Is prevented by the weir portion, and a solder ball is attached to the solder ball attachment pad (claim 1).

According to this configuration, the insulating film of the interposer is provided with a weir portion that partially thickens the thickness of the insulating film and prevents the flow of the mold resin into the via hole for the solder ball. Therefore, when injecting and sealing the mold resin into the window hole used for wire bonding, the mold resin tries to flow from the window hole side into the solder ball via hole where the solder ball mounting pad is located. Even in the case of a flow, the flow is prevented by the weir portion. In other words, the dam portion functions as a dam portion that prevents the flow of the mold resin into the via hole for the solder ball. For this reason, since the solder ball mounting pad is maintained in an exposed state without being covered with the mold resin, the occurrence of a defect that the solder ball mounted on the solder ball mounting pad is lost is prevented.

In the present invention, it is most effective that the weir portion is provided between the bonding pad and the via hole for a solder ball.

Preferably, the interposer comprises a TAB tape using a polyimide resin as a tape base, a copper foil as the metal foil, and a solder resist as the insulating film. ).

In the present invention, the weir portion can be provided in various forms such as a straight line, a wavy line, and a broken line. That is, first, the weir portion is an upright wall configured to partially increase the thickness of the insulating film, and is a mode in which the upright wall is linearly arranged along the window hole. Claim 4). Second, the weir portion is an upright wall configured to partially increase the thickness of the insulating film, and is an upright wall arranged in a wavy line along the window hole. 5). Third, the weir portion is composed of a plurality of independent wall portions constituting the upright wall, and the independent wall portions are continuous in a broken line shape (claim 6).

Further, instead of providing an upright wall as the weir portion, a form may be provided in which the thickness of the insulating film is partially reduced to zero (claim 7).

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 1 shows that a photo solder resist (PSR) is used as an interposer between an LSI chip and external terminals.
FIG. 2 is a cross-sectional view of the BGA type semiconductor device according to the first embodiment using a TAB tape having a layer structure, and FIG. 2 is a partial plan view of the BGA type TAB tape used in the BGA type semiconductor device viewed from a photo solder resist side. .

The BGA type semiconductor device shown in FIG. 1 is configured using a TAB tape configured as follows as an interposer.

That is, the TA used in the semiconductor device shown in FIG.
The B tape 1 is a wiring pattern 3 formed by bonding a copper foil as a metal foil to one surface of a tape base material 5 made of a polyimide resin insulating film with an adhesive 4 and photo-etching the copper foil. The wiring pattern 3
Has a wiring pattern 3 in which a bonding pad 10 for connecting a semiconductor is formed at one end and a solder ball mounting pad 30 is formed at the other end or an intermediate part. On the wiring pattern surface in the region of the solder ball mounting pad 30, there is an insulating film 2 made of a photo solder resist formed by printing, and the solder ball via hole 1 corresponding to the solder ball mounting pad 30 is formed.
2 has an insulating film 2 provided in a predetermined pattern (PSR pattern). The insulating film 2 covers the wiring pattern surface in the area of the solder ball mounting pad 30, and does not cover the bonding pad 10 and the inner part thereof. It is in a state of being exposed like the pad 30 for use.

The TAB tape 1 further includes a predetermined pattern thickness in the insulating film (solder resist PSR) 2 between the bonding pad 10 and the solder ball via hole (PSR via) 12. And a dam portion 20 for preventing the flow of the mold resin 11 into the via hole 12 for the solder ball is provided. The weir portion 20 functions as a dam portion 14 (PSR dam), and is specifically formed of a solder resist portion having a two-layer structure. That is, the weir portion 20 is formed by printing, exposing, and developing an insulating film 2 made of a lower solder resist, and then printing, exposing, and developing a solder resist thereon, thereby forming an upright wall 21. As shown in FIG. 2, a mold resin portion (mold resin 11) and a via hole (PSR via) 12 for a solder ball are provided.
And an upright wall 21 arranged linearly along the longitudinal direction of the window hole (15). In this embodiment, the upright walls 21 are provided on both sides of the window hole (15).

Next, the tape base 5, the adhesive (for bonding copper foil) 4, the wiring pattern 3, the TAB tape 1 comprising the insulating film 2 and the dam portion 20, or the adhesive 6 for mounting a semiconductor chip is further applied. In the provided TAB tape 1, connection window holes 15 for performing wire bonding with a semiconductor element are formed by punching, whereby the TAB tape 1 as a BGA type interposer is completed. When the window hole 15 is viewed as a center, the TAB tape 1 defines, on one surface of the tape base material 5, a scheduled window hole portion for connection with the semiconductor chip 7 for wire bonding. A wiring pattern 3 is formed of metal foil on both sides of the wiring pattern 3. A bonding pad 10 for connecting a semiconductor is formed at one end of each wiring pattern 3 on the side near the expected window hole portion, and a solder is formed at the other end or an intermediate portion. The ball mounting pad 30 is formed, and the insulating film 2 is formed on the wiring pattern surface in the area of the solder ball mounting pad 30. Thereafter, the window hole 15 is formed by punching out along the expected window hole portion. You.

Next, a semiconductor device is assembled using the above interposer. In this semiconductor device, a semiconductor chip 7 is adhered on a tape base material 5 having no copper foil pattern with an elastomer adhesive 6, and a window hole 1 is formed.
5, the bonding pad 4 and the electrode 8 of the semiconductor chip 7 are electrically connected by wire bonding with a bonding wire 9 made of a gold wire. The solder balls 13 formed by the reflow process were attached to the attachment pads 30, and were arranged in an array, thereby producing a BGA type semiconductor device.

The sealing process of the connection portion by the wire bonding is performed by injecting the mold resin 11 into the window hole 15. At that time, the bonding pad 10
And an insulating film 2 between the solder ball via hole 12 and
20 is formed so as to be partially thicker to prevent mold resin from flowing into via holes 12 for solder balls.
Is provided, even if the mold resin 11 injected into the window hole 15 attempts to flow into the via hole 12 for solder balls from the window hole 15 side,
The flow is prevented by the weir section 20. For this reason, the solder ball attachment pad 30 existing at the bottom of the solder ball via hole 12 is not covered with the mold resin 11 and is always kept exposed. Therefore, occurrence of a defect that the solder ball 13 attached thereto is missing can be prevented.

<Other Embodiments and Modifications> In the above-described embodiment, after the insulating film 2 having a predetermined pattern is formed by printing a solder resist, the solder resist is partially printed thereon again to form a window hole. Forming a weir 20 consisting of a straight upright wall 21 along 15;
The dam portion 14 prevents the flow of the mold resin. However, the weir 20 due to the two-layer structure of the solder resist is used.
Can be provided by printing in the form of various standing walls such as a straight line, a wavy line, a broken line, etc., and can function as dam portions for preventing the flow of the mold resin.

FIG. 3 shows that the upstanding wall 22 formed by partially increasing the thickness of the insulating film 2 is arranged in a wavy line along the window hole 15 so that the weir portion 2 is formed.
In this embodiment, one curved barrier wall portion of the upright wall 22 corresponds to one solder ball via hole 12.

FIG. 4 shows a plurality of independent wall portions 23 in which the upright wall 21 or 22 is divided into a plurality of small portions.
This shows an embodiment in which the weir portion 20 is arranged so as to be continuous in a broken line shape, and one independent wall portion 23 corresponds to one solder ball via hole 12. Is configured.

Further, instead of providing the upright wall as the dam section 20 with the solder resist having a two-layer structure, as shown in FIG. 5, the thickness of the insulating film 2 of the solder resist is partially reduced to zero. The groove 24 may be provided, and the groove 24 may be used as a dam portion 14 for preventing the molding resin 11 of the sealing portion from flowing into the via hole 12 for a solder ball. In the embodiment of FIG. 5, by not printing the solder resist linearly, or by thinning the solder resist linearly, the groove 24 having no solder resist or the groove 24 formed by the thin portion of the solder resist is formed. The flow of the mold resin 11 into the grooves 24 prevents flow into the via holes (PSR vias) 12 for solder balls. The groove 24 may also be formed so that a plurality of independent groove portions are continuous in a broken line.

[0031]

As described above, according to the present invention, the thickness of the insulating film is partially thickened, and a weir portion or a groove portion for preventing the flow of the molding resin into the via hole for the solder ball is provided. Therefore, when the molding resin is injected into the window hole used for wire bonding and sealed, even if the molding resin tries to flow from the window hole side to the via hole for the solder ball, the inflow does not occur. It is blocked by the weir or groove.
In other words, the dam portion or the groove portion functions as a dam portion that prevents the mold resin from flowing into the via hole for the solder ball. For this reason, since the solder ball attachment pad is maintained in an exposed state, it is possible to prevent a defect that the solder ball attached to the solder ball attachment pad is lost.

Further, by preventing the mold resin from flowing into the via hole for the solder ball, the yield in assembling the semiconductor device can be improved, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a BGA type semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a part of the BGA type TAB tape used in FIG. 1 as viewed from a PSR side.

FIG. 3 is a partial plan view of a BGA type TAB tape of a semiconductor device in which a PSR dam according to another embodiment of the present invention is arranged in a wavy line.

FIG. 4 is a partial plan view of a BGA type TAB tape of a semiconductor device in which a PSR dam according to another embodiment of the present invention is arranged in a broken line.

FIG. 5 is a cross-sectional view of a semiconductor device using a TAB tape having a PSR pattern in which a PSR is not printed linearly according to still another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional semiconductor device using a TAB tape.

FIG. 7 shows a conventional TAB tape used for a semiconductor device in PS.
It is the top view seen from the R side.

[Explanation of symbols]

 Reference Signs List 1 TAB tape 2 Insulating film (PSR pattern) 3 Wiring pattern 4 Adhesive (for bonding copper foil) 5 Tape base 6 Adhesive (for mounting semiconductor chip) 7 Semiconductor chip 8 Element electrode 9 Bonding wire 10 Bonding pad 11 Mold resin DESCRIPTION OF SYMBOLS 12 Via hole for solder balls (PSR via) 13 Solder ball 14 Dam part 15 Window hole 20 Weir part 21 Standing wall 22 Standing wall 23 Independent wall part 24 Groove part 30 Solder ball mounting pad

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Nakamura 3-1-1, Sukekawa-cho, Hitachi-shi, Ibaraki F-term in the electric wire factory of Hitachi Cable, Ltd. (reference) 4M109 AA01 BA04 CA05 DB07 5F061 AA01 BA03 CA06

Claims (7)

[Claims] 1. A wiring pattern is formed of metal foil on one side of a tape base made of an insulating film made of resin, a bonding pad for connecting a semiconductor is formed at one end of the wiring pattern, and the other end or an intermediate portion is formed. A solder ball mounting pad is formed on the wiring pattern surface in the area of the solder ball mounting pad, an insulating film is formed leaving a solder ball via hole, and a window hole for wire bonding is formed. A BGA-type interposer, wherein the interposer is provided with a weir portion configured to partially increase the thickness of the insulating film to prevent mold resin from flowing into a via hole for a solder ball; A semiconductor element is mounted on a material, and the electrode of the semiconductor element is bonded to the bonding pad through the window hole. Are sealed with a mold resin injected into the window hole, and the flow of the mold resin into the via hole for the solder ball is prevented by the weir portion. A BGA type semiconductor device comprising a solder ball attached thereto. 2. The BGA type semiconductor device according to claim 1, wherein said weir portion is provided between said bonding pad and a via hole for a solder ball. 3. The interposer comprises a TAB tape using a polyimide resin for the tape base, a copper foil for the metal foil, and a solder resist for the insulating film. Or the BG described in 2
A-type semiconductor device. 4. An upright wall in which the thickness of the insulating film is partially thickened, wherein the upright wall is composed of upright walls arranged linearly along the window hole. The BGA type semiconductor device according to claim 1, 2 or 3. 5. The upright wall, wherein the weir portion is an upright wall having a partially thickened insulating film, and the upright wall is arranged in a wavy line along the window hole. The BGA type semiconductor device according to claim 1, 2 or 3. 6. The BG according to claim 4, wherein said weir portion comprises a plurality of independent wall portions constituting said upright wall, and said independent wall portions are continuous in a broken line shape.
A-type semiconductor device. 7. Instead of providing an upright wall as said weir portion,
7. The BGA type semiconductor device according to claim 4, wherein a groove portion in which the thickness of the insulating film is partially zero is provided.