KR100194362B1 - Mold mold for BGA semiconductor package - Google Patents

Abstract

The present invention relates to a mold mold for a BGA semiconductor package, and transfer molding for clamping a PCB 41, which is a raw material of a BGA semiconductor package having a different thickness (t) of each part, to form a package 42 of a predetermined type. In the cavity insert 10 provided in the mold mold MS of the apparatus TS, the height difference of the clamp region 13 corresponding to the thickness t deviation of the PCB 41 is differently formed. TS is applied to the mold mold (MS) to prevent deformation of the PCB 41 formed by the package 42 to prevent the wire sweeping defects such as short of the wire (W) and the lead (L), supplying the compound material The air in the sea cavity can be discharged to the outside through the air vent to improve the formability of the package, and has the effect of improving the quality reliability of the BGA semiconductor package.

Description

Mold mold for BGA semiconductor package

The present invention relates to a mold mold for a BGA semiconductor package, and in particular, to form a different height of the clamp region formed on the cavity insert of the mold mold according to the height corresponding to the PCB raw material thickness variation of the BGA semiconductor package to uniform the clamp force of the PCB As a result, the present invention relates to a mold mold for BGA semiconductor packages which prevents poor wire sweeping of a PCB and improves package formability.

In general, BGA semiconductor packages have been developed to complement the functionality and quality of the high integration limits of Fine Pitch and Pin Grid Arrays. It prevents damage, minimizes the size of the volume, has excellent electrical functional and thermal properties, excellent package yield, excellent substrate assembly yield, and the expansion of multichip modules and the rapid design to production cycle. Has the advantage.

Therefore, it is easy to apply to various electronic peripheral devices that require ultra-small size and variety of use due to the improved quality reliability of BGA semiconductor package, and it is possible to obtain high value-added products with high price competitiveness.

The BGA semiconductor package is provided with leads and mounting plates on the PCB in order to have a higher number of highly integrated circuits, semiconductor chips are attached to the mounting plates, and wires are connected to lands formed on the circuits of the semiconductor chip and the existing leads. And bonded to the metal layer of the substrate to fuse the ball so that the circuit of the semiconductor chip can be connected to the ball.

In the PCB, a plane layer is provided on both sides of epoxy, an epoxy layer is provided on the outside of the plane layer, and a signal layer is provided on the outside of the epoxy layer. The solder mask layer is provided outside the layer, and the PCB is provided in multiple layers.

Therefore, the PCB raw material purchased in the manufacture of the BGA semiconductor package has a serious variation in the thickness of the PCB due to processing technology of laminating each layer in multiple layers, and raw materials having an uneven overall flatness are introduced into each manufacturing process.

The PCB with uneven thickness and flatness is attached to the semiconductor chip in the die attach process, and then subjected to wire bonding between the semiconductor chip and each circuit pattern of the PCB in the wire bonding process. In order to prevent external exposure of wires and wires, and to protect the internal circuit components and functional characteristics, some form of package molding is performed in the molding process.

In the molding process, after the PCB is supplied to the bottom mold having a cavity capable of forming a package, the bottom mold is raised to complete package molding according to the filling of the compound material resin while the PCB is clamped. The solder ball is fused and fixed in the solder ball seating process to obtain a completed BGA semiconductor package.

The PCB of a BGA semiconductor package includes a plurality of integrated circuit parts in a thin thin plate unit, and packages resin materials of a compound material in a predetermined form on the outside of the integrated circuit part, wherein a cavity provided on a mold mold for molding the package is provided. The air vent that discharges the internal air to the outside by a plurality of cavity areas, a clamp area for clamping the PCB outside the cavity area, a runner gate for supplying resin into the cavity area, and a resin material supplied inside the cavity area. Equipped.

Referring to the conventional structure capable of molding a package on such a PCB, as shown in FIG. A plurality of cavities 12 and 12A having grooves in the left and right longitudinal directions of the base 11 of the bottom cavity inserts 10 (hereinafter referred to as cavity inserts) provided on both sides of the block CB are formed, and each cavity The runner gates RG are formed at one corner of the 12 12A, respectively, and the base 11 on the side where the runner gate RG is formed is called the inner side IN.

Clamp regions 13 are formed at the outer circumferential upper portion of each of the cavities 12, on both ends of the inner side IN of the cavity 12A, and on both ends 11A of the base 11, and at both ends 11A. The clamp region 13 extends from the formed clamp region 13 to the out side OUT.

An air vent AV is formed at the corners of the cavity 12, 12A other than the runner R side of the clamp region 13.

The cavity insert 10 is installed on both sides of the center block CB provided in the bottom mold BM of the transfer molding apparatus TS, so that the runner R and the runner gate of the cavity insert 10 of the center block CB are installed. When the PCB 41 having wire bonding is provided after the RG is connected, the integrated circuit part of the PCB 41 is placed in the upper part of the clamp region 13 in the state of being located in each cavity 12 and 12A. When the compound material resin is supplied while the PCB 41 is clamp-pressed by the rise of the bottom mold BM, the runner R of the center block CB and the runner gate RG of the cavity insert 10 are supplied. The resin material of the compound material filled into the cavities 12 and 12A through this allows the package 42 of a predetermined form to be molded.

However, the PCB 41 to be package-molded is a degating (D) in which the thickness of the A portion of both ends is overmolded due to a manufacturing technology problem of the raw material of the PCB 41 having a multilayered thin layer as shown in FIG. : The PCB 41 placed in the clamp region 13 is lower than the top mold TM because the thickness variation of each portion of the PCB 41 is higher than the average thickness t in the opposite direction on the side of the degating region. Press force imbalance occurs when the clamp is pressed in the mold BM.

Therefore, the PCB 41 is severely deformed in the clamp region 10, and as shown in FIG. 10, the wire W and the circuit pattern P provided inside the PCB 41 are broken or shorted. Sweeping failures have occurred.

In addition, as the PCB 41 placed in the clamp region 10 blocks the passage of the air vent AV due to deformation occurring at a site where the thickness deviation is severe due to the clamp pressure imbalance, the high temperature / high pressure liquid compound material is formed in the cavity ( 12) The air in the cavities 12 and 12A, when supplied into 12A, was not discharged through the air vent AV, resulting in poor package molding due to poor filling flow of the compound material.

The above-described prior arts have a uniform height of the clamp region of the outer periphery of the cavity formed in the mold insert cavity insert, so that the PCBs of the BGA semiconductor packages having different thickness deviations are placed and placed on the top of the cavity insert of the bottom mold. When the clamp is pressed due to the joining of the resin, the resin material of the compound material filled into the cavity is not evenly filled, resulting in the occurrence of fresh flashes and defects such as voids or blisters. Due to deformation of the PCB during pressurization, there was a problem of weakening the molding workability and quality reliability of the BGA semiconductor package due to a poor wire sweeping such as a short.

The present invention has been invented to solve the above-described problems, the clamp of the PCB by differently forming the height of the clamp area formed in the cavity insert of the mold mold according to the height corresponding to the PCB raw material thickness deviation of the BGA semiconductor package It aims at making uniform pressing force.

1 is a schematic configuration diagram of a transfer molding apparatus to which a mold mold for molding a package of a BGA semiconductor package of the present invention is applied.

Figure 2 is a mold mold perspective view of the cavity insert of the present invention is applied.

3 is a cavity insert perspective view of the present invention.

Figure 4 is a cavity insert plan view of the present invention.

Figure 5 is a PCB planar structure of the BGA semiconductor package packaged in the mold of the present invention.

6 is a plan view of a mold mold cavity insert of the present invention.

7 is a view illustrating the internal structure of a product in which package molding is completed in the mold mold of the present invention.

8 is a plan view of a cavity insert of a conventional mold mold.

9 is a PCB structure diagram of a typical BGA semiconductor package.

10 is a view illustrating the internal structure of a product in a state in which package molding is completed in a conventional mold mold.

* Explanation of symbols for main parts of the drawings

TS: Transfer Molding Device MS: Mold Mold

BM: Bottom Mold 10: Cavity Insert

12,12A: Cavity 13: Clamp Area

13A: 1st clamp area 13B: 2nd clamp area

13C: 3rd clamp area 13D, 13E: protrusion part

RG: Runner Gate IN: Inner Side

OT: Out side 41: PCB

42: package

Hereinafter, the configuration of the present invention in detail.

The mold 41 of the transfer molding apparatus TS, which is capable of molding the package 42 by clamping and pressing the PCB 41, which is a raw material of a BGA semiconductor package having a different thickness t of each part, is provided. The height difference of the clamp region 13 corresponding to the variation in the thickness t of the PCB 41 is formed on the cavity insert 10 differently.

An embodiment of the present invention thus described will be described in detail with reference to the accompanying drawings.

1 is an improved configuration diagram of a transfer molding apparatus TS of a BGA semiconductor package to which a mold mold MS having an air vent AV of the present invention is applied, and on one side of the supply unit I and the other side of the supply unit I. A top mold (TM) and a bottom mold (BM) are provided above and below the center of the transfer part (F) and the guide part (G) at the upper part of the guide part (G) and the guide part (G), and the other side of each mold is discharged. Part O is provided.

In the transfer molding apparatus TS, the PCB 41 of the BGA semiconductor package, in which wire bonding is completed, is mounted on the bottom part through the guide part G according to the operation of the transfer part F. When supplying to BM, the bottom mold BM rises and is joined to the top mold TM, and at the same time, the PCB 41 provided in the clamp region has a resin material of the compound material in the clamp-pressed state in the mold mold MS. It is supplied to the cavities 12 and 12A of the mold mold MS to form the package 42 of a predetermined form.

2 is a perspective view of a mold mold (MS) capable of molding a package of a BGA semiconductor package according to the present invention. The top cavity inserts are formed on both sides of the center block (TB) and the center block (TB) below the center of the top mold (TM). TCI is provided, and the lower bottom mold BM includes a center block CB having a runner R at the center and a cavity insert 10 at both sides of the center block CB.

FIG. 3 is a perspective view of the cavity insert 10 installed in the bottom mold BM of the present invention, and FIG. 4 is a plan view of the cavity insert.

The cavity insert 10 forms a plurality of cavities 12 and 12A having grooves in the longitudinal direction on the base 11 with a narrow width W1 and a long length ℓ1, and each cavity 12 and 12A. On the outer periphery of the base 11 is formed a clamp region having a protrusion of a predetermined height on the upper surface of the base 11, the center of the bottom mold (BM) of the bottom corner clamp region 13 of each cavity 12 ( Runner gates RG connected to the runners R provided in the CB are respectively formed, and one surface of the cavity insert 10 on the side where each runner gate RG is formed is referred to as the inner side IN and the clamping region 13 is formed. When described in more detail as follows.

The clamp region 13 is located from the inner side IN of the cavity insert 10 to the central position W2 in the width direction and from the inner side of the cavity 12A to the longitudinal center position l2 in each cavity 12. The first clamp region 13 having the protrusion having the largest predetermined height H1 on the upper surface of the base 11 is formed at the inner side IN of the substrate 11.

Width direction position from the width direction center position W2 of the said 1st clamp area | region 13A to the package area | region 11 formed in the outer periphery of the cavity 12 to the outer side of the width W1 direction of the cavity insert 10 direction. A second clamp region 13B having a height H2 lower than the height H1 of the first clamp region 13A at the outer longitudinal center position l3 of W3 and the both end cavities 12A. Form.

In the boundary portion 16 of the first clamp region 13A and the second clamp region 13B of the above-mentioned both end cavity 12A, the clamp region is included in the clamp region outside the longitudinal direction of the both end cavity 12A. (IN) A third clamp region 13C having a height H3 lower than the height of the second clamp region 13B is formed from the outer end to the predetermined length position l4.

At the front end of the third clamp region 13C provided outside the inner side IN of the both end side cavity 12A, the width direction from the both ends 11A of the cavity insert 10 and the inner side IN to the outer side OUT. At the center position W4, a protrusion 13D equal to the height H1 of the first clamp region 13A is formed.

A protrusion 13E having the same height H2 as the second clamp region 13B is formed in the width W5 from the boundary portion of the first clamp region 13A of the both ends 11A to the outer side OT.

The portion of the first clamp region 13A, the second clamp region 13B, and the third clamp region 13C formed on the outer circumference of each cavity 12 and the both ends cavity 12A except the runner gate RG. At each corner of the air vent (AV) forms.

FIG. 5 is a PCB plan view of a BGA semiconductor package packaged in a cavity insert of the present invention, wherein a plurality of package molding parts are provided on a PCB 41 having a multilayer, and the PCB 41 is coated with a solder play layer on a raw material. Both ends are thickly applied during the process, and the thicknesses of the respective portions (1 'to 8') of the PCB 41 illustrated in the drawings are different from each other.

An example of each part thickness of the PCB 41 is as follows.

Thickness of each part of PCB raw material of BGA semiconductor package Unit: M / M Area PCB One' 2' 3 ′ 4' 5 ′ 6 ′ 7 ′ 8' MIN MAX Average One 0.360 0.350 0.348 0.348 0.342 0.341 0.342 0.342 0.341 0.360 0.277 2 0.351 0.352 0.344 0.345 0.342 0.340 0.341 0.340 0.340 0.52 0.276 3 0.348 0.347 0.340 0.345 0.338 0.339 0.340 0.340 0.338 0.348 0.274 4 0.340 0.342 0.330 0.332 0.330 0.298 0.331 0.331 0.298 0.342 0.263 5 0.372 0.358 0.342 0.345 0.340 0.340 0.343 0.341 0.340 0.358 0.278 6 0.352 0.347 0.343 0.342 0.340 0.340 0.340 0.338 0.338 0.352 0.274 7 0.370 0.362 0.361 0.355 0.358 0.350 0.351 0.352 0.350 0.370 0.286 8 0.360 0.357 0.352 0.352 0.349 0.345 0.346 0.352 0.345 0.360 0.281 9 0.350 0.353 0.347 0.345 0.340 0.341 0.340 0.340 0.340 0.353 0.276 10 0.360 0.372 0.360 0.368 0.358 0.358 0.358 0.365 0.358 0.372 0.290 MIN 0.340 0.342 0.330 0.332 0.330 0.298 0.331 0.331 MAX 0.372 0.372 0.361 0.368 0.58 0.358 0.358 0.365 Average 0.356 0.354 0.347 0.348 0.344 0.339 0.343 0.344

As shown in Table 1, the thickness t of the raw material PCB 41 has the highest thickness at both ends 1 'and 2' of the PCB 41 in which a plurality of packages are formed. In the package forming portion 42A, the thickness of the opposite portions 3 'and 4' on the side of the degating region, which is an overmolded portion of the compound resin, is formed to be high, and the other sides of the package forming portion 42A are formed. The degating (D) region side portion 5 ', 8', the degating (D) region side opposing portion 7 'of the central package molding portion 42A, and the runner side 6' are sequentially Has a thin thickness.

Accordingly, the PCB 41 has a high thickness at both ends and opposite portions on the side of the degating (D) region.

As described above, the clamping region 13 formed in the cavity insert 10 of the mold mold MS and the thickness for forming the PCB 41 having different thickness deviations will be described as follows.

When the PCB 41 for forming a package is supplied to the upper part of the cavity insert 10 provided in the bottom mold BM of the transfer molding apparatus TS, the cavity of the clamp region 13 is attached as shown in FIG. Degating (D) region-side portions 5 'and 6' of the thinnest PCB 41 in the first clamp region 13A formed at the largest height H on the inner side IN of the insert 10. ) 8 'is placed on the upper side of the second clamp region 13B indicated by a hatching line at a portion of the height H2 smaller than the height H1 of the first clamp region 13A on the outer side OT. Degating (D) area side portions of the PCB 41 are thicker than the thickness of the degating (D) area side portions (3 ') (7') of the PCB 41 than the thickness of the area (5 '), 6', 8 '. (4 ') is settled, the third clamp region (3) of the portion marked in black, formed smaller than the height (H2) of the second clamp region (13B) on the outside of the cavity 12A at both ends of the cavity insert (10) 13C) Both sides of the thickest PCB 41 on the top Is (1 ') (2') is placed.

When the PCB 41 is placed in each clamp area of the bottom mold BM, the bottom mold BM rises and is joined to the top mold TM, so that the top cavity insert TCI of the top mold TM is connected to the PCB 41. Clamp the upper surface of the

At this time, in the PCB 41 clamped by the cavity insert 10 of the bottom mold BM, each clamp region 13 formed in the cavity insert 10 has a different height corresponding to the thickness deviation of the PCB 41. By the clamp pressing force is made uniform.

That is, each clamp region of the cavity insert 10 is formed to have a deviation with a corresponding height with respect to the thickness deviation of the PCB 41, and both sides of the third clamp region 13C except for the clamp region 13 range. A protrusion 13D corresponding to the first clamp region 13A is formed in the upper part up to a central position W4 in the width W1 direction, and on the outer side OT of the protrusion W in the width W1 direction of the protrusion 13D. The bottom mold when the top cavity insert TCI of the top mold TM clamps the upper surface of the PCB 41 by forming the protrusion 13E equal to the height H2 of the second clamp region 13B. The PCB 41 clamped at the upper part of the cavity insert 10 of BM is kept in a state of being subjected to a uniform pressing force in each clamp region.

Thus, a height step of a predetermined height is formed at the boundary of each clamp region 13 to maintain a uniform clamp pressing force on the PCB 41, and a curved portion R is formed at the upper edge of each height step to clamp the clamp. The PCB 41 is prevented from being damaged by the curved portion R of the corner portion.

Therefore, as shown in FIG. 7, the wire W is shorted by preventing deformation and damage of the wire W and the lead L, which are connected and bonded between the semiconductor chip and the lead L, which are internal circuits of the PCB 41. It is possible to prevent the poor wire sweeping.

In addition, since the deformation of the PCB 41 is prevented by uniform pressing force between the bottom mold (BM) and the top mold (TM), the air vent (AV) passage is prevented from being blocked, so that the high temperature and high pressure liquid compound material is runner gate. The air in the cavities 12 and 12A can be discharged to the outside through the air vent AV when supplied into the cavities 12 and 12A through the RG to improve the formability of the package 42. It is.

As described above, the present invention forms a different height of the clamp area formed in the cavity insert of the mold mold according to the height corresponding to the PCB raw material thickness deviation of the semiconductor package, thereby uniformly clamping the clamp force of the PCB, thereby preventing deformation of the PCB. Prevents poor wire sweeping due to shorting of wires and leads, improves the formability of the package by allowing air in the cavity to be easily discharged to the outside through air vents when supplying the compound material, and improves the quality reliability of the BGA semiconductor package. It is effective.

Claims (6)

In the mold mold MS of the transfer molding apparatus TS, which clamps the PCB 41, which is a raw material of a BGA semiconductor package having a different thickness t, of each part, thereby forming a package 42 of a predetermined type. Mold mold for BGA semiconductor package, characterized in that the cavity insert (10) is formed with different height (t) of the clamp area 13 corresponding to the deviation of the thickness (t) of the PCB (41). The method of claim 1, wherein the clamp region 13 is formed in the cavity insert 10 of the mold mold (MS), the outer periphery of the cavity 12, 12A and both ends 11A of the cavity insert 10 The first clamp region 13A, the second large clamp region 13B, and the third clamp region 13C having different heights are formed in the upper portion, and the third clamp region 13C except for the range of the clamp region 13 is formed. ) Is formed in the upper portion of both sides of the first clamp region (13A) corresponding to the projection (13D) to the center position (W4) in the width (W1) direction, the outer side of the tip (W1) in the width (W1) direction of the projection (13D) OT) is a mold mold for a BGA semiconductor package, characterized in that the protrusion (13E) is formed equal to the height (H2) of the second clamp region (13B). The inner side (IN) of claim 2, wherein the first clamp region (13A) has a runner gate (RG) formed in each of the cavities (12) except for the both ends (12A) of the plurality of cavities (12) (12A). In the width W1 direction of the cavity insert 10, the largest height (H1) is formed from the inner side of the both ends of the cavity (12A) to the longitudinal center position (l2) Mold mold for BGA semiconductor package. 3. The cavity of claim 2, wherein the second clamp region 13B extends from the widthwise center position W2 of the first clamp region 13A toward the width W1 of the cavity insert 10. The widthwise position W3 to the package region 13 formed on the outer circumference and the inner side surface of the both ends 12A of the outer side OT opposite to the inner side IN are extended from the inner side surface of the longitudinal direction to the longitudinal center position l3. Mold mold for BGA semiconductor package, characterized in that the height (H2) is formed smaller than the height (H1) of one clamp region (13A). 3. The third clamp region (13C) is clamped outward in the longitudinal direction from the boundary (16) formed at both end sides (12A) of the first clamp region (13A) and the second clamp region (13B). A height H3 is formed which includes the region 13 and is smaller than the height H2 of the second clamp region 13B from the outer end of the inner side IN of the clamp region 13 to the predetermined length position l4. Mold mold for BGA semiconductor package, characterized in that. The mold mold for a BGA semiconductor package according to claim 2, wherein a curved surface portion (R) is formed at each corner of the height step of the clamp region (13).