JPH04234138A - Package for highly integrated thin-molded semiconductor use, its manufacture - Google Patents

Abstract

PURPOSE: To disclose the structure of a thin molded package and manufacturing method thereof which is made by encapsulating semiconductor elements to realize a high density of the semiconductor elements to be mounted on a printed circuit board, by using an intermediate mold and mounting them on a lead frame. CONSTITUTION: Semiconductor elements and package 10 contain semiconductor chip elements 11 connected to a tape mount. A chip is transfer-molded in the package. A removable plastic square frame 14 encloses the elements 10. After the test and burn-in of the elements, it is removed before mounting the elements on the printed board.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a semiconductor package, and more specifically, a package used for protection during testing and burn-in of semiconductor devices.
The present invention relates to a thin semiconductor package with a removable mold frame.

0002

BACKGROUND OF THE INVENTION The constant demand for high density semiconductor devices mounted on circuit boards has led to semiconductor devices housed in compact packages with small cross sections. Substrate space issues have long been discussed only in two dimensions, with interest in thin packages being secondary. However, package thickness has now become an important factor as the electronics industry has taken up thin packaging as a high-density issue in connection with memory cards, smart cards, emulator cards, and the like.

[0003] Speaking of conventional packaging, National
Semiconductor's TapePak™, Tape Auto Adhesion (TAB), Dual Inline Pin (DI
P) packages, small outline packages (SOPs), etc. TAB packages use liquid epoxy or polyimide to encapsulate semiconductor chips. Traditional packages use wire bonds to connect the chip to the lead frame. TapePak™ has connections on all four sides of the package. Conventional semiconductor devices are packaged before testing or burn-in, so if the test results in a defective product, the cost of manufacturing the entire component is wasted.

0004

SUMMARY OF THE INVENTION The present invention is a package for a semiconductor device in which the device is encapsulated using transfer molding. Multi-point (set) thermocompression internal lead bonding (ILB) is used to connect the device to the internal leads of the lead frame (tape). A "knotty" chip is glued together with a "knotty" internal lead. The lead frame may be in the form of a tape so that the ILB can be bonded "single point" rather than "all at once." A single layer of tape is used for this. This tape format is called knobby TAB (BTAB).

During molding or encapsulation, a plastic frame is created around the encapsulated element. This plastic frame remains around the device during testing. If the unit passes the test, the internal package (device) is removed (or extracted) from the frame, and the device is placed on a printed circuit board and the leads are feathered to facilitate infrared or steam reflow attachment. do.

Connections to the components are made on both sides of the semiconductor chip. During the tape manufacturing process, BTAB is converted to palladium (Pd).
), so when attaching it to the surface, Pb-
No need for Sb plating.

[0007] The technical progress of this invention and its objectives are as follows: preferred embodiments of the invention, drawings,
This will become clear from the features shown in the patent claims.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of the present invention. The packaged device 10 contains a plastic encapsulated semiconductor device 11. The semiconductor chip is attached to a ribbon-shaped lead frame 12 with alignment holes 13 along both ends. Since a lead frame is essentially a series of individually connected strips, the alignment holes 13 are used to advance and align various tools during the device fabrication process.

The lead frame has a plurality of lead wires 15 connected to both ends of the semiconductor chip. A frame 14 surrounds the encapsulated element 11. A lead wire 15 passes through the frame 14 and is bent toward the frame at 16 to facilitate device burn-in and testing. Since the device is mounted on a plastic frame 14, there is no problem in testing and burn-in. If the device is "good", it may be shipped and stocked with the plastic frame 14 attached. When the device is to be used or attached to a printed circuit board, the plastic frame 14 is removed and the lead wires 15 are shaped like bird's wings and bonded to the printed circuit board.

FIG. 2 is a sectional view of FIG. 1 taken along line 2-2. The semiconductor element 11 is completely encapsulated in plastic, and the lead wire 15 and metal tape 12
(See FIG. 1) is housed within a plastic frame 14. The ends of the leads 15 pass through the end 14a of the ring 14 and are bent up at the end of the frame 14 for connection when the element 11 is mounted within the frame 14. Bent or broken leads can be used multiple times to retest the device, and can also be used in burn-in sockets with minimal modification or replacement of the leads. If a bent lead wire is used on top of this, there is no need to rework the bent lead wire during testing or burn-in.

FIG. 3 is a side view of the packaged device 11. Frame 14 is shown with bent ends 16 above leads 15.

FIG. 5 shows the semiconductor element 11 removed from the frame 14. The lead wire 15 is bent into a "bird's wing" shape at one end 15a of the element to facilitate attachment of the element to a printed circuit board. At the other end of element 11, element 11
has been cut (extracted) from the plastic frame 14, so the lead wire 15 is straight. The thickness of the completed package is less than 1 mm.

The knobby tip is shown in FIGS. 6 and 7. Figure 6 shows the connection with thick cap adhesive. The silicon chip 20 has aluminum contacts 26 at the contact portion of the chip. A protective oxide film 21 covers the surfaces of the silicon chip 20 and a portion of the aluminum contacts 26. A layer of insulator 22, such as polyimide, covers protective oxide 21. A diaphragm metal 23, such as TiW, covers the aluminum contacts 26 and fills the gaps in the protective oxide layer 21. A knob-like contact 24 of gold, copper, copper solder, etc. is formed on the upper side of the diaphragm metal 23. A knobby lead wire 25 extending from the lead frame contacts the knobby contact 24.

FIG. 7 shows another embodiment of the knob-shaped contact. The silicon chip 30 has aluminum contacts 31 at the contact portion of the chip. A protective oxide film 32 covers the surface of the silicon chip and a portion of the aluminum contacts 31. A layer of an insulator 33 such as polyimide forms a protective oxide film 32.
is covered. A diaphragm metal 34, such as TiW, covers the aluminum contacts 31 and fills the gaps between the protective oxide layers 32. A knob contact 36 of gold, copper, copper solder, etc. is formed on the upper side of the diaphragm metal 23. A flat lead wire 35 extending from the lead frame is in contact with a knob-like contact 36.

FIG. 8 shows two devices attached to a tape-like lead frame. Lead frame 46 is a continuous strip to which a plurality of semiconductor devices 41 are attached. The element 41 is encased in a plastic capsule and housed in a plastic frame 40. The lead wire 47 is 4
In the 2nd part, they are attached with fine line spacing. The lead wire is diagonal at part 43. The dam bar 44 has not been removed here. Lead wires 47 pass through the plastic frame 40 and are aligned at 45, forming plastic wires to facilitate testing and burn-in connections.
It is bent upward along the frame 40.

The method for manufacturing this element will be described below. A semiconductor wafer is processed to form aluminum bond pads. Cover the wafer with an insulator polyimide. The nubs are then placed over these adhesive pads. At this point, the wafer is cut into individual chips. After performing thermocompression bonding ILB,
Perform an adhesion test using a wire pull test. The tape used to attach the chip is cut into strips, transfer molded, molded again, oil removed using plasma, and encoded. The dam bar is removed and the element is chemically deburred. Cut the device from the tape and prepare it for testing and burn-in. The plastic frame is left on during shipping and kept attached until the device is used. The internal package (element and lead wires) is separated (extracted) from the plastic frame, and the lead wires are shaped like a bird's wing so that they can be easily attached to a printed circuit board.

In connection with the above description, the following sections are further disclosed. 1. A thin molded semiconductor device package with a tape-like lead frame containing integrated leads, consisting of: Semiconductor elements attached to tape-shaped lead frames, hump-shaped contacts on semiconductor elements that are electrically connected to lead wires of lead frames, intermediate mold products that encapsulate semiconductor chip elements, and encapsulated semiconductor chip elements. attached, enclosed,
Removable molded frame with air gap.

2. 2. The packaged semiconductor device of claim 1, wherein the lead wires connected to the semiconductor device extend through both ends of the encapsulated semiconductor device and further through the mold frame.

3. 3. The packaged semiconductor device of claim 2, wherein the lead wires passing through the molded frame are bent upwardly along the molded frame for connection during testing and burn-in of the semiconductor device.

4. TiW knob-shaped contact made of aluminum
The packaged semiconductor device according to claim 1, having plating and gold bumps.

5. TiW knob-shaped contact made of aluminum
2. The packaged semiconductor device of claim 1 having plating and copper bumps.

6. 2. The packaged semiconductor device according to claim 1, wherein the lead wires of the tape-like lead frame have knob-like contacts.

7. 7. The packaged semiconductor device of claim 6, wherein the lead frame is gold-plated knobby copper tape.

8. 7. The packaged semiconductor device of claim 6, wherein the lead frame is palladium-plated knobby copper tape.

9. 2. The packaged semiconductor device of claim 1, having a plurality of alignment holes for aligning the device during manufacturing and frame tape removal.

10. A thin molded semiconductor device package with a tape-shaped lead frame containing integrated lead wires, consisting of: A semiconductor element attached to a tape-shaped lead frame, a knob-shaped contact on the semiconductor element that is electrically connected to the flat lead wire of the lead frame, a transfer mold product that encapsulates the semiconductor chip element, and an encapsulated semiconductor chip. A removable molded frame that is attached to the device, surrounds it, has an air gap, and has a portion of the lead wire passing through the molded frame.

11. The lead wire connected to the semiconductor element passes through both ends of the encapsulated semiconductor element.
11. The packaged semiconductor device according to item 10.

12. 12. The packaged semiconductor device of claim 11, wherein the leads passing through the mold frame are bent up along the mold frame for connection during testing and burn-in of the semiconductor device.

13. T with knob-shaped contacts made of aluminum
11. The packaged semiconductor device according to claim 10, having iW plating and gold nubs.

14. T with knob-shaped contacts made of aluminum
11. The packaged semiconductor device of claim 10 having an iW plating and a copper hump smaller than the bond pad void.

15. 11. The packaged semiconductor device according to claim 10, wherein the lead wires of the tape-shaped lead frame are not knob-shaped but flat.

16. 16. The packaged semiconductor device of claim 15, wherein the lead frame is a gold-plated flat copper tape.

17. 16. The packaged semiconductor device of claim 15, wherein the lead frame is a palladium-plated flat copper tape.

18. 11. The packaged semiconductor device of claim 10, having a plurality of alignment holes for aligning the device during manufacturing and removal of the frame.

19. 11. The packaged semiconductor device according to claim 10, wherein the package has a thickness of 1 mm or less.

20. 2. The packaged semiconductor device according to claim 1, wherein the tape-shaped lead frame is made of 2 ounce copper to provide fine spacing between the lead frames and reduce the overall thickness of the package.

21. 3. The packaged semiconductor device according to claim 2, wherein the lead wires are oblique to provide sufficient force to prevent the semiconductor chip from moving during molding.

22. The package according to paragraph 1, wherein the semiconductor chip attached to the tape-like lead frame has a back surface with a roughened back side to improve adhesion to the molding material and reduce force on the plastic. converted semiconductor elements.

23. 2. The packaged semiconductor device of claim 1, wherein the leads are placed on top of the semiconductor chip to provide a thermal path to improve heat dissipation from the semiconductor device.

24. A manufacturing method for a thin packaged semiconductor device consisting of the following steps: Forming a knob-shaped contact on one surface of a pretreated semiconductor chip, and internally connecting the lead wire on the tape-shaped lead frame and the knob-shaped contact. Semiconductor chips attached to wires and tape are cut into multiple chip-attached strips, the attached chips are encapsulated by transfer molding, and at the same time the chips are encapsulated, a frame is created around the encapsulated chips. molding, removing excess mold resin from lead wires by removing burrs, cutting out dam bars, forming test contacts, testing the device, and cutting the semiconductor device from the mold frame before device installation.

25. The claimed method includes forming a bird's-eye shape on the end of the lead wire prior to attachment.

26. 25. The manufacturing method according to item 24, which includes a step of removing oil from the element using plasma after encapsulation.

27. 25. The method of claim 24, comprising a step of tensile testing the lead wire after adhering the lead wire to the knobby contact.

28. Semiconductor element and package 10
contains a tape-mounted connected semiconductor chip element 11 with knob-like contacts, the chip is transfer molded into a package, and a removable rectangular frame 14 made of plastic surrounds the element 10 and surrounds the element. It is removed after testing and burn-in and before mounting the device on a printed circuit board.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the present invention.

FIG. 2 is a cross-sectional view of the present invention.

FIG. 3 is a side view of the present invention.

FIG. 4 is a perspective view of the present invention.

FIG. 5 is a diagram after the semiconductor element of the present invention is removed from the frame.

FIG. 6 is a diagram showing hump-like contact.

FIG. 7 shows another hump-like contact.

FIG. 8 shows a typical leadframe tape design.

[Explanation of symbols]

10 Elements 11, 41 Chip 12 Lead frame 14, 40 Molded frame 15, 47
Lead wires 26, 31 contacts

Claims (2)

[Claims] 1. A package of a thin molded semiconductor device having a tape-like lead frame containing integrated lead wires, comprising: a semiconductor device attached to the tape-like lead frame; a semiconductor device attached to the tape-like lead frame; A knob-shaped contact on the semiconductor element that is electrically connected to a lead wire, a transfer molded product that encapsulates the semiconductor chip element, and a removable part that is attached to the encapsulated semiconductor chip element and has a surrounding space and a gap. Molded frame possible. 2. A method for manufacturing a thin packaged semiconductor device comprising the following steps: forming a bump-shaped contact on one surface of a pretreated semiconductor chip; connecting lead wires on a tape-shaped lead frame; bonding the knob-shaped contacts with internal leads; cutting the semiconductor chip attached to the tape into a plurality of strips each having the chip attached thereto; and encapsulating the attached chip by transfer molding. , simultaneously with the encapsulation of the chip, molding a frame around the encapsulated chip; removing excess mold resin from the lead wires by deburring; cutting out the dam bar; forming test contacts. testing the device; and removing the semiconductor device from the molded frame prior to device installation.