CN201655791U

CN201655791U - Non-pin integrated circuit component with high-density contacts

Info

Publication number: CN201655791U
Application number: CN2009201323512U
Authority: CN
Inventors: 李同乐
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-04
Filing date: 2009-06-04
Publication date: 2010-11-24
Anticipated expiration: 2019-06-04

Abstract

The utility model relates to a non-pin integrated circuit component, which comprises an IC chip and a plurality of electric contacts, wherein the IC chip is arranged on a metal lead frame; the electric contacts are electrically connected with the IC chip; the IC chip, the electric contacts and part of the metal lead frame are covered by package materials; and one part of the electric contacts can be led out from the bottom surfaces of the package materials.

Description

The leadless integrated circuit element of high density contact

Technical field

The utility model relates to the integrated circuit encapsulation technology, more particularly, but is not only, and has more highdensity contact and crystal grain and pastes the leadless integrated circuit element of pad and its relative manufacturing process.

Background technology

(Integrated circuit, IC) encapsulation is one of last several steps in the IC element production process to integrated circuit.In the IC encapsulation process, one or more IC chips are attached on the base plate for packaging, and are connected with electric contact, are covered the encapsulating material that one deck is made of electrical insulating material (as: epoxy or organosilicon mold sealing material) then again.The shape of final molding be exactly we usually said " IC potted element ", it can be installed to printed circuit board (PCB), and (Printed circuit board PCB) goes up and/or is connected with other electric component.

In most IC potted element, the IC chip is covered fully by moulding material, and electric contact can expose to small part, so that they can be adhered on the other electron component.In other words, electric contact is to be used for forming between the electronic component of the IC of IC element internal chip and IC element-external being electrically connected.Having most cost-benefit way in the IC encapsulation is: replace laminated sheet or gummed paper material with die-attach area.Die-attach area has been used the copper lower than laminated material cost, nickel, other metal or alloy, and the cost of punching press of adopting or etch process is also much lower than the cost of multistep laminating technology.Modal a kind of contact design is: extend " pin " around moulding material.These pins usually are bent downwardly, thereby can couple together with electronic component on printed circuit board (PCB).

Generally, the existence of external pin can make the size of IC potted element increase.For example: the length and the width that have usually increased the IC potted element owing to the horizontal expansion of pin.It is disadvantageous to the limited system in PCB space that size increases the back.In addition, owing to external pin is usually arranged around the IC potted element, so the number of pins of IC potted element can be subjected to the restriction of IC potted element air line distance all around.Another disadvantage is that these pins also require extra inspection step to judge flatness, HEM NOT LEVELED and other dimensional requirement (if inspection item does not reach specification, just should process again or discard).Finally, pin (pointing to outer tip end from welding) length can be added in the total length of the signal of telecommunication (wire length+pin length), thereby influences the electric property of IC chip.

After recognizing these problems that occur in the traditional IC potted element, our researcher designs a kind of new method for packing, that is: replace external pin with electric contact, and the electric contact in IC potted element front is that packed material covers, and the contact of bottom surface exposes out.These contacts and the electronic component that is positioned at IC potted element below are coupled together.These IC potted elements (being " no pin " IC potted element of ripe title) are compared with traditional IC potted element, owing to not existed of external pin taken less space.In addition, again do not need to form and be electrically connected by crooked pin.The patent No. 6498099 and 7049177 United States Patent (USP) disclose several " no pin " IC potted elements commonly used respectively, here quote as a reference.Among other things, the design alteration of no pin IC potted element and the various technology of manufacturing and this no pin IC potted element of use are described and illustrated to these patents.

Figure 1A and Figure 1B are examples of no pin IC packaging part.Figure 1A is the upward view of an IC potted element 100, and it has crystal grain stickup pad (Die attach pad, DAP) 102 that a top surface has been installed an IC chip 104 (shown in Figure 1A dotted line).Can see that a plurality of contacts 106 are disposed in the periphery of DAP102.When being installed to IC potted element 100 on the PCB, contact 106 can be used for forming between IC chip 104 and PCB and be electrically connected.Pourable one deck encapsulating material 108 between DAP102 and a large amount of contact 106 for example, is used for isolating contact 106 and DAP102.Figure 1B be among Figure 1A IC potted element 100 at the profile at A-A line place.IC chip 104 can be attached on the DAP102 by conductive silver glue 110.Lead-in wire 112 is used between IC chip 104 and a plurality of solder joint 116 and forms electrical connection in the end points place, and end points and DAP102 electricity are isolated.Lead-in wire 114 is used in to form between IC chip 104 and a plurality of solder joint 118 and is electrically connected, and solder joint 118 is not isolated with the DAP102 electricity.Because contact 106 is kept apart with DAP102, contact 106 can be used for transmitting signal between I/O (I/O) port on printed circuit board (PCB) (not shown) and the IC chip 104.Because the solder joint 118 of DAP is not kept apart with DAP102, these electrical connections can only be used for the function electrical ground at IC chip 104.

One of this IC potted element limitation part is: can be used to be subjected at the maximum quantity that IC chip I/O port transmits the end points of the signal of telecommunication restriction of the number of endpoint that can arrange around the DAP.As shown in Figure 2, people attempt coming the more end points of arranging by the spacing that reduces end points around DAP, and the line number of end points of can arranging around the increase DAP, can set up the end points quantity that is electrically connected with the I/O port of IC chip so that increase.Yet the line number that increases end points need realize by size that reduces the IC chip or the size that increases the IC potted element.In addition, the amount that distance can be reduced between end points still is subjected to the restriction of the spacing of the last tie point of PCB, and the spacing of the last tie point of PCB is bigger.

The utility model content

The disclosed various embodiments of the application relates to higher leadless integrated circuit of contactor density and manufacture method thereof.In one embodiment, a kind of leadless integrated circuit element comprises die-attach area; Described die-attach area has end face and bottom surface, and comprises that the end points that extends in a large number the bottom surface from end face, each described end points comprise that all the weld zone that is positioned at top surface, the contact areas that is positioned at the bottom surface are connected both metal rail traces with one; Described leadless integrated circuit element also comprises the IC chip; Described IC chip is installed in the end face of die-attach area, and comprises a large amount of welded disc; Described leadless integrated circuit element also comprises a large amount of lead-in wires; Described every lead-in wire all is connected with a weld zone and a welded disc; Described leadless integrated circuit element also comprises encapsulating material; It covers at least a portion of each end points in described IC chip, described a large amount of lead-in wires and the described a large amount of end points; It is characterized in that the contact areas of described a large amount of end points does not have packed material to encapsulate fully; Have at least an end points to comprise the metal rail trace that is electrically connected to the weld zone in described a large amount of end points, this weld zone is from the contact areas horizontal expansion; Come weld zone and contact areas are electrically connected by the metal rail trace.

In certain embodiments, described leadless integrated circuit element may comprise contact areas, and described contact areas is being electrically connected with forming between the weld zone of IC chip periphery below the IC chip; This leadless integrated circuit element also comprises the adhesive layer between metal rail trace and IC chip.This metal rail trace is on the throne in the contact areas of IC chip below and formation electrical connection between the weld zone of IC chip periphery.In certain embodiments, extend from contact areas that to come the weld zone be that one or more modes in the following manner realize:, outwards arrange from contact areas with respect to the IC chip; With respect to the IC chip, inwardly arrange from contact areas; Be arranged in the position parallel with the IC chip edge.

In certain embodiments, the surface area of weld zone is less than the surface area of the contact areas that is connected to the weld zone on described at least one end points, and in described a large amount of end points in the first end points weld zone and the described a large amount of end points centre-to-centre spacing of the second end points weld zone less than the centre-to-centre spacing of described first end points contact areas and the described second end points contact areas.In certain embodiments, the leadless integrated circuit element comprises first end points in described a large amount of end points; Described first end points has first weld zone that is connected to first contact areas, and described contact areas is located immediately at its bottom surface; This leadless integrated circuit element also comprises second end points in described a large amount of end points; Described second end points has first weld zone that is connected to second contact areas, and described contact areas is located immediately at its bottom surface; And the 3rd end points in described a large amount of end points; Described the 3rd end points has first weld zone that is connected to the 3rd contact areas; It is characterized in that the 3rd weld zone is between first weld zone and second weld zone; And described the 3rd contact areas is from the regional horizontal expansion between first contact areas and second contact areas.Among some other embodiment, may also comprise the 4th end points in described a large amount of end points; Described the 4th end points has the 4th weld zone that is connected to the 4th contact areas; It is characterized in that described the 4th weld zone is between first weld zone and second weld zone; And described the 4th contact areas is from the regional horizontal expansion between first contact areas and second contact areas.

In certain embodiments, the leadless integrated circuit element may comprise: first end points in described a large amount of end points; Described first end points has one first contact areas; Second end points in described a large amount of end points; Described second end points has the second contiguous contact areas of one and first contact areas; And the 3rd end points in described a large amount of end points; Described the 3rd end points has one to extend to the metal rail trace of second contact areas from first contact areas.In certain embodiments, fit with the encapsulating material bottom surface in etched back, the bottom surface of described die-attach area; And/or fit with the encapsulating material bottom surface portions in etched back, the bottom surface of described die-attach area.In certain embodiments, described leadless integrated circuit element comprises that the bottom surface of described die-attach area is positioned at etched the removing of part of encapsulating material inside; And/or the bottom surface of described metal rail trace is positioned at etched the removing of part of encapsulating material inside.

In certain embodiments, described leadless integrated circuit element further comprises a coat of metal; The described coat of metal is arranged at least one end face of described weld zone; And it is characterized in that die-attach area is positioned at etched the removing of part under the coat of metal.In certain embodiments, all etched removing of die-attach area that are positioned under the coat of metal.In certain embodiments, the width of first weld zone in described a large amount of weld zone is less than 5 mils; Distance between described edge, first weld zone and the edge, second weld zone is less than 5 mils; And/or the bottom surface of described at least one metal rail trace scribbles one deck protective material; Described protective material is elargol, oxide or solder resist.

In certain embodiments, described leadless integrated circuit element comprises: the welding resistance protective layer that forms in the contact areas bottom surface; It is characterized in that described welding resistance protective layer is chosen from following several groups: the plating lamination of nickel, palladium and gold; The plating lamination of nickel and gold; The plating lamination of nickel and silver; The coat of metal of silver, gold or nickel and gold; Tin electroplating layer or replacement coating; By tin and the plumbous solder coat of forming, or tin alloy solder; By tin and the plumbous soldered ball of forming, or tin alloy solder; And naked copper with organic solderability preservative coating.In certain embodiments, the end face of described die-attach area comprises crystal grain stickup pad; And the IC chip is installed in crystal grain and pastes on the pad.In certain embodiments, described leadless integrated circuit element comprises and being installed on the described IC chip, and the one or more IC chips that are electrically connected with die-attach area.

Above-mentioned content of the present utility model is not represented each execution mode of the present utility model or all aspects of the present utility model.

Description of drawings

By also can a more complete understanding being arranged to every embodiment of the present utility model in conjunction with the accompanying drawings with reference to following detailed description.

Figure 1A-B is the embodiment schematic diagram of the no pin IC of a no pin quad flat package (QFN) potted element;

Fig. 2 is the embodiment schematic diagram of heat no pin array (TLA) IC potted element;

Fig. 3 A-B is an embodiment schematic diagram of comparing the no pin IC potted element with large-size IC chip with potted element;

Fig. 4 A-B is the embodiment schematic diagram of the top surface die-attach area that formed a large amount of metal rail traces;

Fig. 5 A-E is the schematic diagram of no pin IC potted element embodiment different phase in manufacture process;

Fig. 6 A-C has the schematic diagram of the IC potted element embodiment of two row weld zones and many row's contact areas in different angles;

Fig. 7 A-B has the schematic diagram that crystal grain is pasted a plurality of embodiment of no pin IC potted element of pad;

Fig. 7 C-J is the schematic diagram of each face different phase in manufacture process of IC potted element among Fig. 7 B;

Fig. 8 A-D is the schematic diagram of a plurality of embodiment of no pin IC potted element;

Fig. 9 A-C is the exemplary embodiments schematic diagram with no pin IC potted element of two brilliant encapsulation IC chips and cord array;

Figure 10 A-B is the exemplary embodiments schematic diagram of inner leachy no pin IC potted element;

Figure 11 A-B is the exemplary embodiments schematic diagram of no pin IC potted element lead frame;

Figure 12 A-H is the legend of various IC potted element configurations, and the form of I/O port number among each embodiment.

Embodiment

The below will further specify each specific embodiment of the present utility model in conjunction with the accompanying drawings.Though the utility model combines specific embodiment and describes, be to be understood that the utility model can have multiple mode to implement, and the specific embodiment that is not limited only to here to be announced; The specific embodiment that the utility model provides makes the utility model openly more fully with complete, and makes that those skilled in the art can scope on top of of the present utility model.

Fig. 3 A-B is the view of two different angles of no pin IC potted element 300 embodiment.The vertical view that Fig. 3 A was an IC potted element 300 before encapsulation, Fig. 3 B be among Fig. 3 A IC potted element 300 at the profile at A-A line place.Shown in embodiment among Fig. 3 B, IC potted element 300 comprises IC chip 304, and it is installed in the middle part of IC potted element 300, and packed material 308 covers, and be convenient to and outer member (showing among the figure) as PCB between form by a large amount of end points and to be electrically connected; Each end points comprise weld zone 318, contact areas 306 and be connected weld zone 318 and contact areas 306 between metal rail trace 322.In this embodiment, 314 formed electrical connection by going between between IC chip 304 and the weld zone 318.IC potted element 300 also comprises a large amount of metal rail traces 322, and it forms electrical connection between weld zone 318 and contact areas 306.Like this, can reduce the spacing of any two weld zones 318, and the spacing of the corresponding contact areas 306 of nonessential minimizing.For example, in Fig. 3 A, the centre-to-centre spacing of

weld zone

318A and 318B is approximately 0.2mm, but the centre-to-centre spacing of associated

contacts district

306A and 306B is approximately 0.5mm.In each embodiment, can increase the quantity of weld zone, and not need to reduce the size of IC chip.

Shown in Fig. 4 A, the top surface of die-attach area (LF) 424 has made up a large amount of metal rail traces 422.In certain embodiments, LF424 may be actually the one flat plate sheet metal.Fig. 4 B is the enlarged drawing of details A among Fig. 4 A.End face at LF424 carries out etching according to predetermined pattern, has just formed groove 426, and the part that keeps between the groove 426 has just formed metal rail trace 422 (shown in details A).Among Fig. 4 A, the dash area on the LF424 is a metal rail trace 422, and the last shadeless part of LF424 promptly is a groove 426.Though the utility model has provided a kind of concrete etched pattern, can select for use arbitrary graphic pattern that metal LF424 is carried out etching.Weld zone 418 (being used for being connected to the IC chip by lead-in wire) can comprise that a part is positioned at LF424 metal rail trace 422 all around.More particularly, contact areas 406 (be used for forming between contact relevant on IC chip and the PCB and be electrically connected) can be arranged to the other end with respect to weld zone 418 of metal rail trace 422.In Fig. 4 A, for weld zone 418, all contact areas 406 (being square among the figure) all are positioned at the inner position of IC potted element.Yet in different embodiment, some contact areas 406 may be placed directly on the below of weld zone 418, maybe may be placed on 418 surfaces, weld zone near the LF424 periphery.

Generally speaking, when the IC chip was installed on the LF, the part that LF is positioned at IC chip below was called crystal grain stickup district (DA district).After some part of the end face of LF is etched, just formed groove on the LF, and the part of projection has just formed the metal rail trace between groove.When the LF that is installed in the groove (extending to the DA district) that has when the IC chip went up, the IC chip will be supported by the determined metal rail trace of etched groove, will form the space between IC chip and groove.Applying in order to ensure between IC chip and the metal rail trace has been coated with adhesive layer in the bottom surface of IC chip.In certain embodiments, adhesive layer may be nonconducting medium, makes mutually insulated between the metal rail trace of the bottom surface of IC chip and IC chip.After guaranteeing that IC chip and metal rail trace electricity is isolated, molding be can adopt, glue, spraying or other encapsulation technologies dripped, use encapsulating material (as elargol, silicones or other moulding materials) to pour into a mould, overlay on surface, the metal rail trace of IC chip and be filled in the groove of LF, comprise and fill the space that is positioned at DA district groove and IC chip chamber.

Fig. 5 A to Fig. 5 D is the schematic diagram of no pin IC potted element embodiment different phase in manufacture process.Shown in Fig. 5 A, manufacture process is from die-attach area 524.In Fig. 5 B, the end face of die-attach area 524 is carried out etching make up groove 526, thereby determine metal rail trace 522.Weld zone 528 is disposed on the part of metal rail trace end face equally.But the part at the end face of metal rail trace 522 is enclosed one deck welding material, can make up weld zone 528.For example, on metal rail trace 522, plate or wrap layer of metal, as silver (Ag), gold (Au), copper (Cu) or other welding material.In Fig. 5 C, encapsulate with 510 pairs of IC chips 504 of a kind of bonded adhesives and die-attach area 524, for example, elargol.In certain embodiments, before the crystal grain stickup district that IC chip 504 is pasted on the die-attach area 524, the whole bottom surface of IC chip 504 is coated with last layer bonded adhesives 510 equably.In certain embodiments, 510 of bonded adhesivess are coated on the subregion or die-attach area 524 of IC chip 504 bottom surfaces.After being installed to the IC chip on the die-attach area 524, can form electrical connection between IC chip and the weld zone 528 outside crystal grain is pasted the district.In the present embodiment, lead-in wire 514 is as being electrically connected medium.

Shown in Fig. 5 D, encapsulating material 508 (part shown in the shade among the figure) is used for IC chip 504 and lead-in wire 514 are encapsulated.In addition, encapsulating material 508 also is filled in the groove 526, comprises being filled in being arranged in the groove 526 that crystal grain is pasted the district.

Shown in Fig. 5 E, the bottom surface of LF524 is etched back.In each embodiment, the position of eat-backing comprises the corresponding position of groove that forms with the LF end face on the LF524 bottom surface, and these zones of LF are etched away fully, thereby exposes the bottom surface of encapsulating material 508.In certain embodiments, eat-back and to comprise and carry out partially-etched some metal rail traces.In certain embodiments, but the part of metal rail trace 522 may be coated with one deck welding material 528, as the coat of metal 528.At some is in the example, and the part of metal rail trace 522 bottom surfaces may be etched back, thereby fits with the bottom surface of encapsulating material 508.In certain embodiments, coated protective finish 529 in the part of metal rail trace 522 bottom surfaces.

Fig. 6 A-C is the different angles view of a no pin IC potted element 600.Fig. 6 A is the vertical view of IC potted element 600.For convenience of description, show lead-in wire among the figure, and only shown that the profile of encapsulating material 608 and LF go up the profile in crystal grain stickup district (the DA district) 602 of pasting IC chip 604.In the present embodiment, the weld zone 616 that effluxes end points is located immediately at the top of its pairing contact areas 606 (shown in hacures), and be electrically connected with interior row's end points formation by metal rail trace 622, the weld zone 618 of interior row's end points is positioned at its pairing contact areas 606 horizontal positions far away, and is electrically connected by 622 formation of metal rail trace with it.Can see that interior row weld zone 618 may be connected to the contact areas 606 of 602 belows, DA district.

Fig. 6 B is the profile at the IC potted element 600 online A-A places among Fig. 6 A.IC potted element 600 comprises IC chip 604, and there is an adhesive layer 610 below of IC chip 604, is used for IC chip 604 is fixed on the metal rail trace 622.In certain embodiments, adhesive layer 610 may be made up of the elargol material of insulation.In certain embodiments, IC chip 604 and the weld zone 616 that effluxes form by lead-in wire 612 and are electrically connected, and with interior row's weld zone 618 between be electrically connected by 614 formation that go between.In certain embodiments, metal rail trace 622 has constituted the electrical connecting passage between interior row weld zone 618 and the DA district 602 below contact areas 606.Can see that encapsulating material 608 (part shown in the shade among the figure) is with the

IC chip

604 and 612 and 614 encapsulation that go between.In addition, also can see the zone of encapsulating material 608 between the metal rail trace 622 below the IC chip 604.

Fig. 6 C is the upward view of IC potted element 600.The bottom surface of IC potted element 600 comprises encapsulating material 608 (unblanketed part among the figure), metal rail trace 622 (part shown in the shade among the figure) and contact areas 606 (unblanketed square among the figure).In certain embodiments, between the contact areas 606 of IC potted element 600 peripheries, be spaced from each other.In certain embodiments, because these contacts do not have track to extend to the outside, so its spacing may be more than or equal to the minimum spacing of PCB design specification requirement.In certain embodiments, metal rail trace 622 provide interior row weld zone 618 with being electrically connected between the contact areas 606 below the DA district, the minimum spacing that the spacing of row weld zone 618 requires less than the PCB design specification in making also makes the minimum spacing that can keep at least between the contact areas 606 to each other simultaneously.Thereby make the IC chip that is installed on the LF and installed and set up more the electrical connection between the PCB of IC potted element 600.

Fig. 7 A and B are depicted as the vertical view of two embodiment of IC potted element 700.For convenience of description, will not show lead-in wire among the figure, and only show the profile of encapsulating material 708 and IC chip 704.In the present embodiment, by to LF end face etching formation groove 726, thereby determined

weld zone

716 and 718, and metal rail trace 722.In addition, the groove 726 that forms after the etching has also been determined crystal grain stickup pad (DAP, Die Attach Pad) 702.In different embodiment, DAP702 may be positioned at the middle part of LF end face, and the position of IC chip promptly is installed.In the present embodiment, it is the position that is used to install the IC chip on the LF that crystal grain is pasted district (DA district), and it may comprise DAP702 and a part of metal rail trace 722.In certain embodiments, preferably comprise DAP702, so that IC chip 704 is dispelled the heat, can be IC chip 704 provide the structural supports simultaneously, and/or provide electrical grounding for IC chip 704.For example, in the present embodiment, by metal rail trace 722a is electrically connected to the ground connection that provides extra on the DAP702.

Be depicted as the embodiment schematic diagram of IC potted element 700 with two row weld zones as Fig. 7 B.In the present embodiment, the size and dimension of the first row weld zone is different with the size and dimension of the second row weld zone.For convenience of description, do not show lead-in wire among the figure, and only shown the profile of encapsulating material 708 and IC chip 704.Details B is the enlarged drawing that is positioned at three weld zones that IC potted element 700 contact areas efflux.Details C is the enlarged drawing that is positioned at three weld zones of 700 liang of rows of IC potted element contact areas.Shown in details B, weld zone 716 is located immediately at the top of contact areas 706, so must interval and the identical distance of contact areas 706 centre-to-centre spacing between weld zone 716 center lines.Can see that from details C when a contact areas in the contact areas was not located immediately at 718 belows, weld zone, weld zone 716 and 718 s' distance can be nearer.In certain embodiments, on DAP702, made up passage 703, encapsulating material can successfully be flowed into, otherwise encapsulating material can not or be difficult to arrive desired area.

Fig. 7 I-J is depicted as the enlarged drawing of details B and details C.Shown in Fig. 7 C-H is the end view of different phase in details B and the details C manufacturing process.Among Fig. 7 C, the groove 726 that forms on LF724 has been determined the position of weld zone 716.In addition, the end face of LF724 and bottom surface are optionally plated layer of substance.In Fig. 7 D, encapsulating material 708 is cast in the top and groove 726 of LF724.In Fig. 7 E, selective etch falls the bottom surface of LF, thereby makes weld zone 716 keep apart each other, and has determined contact areas 706.As shown in this embodiment, the diameter of weld zone 716 and contact areas 706 is roughly the same.Even the diameter of weld zone 716 reduces, the quantity of the weld zone 716 in the specific region still is subjected to being positioned at the restriction of these regional inner contact district 706 quantity.

As details C among Fig. 7 B is the enlarged drawing of one of weld zone 718, and its metal rail trace is between two weld zones 716, and weld zone 716 comprises the contact areas 706 that is located immediately at its below.In the present embodiment,

weld zone

716 and 718 is positioned at the end face of LF and is rectangle, and contact areas 706 then is positioned at the bottom surface of LF and rounded.Shown in details C, interior row's

weld zone

716 and 718 width are with respect to having reduced (shown in details B) effluxing the weld zone.Because the width of

weld zone

716 and 718 is less than the width of contact areas 706, so can be than placing more approachingly between the contact areas 706 between weld zone 716 and 718.In addition, in order to reduce the distance between

weld zone

716 and 718, contact areas 706 will directly not placed in 718 belows, weld zone.

Shown in Fig. 7 F-H is that IC potted element 700 makes up

weld zone

716 and 718 in specific embodiment, and each stage schematic diagram of contact areas 706.Shown in Fig. 7 F is the part of LF724, the end face of LF724 has carried out partially-etched, made up groove 726, and further determined weld zone 716,

weld zone

718 and 718 extended metal rail traces 722 (a metal rail trace is promptly arranged the details C) from the weld zone.In Fig. 7 G, encapsulating material 708 is used for covering weld zone and groove.In addition, plate the coat of metal 728 regioselectivity below the bottom surface of LF724 is positioned at weld zone 716.In Fig. 7 H, the bottom surface of LF724 is carried out after selectivity eat-backs, the LF724 that is positioned at 718 belows, weld zone is partly removed, thereby the weld zone 718 and contact areas 706 electricity of weld zone 716 and below thereof are isolated.

Partially-etched step can be finished by etching and processing repeatedly, for example, is coated with one deck Photoimageable corrosion inhibitor at the LF724 end face, as the Photoimageable elargol.Photoresist can be rotated and be coated on the LF724, encloses one deck photomask then, is exposed under the ultraviolet light, and wherein, exposed portions can be removed.Therefore, corrosion inhibitor has been determined the position of groove 726 at the end face of LF724 according to pattern.Next, by soaking or pressure atomization, LF724 is carried out etching, part forms weld zone 716,718 and metal rail trace 722.Then, corrosion inhibitor can be removed with conventional method.

Fig. 8 A-D for the weld zone of the LF end face of each embodiment how by the metal rail trace with have the legend that the IC potted element of isomorphism type not is connected.Fig. 8 A is IC potted element 800 embodiment that two

IC chip

804a and 804b are housed, and wherein chip piece is stacked on another piece, can see that the IC chip 804b of bottom is installed on the extended metal rail trace in IC chip below.Fig. 8 B is IC potted element 800 embodiment that two

IC chip

804a and 804b are housed, and wherein chip piece is stacked on another piece.Described in following more detailed description, the IC chip 804b of bottom is for falling brilliant encapsulation configuration.Fig. 8 C is IC potted element 800 embodiment that two

IC chip

804a and 804b are housed, two chip blocks be installed in side by side multi-chip module (multi-chip module, MCM) in.Though present embodiment only comprises two

IC chip

804a and 804b, a large amount of IC chips can be installed on LF.Fig. 8 D is IC potted element 800 embodiment of system in package configuration, IC chip 804 and one or more passive block 830 is housed, as resistance or electric capacity on the LF.Though present embodiment includes only an IC chip 804 and two passive blocks 830, still a large amount of IC chips and passive block can be installed on the LF in the IC potted element.

In the past, it is expensive using contact and/or passive block between two IC chip chambers, IC chip and other contact and/or passive block, because its contact that is connected to PCB is surrounded by other contact.For the independent electric path that is connected to contact is provided, PCB needs the second layer, the 3rd layer, the remarkable like this production cost that increased.Use the metal rail trace to connect welded disc and other position,, can set up independently electrical connection, need not because of using multi-layer PCB increase expense as below, DA district.

Among Fig. 9 A-C, the embodiment of the IC potted element of Fig. 9 B has two

IC chip

904a and 904b, and two chip blocks fall crystalline substance and are packaged together.Can see that from Fig. 9 B the IC chip 904b of bottom directly is attached on the electric contact by falling brilliant solder technology, for example, wherein the welded disc of IC chip 904b comprises the pedestal on it, and this pedestal can reflux to go up the upper surface of electric contact in conjunction with LF.In the present embodiment, the IC chip 904a at top can be connected to a large amount of weld zones 916 that are positioned at IC potted element 900 peripheries by lead-in wire.The metal rail trace can be used in a large amount of weld zones 916 and flip-chip (flip chip, formation electrical connection between contact FC).Fig. 9 C is the upward view of IC potted element 900.Metal rail trace 922 (among the figure shown in the dash area) can be connected the weld zone of IC potted element 900 peripheries with the FC contact of the IC chip 904b below of bottom.

Among Figure 10 A and the 10B, Figure 10 A is the embodiment that is used to establish the LF1024 of air cavity IC potted element, and Figure 10 B is the completed embodiment that air cavity IC potted element 1000 is arranged, and an IC chip 1004 has been installed on its LF1024.In Figure 10 A, the end face of LF1024 is carried out partially-etched, thereby make up groove 1026 and therefore determined metal rail trace 1022 between groove 1026.On the contact areas of the weld zone of metal rail trace 1022 end faces and LF1024 bottom surface, be coated with the coat of metal 1028.On LF1024, also used encapsulating material 1008, so inserted encapsulating material 1008 in the groove, and formed upwardly extending two columns from the LF1024 edge.It is completed shown in Figure 10 B that air cavity IC potted element 1000 is arranged is to be made up by the LF1024 among Figure 10 A, the last bonding IC chip 1004 of LF1024, and by going between IC chip 1004 is connected with the weld zone of LF1024.In addition, a lid is arranged, the IC potted element is sealed, above IC chip 1004, set up air cavity across the column top.Lid is by the solid material manufacturing, such as: metal, plastics, glass, pottery, or other solid material, the perhaps combination of one or more in these materials.In addition, the bottom surface of LF1024 is etched, to isolate contact areas and metal rail trace.

Figure 11 A and 11B are the embodiment that is used in the LF1124 in the IC potted element.Figure 11 A is the vertical view of LF1124, its further groove 1126 (among the figure shown in the shade zone) by the selective etch method away from the part end face place of LF1124 according to the predetermined pattern structure.Not etched part is a metal rail trace 1118 between the LF1124 upper groove 1126, and it is used for that IC circuit mounted thereto provides support and/or provides electric path for the line signal between the contact areas of the weld zone of LF1024 end face and LF1024 bottom surface.Figure 11 B is the upward view of LF1024, and wherein metal rail trace (among the figure shown in the shade zone) provides circuit for the weld zone of LF1024 end face and the contact areas 1106 of LF1024 bottom surface.Usually, the position in LF1024 upper contact district 1106 is by the pattern decision of the PCB upper contact that the IC potted element will be installed.For example, in the present embodiment, require contact areas 1106 around the IC potted element, equidistantly to be arranged in two rows.Can see, use complicated metal rail trace pattern to allow to transmit the signal of telecommunication, and used metal LF not have this ability in the past from the non-equidistance weld zone to the equidistant contact areas of two rows.

Except that the relevant improvement of above-mentioned Figure 11 A-B, use the metal rail trace to allow contact areas away from they weld zones separately, also significantly increased simultaneously IC potted element and the chip size combined I/O linking number that can be used for stipulating, and the size that allows the IC chip to increase is used together with the IC potted element size of stipulating.In Figure 12 A-H, a table that has provided for the typical available I/O linking number of various IC potted element configurations is arranged, and the example of various IC potted element configurations.Table shown in Figure 12 A is for three kinds with 0.5mm contact point spacing dissimilar 5 * 5mm IC potted elements, when three kinds of different size IC chips are installed in wherein, and the typical number that available I/O connects.This three class IC potted element is: QFN potted element (Figure 12 B and 12C), TAPP potted element (Figure 12 D and 12E) and HLA potted element (Figure 12 F-H).Shown in the die size of first row in the table, the IC chip of 4 * 4mm is too big, and can not be installed among the QFN or TAPP type IC potted element of 5 * 5mm.Yet, utilize the metal rail trace placing contact areas away from the place, weld zone, allow the IC chip of 4 * 4mm to be used in the HLA type IC potted element of 5 * 5mm, about this a example shown in Figure 12 F.It is as shown in the table, and typical embodiment has about 64 I/O and connects, and is used for the row of two on connection PCB contact.Though this table embodiment of 4 * 4mm IC chip, even bigger IC chip also may be contained on the HLA type IC potted element of 5 * 5mm.

Next column is depicted as when 3 * 3mm IC chip uses together with three kinds of dissimilar 5 * 5mm IC potted elements, the typical number that I/O connects.When the IC of 3 * 3mm chip uses with QFN or TAPP type i C potted element, enough row's contacts are only arranged around the IC circuit, only the space of 32 or 36 I/O connections is for available.When same IC chip and potted element size combinations were used with HLA type IC potted element, the quantity that available I/O connects rose to 88, has 4 row's contact areas to can be used for being connected to PCB.

Last row are depicted as when 2 * 2mm IC chip uses together with three kinds of dissimilar 5 * 5mm IC potted elements, the typical number that I/O connects.When the IC of 2 * 2mm chip uses with QFN or TAPP type i C potted element, nearly two rows' contact areas can be arranged around the IC circuit, be connected with PCB with 60 I/O by maximum 44 respectively and link to each other.When same IC chip and potted element size combinations were used with HLA type IC potted element, the quantity that available I/O connects rose to 100, and having nearly, 5 rows' contact areas (shown in the 1201-1205) can be used for being connected to PCB.

The form of Figure 12 A has been listed the concrete combination for IC chip, contact spacing and potted element size in the HLA type potted element, the concrete quantity that its available I/O connects, and this just plays the effect of explanation.These quantity should not be understood that the maximum quantity of available contact.For example, in different designs, 5 * 5mm HLA type IC potted element of 2 * 2mm IC chip has been installed in inside, and the quantity of its I/O interface may be about twice of quantity among Figure 12 H.Among other different embodiment, also may surpass these quantity.In addition, though form has only provided the quantity contrast of three kinds of 5 * 5mm IC models, but HLA type IC potted element is with respect to the IC potted element of other two kinds of models, the remarkable increase of its I/O interface quantity, can be understood as other size greater than 5 * 5mm or IC potted element less than 5 * 5mm in, interface quantity also can significantly increase.

Below Figure 12 H is specified that this embodiment is depicted as on the surface, weld zone and utilizes the metal rail trace to connect weld zone and contact areas.To connecting up, just can use short lead-in wire to connect IC chip and weld zone near the weld zone the IC chip from IC chip contact areas far away.Reduced the connection number of times like this, thereby significantly saved cost, especially when lead-in wire adopts expensive metal (as: gold).Can treat the mode that different embodiment can adopt surface wiring and internal wiring to combine among Figure 12 H.In certain embodiments, may only adopt the mode of surface wiring, and some other embodiment may only adopt the mode of internal wiring.

Though each embodiment to the utility model method and system is illustrated by accompanying drawing and preceding detailed description, but should be appreciated that the utility model is not limited only to the embodiment disclosed herein, and can under the prerequisite of the utility model essence, carry out multiple rearrangement, correction and equivalent transformation.

The cross reference of related application

It is that the application number submitted on April 3rd, 61/158,170 and 2009 is the priority of 61/166,547 U.S. Provisional Patent Application that the application requires to enjoy in the application number of submitting on March 6th, 2009, and both full text is incorporated into this by reference.

Claims

1. leadless integrated circuit element comprises:

Die-attach area, described die-attach area has end face and bottom surface, and comprises that the end points that extends in a large number the bottom surface from end face, each described end points comprise that all the weld zone that is positioned at top surface, the contact areas that is positioned at the bottom surface are connected both metal rail traces with one;

The IC chip, described IC chip is installed in the end face of die-attach area, and comprises a large amount of welded disc;

A large amount of lead-in wires, described every lead-in wire all is connected with a weld zone and a welded disc;

Encapsulating material, it covers at least a portion of each end points in described IC chip, described a large amount of lead-in wires and the described a large amount of end points;

It is characterized in that the contact areas of described a large amount of end points does not have packed material to encapsulate fully;

Have at least an end points to comprise the metal rail trace that is electrically connected to the weld zone in described a large amount of end points, this weld zone is from the contact areas horizontal expansion.

2. leadless integrated circuit element according to claim 1, it is characterized in that, have at least a described end points to comprise the metal rail trace, this metal rail trace is on the throne in the contact areas of IC chip below and formation electrical connection between the weld zone of IC chip periphery.

3. leadless integrated circuit element according to claim 2 is characterized in that, comprises the adhesive layer between metal rail trace and IC chip.

4. leadless integrated circuit element according to claim 1 is characterized in that, is that one or more modes in the following manner realize from the weld zone of contact areas horizontal expansion: with respect to the IC chip, outwards arrange from contact areas; With respect to the IC chip, inwardly arrange from contact areas; Be arranged in the position parallel with the IC chip edge.

5. leadless integrated circuit element according to claim 1 is characterized in that, the surface area of weld zone is less than the surface area of the contact areas that is connected to the weld zone on described at least one end points.

6. leadless integrated circuit element according to claim 1, it is characterized in that, in described a large amount of end points in the first end points weld zone and the described a large amount of end points centre-to-centre spacing of the second end points weld zone less than the centre-to-centre spacing of described first end points contact areas and the described second end points contact areas.

7. leadless integrated circuit element according to claim 1 is characterized in that, comprising:

First end points in described a large amount of end points, described first end points have first weld zone that is connected to first contact areas, and described contact areas is located immediately at its bottom surface;

Second end points in described a large amount of end points, described second end points have first weld zone that is connected to second contact areas, and described contact areas is located immediately at its bottom surface;

The 3rd end points in described a large amount of end points, described the 3rd end points have first weld zone that is connected to the 3rd contact areas;

The 3rd weld zone is between first weld zone and second weld zone; And

The regional horizontal expansion between first contact areas and second contact areas of described the 3rd contact areas.

8. leadless integrated circuit element according to claim 7 is characterized in that, comprising:

The 4th end points in described a large amount of end points; Described the 4th end points has the 4th weld zone that is connected to the 4th contact areas;

Described the 4th weld zone is between first weld zone and second weld zone; And

The regional horizontal expansion between first contact areas and second contact areas of described the 4th contact areas.

9. leadless integrated circuit element according to claim 1 is characterized in that, comprising:

First end points in described a large amount of end points, described first end points has one first contact areas;

Second end points in described a large amount of end points, described second end points have the second contiguous contact areas of one and first contact areas; And

The 3rd end points in described a large amount of end points, described the 3rd end points have one to extend to the metal rail trace of second contact areas from first contact areas.

10. leadless integrated circuit element according to claim 1 is characterized in that, fits with the encapsulating material bottom surface in etched back, the bottom surface of described die-attach area.

11. leadless integrated circuit element according to claim 1 is characterized in that, fit with the encapsulating material bottom surface portions in etched back, the bottom surface of described die-attach area.

12. leadless integrated circuit element according to claim 1 is characterized in that, the bottom surface of described die-attach area is positioned at etched the removing of part of encapsulating material inside.

13. leadless integrated circuit element according to claim 1 is characterized in that, the bottom surface of described metal rail trace is positioned at etched the removing of part of encapsulating material inside.

14. leadless integrated circuit element according to claim 1 is characterized in that, comprising:

The coat of metal, the described coat of metal are arranged at least one end face of described weld zone; And

Die-attach area is positioned at etched the removing of part under the coat of metal.

15. leadless integrated circuit element according to claim 14 is characterized in that, all etched removing of die-attach area that are positioned under the coat of metal.

16. leadless integrated circuit element according to claim 1 is characterized in that:

The width of first weld zone in the described weld zone is less than 5 mils;

Distance between described edge, first weld zone and the edge, second weld zone is less than 5 mils.

17. leadless integrated circuit element according to claim 1 is characterized in that, the part bottom surface of described at least one metal rail trace scribbles one deck protective material.

18. leadless integrated circuit element according to claim 1 is characterized in that, described protective material is elargol, oxide or solder resist.

19. leadless integrated circuit element according to claim 1 is characterized in that, the end face of described die-attach area comprises crystal grain stickup pad; And the IC chip is installed in crystal grain and pastes on the pad.

20. leadless integrated circuit element according to claim 1 is characterized in that, comprises being installed on the described IC chip, and the one or more IC chips that are electrically connected with die-attach area.