CN208400853U - A kind of super large chip area N substrate unidirectionally returns TVS device structure suddenly - Google Patents

Abstract

The utility model discloses a kind of super large chip area N substrate and unidirectionally returns TVS device structure suddenly, including TVS chip and carrier, the TVS chip is consistent with size of the carrier in length and width, it is characterized in that, the area of the TVS chip back anode metal is less than the area of the carrier and is not extend to carrier edge.The utility model changes back metal graphics art, reduces back metal size, will not draw back metal in scribing in this way, and the generation for avoiding Ag wadding improves encapsulation yield to reduce short-circuit risks.

Description

A kind of super large chip area N substrate unidirectionally returns TVS device structure suddenly

Technical field

The utility model belongs to semiconductor chip packaging technology field, and in particular to a kind of super large chip area N lining Bill kept on file returns TVS device structure to rapid.

Background technique

As industry instantly of greatest concern, the center of entire integrated circuit industry all exists for mobile phone and its auxiliary product at present It is deviated towards mobile phone and its auxiliary product industry: state-of-the-art chip technology, the manufacturing process of most significant end and most efficient assembling Technology etc. is all drawn close to mobile phone industry.As chip technology technology, high speed fast charge technology, ultra-thin and ultra-light require to be continuously improved, Reliability is faced with great challenge, and the failure of EOS and ESD, surge are more and more, and repair rate is also sharply increasing, thus So that overvoltage protection just becomes most important in entire circuit system.In the consumer electronics charging circuit such as mobile phone, it is desirable that surge Just the ultralow unidirectional device of residual voltage is able to satisfy protection demand, so that meet the ultralow requirement of positive negative sense surge residual voltage, it is compatible simultaneously The requirement of the N substrate chip of the market mainstream, the unidirectional TVS device of returning suddenly of N substrate is just at most effective scheme.It charges in protection When IC chip, cooperation OVP device can achieve the effect that positive surge residual voltage and negative sense surge residual voltage are ultralow, ICs all kinds of to rear end Chip can play outstanding protective effect.

The protection of overwhelming majority power supply and charging port is all intended to select the protection device of unidirectional N substrate at present, with The electronic equipment for consumption shipment amounts such as mobile phone, plate and periphery accessory increasingly increase severely, and battery capacity was originally bigger, lead to charging electricity Stream, charging voltage are higher and higher, and all charge power and charge efficiency is being continuously improved in the fast charge of various versions, in order to guarantee to charge Safety and reliability, to protection device, more stringent requirements are proposed, while requiring small in size, thickness thin for encapsulation and more Easily welding.

For existing DFN2020 encapsulation technology using core on gluing process, Fig. 1 is that grooving structure N substrate unidirectionally returns TVS chip suddenly Core post package schematic diagram in dispensing, it is phosphorosilicate glass 24, phosphorus that grooving structure N substrate unidirectionally returns the current filler of TVS chip suddenly Silica glass 24 can sufficiently fill and lead up deep trouth, while can obtain extraordinary surface smoothness, be insulation characterisitic extraordinary one Kind material, the disadvantage is that phosphorosilicate glass 24 is a kind of leaded material, it is exemption in industry and communication aspects, but it is electric in consumption Sub- aspect has certain degree of harm to people；And other lead-free fillers can not be filled and led up when filling deep trouth, so Conventional grooving structure filling object is all phosphorosilicate glass 24.Available from Fig. 1,52 fillet height of excessive glue is about in chip thickness 40% position, due to the presence of side grooving and filler 24, the PN junction that will be formed by substrate 22 and the back side diffusion region N 31 It protects, avoids by conductive adhesive shorts.But due to grooving depth, grooving will lead to very much chip deformation, shallow slot deeply It then will lead to glue and spill into substrate 22, will lead to about 50% or so poor short circuit phenomenon generation；Filler 24 simultaneously Containing lead as harmful matter, when being applied to consumer electronics, damage can be generated to human body, therefore conventional gluing process encapsulates grooving knot It is also that there are problems that structure N substrate unidirectionally returns TVS chip suddenly.

Fig. 2 is the package structure diagram that plane N substrate unidirectionally returns core in TVS chip brush coating technique suddenly, plane N substrate list The place for unidirectionally returning TVS chip suddenly with grooving structure N substrate to rapid time chip difference is that planar structure does not need grooving and fills out It fills, therefore leaded substance will not be introduced, can satisfy the requirement of RoHS and PB Free；Relative to gluing process, brush coating technique makes Glue 8008MD poor fluidity, therefore can be generated when upper core to avoid excessive glue.Planar structure be by one layer thin oxygen 23 come Realize isolation, it is substantially concordant with chip edge holding if on brush coating when core, glue 51 is not in excessive glue in Fig. 2, at this time may be used To find out that brush coating technique will not allow chip short-circuit.But the Ag wadding 42 that back metal 41 generates when due to scribing can be by back metal It links together with the back side diffusion region P 32, glue 51 is formd by back gold 41, Ag wadding 42 with the back side diffusion region P 32 short at this time Paths make device poor short circuit phenomenon occur.

Utility model content

In order to improve conventional package and traditional die structure there are the problem of, the utility model discloses a kind of super large chips Area N substrate unidirectionally returns TVS device structure suddenly.

The technical solution of the utility model is as follows:

A kind of super large chip area N substrate unidirectionally returns TVS device structure, including TVS chip and carrier, the TVS core suddenly Piece is consistent with size of the carrier in length and width, which is characterized in that the area of the TVS chip back anode metal is less than The area of the carrier and it is not extend to carrier edge.

The TVS chip back is equipped with oxide layer and the difference in height of back anode metal and the oxide layer is less than 1um.

The utility model changes back metal graphics art, reduces back metal size, in this way will not in scribing It draws and arrives back metal, the generation for avoiding Ag wadding improves encapsulation yield to reduce short-circuit risks.

Detailed description of the invention

Fig. 1 is that grooving structure N substrate unidirectionally returns core post package schematic diagram in TVS chip dispensing suddenly；

Fig. 2 is the package structure diagram that plane N substrate unidirectionally returns core in TVS chip brush coating technique suddenly；

Fig. 3 is that the utility model super large chip area N substrate unidirectionally returns TVS device structural schematic diagram suddenly；

In figure, 21 be p-type extension, and 22 be N-type substrate, and 23 be oxide layer, and 24 be filler PI, and 31 are the diffusion region N, 32 It is metal layer for the diffusion region P, 41,42 wad a quilt with cotton for position Ag, and 51 be conducting resinl, and 52 be side excessive glue, 61 packaging frames.

Specific embodiment

The utility model preferred embodiment is provided, with reference to the accompanying drawing the technical solution of the utility model is described in detail.

Embodiment:

As shown in figure 3, a kind of super large chip area N substrate of the utility model unidirectionally returns TVS device structure suddenly, including TVS chip and carrier, the TVS chip are consistent with size of the carrier in length and width, which is characterized in that the TVS core The area of piece back anode metal is less than the area of the carrier and is not extend to carrier edge.

The TVS chip back is equipped with oxide layer and the difference in height of back anode metal and the oxide layer is less than 1um.

Under the structure of the utility model, back metal and oxide layer difference in height are less than 1um, do not have shadow to brush coating technique It rings, while brush coating difficulty and the loss to equipment can also be reduced, core efficiency in raising；And such planar structure does not need to make With filler, thus chip and finished product all will not leaded and halogen, meet client to RoHS and PB free requirement.This is practical new Type changes chip back structure, changes the metallic pattern at the back side, and in scribing, dicing lane does not have metal Ag, can The generation for avoiding Ag from wadding a quilt with cotton avoids short circuit caused by Ag wadding from occurring, and improves encapsulation yield.Chip and frame under the utility model structure Ratio reached the ratio of 1:1, volume production stability can achieve 98% or more yield.

Claims (2)

1. a kind of super large chip area N substrate unidirectionally returns TVS device structure, including TVS chip and carrier, the TVS chip suddenly It is consistent with size of the carrier in length and width, which is characterized in that the area of the TVS chip back anode metal is less than institute It states the area of carrier and is not extend to carrier edge.

2. super large chip area N substrate according to claim 1 unidirectionally returns TVS device structure, the TVS chip back suddenly Difference in height equipped with oxide layer and back anode metal and the oxide layer is less than 1um.