CN202471879U

CN202471879U - Circuit for detecting undesirable characteristics of paster packaging semiconductor component

Info

Publication number: CN202471879U
Application number: CN2012200523250U
Authority: CN
Inventors: 彭坚; 李升桦
Original assignee: SICHUAN DAYAN ELECTRONICS CO Ltd
Current assignee: SICHUAN DAYAN ELECTRONICS CO Ltd
Priority date: 2012-02-17
Filing date: 2012-02-17
Publication date: 2012-10-03
Anticipated expiration: 2022-02-17

Abstract

The utility model provides a circuit for detecting undesirable characteristics of a paster packaging semiconductor component. The paster packaging semiconductor component has a pin for connecting a chip loading area and a pin outside the chip loading area. The pin outside the chip loading area is connected with silver paste or solder in the chip loading area by a lead. The silver paste or the solder is connected with a chip, and the chip is connected with the pin for connecting the chip loading area. A current source having a small current and a clamping voltage is connected between the pin for connecting the chip loading area and the pin outside the chip loading area. Besides, a voltmeter for detecting a voltage between two pins is connected between the pin for connecting the chip loading area and the pin outside the chip loading area. By a magnitude of voltage detected by the voltmeter, the component of undesirable characteristics can be screened rapidly and accurately, and besides products can not be damaged and detection of other parameters can not be affected. The component after screening has good quality and can reduce failure probability of client application.

Description

The testing circuit that paster encapsulated semiconductor part characteristic is bad

Technical field

The utility model relates to the semiconductor assembly and test technical field, is the bad testing circuit of a kind of paster encapsulated semiconductor part characteristic.

Background technology

Semiconductor assembly and test is meant the process that obtains the independent entry device through the wafer of test according to functional requirement processing; Its process is: wafer is cut into the chip (Die) of simple grain after through scribing process; Simple grain chip attachment with well cutting arrives in the slide glass district of corresponding frame substrate (Leadframe) then; Utilize metal (golden copper aluminium etc.) lead that the bond pad (Bond Pad) of wafer is connected to the respective pins (Lead) of substrate again, constitute desired circuit; With plastic casing packaging protection in addition, product pin and heat sink are carried out zinc-plated protection then, filter out non-defective unit through test machine and automatic fraction collector at last.

For the paster packaging; Spacing is less between chip slide glass zone and other pin; Because will be in the process of mounting at the bond (silver slurry or scolder) of the slide glass district of framework brush one deck framework and chip; When the bigger chip of loading space, silver slurry or scolder overflow framework slide glass district easily and contact with pin on every side and to cause short circuit.

Semiconductor assembly and test factory mainly is the PN junction characteristic according to semiconductor devices to the short-circuit detecting of paster packaging at present; Promptly on PN junction, add a voltage, if P type one edge joint is anodal, N type one edge joint negative pole; Electric current just from the P type while flowing to the N type; Hole and electronics all to the interface motion, narrow down the space charge region, and electric current can pass through smoothly.If the positive pole of N type one edge joint impressed voltage, P type one edge joint negative pole, then hole and electronics all to the direction motion away from the interface, broaden the space charge region, and electric current can not flow through.The method detects short circuit and can accurately screen there being the components and parts of PN junction characteristic between each pin; And be not all to have the PN junction characteristic between each pin of most of components and parts; So the short-circuit detecting project of semiconductor assembly and test factory just can not be applicable between each pin now; When automatic screening, cause erroneous judgement (the product erroneous judgement that is about to the pin short circuit is that non-defective unit or other electrical quantity are bad) easily; Make troubles for the subsequent device failure analysis, and in semiconductor OEM factory, the encapsulation overhead that short circuit produces generally is to be born by encapsulation factory; If can not screen the device of short circuit accurately, will cause the discontented of client even customer complaint takes place.

The utility model content

The utility model provides a kind of paster encapsulated semiconductor part characteristic bad testing circuit; Can separate the situation that must not short circuit phenomenon between each pin of components and parts accurately be detected; Adopt the utility model can fast, accurately filter out pin short circuit components and parts, the while can not caused the damage of product and influenced the detection of other parameter.

The testing circuit that paster encapsulated semiconductor part characteristic is bad; Unit's base device has the pin that is connected with the slide glass district; Also has the pin outside the slide glass district; Pin outside the slide glass district is starched or scolder through the silver that lead-in wire connects the slide glass district, and silver slurry or scolder connect chip, and chip connects the pin that is connected with the slide glass district; It is characterized in that: have Weak current and the current source of clamping down on voltage with connecting one between said pin that is connected with the slide glass district and the pin outside the slide glass district, between said pin that is connected with the slide glass district and the pin outside the slide glass district, connect a voltage table more simultaneously; For avoiding that device is caused damage, the current value of said Weak current is set in below the 1mA.

Voltage table is used for the voltage between two pins is detected.

The said pin that is connected with the slide glass district also is connected with a relay switch, connects current source and voltage table through relay switch.

In testing process, the current path of formation is following: silver slurry or scolder that the pin that is connected with the slide glass district connects through encapsulation connect chip, and chip connects the pin outside the slide glass district through lead-in wire; Owing to do not have the PN junction characteristic between two pins; Be equivalent to open circuit between two pins in theory; It is infinitely great that the detected voltage of voltage table should be; Be used to protect the voltage of clamping down on that components and parts are not damaged but between two pins, also be set with one, set clamp down on voltage after, let test machine return this and clamp down on magnitude of voltage; During with the pin contact that is connected with the slide glass district, current path is following: the pin the slide glass district outside connects silver slurry or scolder, the pin that silver is starched or the scolder connection is connected with the slide glass district when occurring in the encapsulation process causing silver slurry or scolder to overflow framework slide glass district unusually; Pin outside the described slide glass district, silver-colored slurry or scolder, the pin three who is connected with the slide glass district are all conductive materials, and electric current forms a short-circuit loop between the three, and the voltage between two pins that this moment, voltage table measured is close to 0V.

Therefore, when encapsulation process does not have when unusual, the clamp down on voltage of magnitude of voltage between two pins for setting, when encapsulation caused silver-colored slurry or scolder to contact with device pin unusually, the magnitude of voltage between two pins was close to 0V; In like manner detect the short circuit problem in other pin and slide glass district.

Clamp down on voltage or be close to 0V through the magnitude of voltage of reading between two pins, just can accurately filter out the device pin short circuit product in the encapsulation process at test step.

The beneficial effect of the utility model is following:

The utility model can fast, accurately filter out pin short circuit components and parts, and the while can not caused the damage of product and influenced the detection of other parameter; Because test all is to be connected with automatic fraction collector through test machine to realize; So as long as when test procedure is write, add the test item that flows pressure measurement; Just can easily the product screening of device pin short circuit be come out, it is very short to add the stream pressure measurement test duration, and each project testing time just can realize below 1ms; So testing efficiency is not had big influence; As long as relay switch is broken off, current source and voltage table are not just introduced in the test circuit, and other parameter testing is not had influence when testing other electricity ginseng; Be specially adapted to detect accurately when less paster components and parts such as paster semiconductor packages profile such as SOT-2X, TSOT-2X etc. in encapsulation process the pin short circuit take place.

Description of drawings

Fig. 1 is the short-circuit detecting circuit synoptic diagram of the utility model

Fig. 2 is the short-circuit detecting circuit synoptic diagram of the utility model

Among the figure: the pin outside the 1 slide glass district, 2 pins that are connected with the slide glass district, 3 lead-in wires, 4 silver medals slurry or scolder, 5 chips, 6 voltage tables, 7 current sources, K are relay switch.

Embodiment

Below in conjunction with accompanying drawing the utility model is described.

Shown in Fig. 1-2, be a kind of paster encapsulated semiconductor components and parts, below embodiment as example.

To detect current settings is 1mA, and the control upper voltage limit is set at 1.5V, and the control lower voltage limit is set at 0.5V.Closing Switch K; At the pin 1 of components and parts, apply between 2 and detect electric current 1mA, apply a voltage table simultaneously device pin 1, voltage between 2 detected, current path is following: device pin 2--silver slurry or scolder--chip--lead-in wire--device pin 1; Owing to device pin 1, do not have the PN junction characteristic between 2; In theory device pin 1, be equivalent to open circuit between 2, voltage table detects voltage and should be infinitely great, but we can set one and clamp down on voltage 1V and be not damaged with the protection device in the practical application; After voltage is clamped down in setting, let test machine return this and clamp down on magnitude of voltage 1V; When contacting with device pin 1 when occurring in the encapsulation process causing silver slurry or scolder to overflow framework slide glass district unusually; Current path is following: device pin 2--silver slurry or scolder--device pin 1; This three is all conductive materials; Electric current forms a short-circuit loop between the three, this moment the device pin 1 that measures of voltage table, voltage is close to 0V between 2.When not having short circuit between two pins of device; Test machine returns clamps down on magnitude of voltage 1V; When between two pins of device during short circuit, the magnitude of voltage that test machine is read is near 0V, because 0V exceeds qualified type of scope 0.5 ~ 1.5V that we set; So just can in the sorting item of program back, be classified in the defective products bucket of short circuit, thereby can accurately distinguish the device pin short circuit.

Test if get the product of 5 device 12 pin short circuits, test machine will return 0V left and right sides magnitude of voltage, and the GD magnitude of voltage that test machine returns is shown in table one:

Table one

Project	Pin 12
		Detect electric current	500uA
Clamp down on voltage	1V
		The voltage measurement lower limit	? 0.500 V
The voltage measurement upper limit	? 1.500 V
		Device 1	-0.004 V
Device 2	-0.003 V
		Device 3	-0.006 V
Device 4	-0.004 V
		Device 5	0.000 V

If get between 5 device 12 pins just often, test machine returns clamps down on the voltage 1V value of reading, and 1V is within certified products judgement scope 0.5 ~ 1.5V, and device is judged as non-defective unit, shown in table two:

Table two

Project	Pin 12
		Detect electric current	500uA
Clamp down on voltage	1V
		The voltage measurement lower limit	0.500 V
The voltage measurement upper limit	1.500 V
		Device 11	1.000 V
Device 12	1.000 V
		Device 13	1.000 V
Device 14	1.000 V
		Device 15	1.000 V

Test equally between other pin,, just can the product of short circuit between the pin be rejected, and above screening all is included in and realizes in the test procedure through after the leakage current between all pins test, very convenient.

Claims

1. the bad testing circuit of paster encapsulated semiconductor part characteristic; Components and parts have the pin that is connected with the slide glass district; Also has the pin outside the slide glass district; Pin outside the slide glass district is starched or scolder through the silver that lead-in wire connects the slide glass district, and silver slurry or scolder connect chip, and chip connects the pin that is connected with the slide glass district; It is characterized in that: have Weak current and the current source of clamping down on voltage with connecting one between said pin that is connected with the slide glass district and the pin outside the slide glass district, between said pin that is connected with the slide glass district and the pin outside the slide glass district, connect one simultaneously again and be used for voltage table that the voltage between two pins is detected.

2. testing circuit according to claim 1 is characterized in that: the current value of said Weak current is less than or equal to 1mA.

3. testing circuit according to claim 1 is characterized in that: the said pin that is connected with the slide glass district also is connected with a relay switch, and this pin connects current source and voltage table through relay switch.

4. testing circuit according to claim 1 is characterized in that: the current path that detects normal components and parts is following: silver slurry or scolder that the pin that is connected with the slide glass district connects through encapsulation connect chip, and chip connects the pin outside the slide glass district through lead-in wire; Between two pins for clamping down on voltage.

5. testing circuit according to claim 1 is characterized in that: the current path that detects the components and parts that damage is following: the pin outside the slide glass district connects silver slurry or scolder, and silver slurry or scolder connect the pin that is connected with the slide glass district; Pin, silver-colored slurry or the scolder of electric current outside described slide glass district, with pin three that the slide glass district is connected between form a short-circuit loop, the voltage between this moment two pins is 0V.