JPH02255861A - Ic socket - Google Patents

Abstract

PURPOSE:To obtain an IC socket excellent in heat resistance, chemical resistance, water vapor resistance, flame retardancy, etc., by using a specified polyimide as a starting material. CONSTITUTION:This IC socket is made from a polyimide having repeating units of formula I wherein X is a direct bond, a 1-10C bivalent hydrocarbon group, a hexafluorinated isopropylydene, a carbonyl, a thio or a sulfonyl; and R is a tetravalent group selected from among a 2C or higher aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, and a nonfused polycyclic aromatic group composed of aromatic groups bonded directly or through bridging members. It is desirable that the polyimide has an inherent viscosity in the range of 0.40-0.60dl/g.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to semiconductors 1 to 7 for integrated circuits (hereinafter abbreviated as IC) made from a specific polyimide, and particularly to burn-in ICs. Related to sockets [Prior art] In general, ICs undergo a performance check under high temperature, a so-called burn test, before being installed in equipment to confirm their reliability.
A burn-in is performed to bring the energized IC into an operating state, usually at 7
The device is kept at a high temperature of 0-170°C to check for deterioration in operating conditions or instability. ICs that pass this test will be highly reliable for various types of equipment.

By the way, the IC socket, which is the connection part that connects the IC to the printed circuit board, is exposed to the above-mentioned high temperature conditions with the IC inserted, so the lance material used for it is naturally required to have heat resistance. Ru.

However, in recent years, IC performance tests (burn-in) have been conducted at increasingly high temperatures for the purpose of promoting evaluation and improving reliability, and there are cases where IC sockets made of conventional resin cannot handle the test. It looked like it was coming.

For example, glass fiber-reinforced polybutylene terephthalate resin, polybutylene terephthalate resin, nylon resin, etc. can be used up to around 120℃, but if the temperature exceeds that temperature, dimensional stability, creep properties, etc. will deteriorate significantly, so they cannot be used. I can't stand it. Therefore, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, etc., which have better heat resistance, have come to be used.

However, the actual operating temperature for both resins is 170°C.
It stopped at around ℃.

In addition to heat resistance, we also provide chemical resistance during cleaning (e.g. against isopropyl alcohol, ethyl alcohol, toluene, benzene, trichlene, chlorocene, freon, acetone, methanol, etc.), water vapor resistance, flame retardance, etc. In many cases, excellent properties are required, making it difficult for conventional resins to meet these demands.

Furthermore, polyimide is well known as a resin with excellent heat resistance, chemical resistance, etc., but since conventional polyimide does not melt and flow in its polyimide state, it can be molded using conventional molding methods, such as injection molding. It was impossible to manufacture. Also within the technical scope of polyimide, for example, polyetherimide made from tetracarboxylic dianhydride having an ether bond in the molecule (manufactured by General Electric Company, USA, trademark, ULTEMlooO, etc.)
Because it melts and flows at high temperatures, it is possible to manufacture molded bodies by compression molding, injection molding, etc. However, even when this polyetherimide was applied to IC sockets, the heat resistance and chemical resistance were not satisfactory.

[Problems to be Solved by the Invention] An object of the present invention is to provide an IC socket that uses a specific polyimide as a raw material and has excellent heat resistance, chemical resistance, water vapor resistance, flame retardance, etc.

[Means for Solving the Problems] As a result of various studies regarding the materials for the above-mentioned IC socket I, the present invention has been made to solve the above-mentioned drawbacks of conventional products by using a specific polyimide. They discovered that an IC socket with significantly superior performance could be obtained, and completed the present invention.

That is, the IC socket according to the present invention is made of polyimide having a repeating unit of the following formula (I).

A tetravalent group selected from the group consisting of a group group, a monocyclic aromatic group, a fused polycyclic aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. represents the group of ) The above polyimide is a polyimide obtained by reacting an ether diamine represented by the following formula (II) with one or more tetracarboxylic dianhydrides represented by the following formula (III) (wherein X is the same as before). It is.

(I) (wherein, X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, or a sulfonyl group; Two or more aliphatic groups, cycloaliphatic (in the formula, R is the same as before) The polyimide according to the present invention is characterized in that a diamine having an ether bond is used as a raw material.Specifically, for example, JP-A No. 61 -143478, 62-68817
, No. 62-86021, U.S. Patent No. 48.473.49
It can be easily produced by the method described in No. 5 etc., and all thermoplastic polyimides produced by these methods can be used in the present invention. Among them, preferred polyimides can be produced using the following raw materials. That is, 4.4°-bis[4-(3-aminophenoxy)phenyl]sulfide, 4.4′-bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4′-bis( 3-
aminophenoxy)benzophenone, 4,4°-bis(
3-aminophenoxy)biphenyl, 2.2-bis[
4-(3-aminophenoxy)phenylcopropane or 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, among which A compound selected from the following may be used alone or as a mixture of two or more thereof, and as a tetracarboxylic dianhydride, pyromellitic dianhydride, 3.3'.

4.4゛-Biphenyltetracarboxylic dianhydride, 3゜3', 4.4'-benzophenonetetracarboxylic dianhydride, 3.3°, 4.4'-diphenyltetracarboxylic dianhydride, p -Feni 1. / Nwogishiji (4-
phthalic acid) dianhydride, and a compound selected from these can be used alone or 2f! It is a mixture of one or more.

The logarithmic viscosity of the polyimide of the present invention obtained as above is:
Usually 0.35-0.65 d12/g, preferably 04
It is in the range of 40 to 0.60 df2.7g. If the logarithmic viscosity exceeds the above range and is less than 0.35, the mechanical properties and durability will be insufficient, and if it is more than 0.60, moldability will deteriorate and injection molding will become difficult. This logarithmic viscosity is parachlorophenol/phenol (90/1
0 weight ratio) in a mixed solvent with a concentration of 0.5 g/100 mβ-
After heating and dissolving with a solvent, it is cooled to 35°C and measured.

Although IC sockets are manufactured using the above-mentioned polyimide as a raw material, in this case, glass fiber may be used in combination with this polyimide for the purpose of further imparting heat resistance, mechanical properties, etc.

The glass fiber used in combination has alkali (NazO) content,
Various types are commercially available depending on fiber length and diameter, but
Any of these can be used and is not particularly limited. The amount of glass fiber used is 40% by weight or less, preferably 30% by weight or less, based on the composition containing polyimide and glass fiber. If 40% by weight or more of glass m fibers is used, the melt flowability of the composition will be poor, injection moldability will be poor, and the surface condition of the molded product will also be poor. In addition to glass fibers, it is also possible to add pigments, various fillers other than glass fibers t and i, extenders, stabilizers, lubricants, etc.

The IC socket of the present invention uses polyimide as a raw material in powder or pellet form, and when polyimide and glass fiber or various additives are used together, it is prepared in advance using a hot roll, Banbury mixer, Henschel mixer, Brabender, etc. It can be melted or mixed using a conventional blending device such as a tumbler 2 extruder, and then molded into powder or pellets by injection molding.

Injection molding conditions are - Cylinder temperature 300 to 4 for boat fishing
50℃, mold temperature 150~230℃, injection pressure 500~
Various IC sockets in the range of 1500 to 1500 g/cm;
For example, quad flat package (QuardFla)
t Package: QFP) Typically, the number of bins is 40 or more.
100, pitch 0.5mm, leadless chip carrier (:hip Carroe
r: LCC) Typically, the number of bins is 18 to 84, and the pitch is 1.
27mm one, dual inline package (Du
al In Line Package: DIP), Single In Line Package (Single In L
inePackage:SIP), Small Outline Package (Small Out Line P)
ackage: 5OP), Chito Carrier (Chi
p Carrier: CC), Ping Kuts Door 1/
i Subst i Note (Pin Grid Array
Various types of IC sockets such as 5-substrate (PGA) can be manufactured.

[Example] Hereinafter, the present invention will be explained by examples.

Example 1 Ingredients (thromellitic dianhydride as II and ingredients (
4,4-bis(3-aminophenoxy) as II)
Logarithmic viscosity obtained from biphenyl as raw material: 0°45 d
A polyimide powder of β/g was extruded into the shape of a sheet using an extruder at a cylinder temperature of 400'C.

Here, the logarithmic viscosity is parachloroph, in a mixed solvent of -Lnol/°noenol (weight ratio 90/10), concentration 0.5g
/room f2- This is a value measured after heating and dissolving in a solvent and then cooling to 35°C.

Note: The cylinder temperature is 380-410'
C1 mold temperature 190℃, injection pressure cuff 00gf/cm2
Condition F) This injection molding has a number of bins of 6.1 and a pitch of 0.
．． A 5 mm IC socket (quad flat package: QFP) was obtained. This product was brownish-brown, transparent C-silver, and had no sink marks, flow marks, etc., and was excellent.

The following test was conducted using this ■C socket 1-.

■Appearance after 10 days of immersion in tolueno and trichlene; ■Appearance after 200 hours of exposure to heated steam at 2 kg/cm2; Appearance after 100 hours of exposure to 0230°C heated oven. There was no change in appearance.

Also, book! A test piece specified by ASTM was prepared from the knot under the same molding conditions and its physical properties were measured.The heat distortion temperature was 240℃ (D-6411) and the bending strength was 1400kg.
/cm2 (D-790), limiting oxygen index 47 (3,2
mm l'J-1D2863).

Therefore, it can be seen that this product has good properties as an IC socket.

Comparative Example 1 Instead of the polyimide powder in Example 1, polyetherimide IJLTEMlooO (trademark, manufactured by General Electric Company, USA) was used at a cylinder temperature of 330.
~400℃, mold temperature 150℃, injection pressure 800Kgf
/cm2 by injection molding under the same conditions as in Example 1.
C socket (quad flat backer”:/:QFP
) was obtained.

When this IC socket was immersed in Triku 1 Non for 10 days, the entire surface became noticeably whitened. Also 2 kg/c
After being exposed to m2 of heated steam for 200 hours, the IC socket had many cracks. Furthermore, after being exposed to a heating oven at 230° C. for 100 hours, the shape of the IC socket was significantly deformed into a culm that could not be kept in its original shape.

Example 2 70 parts by weight of the polyimide powder used in Example 1 and 30 parts by weight of glass fibers (3 mm length, aspect ratio 250) were sufficiently stirred in a tumbler and then formed into bell knots.

Next, the cylinder temperature from the injection molding machine ζ is 390~4
20℃, mold temperature 200℃1 injection pressure 1000gf
When an IC socket similar to that of Example 1 was molded under the condition of /cm2, an excellent product was obtained without silver, sink marks, flow marks, etc.

Appearance after immersing this IC socket in toluene and trichlene for 10 days in the same manner as in Example 1, 2 kg/c
There was no change in appearance after 200 hours of exposure to m2 of heated steam in any of the tests.

A test piece specified by ASTM was prepared under the same molding conditions under the same molding conditions and the physical properties were measured, and it was found that the heat distortion temperature was 243°C and the bending strength was 2400 kg/cm''.

Comparative Example 2 Polyetherimide containing 30% glass fiber instead of the glass fiber-containing polyimide pellet in Example 2]
LTEM2300 (trademark, manufactured by General Electric Company, USA) pellet was heated to a cylinder temperature of 340 to 41.
0℃, mold temperature 150℃, injection pressure 100100O/c
An IC socket (quad flat package QFP) similar to that in Example 1 was obtained by injection molding under the conditions of ``m''.

When this IC socket was immersed in Triclean for 10 days, the entire surface was significantly whitened and glass fibers were observed to be embossed. The entire surface was also self-made after being exposed to heated steam at 2 kg/cm2 for 200 hours. 23 more
After being exposed to a heating oven at 0°C at 17F for 100 hours, the shape of the IC socket collapsed and pitch wobble became noticeable.

Example 3 Using the beret 1 used in Example 2 as a raw material, the cylinder temperature was 390 to 420°C, the mold temperature was 200°C, and the injection pressure was 9.
When an IC socket (leadless chip carrier; LCC) with 84 bins and a pitch of 1.27 mm was molded using gf/cm2 conditions on 00, silver picket,
An excellent product with no flow marks etc. was obtained.

Appearance after immersing this IC socket in toluene and l-licen for 10 days in the same manner as in Example 1, 2 kg/
There was no change in appearance after 200 hours of exposure to am2 heated steam in any of the tests.

Comparative Example 3 The pellet of LILTEM2300 used in Comparative Example 2 was injection molded under the conditions of a cylinder temperature of 340 to 410°C, a mold temperature of 150°C, and an injection pressure of 100,100 O/cm'' to make an IC socket similar to that of Example 3 ( A leadless chip carrier (LCC) was obtained.

When this IC socket was immersed in Triclean for 10 days, the entire surface turned white and glass fibers were observed to be embossed. Similarly, after 200 hours of exposure to 2 kg/am'' heated steam, the entire surface turned white.Furthermore, after 100 hours of exposure to 230°C heating oven, the shape of the IC socket collapsed and the pitch wobble became noticeable. became.

Example 4 Polyimide powder (logarithmic viscosity 0.461/ g) as in Example 1 and 2
After forming the L/JIT, an IC socket (quad flat package: QFP) with 64 bottles and a pitch of 0.5 mm was molded using an injection molding machine, and as in Example 1, an excellent product was obtained.

In addition, when a test piece was prepared in the same manner as in Example 1 and its physical properties were measured, the thermal deformation temperature was 238°C, and the bending strength was 1350 kg.
/cm2.

Example 5 70 parts by weight of the poly1'amide powder used in Example 4 was thoroughly stirred with 30 parts by weight of glass fibers (3 mm length, aspect ratio 250) in a tumbler, and then formed into L-knots.

Next, in the same manner as in Example 2, the number of bins is 64 and the pitch is 0.
When a 5 mm IC socket (quad flat package: QFP) was molded, an excellent product similar to Example 2 was obtained.

Appearance after immersing this IC socket in toluene and trichlene for 10 days in the same manner as in Example 1, 2 kg/c
Appearance after 200 hours of exposure to heated steam of 230 m”
There was no change in appearance in any of the tests after exposure for 10/2 hours in a heating oven at .degree.

In addition, when a test piece was prepared in the same manner as in Example 2 and its physical properties were measured, the thermal deformation temperature was 242°C, and the bending strength was 2300 kg.
/cm2.

Example 6 2.2-bis(4-(3-aminophenoxy)phenyl)propane as component (II) and component (III)
Polyimide powder obtained using 3.3°, 4.4°-benzophenone tetracarboxylic dianhydride as a raw material (
After forming pellets with logarithmic viscosity of 0.45 dβ/g in the same manner as in Example 1, the number of bottles was 64 and the pitch was 0.
5mm IC socket (quad flat package;
QFP) was molded, and as in Example 1, an excellent product was obtained.

In addition, when a test piece was prepared in the same manner as in Example 1 and its physical properties were measured, the heat distortion temperature was 240°C, and the bending strength was 1370 kg.
/am”.

Example 7 Glass fiber (3 mm length, aspect ratio 250) was added to 70 parts by weight of the polyimide powder used in Example 5. After thoroughly stirring the i-placed portion with a tumbler, it was formed into pellets.

Next, in the same manner as in Example 2, the number of bins is 64 and the pitch is 0.
5mm IC socket (quad flat package:
QFP) was molded, and as in Example 2, an excellent product was obtained.

Appearance after immersing this IC socket in toluene and trichlene for 10 days in the same manner as in Example 1, 2 kg/c
Appearance after 200 hours of exposure to heated steam of 230 m”
There was no change in appearance after 100 hours of exposure in a heating oven at 0.degree. C. in any of the tests.

In addition, when a test piece was prepared in the same manner as in Example 2 and its physical properties were measured, the thermal deformation temperature was 241°C, and the bending strength was 2300 kg.
/am2.

[Effects of the Invention] Since the IC socket of the present invention uses a new polyimide resin that has excellent heat resistance, chemical resistance, water vapor resistance, flame retardancy, etc., it has very good characteristics as an IC socket. It can be used for a wide range of connection parts of ICs.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] (1) IC socket made of polyimide having the repeating unit of formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (I) (wherein, X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms) , a hexafluorinated isopropylidene group, a carbonyl group, a thio group, or a sulfonyl group, and R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, or a fused polycyclic group. (represents a tetravalent group selected from the group consisting of an aromatic group of the formula aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member).